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Generic semaphore implementation 

Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility.  Thanks to Peter Zijlstra for fixing the lockdep
warning.  Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Matthew Wilcox 2008-03-07 21:55:58 -05:00 committed by Matthew Wilcox
parent e48b3deee4
commit 64ac24e738
113 changed files with 314 additions and 7679 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/alpha/kernel/Makefile
View File

@ -7,7 +7,7 @@ EXTRA_AFLAGS := $(KBUILD_CFLAGS)
EXTRA_CFLAGS := -Werror -Wno-sign-compare
obj-y := entry.o traps.o process.o init_task.o osf_sys.o irq.o \
irq_alpha.o signal.o setup.o ptrace.o time.o semaphore.o \
irq_alpha.o signal.o setup.o ptrace.o time.o \
alpha_ksyms.o systbls.o err_common.o io.o
obj-$(CONFIG_VGA_HOSE) += console.o

9
arch/alpha/kernel/alpha_ksyms.c
View File

@ -77,15 +77,6 @@ EXPORT_SYMBOL(__do_clear_user);
EXPORT_SYMBOL(__strncpy_from_user);
EXPORT_SYMBOL(__strnlen_user);
/* Semaphore helper functions. */
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__up_wakeup);
EXPORT_SYMBOL(down);
EXPORT_SYMBOL(down_interruptible);
EXPORT_SYMBOL(down_trylock);
EXPORT_SYMBOL(up);
/*
* SMP-specific symbols.
*/

224
arch/alpha/kernel/semaphore.c
View File

@ -1,224 +0,0 @@
/*
* Alpha semaphore implementation.
*
* (C) Copyright 1996 Linus Torvalds
* (C) Copyright 1999, 2000 Richard Henderson
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/init.h>
/*
* This is basically the PPC semaphore scheme ported to use
* the Alpha ll/sc sequences, so see the PPC code for
* credits.
*/
/*
* Atomically update sem->count.
* This does the equivalent of the following:
*
* old_count = sem->count;
* tmp = MAX(old_count, 0) + incr;
* sem->count = tmp;
* return old_count;
*/
static inline int __sem_update_count(struct semaphore *sem, int incr)
{
long old_count, tmp = 0;
__asm__ __volatile__(
"1: ldl_l %0,%2\n"
" cmovgt %0,%0,%1\n"
" addl %1,%3,%1\n"
" stl_c %1,%2\n"
" beq %1,2f\n"
" mb\n"
".subsection 2\n"
"2: br 1b\n"
".previous"
: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
: "Ir" (incr), "1" (tmp), "m" (sem->count));
return old_count;
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*/
void __sched
__down_failed(struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down failed(%p)\n",
tsk->comm, task_pid_nr(tsk), sem);
#endif
tsk->state = TASK_UNINTERRUPTIBLE;
wmb();
add_wait_queue_exclusive(&sem->wait, &wait);
/*
* Try to get the semaphore. If the count is > 0, then we've
* got the semaphore; we decrement count and exit the loop.
* If the count is 0 or negative, we set it to -1, indicating
* that we are asleep, and then sleep.
*/
while (__sem_update_count(sem, -1) <= 0) {
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
/*
* If there are any more sleepers, wake one of them up so
* that it can either get the semaphore, or set count to -1
* indicating that there are still processes sleeping.
*/
wake_up(&sem->wait);
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down acquired(%p)\n",
tsk->comm, task_pid_nr(tsk), sem);
#endif
}
int __sched
__down_failed_interruptible(struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
long ret = 0;
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down failed(%p)\n",
tsk->comm, task_pid_nr(tsk), sem);
#endif
tsk->state = TASK_INTERRUPTIBLE;
wmb();
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
if (signal_pending(current)) {
/*
* A signal is pending - give up trying.
* Set sem->count to 0 if it is negative,
* since we are no longer sleeping.
*/
__sem_update_count(sem, 0);
ret = -EINTR;
break;
}
schedule();
set_task_state(tsk, TASK_INTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
wake_up(&sem->wait);
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down %s(%p)\n",
current->comm, task_pid_nr(current),
(ret < 0 ? "interrupted" : "acquired"), sem);
#endif
return ret;
}
void
__up_wakeup(struct semaphore *sem)
{
/*
* Note that we incremented count in up() before we came here,
* but that was ineffective since the result was <= 0, and
* any negative value of count is equivalent to 0.
* This ends up setting count to 1, unless count is now > 0
* (i.e. because some other cpu has called up() in the meantime),
* in which case we just increment count.
*/
__sem_update_count(sem, 1);
wake_up(&sem->wait);
}
void __sched
down(struct semaphore *sem)
{
#ifdef WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down(%p) <count=%d> from %p\n",
current->comm, task_pid_nr(current), sem,
atomic_read(&sem->count), __builtin_return_address(0));
#endif
__down(sem);
}
int __sched
down_interruptible(struct semaphore *sem)
{
#ifdef WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down(%p) <count=%d> from %p\n",
current->comm, task_pid_nr(current), sem,
atomic_read(&sem->count), __builtin_return_address(0));
#endif
return __down_interruptible(sem);
}
int
down_trylock(struct semaphore *sem)
{
int ret;
#ifdef WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
ret = __down_trylock(sem);
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): down_trylock %s from %p\n",
current->comm, task_pid_nr(current),
ret ? "failed" : "acquired",
__builtin_return_address(0));
#endif
return ret;
}
void
up(struct semaphore *sem)
{
#ifdef WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
#ifdef CONFIG_DEBUG_SEMAPHORE
printk("%s(%d): up(%p) <count=%d> from %p\n",
current->comm, task_pid_nr(current), sem,
atomic_read(&sem->count), __builtin_return_address(0));
#endif
__up(sem);
}

2
arch/arm/kernel/Makefile
View File

@ -7,7 +7,7 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
# Object file lists.
obj-y := compat.o entry-armv.o entry-common.o irq.o \
process.o ptrace.o semaphore.o setup.o signal.o \
process.o ptrace.o setup.o signal.o \
sys_arm.o stacktrace.o time.o traps.o
obj-$(CONFIG_ISA_DMA_API) += dma.o

221
arch/arm/kernel/semaphore.c
View File

@ -1,221 +0,0 @@
/*
* ARM semaphore implementation, taken from
*
* i386 semaphore implementation.
*
* (C) Copyright 1999 Linus Torvalds
*
* Modified for ARM by Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <asm/semaphore.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to acquire the semaphore, while the "sleeping"
* variable is a count of such acquires.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* "sleeping" and the contention routine ordering is
* protected by the semaphore spinlock.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
/*
* Logic:
* - only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - when we go from a non-negative count to a negative do we
* (a) synchronize with the "sleeper" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
void __up(struct semaphore *sem)
{
wake_up(&sem->wait);
}
static DEFINE_SPINLOCK(semaphore_lock);
void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_UNINTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
spin_lock_irq(&semaphore_lock);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irq(&semaphore_lock);
schedule();
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irq(&semaphore_lock);
}
spin_unlock_irq(&semaphore_lock);
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
wake_up(&sem->wait);
}
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_INTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
spin_lock_irq(&semaphore_lock);
sem->sleepers ++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into
* the trylock failure case - we won't be
* sleeping, and we* can't get the lock as
* it has contention. Just correct the count
* and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock. The
* "-1" is because we're still hoping to get
* the lock.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irq(&semaphore_lock);
schedule();
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irq(&semaphore_lock);
}
spin_unlock_irq(&semaphore_lock);
tsk->state = TASK_RUNNING;
remove_wait_queue(&sem->wait, &wait);
wake_up(&sem->wait);
return retval;
}
/*
* Trylock failed - make sure we correct for
* having decremented the count.
*
* We could have done the trylock with a
* single "cmpxchg" without failure cases,
* but then it wouldn't work on a 386.
*/
int __down_trylock(struct semaphore * sem)
{
int sleepers;
unsigned long flags;
spin_lock_irqsave(&semaphore_lock, flags);
sleepers = sem->sleepers + 1;
sem->sleepers = 0;
/*
* Add "everybody else" and us into it. They aren't
* playing, because we own the spinlock.
*/
if (!atomic_add_negative(sleepers, &sem->count))
wake_up(&sem->wait);
spin_unlock_irqrestore(&semaphore_lock, flags);
return 1;
}
/*
* The semaphore operations have a special calling sequence that
* allow us to do a simpler in-line version of them. These routines
* need to convert that sequence back into the C sequence when
* there is contention on the semaphore.
*
* ip contains the semaphore pointer on entry. Save the C-clobbered
* registers (r0 to r3 and lr), but not ip, as we use it as a return
* value in some cases..
* To remain AAPCS compliant (64-bit stack align) we save r4 as well.
*/
asm(" .section .sched.text,\"ax\",%progbits \n\
.align 5 \n\
.globl __down_failed \n\
__down_failed: \n\
stmfd sp!, {r0 - r4, lr} \n\
mov r0, ip \n\
bl __down \n\
ldmfd sp!, {r0 - r4, pc} \n\
\n\
.align 5 \n\
.globl __down_interruptible_failed \n\
__down_interruptible_failed: \n\
stmfd sp!, {r0 - r4, lr} \n\
mov r0, ip \n\
bl __down_interruptible \n\
mov ip, r0 \n\
ldmfd sp!, {r0 - r4, pc} \n\
\n\
.align 5 \n\
.globl __down_trylock_failed \n\
__down_trylock_failed: \n\
stmfd sp!, {r0 - r4, lr} \n\
mov r0, ip \n\
bl __down_trylock \n\
mov ip, r0 \n\
ldmfd sp!, {r0 - r4, pc} \n\
\n\
.align 5 \n\
.globl __up_wakeup \n\
__up_wakeup: \n\
stmfd sp!, {r0 - r4, lr} \n\
mov r0, ip \n\
bl __up \n\
ldmfd sp!, {r0 - r4, pc} \n\
");
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_interruptible_failed);
EXPORT_SYMBOL(__down_trylock_failed);
EXPORT_SYMBOL(__up_wakeup);

2
arch/avr32/kernel/Makefile
View File

@ -6,7 +6,7 @@ extra-y := head.o vmlinux.lds
obj-$(CONFIG_SUBARCH_AVR32B) += entry-avr32b.o
obj-y += syscall_table.o syscall-stubs.o irq.o
obj-y += setup.o traps.o semaphore.o ocd.o ptrace.o
obj-y += setup.o traps.o ocd.o ptrace.o
obj-y += signal.o sys_avr32.o process.o time.o
obj-y += init_task.o switch_to.o cpu.o
obj-$(CONFIG_MODULES) += module.o avr32_ksyms.o

148
arch/avr32/kernel/semaphore.c
View File

@ -1,148 +0,0 @@
/*
* AVR32 sempahore implementation.
*
* Copyright (C) 2004-2006 Atmel Corporation
*
* Based on linux/arch/i386/kernel/semaphore.c
* Copyright (C) 1999 Linus Torvalds
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <asm/semaphore.h>
#include <asm/atomic.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to acquire the semaphore, while the "sleeping"
* variable is a count of such acquires.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* "sleeping" and the contention routine ordering is protected
* by the spinlock in the semaphore's waitqueue head.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
/*
* Logic:
* - only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - when we go from a non-negative count to a negative do we
* (a) synchronize with the "sleeper" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
void __up(struct semaphore *sem)
{
wake_up(&sem->wait);
}
EXPORT_SYMBOL(__up);
void __sched __down(struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* the wait_queue_head.
*/
if (atomic_add_return(sleepers - 1, &sem->count) >= 0) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_UNINTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
}
EXPORT_SYMBOL(__down);
int __sched __down_interruptible(struct semaphore *sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into the trylock
* failure case - we won't be sleeping, and we can't
* get the lock as it has contention. Just correct the
* count and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* the wait_queue_head.
*/
if (atomic_add_return(sleepers - 1, &sem->count) >= 0) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_INTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
return retval;
}
EXPORT_SYMBOL(__down_interruptible);

4
arch/blackfin/Kconfig
View File

@ -31,10 +31,6 @@ config ZONE_DMA
bool
default y
config SEMAPHORE_SLEEPERS
bool
default y
config GENERIC_FIND_NEXT_BIT
bool
default y

5
arch/blackfin/kernel/bfin_ksyms.c
View File

@ -42,11 +42,6 @@ EXPORT_SYMBOL(ip_fast_csum);
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_trylock);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(is_in_rom);
EXPORT_SYMBOL(bfin_return_from_exception);

3
arch/cris/kernel/Makefile
View File

@ -5,8 +5,7 @@
extra-y := vmlinux.lds
obj-y := process.o traps.o irq.o ptrace.o setup.o \
time.o sys_cris.o semaphore.o
obj-y := process.o traps.o irq.o ptrace.o setup.o time.o sys_cris.o
obj-$(CONFIG_MODULES) += crisksyms.o
obj-$(CONFIG_MODULES) += module.o

7
arch/cris/kernel/crisksyms.c
View File

@ -9,7 +9,6 @@
#include <linux/string.h>
#include <linux/tty.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
@ -49,12 +48,6 @@ EXPORT_SYMBOL(__negdi2);
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(iounmap);
/* Semaphore functions */
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(__down_trylock);
/* Userspace access functions */
EXPORT_SYMBOL(__copy_user_zeroing);
EXPORT_SYMBOL(__copy_user);

129
arch/cris/kernel/semaphore.c
View File

@ -1,129 +0,0 @@
/*
* Generic semaphore code. Buyer beware. Do your own
* specific changes in <asm/semaphore-helper.h>
*/
#include <linux/sched.h>
#include <asm/semaphore-helper.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to sleep, while the "waking" variable is
* incremented when the "up()" code goes to wake up waiting
* processes.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* waking_non_zero() (from asm/semaphore.h) must execute
* atomically.
*
* When __up() is called, the count was negative before
* incrementing it, and we need to wake up somebody.
*
* This routine adds one to the count of processes that need to
* wake up and exit. ALL waiting processes actually wake up but
* only the one that gets to the "waking" field first will gate
* through and acquire the semaphore. The others will go back
* to sleep.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
wake_one_more(sem);
wake_up(&sem->wait);
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from __down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from __down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*
*/
#define DOWN_VAR \
struct task_struct *tsk = current; \
wait_queue_t wait; \
init_waitqueue_entry(&wait, tsk);
#define DOWN_HEAD(task_state) \
\
\
tsk->state = (task_state); \
add_wait_queue(&sem->wait, &wait); \
\
/* \
* Ok, we're set up. sem->count is known to be less than zero \
* so we must wait. \
* \
* We can let go the lock for purposes of waiting. \
* We re-acquire it after awaking so as to protect \
* all semaphore operations. \
* \
* If "up()" is called before we call waking_non_zero() then \
* we will catch it right away. If it is called later then \
* we will have to go through a wakeup cycle to catch it. \
* \
* Multiple waiters contend for the semaphore lock to see \
* who gets to gate through and who has to wait some more. \
*/ \
for (;;) {
#define DOWN_TAIL(task_state) \
tsk->state = (task_state); \
} \
tsk->state = TASK_RUNNING; \
remove_wait_queue(&sem->wait, &wait);
void __sched __down(struct semaphore * sem)
{
DOWN_VAR
DOWN_HEAD(TASK_UNINTERRUPTIBLE)
if (waking_non_zero(sem))
break;
schedule();
DOWN_TAIL(TASK_UNINTERRUPTIBLE)
}
int __sched __down_interruptible(struct semaphore * sem)
{
int ret = 0;
DOWN_VAR
DOWN_HEAD(TASK_INTERRUPTIBLE)
ret = waking_non_zero_interruptible(sem, tsk);
if (ret)
{
if (ret == 1)
/* ret != 0 only if we get interrupted -arca */
ret = 0;
break;
}
schedule();
DOWN_TAIL(TASK_INTERRUPTIBLE)
return ret;
}
int __down_trylock(struct semaphore * sem)
{
return waking_non_zero_trylock(sem);
}

2
arch/frv/kernel/Makefile
View File

@ -9,7 +9,7 @@ extra-y:= head.o init_task.o vmlinux.lds
obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o kernel_thread.o \
kernel_execve.o process.o traps.o ptrace.o signal.o dma.o \
sys_frv.o time.o semaphore.o setup.o frv_ksyms.o \
sys_frv.o time.o setup.o frv_ksyms.o \
debug-stub.o irq.o sleep.o uaccess.o
obj-$(CONFIG_GDBSTUB) += gdb-stub.o gdb-io.o

1
arch/frv/kernel/frv_ksyms.c
View File

@ -12,7 +12,6 @@
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/semaphore.h>
#include <asm/checksum.h>
#include <asm/hardirq.h>
#include <asm/cacheflush.h>

155
arch/frv/kernel/semaphore.c
View File

@ -1,155 +0,0 @@
/* semaphore.c: FR-V semaphores
*
* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from lib/rwsem-spinlock.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <linux/module.h>
#include <asm/semaphore.h>
struct sem_waiter {
struct list_head list;
struct task_struct *task;
};
#ifdef CONFIG_DEBUG_SEMAPHORE
void semtrace(struct semaphore *sem, const char *str)
{
if (sem->debug)
printk("[%d] %s({%d,%d})\n",
current->pid,
str,
sem->counter,
list_empty(&sem->wait_list) ? 0 : 1);
}
#else
#define semtrace(SEM,STR) do { } while(0)
#endif
/*
* wait for a token to be granted from a semaphore
* - entered with lock held and interrupts disabled
*/
void __down(struct semaphore *sem, unsigned long flags)
{
struct task_struct *tsk = current;
struct sem_waiter waiter;
semtrace(sem, "Entering __down");
/* set up my own style of waitqueue */
waiter.task = tsk;
get_task_struct(tsk);
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the semaphore */
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
for (;;) {
if (list_empty(&waiter.list))
break;
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
}
tsk->state = TASK_RUNNING;
semtrace(sem, "Leaving __down");
}
EXPORT_SYMBOL(__down);
/*
* interruptibly wait for a token to be granted from a semaphore
* - entered with lock held and interrupts disabled
*/
int __down_interruptible(struct semaphore *sem, unsigned long flags)
{
struct task_struct *tsk = current;
struct sem_waiter waiter;
int ret;
semtrace(sem,"Entering __down_interruptible");
/* set up my own style of waitqueue */
waiter.task = tsk;
get_task_struct(tsk);
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
set_task_state(tsk, TASK_INTERRUPTIBLE);
spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the semaphore */
ret = 0;
for (;;) {
if (list_empty(&waiter.list))
break;
if (unlikely(signal_pending(current)))
goto interrupted;
schedule();
set_task_state(tsk, TASK_INTERRUPTIBLE);
}
out:
tsk->state = TASK_RUNNING;
semtrace(sem, "Leaving __down_interruptible");
return ret;
interrupted:
spin_lock_irqsave(&sem->wait_lock, flags);
if (!list_empty(&waiter.list)) {
list_del(&waiter.list);
ret = -EINTR;
}
spin_unlock_irqrestore(&sem->wait_lock, flags);
if (ret == -EINTR)
put_task_struct(current);
goto out;
}
EXPORT_SYMBOL(__down_interruptible);
/*
* release a single token back to a semaphore
* - entered with lock held and interrupts disabled
*/
void __up(struct semaphore *sem)
{
struct task_struct *tsk;
struct sem_waiter *waiter;
semtrace(sem,"Entering __up");
/* grant the token to the process at the front of the queue */
waiter = list_entry(sem->wait_list.next, struct sem_waiter, list);
/* We must be careful not to touch 'waiter' after we set ->task = NULL.
* It is allocated on the waiter's stack and may become invalid at
* any time after that point (due to a wakeup from another source).
*/
list_del_init(&waiter->list);
tsk = waiter->task;
mb();
waiter->task = NULL;
wake_up_process(tsk);
put_task_struct(tsk);
semtrace(sem,"Leaving __up");
}
EXPORT_SYMBOL(__up);

2
arch/h8300/kernel/Makefile
View File

@ -5,7 +5,7 @@
extra-y := vmlinux.lds
obj-y := process.o traps.o ptrace.o irq.o \
sys_h8300.o time.o semaphore.o signal.o \
sys_h8300.o time.o signal.o \
setup.o gpio.o init_task.o syscalls.o \
entry.o

1
arch/h8300/kernel/h8300_ksyms.c
View File

@ -12,7 +12,6 @@
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/semaphore.h>
#include <asm/checksum.h>
#include <asm/current.h>
#include <asm/gpio.h>

132
arch/h8300/kernel/semaphore.c
View File

@ -1,132 +0,0 @@
/*
* Generic semaphore code. Buyer beware. Do your own
* specific changes in <asm/semaphore-helper.h>
*/
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/semaphore-helper.h>
#ifndef CONFIG_RMW_INSNS
spinlock_t semaphore_wake_lock;
#endif
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to sleep, while the "waking" variable is
* incremented when the "up()" code goes to wake up waiting
* processes.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* waking_non_zero() (from asm/semaphore.h) must execute
* atomically.
*
* When __up() is called, the count was negative before
* incrementing it, and we need to wake up somebody.
*
* This routine adds one to the count of processes that need to
* wake up and exit. ALL waiting processes actually wake up but
* only the one that gets to the "waking" field first will gate
* through and acquire the semaphore. The others will go back
* to sleep.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
wake_one_more(sem);
wake_up(&sem->wait);
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from __down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from __down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*
*/
#define DOWN_HEAD(task_state) \
\
\
current->state = (task_state); \
add_wait_queue(&sem->wait, &wait); \
\
/* \
* Ok, we're set up. sem->count is known to be less than zero \
* so we must wait. \
* \
* We can let go the lock for purposes of waiting. \
* We re-acquire it after awaking so as to protect \
* all semaphore operations. \
* \
* If "up()" is called before we call waking_non_zero() then \
* we will catch it right away. If it is called later then \
* we will have to go through a wakeup cycle to catch it. \
* \
* Multiple waiters contend for the semaphore lock to see \
* who gets to gate through and who has to wait some more. \
*/ \
for (;;) {
#define DOWN_TAIL(task_state) \
current->state = (task_state); \
} \
current->state = TASK_RUNNING; \
remove_wait_queue(&sem->wait, &wait);
void __sched __down(struct semaphore * sem)
{
DECLARE_WAITQUEUE(wait, current);
DOWN_HEAD(TASK_UNINTERRUPTIBLE)
if (waking_non_zero(sem))
break;
schedule();
DOWN_TAIL(TASK_UNINTERRUPTIBLE)
}
int __sched __down_interruptible(struct semaphore * sem)
{
DECLARE_WAITQUEUE(wait, current);
int ret = 0;
DOWN_HEAD(TASK_INTERRUPTIBLE)
ret = waking_non_zero_interruptible(sem, current);
if (ret)
{
if (ret == 1)
/* ret != 0 only if we get interrupted -arca */
ret = 0;
break;
}
schedule();
DOWN_TAIL(TASK_INTERRUPTIBLE)
return ret;
}
int __down_trylock(struct semaphore * sem)
{
return waking_non_zero_trylock(sem);
}

2
arch/ia64/kernel/Makefile
View File

@ -6,7 +6,7 @@ extra-y := head.o init_task.o vmlinux.lds
obj-y := acpi.o entry.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o \
irq_lsapic.o ivt.o machvec.o pal.o patch.o process.o perfmon.o ptrace.o sal.o \
salinfo.o semaphore.o setup.o signal.o sys_ia64.o time.o traps.o unaligned.o \
salinfo.o setup.o signal.o sys_ia64.o time.o traps.o unaligned.o \
unwind.o mca.o mca_asm.o topology.o
obj-$(CONFIG_IA64_BRL_EMU) += brl_emu.o

6
arch/ia64/kernel/ia64_ksyms.c
View File

@ -19,12 +19,6 @@ EXPORT_SYMBOL_GPL(empty_zero_page);
EXPORT_SYMBOL(ip_fast_csum); /* hand-coded assembly */
EXPORT_SYMBOL(csum_ipv6_magic);
#include <asm/semaphore.h>
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(__down_trylock);
EXPORT_SYMBOL(__up);
#include <asm/page.h>
EXPORT_SYMBOL(clear_page);

165
arch/ia64/kernel/semaphore.c
View File

@ -1,165 +0,0 @@
/*
* IA-64 semaphore implementation (derived from x86 version).
*
* Copyright (C) 1999-2000, 2002 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
/*
* Semaphores are implemented using a two-way counter: The "count"
* variable is decremented for each process that tries to acquire the
* semaphore, while the "sleepers" variable is a count of such
* acquires.
*
* Notably, the inline "up()" and "down()" functions can efficiently
* test if they need to do any extra work (up needs to do something
* only if count was negative before the increment operation.
*
* "sleeping" and the contention routine ordering is protected
* by the spinlock in the semaphore's waitqueue head.
*
* Note that these functions are only called when there is contention
* on the lock, and as such all this is the "non-critical" part of the
* whole semaphore business. The critical part is the inline stuff in
* <asm/semaphore.h> where we want to avoid any extra jumps and calls.
*/
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/errno.h>
#include <asm/semaphore.h>
/*
* Logic:
* - Only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - When we go from a non-negative count to a negative do we
* (a) synchronize with the "sleepers" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
void
__up (struct semaphore *sem)
{
wake_up(&sem->wait);
}
void __sched __down (struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* the wait_queue_head.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_UNINTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
}
int __sched __down_interruptible (struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers ++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into
* the trylock failure case - we won't be
* sleeping, and we* can't get the lock as
* it has contention. Just correct the count
* and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* wait_queue_head. The "-1" is because we're
* still hoping to get the semaphore.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_INTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
return retval;
}
/*
* Trylock failed - make sure we correct for having decremented the
* count.
*/
int
__down_trylock (struct semaphore *sem)
{
unsigned long flags;
int sleepers;
spin_lock_irqsave(&sem->wait.lock, flags);
sleepers = sem->sleepers + 1;
sem->sleepers = 0;
/*
* Add "everybody else" and us into it. They aren't
* playing, because we own the spinlock in the
* wait_queue_head.
*/
if (!atomic_add_negative(sleepers, &sem->count)) {
wake_up_locked(&sem->wait);
}
spin_unlock_irqrestore(&sem->wait.lock, flags);
return 1;
}

2
arch/m32r/kernel/Makefile
View File

@ -5,7 +5,7 @@
extra-y := head.o init_task.o vmlinux.lds
obj-y := process.o entry.o traps.o align.o irq.o setup.o time.o \
m32r_ksyms.o sys_m32r.o semaphore.o signal.o ptrace.o
m32r_ksyms.o sys_m32r.o signal.o ptrace.o
obj-$(CONFIG_SMP) += smp.o smpboot.o
obj-$(CONFIG_MODULES) += module.o

5
arch/m32r/kernel/m32r_ksyms.c
View File

@ -7,7 +7,6 @@
#include <linux/interrupt.h>
#include <linux/string.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
@ -22,10 +21,6 @@ EXPORT_SYMBOL(dump_fpu);
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(iounmap);
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down_trylock);
/* Networking helper routines. */
/* Delay loops */

185
arch/m32r/kernel/semaphore.c
View File

@ -1,185 +0,0 @@
/*
* linux/arch/m32r/semaphore.c
* orig : i386 2.6.4
*
* M32R semaphore implementation.
*
* Copyright (c) 2002 - 2004 Hitoshi Yamamoto
*/
/*
* i386 semaphore implementation.
*
* (C) Copyright 1999 Linus Torvalds
*
* Portions Copyright 1999 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
*/
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/init.h>
#include <asm/semaphore.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to acquire the semaphore, while the "sleeping"
* variable is a count of such acquires.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* "sleeping" and the contention routine ordering is protected
* by the spinlock in the semaphore's waitqueue head.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
/*
* Logic:
* - only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - when we go from a non-negative count to a negative do we
* (a) synchronize with the "sleeper" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
asmlinkage void __up(struct semaphore *sem)
{
wake_up(&sem->wait);
}
asmlinkage void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* the wait_queue_head.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_UNINTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
}
asmlinkage int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into
* the trylock failure case - we won't be
* sleeping, and we* can't get the lock as
* it has contention. Just correct the count
* and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* wait_queue_head. The "-1" is because we're
* still hoping to get the semaphore.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_INTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
return retval;
}
/*
* Trylock failed - make sure we correct for
* having decremented the count.
*
* We could have done the trylock with a
* single "cmpxchg" without failure cases,
* but then it wouldn't work on a 386.
*/
asmlinkage int __down_trylock(struct semaphore * sem)
{
int sleepers;
unsigned long flags;
spin_lock_irqsave(&sem->wait.lock, flags);
sleepers = sem->sleepers + 1;
sem->sleepers = 0;
/*
* Add "everybody else" and us into it. They aren't
* playing, because we own the spinlock in the
* wait_queue_head.
*/
if (!atomic_add_negative(sleepers, &sem->count)) {
wake_up_locked(&sem->wait);
}
spin_unlock_irqrestore(&sem->wait.lock, flags);
return 1;
}

2
arch/m68k/kernel/Makefile
View File

@ -10,7 +10,7 @@ endif
extra-y += vmlinux.lds
obj-y := entry.o process.o traps.o ints.o signal.o ptrace.o module.o \
sys_m68k.o time.o semaphore.o setup.o m68k_ksyms.o devres.o
sys_m68k.o time.o setup.o m68k_ksyms.o devres.o
devres-y = ../../../kernel/irq/devres.o

6
arch/m68k/kernel/m68k_ksyms.c
View File

@ -1,5 +1,4 @@
#include <linux/module.h>
#include <asm/semaphore.h>
asmlinkage long long __ashldi3 (long long, int);
asmlinkage long long __ashrdi3 (long long, int);
@ -15,8 +14,3 @@ EXPORT_SYMBOL(__ashrdi3);
EXPORT_SYMBOL(__lshrdi3);
EXPORT_SYMBOL(__muldi3);
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__down_failed_trylock);
EXPORT_SYMBOL(__up_wakeup);

132
arch/m68k/kernel/semaphore.c
View File

@ -1,132 +0,0 @@
/*
* Generic semaphore code. Buyer beware. Do your own
* specific changes in <asm/semaphore-helper.h>
*/
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/semaphore-helper.h>
#ifndef CONFIG_RMW_INSNS
spinlock_t semaphore_wake_lock;
#endif
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to sleep, while the "waking" variable is
* incremented when the "up()" code goes to wake up waiting
* processes.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* waking_non_zero() (from asm/semaphore.h) must execute
* atomically.
*
* When __up() is called, the count was negative before
* incrementing it, and we need to wake up somebody.
*
* This routine adds one to the count of processes that need to
* wake up and exit. ALL waiting processes actually wake up but
* only the one that gets to the "waking" field first will gate
* through and acquire the semaphore. The others will go back
* to sleep.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
wake_one_more(sem);
wake_up(&sem->wait);
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from __down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from __down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*
*/
#define DOWN_HEAD(task_state) \
\
\
current->state = (task_state); \
add_wait_queue(&sem->wait, &wait); \
\
/* \
* Ok, we're set up. sem->count is known to be less than zero \
* so we must wait. \
* \
* We can let go the lock for purposes of waiting. \
* We re-acquire it after awaking so as to protect \
* all semaphore operations. \
* \
* If "up()" is called before we call waking_non_zero() then \
* we will catch it right away. If it is called later then \
* we will have to go through a wakeup cycle to catch it. \
* \
* Multiple waiters contend for the semaphore lock to see \
* who gets to gate through and who has to wait some more. \
*/ \
for (;;) {
#define DOWN_TAIL(task_state) \
current->state = (task_state); \
} \
current->state = TASK_RUNNING; \
remove_wait_queue(&sem->wait, &wait);
void __sched __down(struct semaphore * sem)
{
DECLARE_WAITQUEUE(wait, current);
DOWN_HEAD(TASK_UNINTERRUPTIBLE)
if (waking_non_zero(sem))
break;
schedule();
DOWN_TAIL(TASK_UNINTERRUPTIBLE)
}
int __sched __down_interruptible(struct semaphore * sem)
{
DECLARE_WAITQUEUE(wait, current);
int ret = 0;
DOWN_HEAD(TASK_INTERRUPTIBLE)
ret = waking_non_zero_interruptible(sem, current);
if (ret)
{
if (ret == 1)
/* ret != 0 only if we get interrupted -arca */
ret = 0;
break;
}
schedule();
DOWN_TAIL(TASK_INTERRUPTIBLE)
return ret;
}
int __down_trylock(struct semaphore * sem)
{
return waking_non_zero_trylock(sem);
}

2
arch/m68k/lib/Makefile
View File

@ -5,4 +5,4 @@
EXTRA_AFLAGS := -traditional
lib-y := ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \
checksum.o string.o semaphore.o uaccess.o
checksum.o string.o uaccess.o

53
arch/m68k/lib/semaphore.S
View File

@ -1,53 +0,0 @@
/*
* linux/arch/m68k/lib/semaphore.S
*
* Copyright (C) 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
#include <linux/linkage.h>
#include <asm/semaphore.h>
/*
* The semaphore operations have a special calling sequence that
* allow us to do a simpler in-line version of them. These routines
* need to convert that sequence back into the C sequence when
* there is contention on the semaphore.
*/
ENTRY(__down_failed)
moveml %a0/%d0/%d1,-(%sp)
movel %a1,-(%sp)
jbsr __down
movel (%sp)+,%a1
moveml (%sp)+,%a0/%d0/%d1
rts
ENTRY(__down_failed_interruptible)
movel %a0,-(%sp)
movel %d1,-(%sp)
movel %a1,-(%sp)
jbsr __down_interruptible
movel (%sp)+,%a1
movel (%sp)+,%d1
movel (%sp)+,%a0
rts
ENTRY(__down_failed_trylock)
movel %a0,-(%sp)
movel %d1,-(%sp)
movel %a1,-(%sp)
jbsr __down_trylock
movel (%sp)+,%a1
movel (%sp)+,%d1
movel (%sp)+,%a0
rts
ENTRY(__up_wakeup)
moveml %a0/%d0/%d1,-(%sp)
movel %a1,-(%sp)
jbsr __up
movel (%sp)+,%a1
moveml (%sp)+,%a0/%d0/%d1
rts

2
arch/m68knommu/kernel/Makefile
View File

@ -5,7 +5,7 @@
extra-y := vmlinux.lds
obj-y += dma.o entry.o init_task.o irq.o m68k_ksyms.o process.o ptrace.o \
semaphore.o setup.o signal.o syscalltable.o sys_m68k.o time.o traps.o
setup.o signal.o syscalltable.o sys_m68k.o time.o traps.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_COMEMPCI) += comempci.o

6
arch/m68knommu/kernel/m68k_ksyms.c
View File

@ -13,7 +13,6 @@
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/semaphore.h>
#include <asm/checksum.h>
#include <asm/current.h>
@ -39,11 +38,6 @@ EXPORT_SYMBOL(csum_partial_copy_nocheck);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__down_failed_trylock);
EXPORT_SYMBOL(__up_wakeup);
/*
* libgcc functions - functions that are used internally by the
* compiler... (prototypes are not correct though, but that

133
arch/m68knommu/kernel/semaphore.c
View File

@ -1,133 +0,0 @@
/*
* Generic semaphore code. Buyer beware. Do your own
* specific changes in <asm/semaphore-helper.h>
*/
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/init.h>
#include <asm/semaphore-helper.h>
#ifndef CONFIG_RMW_INSNS
spinlock_t semaphore_wake_lock;
#endif
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to sleep, while the "waking" variable is
* incremented when the "up()" code goes to wake up waiting
* processes.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* waking_non_zero() (from asm/semaphore.h) must execute
* atomically.
*
* When __up() is called, the count was negative before
* incrementing it, and we need to wake up somebody.
*
* This routine adds one to the count of processes that need to
* wake up and exit. ALL waiting processes actually wake up but
* only the one that gets to the "waking" field first will gate
* through and acquire the semaphore. The others will go back
* to sleep.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
wake_one_more(sem);
wake_up(&sem->wait);
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from __down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from __down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*
*/
#define DOWN_HEAD(task_state) \
\
\
current->state = (task_state); \
add_wait_queue(&sem->wait, &wait); \
\
/* \
* Ok, we're set up. sem->count is known to be less than zero \
* so we must wait. \
* \
* We can let go the lock for purposes of waiting. \
* We re-acquire it after awaking so as to protect \
* all semaphore operations. \
* \
* If "up()" is called before we call waking_non_zero() then \
* we will catch it right away. If it is called later then \
* we will have to go through a wakeup cycle to catch it. \
* \
* Multiple waiters contend for the semaphore lock to see \
* who gets to gate through and who has to wait some more. \
*/ \
for (;;) {
#define DOWN_TAIL(task_state) \
current->state = (task_state); \
} \
current->state = TASK_RUNNING; \
remove_wait_queue(&sem->wait, &wait);
void __sched __down(struct semaphore * sem)
{
DECLARE_WAITQUEUE(wait, current);
DOWN_HEAD(TASK_UNINTERRUPTIBLE)
if (waking_non_zero(sem))
break;
schedule();
DOWN_TAIL(TASK_UNINTERRUPTIBLE)
}
int __sched __down_interruptible(struct semaphore * sem)
{
DECLARE_WAITQUEUE(wait, current);
int ret = 0;
DOWN_HEAD(TASK_INTERRUPTIBLE)
ret = waking_non_zero_interruptible(sem, current);
if (ret)
{
if (ret == 1)
/* ret != 0 only if we get interrupted -arca */
ret = 0;
break;
}
schedule();
DOWN_TAIL(TASK_INTERRUPTIBLE)
return ret;
}
int __down_trylock(struct semaphore * sem)
{
return waking_non_zero_trylock(sem);
}

2
arch/m68knommu/lib/Makefile
View File

@ -4,4 +4,4 @@
lib-y := ashldi3.o ashrdi3.o lshrdi3.o \
muldi3.o mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o \
checksum.o semaphore.o memcpy.o memset.o delay.o
checksum.o memcpy.o memset.o delay.o

66
arch/m68knommu/lib/semaphore.S
View File

@ -1,66 +0,0 @@
/*
* linux/arch/m68k/lib/semaphore.S
*
* Copyright (C) 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*
* MAR/1999 -- modified to support ColdFire (gerg@snapgear.com)
*/
#include <linux/linkage.h>
#include <asm/semaphore.h>
/*
* "down_failed" is called with the eventual return address
* in %a0, and the address of the semaphore in %a1. We need
* to increment the number of waiters on the semaphore,
* call "__down()", and then eventually return to try again.
*/
ENTRY(__down_failed)
#ifdef CONFIG_COLDFIRE
subl #12,%sp
moveml %a0/%d0/%d1,(%sp)
#else
moveml %a0/%d0/%d1,-(%sp)
#endif
movel %a1,-(%sp)
jbsr __down
movel (%sp)+,%a1
movel (%sp)+,%d0
movel (%sp)+,%d1
rts
ENTRY(__down_failed_interruptible)
movel %a0,-(%sp)
movel %d1,-(%sp)
movel %a1,-(%sp)
jbsr __down_interruptible
movel (%sp)+,%a1
movel (%sp)+,%d1
rts
ENTRY(__up_wakeup)
#ifdef CONFIG_COLDFIRE
subl #12,%sp
moveml %a0/%d0/%d1,(%sp)
#else
moveml %a0/%d0/%d1,-(%sp)
#endif
movel %a1,-(%sp)
jbsr __up
movel (%sp)+,%a1
movel (%sp)+,%d0
movel (%sp)+,%d1
rts
ENTRY(__down_failed_trylock)
movel %a0,-(%sp)
movel %d1,-(%sp)
movel %a1,-(%sp)
jbsr __down_trylock
movel (%sp)+,%a1
movel (%sp)+,%d1
movel (%sp)+,%a0
rts

2
arch/mips/kernel/Makefile
View File

@ -5,7 +5,7 @@
extra-y := head.o init_task.o vmlinux.lds
obj-y += cpu-probe.o branch.o entry.o genex.o irq.o process.o \
ptrace.o reset.o semaphore.o setup.o signal.o syscall.o \
ptrace.o reset.o setup.o signal.o syscall.o \
time.o topology.o traps.o unaligned.o
obj-$(CONFIG_CEVT_BCM1480) += cevt-bcm1480.o

168
arch/mips/kernel/semaphore.c
View File

@ -1,168 +0,0 @@
/*
* MIPS-specific semaphore code.
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
* Copyright (C) 2004 Ralf Baechle <ralf@linux-mips.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* April 2001 - Reworked by Paul Mackerras <paulus@samba.org>
* to eliminate the SMP races in the old version between the updates
* of `count' and `waking'. Now we use negative `count' values to
* indicate that some process(es) are waiting for the semaphore.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/atomic.h>
#include <asm/cpu-features.h>
#include <asm/errno.h>
#include <asm/semaphore.h>
#include <asm/war.h>
/*
* Atomically update sem->count.
* This does the equivalent of the following:
*
* old_count = sem->count;
* tmp = MAX(old_count, 0) + incr;
* sem->count = tmp;
* return old_count;
*
* On machines without lld/scd we need a spinlock to make the manipulation of
* sem->count and sem->waking atomic. Scalability isn't an issue because
* this lock is used on UP only so it's just an empty variable.
*/
static inline int __sem_update_count(struct semaphore *sem, int incr)
{
int old_count, tmp;
if (cpu_has_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set mips3 \n"
"1: ll %0, %2 # __sem_update_count \n"
" sra %1, %0, 31 \n"
" not %1 \n"
" and %1, %0, %1 \n"
" addu %1, %1, %3 \n"
" sc %1, %2 \n"
" beqzl %1, 1b \n"
" .set mips0 \n"
: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
: "r" (incr), "m" (sem->count));
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
"1: ll %0, %2 # __sem_update_count \n"
" sra %1, %0, 31 \n"
" not %1 \n"
" and %1, %0, %1 \n"
" addu %1, %1, %3 \n"
" sc %1, %2 \n"
" beqz %1, 1b \n"
" .set mips0 \n"
: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
: "r" (incr), "m" (sem->count));
} else {
static DEFINE_SPINLOCK(semaphore_lock);
unsigned long flags;
spin_lock_irqsave(&semaphore_lock, flags);
old_count = atomic_read(&sem->count);
tmp = max_t(int, old_count, 0) + incr;
atomic_set(&sem->count, tmp);
spin_unlock_irqrestore(&semaphore_lock, flags);
}
return old_count;
}
void __up(struct semaphore *sem)
{
/*
* Note that we incremented count in up() before we came here,
* but that was ineffective since the result was <= 0, and
* any negative value of count is equivalent to 0.
* This ends up setting count to 1, unless count is now > 0
* (i.e. because some other cpu has called up() in the meantime),
* in which case we just increment count.
*/
__sem_update_count(sem, 1);
wake_up(&sem->wait);
}
EXPORT_SYMBOL(__up);
/*
* Note that when we come in to __down or __down_interruptible,
* we have already decremented count, but that decrement was
* ineffective since the result was < 0, and any negative value
* of count is equivalent to 0.
* Thus it is only when we decrement count from some value > 0
* that we have actually got the semaphore.
*/
void __sched __down(struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
__set_task_state(tsk, TASK_UNINTERRUPTIBLE);
add_wait_queue_exclusive(&sem->wait, &wait);
/*
* Try to get the semaphore. If the count is > 0, then we've
* got the semaphore; we decrement count and exit the loop.
* If the count is 0 or negative, we set it to -1, indicating
* that we are asleep, and then sleep.
*/
while (__sem_update_count(sem, -1) <= 0) {
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
__set_task_state(tsk, TASK_RUNNING);
/*
* If there are any more sleepers, wake one of them up so
* that it can either get the semaphore, or set count to -1
* indicating that there are still processes sleeping.
*/
wake_up(&sem->wait);
}
EXPORT_SYMBOL(__down);
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
__set_task_state(tsk, TASK_INTERRUPTIBLE);
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
if (signal_pending(current)) {
/*
* A signal is pending - give up trying.
* Set sem->count to 0 if it is negative,
* since we are no longer sleeping.
*/
__sem_update_count(sem, 0);
retval = -EINTR;
break;
}
schedule();
set_task_state(tsk, TASK_INTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
__set_task_state(tsk, TASK_RUNNING);
wake_up(&sem->wait);
return retval;
}
EXPORT_SYMBOL(__down_interruptible);

2
arch/mn10300/kernel/Makefile
View File

@ -3,7 +3,7 @@
#
extra-y := head.o init_task.o vmlinux.lds
obj-y := process.o semaphore.o signal.o entry.o fpu.o traps.o irq.o \
obj-y := process.o signal.o entry.o fpu.o traps.o irq.o \
ptrace.o setup.o time.o sys_mn10300.o io.o kthread.o \
switch_to.o mn10300_ksyms.o kernel_execve.o

149
arch/mn10300/kernel/semaphore.c
View File

@ -1,149 +0,0 @@
/* MN10300 Semaphore implementation
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <linux/module.h>
#include <asm/semaphore.h>
struct sem_waiter {
struct list_head list;
struct task_struct *task;
};
#if SEMAPHORE_DEBUG
void semtrace(struct semaphore *sem, const char *str)
{
if (sem->debug)
printk(KERN_DEBUG "[%d] %s({%d,%d})\n",
current->pid,
str,
atomic_read(&sem->count),
list_empty(&sem->wait_list) ? 0 : 1);
}
#else
#define semtrace(SEM, STR) do { } while (0)
#endif
/*
* wait for a token to be granted from a semaphore
* - entered with lock held and interrupts disabled
*/
void __down(struct semaphore *sem, unsigned long flags)
{
struct task_struct *tsk = current;
struct sem_waiter waiter;
semtrace(sem, "Entering __down");
/* set up my own style of waitqueue */
waiter.task = tsk;
get_task_struct(tsk);
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the semaphore */
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
for (;;) {
if (!waiter.task)
break;
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
}
tsk->state = TASK_RUNNING;
semtrace(sem, "Leaving __down");
}
EXPORT_SYMBOL(__down);
/*
* interruptibly wait for a token to be granted from a semaphore
* - entered with lock held and interrupts disabled
*/
int __down_interruptible(struct semaphore *sem, unsigned long flags)
{
struct task_struct *tsk = current;
struct sem_waiter waiter;
int ret;
semtrace(sem, "Entering __down_interruptible");
/* set up my own style of waitqueue */
waiter.task = tsk;
get_task_struct(tsk);
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
set_task_state(tsk, TASK_INTERRUPTIBLE);
spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the semaphore */
ret = 0;
for (;;) {
if (!waiter.task)
break;
if (unlikely(signal_pending(current)))
goto interrupted;
schedule();
set_task_state(tsk, TASK_INTERRUPTIBLE);
}
out:
tsk->state = TASK_RUNNING;
semtrace(sem, "Leaving __down_interruptible");
return ret;
interrupted:
spin_lock_irqsave(&sem->wait_lock, flags);
list_del(&waiter.list);
spin_unlock_irqrestore(&sem->wait_lock, flags);
ret = 0;
if (!waiter.task) {
put_task_struct(current);
ret = -EINTR;
}
goto out;
}
EXPORT_SYMBOL(__down_interruptible);
/*
* release a single token back to a semaphore
* - entered with lock held and interrupts disabled
*/
void __up(struct semaphore *sem)
{
struct task_struct *tsk;
struct sem_waiter *waiter;
semtrace(sem, "Entering __up");
/* grant the token to the process at the front of the queue */
waiter = list_entry(sem->wait_list.next, struct sem_waiter, list);
/* We must be careful not to touch 'waiter' after we set ->task = NULL.
* It is an allocated on the waiter's stack and may become invalid at
* any time after that point (due to a wakeup from another source).
*/
list_del_init(&waiter->list);
tsk = waiter->task;
smp_mb();
waiter->task = NULL;
wake_up_process(tsk);
put_task_struct(tsk);
semtrace(sem, "Leaving __up");
}
EXPORT_SYMBOL(__up);

2
arch/parisc/kernel/Makefile
View File

@ -9,7 +9,7 @@ AFLAGS_pacache.o := -traditional
obj-y := cache.o pacache.o setup.o traps.o time.o irq.o \
pa7300lc.o syscall.o entry.o sys_parisc.o firmware.o \
ptrace.o hardware.o inventory.o drivers.o semaphore.o \
ptrace.o hardware.o inventory.o drivers.o \
signal.o hpmc.o real2.o parisc_ksyms.o unaligned.o \
process.o processor.o pdc_cons.o pdc_chassis.o unwind.o \
topology.o

5
arch/parisc/kernel/parisc_ksyms.c
View File

@ -69,11 +69,6 @@ EXPORT_SYMBOL(memcpy_toio);
EXPORT_SYMBOL(memcpy_fromio);
EXPORT_SYMBOL(memset_io);
#include <asm/semaphore.h>
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(__down);
extern void $$divI(void);
extern void $$divU(void);
extern void $$remI(void);

102
arch/parisc/kernel/semaphore.c
View File

@ -1,102 +0,0 @@
/*
* Semaphore implementation Copyright (c) 2001 Matthew Wilcox, Hewlett-Packard
*/
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/init.h>
/*
* Semaphores are complex as we wish to avoid using two variables.
* `count' has multiple roles, depending on its value. If it is positive
* or zero, there are no waiters. The functions here will never be
* called; see <asm/semaphore.h>
*
* When count is -1 it indicates there is at least one task waiting
* for the semaphore.
*
* When count is less than that, there are '- count - 1' wakeups
* pending. ie if it has value -3, there are 2 wakeups pending.
*
* Note that these functions are only called when there is contention
* on the lock, and as such all this is the "non-critical" part of the
* whole semaphore business. The critical part is the inline stuff in
* <asm/semaphore.h> where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
sem->count--;
wake_up(&sem->wait);
}
#define wakers(count) (-1 - count)
#define DOWN_HEAD \
int ret = 0; \
DECLARE_WAITQUEUE(wait, current); \
\
/* Note that someone is waiting */ \
if (sem->count == 0) \
sem->count = -1; \
\
/* protected by the sentry still -- use unlocked version */ \
wait.flags = WQ_FLAG_EXCLUSIVE; \
__add_wait_queue_tail(&sem->wait, &wait); \
lost_race: \
spin_unlock_irq(&sem->sentry); \
#define DOWN_TAIL \
spin_lock_irq(&sem->sentry); \
if (wakers(sem->count) == 0 && ret == 0) \
goto lost_race; /* Someone stole our wakeup */ \
__remove_wait_queue(&sem->wait, &wait); \
current->state = TASK_RUNNING; \
if (!waitqueue_active(&sem->wait) && (sem->count < 0)) \
sem->count = wakers(sem->count);
#define UPDATE_COUNT \
sem->count += (sem->count < 0) ? 1 : - 1;
void __sched __down(struct semaphore * sem)
{
DOWN_HEAD
for(;;) {
set_task_state(current, TASK_UNINTERRUPTIBLE);
/* we can _read_ this without the sentry */
if (sem->count != -1)
break;
schedule();
}
DOWN_TAIL
UPDATE_COUNT
}
int __sched __down_interruptible(struct semaphore * sem)
{
DOWN_HEAD
for(;;) {
set_task_state(current, TASK_INTERRUPTIBLE);
/* we can _read_ this without the sentry */
if (sem->count != -1)
break;
if (signal_pending(current)) {
ret = -EINTR;
break;
}
schedule();
}
DOWN_TAIL
if (!ret) {
UPDATE_COUNT
}
return ret;
}

2
arch/powerpc/kernel/Makefile
View File

@ -12,7 +12,7 @@ CFLAGS_prom_init.o += -fPIC
CFLAGS_btext.o += -fPIC
endif
obj-y := semaphore.o cputable.o ptrace.o syscalls.o \
obj-y := cputable.o ptrace.o syscalls.o \
irq.o align.o signal_32.o pmc.o vdso.o \
init_task.o process.o systbl.o idle.o \
signal.o

1
arch/powerpc/kernel/ppc_ksyms.c
View File

@ -15,7 +15,6 @@
#include <linux/bitops.h>
#include <asm/page.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/uaccess.h>

135
arch/powerpc/kernel/semaphore.c
View File

@ -1,135 +0,0 @@
/*
* PowerPC-specific semaphore code.
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* April 2001 - Reworked by Paul Mackerras <paulus@samba.org>
* to eliminate the SMP races in the old version between the updates
* of `count' and `waking'. Now we use negative `count' values to
* indicate that some process(es) are waiting for the semaphore.
*/
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/module.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
#include <asm/errno.h>
/*
* Atomically update sem->count.
* This does the equivalent of the following:
*
* old_count = sem->count;
* tmp = MAX(old_count, 0) + incr;
* sem->count = tmp;
* return old_count;
*/
static inline int __sem_update_count(struct semaphore *sem, int incr)
{
int old_count, tmp;
__asm__ __volatile__("\n"
"1: lwarx %0,0,%3\n"
" srawi %1,%0,31\n"
" andc %1,%0,%1\n"
" add %1,%1,%4\n"
PPC405_ERR77(0,%3)
" stwcx. %1,0,%3\n"
" bne 1b"
: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
: "r" (&sem->count), "r" (incr), "m" (sem->count)
: "cc");
return old_count;
}
void __up(struct semaphore *sem)
{
/*
* Note that we incremented count in up() before we came here,
* but that was ineffective since the result was <= 0, and
* any negative value of count is equivalent to 0.
* This ends up setting count to 1, unless count is now > 0
* (i.e. because some other cpu has called up() in the meantime),
* in which case we just increment count.
*/
__sem_update_count(sem, 1);
wake_up(&sem->wait);
}
EXPORT_SYMBOL(__up);
/*
* Note that when we come in to __down or __down_interruptible,
* we have already decremented count, but that decrement was
* ineffective since the result was < 0, and any negative value
* of count is equivalent to 0.
* Thus it is only when we decrement count from some value > 0
* that we have actually got the semaphore.
*/
void __sched __down(struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
__set_task_state(tsk, TASK_UNINTERRUPTIBLE);
add_wait_queue_exclusive(&sem->wait, &wait);
/*
* Try to get the semaphore. If the count is > 0, then we've
* got the semaphore; we decrement count and exit the loop.
* If the count is 0 or negative, we set it to -1, indicating
* that we are asleep, and then sleep.
*/
while (__sem_update_count(sem, -1) <= 0) {
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
__set_task_state(tsk, TASK_RUNNING);
/*
* If there are any more sleepers, wake one of them up so
* that it can either get the semaphore, or set count to -1
* indicating that there are still processes sleeping.
*/
wake_up(&sem->wait);
}
EXPORT_SYMBOL(__down);
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
__set_task_state(tsk, TASK_INTERRUPTIBLE);
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
if (signal_pending(current)) {
/*
* A signal is pending - give up trying.
* Set sem->count to 0 if it is negative,
* since we are no longer sleeping.
*/
__sem_update_count(sem, 0);
retval = -EINTR;
break;
}
schedule();
set_task_state(tsk, TASK_INTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
__set_task_state(tsk, TASK_RUNNING);
wake_up(&sem->wait);
return retval;
}
EXPORT_SYMBOL(__down_interruptible);

131
arch/ppc/kernel/semaphore.c
View File

@ -1,131 +0,0 @@
/*
* PowerPC-specific semaphore code.
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* April 2001 - Reworked by Paul Mackerras <paulus@samba.org>
* to eliminate the SMP races in the old version between the updates
* of `count' and `waking'. Now we use negative `count' values to
* indicate that some process(es) are waiting for the semaphore.
*/
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
#include <asm/errno.h>
/*
* Atomically update sem->count.
* This does the equivalent of the following:
*
* old_count = sem->count;
* tmp = MAX(old_count, 0) + incr;
* sem->count = tmp;
* return old_count;
*/
static inline int __sem_update_count(struct semaphore *sem, int incr)
{
int old_count, tmp;
__asm__ __volatile__("\n"
"1: lwarx %0,0,%3\n"
" srawi %1,%0,31\n"
" andc %1,%0,%1\n"
" add %1,%1,%4\n"
PPC405_ERR77(0,%3)
" stwcx. %1,0,%3\n"
" bne 1b"
: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
: "r" (&sem->count), "r" (incr), "m" (sem->count)
: "cc");
return old_count;
}
void __up(struct semaphore *sem)
{
/*
* Note that we incremented count in up() before we came here,
* but that was ineffective since the result was <= 0, and
* any negative value of count is equivalent to 0.
* This ends up setting count to 1, unless count is now > 0
* (i.e. because some other cpu has called up() in the meantime),
* in which case we just increment count.
*/
__sem_update_count(sem, 1);
wake_up(&sem->wait);
}
/*
* Note that when we come in to __down or __down_interruptible,
* we have already decremented count, but that decrement was
* ineffective since the result was < 0, and any negative value
* of count is equivalent to 0.
* Thus it is only when we decrement count from some value > 0
* that we have actually got the semaphore.
*/
void __sched __down(struct semaphore *sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_UNINTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
smp_wmb();
/*
* Try to get the semaphore. If the count is > 0, then we've
* got the semaphore; we decrement count and exit the loop.
* If the count is 0 or negative, we set it to -1, indicating
* that we are asleep, and then sleep.
*/
while (__sem_update_count(sem, -1) <= 0) {
schedule();
tsk->state = TASK_UNINTERRUPTIBLE;
}
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
/*
* If there are any more sleepers, wake one of them up so
* that it can either get the semaphore, or set count to -1
* indicating that there are still processes sleeping.
*/
wake_up(&sem->wait);
}
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_INTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
smp_wmb();
while (__sem_update_count(sem, -1) <= 0) {
if (signal_pending(current)) {
/*
* A signal is pending - give up trying.
* Set sem->count to 0 if it is negative,
* since we are no longer sleeping.
*/
__sem_update_count(sem, 0);
retval = -EINTR;
break;
}
schedule();
tsk->state = TASK_INTERRUPTIBLE;
}
tsk->state = TASK_RUNNING;
remove_wait_queue(&sem->wait, &wait);
wake_up(&sem->wait);
return retval;
}

2
arch/s390/kernel/Makefile
View File

@ -11,7 +11,7 @@ CFLAGS_smp.o := -Wno-nonnull
obj-y := bitmap.o traps.o time.o process.o base.o early.o \
setup.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o \
semaphore.o s390_ext.o debug.o irq.o ipl.o dis.o diag.o
s390_ext.o debug.o irq.o ipl.o dis.o diag.o
obj-y += $(if $(CONFIG_64BIT),entry64.o,entry.o)
obj-y += $(if $(CONFIG_64BIT),reipl64.o,reipl.o)

7
arch/s390/kernel/s390_ksyms.c
View File

@ -26,13 +26,6 @@ EXPORT_SYMBOL(_ni_bitmap);
EXPORT_SYMBOL(_zb_findmap);
EXPORT_SYMBOL(_sb_findmap);
/*
* semaphore ops
*/
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_interruptible);
/*
* binfmt_elf loader
*/

108
arch/s390/kernel/semaphore.c
View File

@ -1,108 +0,0 @@
/*
* linux/arch/s390/kernel/semaphore.c
*
* S390 version
* Copyright (C) 1998-2000 IBM Corporation
* Author(s): Martin Schwidefsky
*
* Derived from "linux/arch/i386/kernel/semaphore.c
* Copyright (C) 1999, Linus Torvalds
*
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <asm/semaphore.h>
/*
* Atomically update sem->count. Equivalent to:
* old_val = sem->count.counter;
* new_val = ((old_val >= 0) ? old_val : 0) + incr;
* sem->count.counter = new_val;
* return old_val;
*/
static inline int __sem_update_count(struct semaphore *sem, int incr)
{
int old_val, new_val;
asm volatile(
" l %0,0(%3)\n"
"0: ltr %1,%0\n"
" jhe 1f\n"
" lhi %1,0\n"
"1: ar %1,%4\n"
" cs %0,%1,0(%3)\n"
" jl 0b\n"
: "=&d" (old_val), "=&d" (new_val), "=m" (sem->count)
: "a" (&sem->count), "d" (incr), "m" (sem->count)
: "cc");
return old_val;
}
/*
* The inline function up() incremented count but the result
* was <= 0. This indicates that some process is waiting on
* the semaphore. The semaphore is free and we'll wake the
* first sleeping process, so we set count to 1 unless some
* other cpu has called up in the meantime in which case
* we just increment count by 1.
*/
void __up(struct semaphore *sem)
{
__sem_update_count(sem, 1);
wake_up(&sem->wait);
}
/*
* The inline function down() decremented count and the result
* was < 0. The wait loop will atomically test and update the
* semaphore counter following the rules:
* count > 0: decrement count, wake up queue and exit.
* count <= 0: set count to -1, go to sleep.
*/
void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
__set_task_state(tsk, TASK_UNINTERRUPTIBLE);
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
__set_task_state(tsk, TASK_RUNNING);
wake_up(&sem->wait);
}
/*
* Same as __down() with an additional test for signals.
* If a signal is pending the count is updated as follows:
* count > 0: wake up queue and exit.
* count <= 0: set count to 0, wake up queue and exit.
*/
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
__set_task_state(tsk, TASK_INTERRUPTIBLE);
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
if (signal_pending(current)) {
__sem_update_count(sem, 0);
retval = -EINTR;
break;
}
schedule();
set_task_state(tsk, TASK_INTERRUPTIBLE);
}
remove_wait_queue(&sem->wait, &wait);
__set_task_state(tsk, TASK_RUNNING);
wake_up(&sem->wait);
return retval;
}

2
arch/sh/kernel/Makefile_32
View File

@ -5,7 +5,7 @@
extra-y := head_32.o init_task.o vmlinux.lds
obj-y := debugtraps.o io.o io_generic.o irq.o machvec.o process_32.o \
ptrace_32.o semaphore.o setup.o signal_32.o sys_sh.o sys_sh32.o \
ptrace_32.o setup.o signal_32.o sys_sh.o sys_sh32.o \
syscalls_32.o time_32.o topology.o traps.o traps_32.o
obj-y += cpu/ timers/

2
arch/sh/kernel/Makefile_64
View File

@ -1,7 +1,7 @@
extra-y := head_64.o init_task.o vmlinux.lds
obj-y := debugtraps.o io.o io_generic.o irq.o machvec.o process_64.o \
ptrace_64.o semaphore.o setup.o signal_64.o sys_sh.o sys_sh64.o \
ptrace_64.o setup.o signal_64.o sys_sh.o sys_sh64.o \
syscalls_64.o time_64.o topology.o traps.o traps_64.o
obj-y += cpu/ timers/

139
arch/sh/kernel/semaphore.c
View File

@ -1,139 +0,0 @@
/*
* Just taken from alpha implementation.
* This can't work well, perhaps.
*/
/*
* Generic semaphore code. Buyer beware. Do your own
* specific changes in <asm/semaphore-helper.h>
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/init.h>
#include <asm/semaphore.h>
#include <asm/semaphore-helper.h>
DEFINE_SPINLOCK(semaphore_wake_lock);
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to sleep, while the "waking" variable is
* incremented when the "up()" code goes to wake up waiting
* processes.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* waking_non_zero() (from asm/semaphore.h) must execute
* atomically.
*
* When __up() is called, the count was negative before
* incrementing it, and we need to wake up somebody.
*
* This routine adds one to the count of processes that need to
* wake up and exit. ALL waiting processes actually wake up but
* only the one that gets to the "waking" field first will gate
* through and acquire the semaphore. The others will go back
* to sleep.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
wake_one_more(sem);
wake_up(&sem->wait);
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from __down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from __down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*
*/
#define DOWN_VAR \
struct task_struct *tsk = current; \
wait_queue_t wait; \
init_waitqueue_entry(&wait, tsk);
#define DOWN_HEAD(task_state) \
\
\
tsk->state = (task_state); \
add_wait_queue(&sem->wait, &wait); \
\
/* \
* Ok, we're set up. sem->count is known to be less than zero \
* so we must wait. \
* \
* We can let go the lock for purposes of waiting. \
* We re-acquire it after awaking so as to protect \
* all semaphore operations. \
* \
* If "up()" is called before we call waking_non_zero() then \
* we will catch it right away. If it is called later then \
* we will have to go through a wakeup cycle to catch it. \
* \
* Multiple waiters contend for the semaphore lock to see \
* who gets to gate through and who has to wait some more. \
*/ \
for (;;) {
#define DOWN_TAIL(task_state) \
tsk->state = (task_state); \
} \
tsk->state = TASK_RUNNING; \
remove_wait_queue(&sem->wait, &wait);
void __sched __down(struct semaphore * sem)
{
DOWN_VAR
DOWN_HEAD(TASK_UNINTERRUPTIBLE)
if (waking_non_zero(sem))
break;
schedule();
DOWN_TAIL(TASK_UNINTERRUPTIBLE)
}
int __sched __down_interruptible(struct semaphore * sem)
{
int ret = 0;
DOWN_VAR
DOWN_HEAD(TASK_INTERRUPTIBLE)
ret = waking_non_zero_interruptible(sem, tsk);
if (ret)
{
if (ret == 1)
/* ret != 0 only if we get interrupted -arca */
ret = 0;
break;
}
schedule();
DOWN_TAIL(TASK_INTERRUPTIBLE)
return ret;
}
int __down_trylock(struct semaphore * sem)
{
return waking_non_zero_trylock(sem);
}

7
arch/sh/kernel/sh_ksyms_32.c
View File

@ -9,7 +9,6 @@
#include <linux/pci.h>
#include <linux/irq.h>
#include <asm/sections.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
@ -48,12 +47,6 @@ EXPORT_SYMBOL(__copy_user);
EXPORT_SYMBOL(get_vm_area);
#endif
/* semaphore exports */
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(__down_trylock);
EXPORT_SYMBOL(__udelay);
EXPORT_SYMBOL(__ndelay);
EXPORT_SYMBOL(__const_udelay);

4
arch/sh/kernel/sh_ksyms_64.c
View File

@ -16,7 +16,6 @@
#include <linux/in6.h>
#include <linux/interrupt.h>
#include <linux/screen_info.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
@ -37,9 +36,6 @@ EXPORT_SYMBOL(csum_partial_copy_nocheck);
EXPORT_SYMBOL(screen_info);
#endif
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_trylock);
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__put_user_asm_l);
EXPORT_SYMBOL(__get_user_asm_l);
EXPORT_SYMBOL(copy_page);

2
arch/sparc/kernel/Makefile
View File

@ -12,7 +12,7 @@ obj-y := entry.o wof.o wuf.o etrap.o rtrap.o traps.o $(IRQ_OBJS) \
sys_sparc.o sunos_asm.o systbls.o \
time.o windows.o cpu.o devices.o sclow.o \
tadpole.o tick14.o ptrace.o sys_solaris.o \
unaligned.o una_asm.o muldiv.o semaphore.o \
unaligned.o una_asm.o muldiv.o \
prom.o of_device.o devres.o
devres-y = ../../../kernel/irq/devres.o

155
arch/sparc/kernel/semaphore.c
View File

@ -1,155 +0,0 @@
/* $Id: semaphore.c,v 1.7 2001/04/18 21:06:05 davem Exp $ */
/* sparc32 semaphore implementation, based on i386 version */
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <asm/semaphore.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to acquire the semaphore, while the "sleeping"
* variable is a count of such acquires.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* "sleeping" and the contention routine ordering is
* protected by the semaphore spinlock.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
/*
* Logic:
* - only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - when we go from a non-negative count to a negative do we
* (a) synchronize with the "sleeper" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
void __up(struct semaphore *sem)
{
wake_up(&sem->wait);
}
static DEFINE_SPINLOCK(semaphore_lock);
void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_UNINTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
spin_lock_irq(&semaphore_lock);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock.
*/
if (!atomic24_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irq(&semaphore_lock);
schedule();
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irq(&semaphore_lock);
}
spin_unlock_irq(&semaphore_lock);
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
wake_up(&sem->wait);
}
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_INTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
spin_lock_irq(&semaphore_lock);
sem->sleepers ++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into
* the trylock failure case - we won't be
* sleeping, and we* can't get the lock as
* it has contention. Just correct the count
* and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic24_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock. The
* "-1" is because we're still hoping to get
* the lock.
*/
if (!atomic24_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irq(&semaphore_lock);
schedule();
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irq(&semaphore_lock);
}
spin_unlock_irq(&semaphore_lock);
tsk->state = TASK_RUNNING;
remove_wait_queue(&sem->wait, &wait);
wake_up(&sem->wait);
return retval;
}
/*
* Trylock failed - make sure we correct for
* having decremented the count.
*/
int __down_trylock(struct semaphore * sem)
{
int sleepers;
unsigned long flags;
spin_lock_irqsave(&semaphore_lock, flags);
sleepers = sem->sleepers + 1;
sem->sleepers = 0;
/*
* Add "everybody else" and us into it. They aren't
* playing, because we own the spinlock.
*/
if (!atomic24_add_negative(sleepers, &sem->count))
wake_up(&sem->wait);
spin_unlock_irqrestore(&semaphore_lock, flags);
return 1;
}

5
arch/sparc/kernel/sparc_ksyms.c
View File

@ -107,11 +107,6 @@ EXPORT_SYMBOL(___rw_read_try);
EXPORT_SYMBOL(___rw_read_exit);
EXPORT_SYMBOL(___rw_write_enter);
#endif
/* semaphores */
EXPORT_SYMBOL(__up);
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_trylock);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(sparc_valid_addr_bitmap);
EXPORT_SYMBOL(phys_base);

2
arch/sparc64/kernel/Makefile
View File

@ -10,7 +10,7 @@ extra-y := head.o init_task.o vmlinux.lds
obj-y := process.o setup.o cpu.o idprom.o \
traps.o auxio.o una_asm.o sysfs.o iommu.o \
irq.o ptrace.o time.o sys_sparc.o signal.o \
unaligned.o central.o pci.o starfire.o semaphore.o \
unaligned.o central.o pci.o starfire.o \
power.o sbus.o sparc64_ksyms.o chmc.o \
visemul.o prom.o of_device.o hvapi.o sstate.o mdesc.o

254
arch/sparc64/kernel/semaphore.c
View File

@ -1,254 +0,0 @@
/* semaphore.c: Sparc64 semaphore implementation.
*
* This is basically the PPC semaphore scheme ported to use
* the sparc64 atomic instructions, so see the PPC code for
* credits.
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/init.h>
/*
* Atomically update sem->count.
* This does the equivalent of the following:
*
* old_count = sem->count;
* tmp = MAX(old_count, 0) + incr;
* sem->count = tmp;
* return old_count;
*/
static inline int __sem_update_count(struct semaphore *sem, int incr)
{
int old_count, tmp;
__asm__ __volatile__("\n"
" ! __sem_update_count old_count(%0) tmp(%1) incr(%4) &sem->count(%3)\n"
"1: ldsw [%3], %0\n"
" mov %0, %1\n"
" cmp %0, 0\n"
" movl %%icc, 0, %1\n"
" add %1, %4, %1\n"
" cas [%3], %0, %1\n"
" cmp %0, %1\n"
" membar #StoreLoad | #StoreStore\n"
" bne,pn %%icc, 1b\n"
" nop\n"
: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
: "r" (&sem->count), "r" (incr), "m" (sem->count)
: "cc");
return old_count;
}
static void __up(struct semaphore *sem)
{
__sem_update_count(sem, 1);
wake_up(&sem->wait);
}
void up(struct semaphore *sem)
{
/* This atomically does:
* old_val = sem->count;
* new_val = sem->count + 1;
* sem->count = new_val;
* if (old_val < 0)
* __up(sem);
*
* The (old_val < 0) test is equivalent to
* the more straightforward (new_val <= 0),
* but it is easier to test the former because
* of how the CAS instruction works.
*/
__asm__ __volatile__("\n"
" ! up sem(%0)\n"
" membar #StoreLoad | #LoadLoad\n"
"1: lduw [%0], %%g1\n"
" add %%g1, 1, %%g7\n"
" cas [%0], %%g1, %%g7\n"
" cmp %%g1, %%g7\n"
" bne,pn %%icc, 1b\n"
" addcc %%g7, 1, %%g0\n"
" membar #StoreLoad | #StoreStore\n"
" ble,pn %%icc, 3f\n"
" nop\n"
"2:\n"
" .subsection 2\n"
"3: mov %0, %%g1\n"
" save %%sp, -160, %%sp\n"
" call %1\n"
" mov %%g1, %%o0\n"
" ba,pt %%xcc, 2b\n"
" restore\n"
" .previous\n"
: : "r" (sem), "i" (__up)
: "g1", "g2", "g3", "g7", "memory", "cc");
}
static void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_UNINTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
schedule();
tsk->state = TASK_UNINTERRUPTIBLE;
}
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
wake_up(&sem->wait);
}
void __sched down(struct semaphore *sem)
{
might_sleep();
/* This atomically does:
* old_val = sem->count;
* new_val = sem->count - 1;
* sem->count = new_val;
* if (old_val < 1)
* __down(sem);
*
* The (old_val < 1) test is equivalent to
* the more straightforward (new_val < 0),
* but it is easier to test the former because
* of how the CAS instruction works.
*/
__asm__ __volatile__("\n"
" ! down sem(%0)\n"
"1: lduw [%0], %%g1\n"
" sub %%g1, 1, %%g7\n"
" cas [%0], %%g1, %%g7\n"
" cmp %%g1, %%g7\n"
" bne,pn %%icc, 1b\n"
" cmp %%g7, 1\n"
" membar #StoreLoad | #StoreStore\n"
" bl,pn %%icc, 3f\n"
" nop\n"
"2:\n"
" .subsection 2\n"
"3: mov %0, %%g1\n"
" save %%sp, -160, %%sp\n"
" call %1\n"
" mov %%g1, %%o0\n"
" ba,pt %%xcc, 2b\n"
" restore\n"
" .previous\n"
: : "r" (sem), "i" (__down)
: "g1", "g2", "g3", "g7", "memory", "cc");
}
int down_trylock(struct semaphore *sem)
{
int ret;
/* This atomically does:
* old_val = sem->count;
* new_val = sem->count - 1;
* if (old_val < 1) {
* ret = 1;
* } else {
* sem->count = new_val;
* ret = 0;
* }
*
* The (old_val < 1) test is equivalent to
* the more straightforward (new_val < 0),
* but it is easier to test the former because
* of how the CAS instruction works.
*/
__asm__ __volatile__("\n"
" ! down_trylock sem(%1) ret(%0)\n"
"1: lduw [%1], %%g1\n"
" sub %%g1, 1, %%g7\n"
" cmp %%g1, 1\n"
" bl,pn %%icc, 2f\n"
" mov 1, %0\n"
" cas [%1], %%g1, %%g7\n"
" cmp %%g1, %%g7\n"
" bne,pn %%icc, 1b\n"
" mov 0, %0\n"
" membar #StoreLoad | #StoreStore\n"
"2:\n"
: "=&r" (ret)
: "r" (sem)
: "g1", "g7", "memory", "cc");
return ret;
}
static int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_INTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
while (__sem_update_count(sem, -1) <= 0) {
if (signal_pending(current)) {
__sem_update_count(sem, 0);
retval = -EINTR;
break;
}
schedule();
tsk->state = TASK_INTERRUPTIBLE;
}
tsk->state = TASK_RUNNING;
remove_wait_queue(&sem->wait, &wait);
wake_up(&sem->wait);
return retval;
}
int __sched down_interruptible(struct semaphore *sem)
{
int ret = 0;
might_sleep();
/* This atomically does:
* old_val = sem->count;
* new_val = sem->count - 1;
* sem->count = new_val;
* if (old_val < 1)
* ret = __down_interruptible(sem);
*
* The (old_val < 1) test is equivalent to
* the more straightforward (new_val < 0),
* but it is easier to test the former because
* of how the CAS instruction works.
*/
__asm__ __volatile__("\n"
" ! down_interruptible sem(%2) ret(%0)\n"
"1: lduw [%2], %%g1\n"
" sub %%g1, 1, %%g7\n"
" cas [%2], %%g1, %%g7\n"
" cmp %%g1, %%g7\n"
" bne,pn %%icc, 1b\n"
" cmp %%g7, 1\n"
" membar #StoreLoad | #StoreStore\n"
" bl,pn %%icc, 3f\n"
" nop\n"
"2:\n"
" .subsection 2\n"
"3: mov %2, %%g1\n"
" save %%sp, -160, %%sp\n"
" call %3\n"
" mov %%g1, %%o0\n"
" ba,pt %%xcc, 2b\n"
" restore\n"
" .previous\n"
: "=r" (ret)
: "0" (ret), "r" (sem), "i" (__down_interruptible)
: "g1", "g2", "g3", "g7", "memory", "cc");
return ret;
}

6
arch/sparc64/kernel/sparc64_ksyms.c
View File

@ -130,12 +130,6 @@ EXPORT_SYMBOL(_mcount);
EXPORT_SYMBOL(sparc64_get_clock_tick);
/* semaphores */
EXPORT_SYMBOL(down);
EXPORT_SYMBOL(down_trylock);
EXPORT_SYMBOL(down_interruptible);
EXPORT_SYMBOL(up);
/* RW semaphores */
EXPORT_SYMBOL(__down_read);
EXPORT_SYMBOL(__down_read_trylock);

4
arch/um/Kconfig.i386
View File

@ -19,10 +19,6 @@ config 64BIT
bool
default n
config SEMAPHORE_SLEEPERS
bool
default y
config 3_LEVEL_PGTABLES
bool "Three-level pagetables (EXPERIMENTAL)"
default n

4
arch/um/Kconfig.x86_64
View File

@ -11,10 +11,6 @@ config RWSEM_GENERIC_SPINLOCK
bool
default y
config SEMAPHORE_SLEEPERS
bool
default y
config 3_LEVEL_PGTABLES
bool
default y

12
arch/um/sys-i386/ksyms.c
View File

@ -1,17 +1,5 @@
#include "linux/module.h"
#include "linux/in6.h"
#include "linux/rwsem.h"
#include "asm/byteorder.h"
#include "asm/delay.h"
#include "asm/semaphore.h"
#include "asm/uaccess.h"
#include "asm/checksum.h"
#include "asm/errno.h"
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__down_failed_trylock);
EXPORT_SYMBOL(__up_wakeup);
/* Networking helper routines. */
EXPORT_SYMBOL(csum_partial);

8
arch/um/sys-ppc/Makefile
View File

@ -3,7 +3,7 @@ OBJ = built-in.o
.S.o:
$(CC) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
OBJS = ptrace.o sigcontext.o semaphore.o checksum.o miscthings.o misc.o \
OBJS = ptrace.o sigcontext.o checksum.o miscthings.o misc.o \
ptrace_user.o sysrq.o
EXTRA_AFLAGS := -DCONFIG_PPC32 -I. -I$(srctree)/arch/ppc/kernel
@ -20,10 +20,6 @@ ptrace_user.o: ptrace_user.c
sigcontext.o: sigcontext.c
$(CC) $(USER_CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
semaphore.c:
rm -f $@
ln -s $(srctree)/arch/ppc/kernel/$@ $@
checksum.S:
rm -f $@
ln -s $(srctree)/arch/ppc/lib/$@ $@
@ -66,4 +62,4 @@ misc.o: misc.S ppc_defs.h
$(CC) $(EXTRA_AFLAGS) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
rm -f asm
clean-files := $(OBJS) ppc_defs.h checksum.S semaphore.c mk_defs.c
clean-files := $(OBJS) ppc_defs.h checksum.S mk_defs.c

13
arch/um/sys-x86_64/ksyms.c
View File

@ -1,16 +1,5 @@
#include "linux/module.h"
#include "linux/in6.h"
#include "linux/rwsem.h"
#include "asm/byteorder.h"
#include "asm/semaphore.h"
#include "asm/uaccess.h"
#include "asm/checksum.h"
#include "asm/errno.h"
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__down_failed_trylock);
EXPORT_SYMBOL(__up_wakeup);
#include "asm/string.h"
/*XXX: we need them because they would be exported by x86_64 */
EXPORT_SYMBOL(__memcpy);

2
arch/v850/kernel/Makefile
View File

@ -11,7 +11,7 @@
extra-y := head.o init_task.o vmlinux.lds
obj-y += intv.o entry.o process.o syscalls.o time.o semaphore.o setup.o \
obj-y += intv.o entry.o process.o syscalls.o time.o setup.o \
signal.o irq.o mach.o ptrace.o bug.o
obj-$(CONFIG_MODULES) += module.o v850_ksyms.o
# chip-specific code

166
arch/v850/kernel/semaphore.c
View File

@ -1,166 +0,0 @@
/*
* arch/v850/kernel/semaphore.c -- Semaphore support
*
* Copyright (C) 1998-2000 IBM Corporation
* Copyright (C) 1999 Linus Torvalds
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*
* This file is a copy of the s390 version, arch/s390/kernel/semaphore.c
* Author(s): Martin Schwidefsky
* which was derived from the i386 version, linux/arch/i386/kernel/semaphore.c
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/semaphore.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to acquire the semaphore, while the "sleeping"
* variable is a count of such acquires.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* "sleeping" and the contention routine ordering is
* protected by the semaphore spinlock.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
/*
* Logic:
* - only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - when we go from a non-negative count to a negative do we
* (a) synchronize with the "sleeper" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
void __up(struct semaphore *sem)
{
wake_up(&sem->wait);
}
static DEFINE_SPINLOCK(semaphore_lock);
void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_UNINTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
spin_lock_irq(&semaphore_lock);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irq(&semaphore_lock);
schedule();
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irq(&semaphore_lock);
}
spin_unlock_irq(&semaphore_lock);
remove_wait_queue(&sem->wait, &wait);
tsk->state = TASK_RUNNING;
wake_up(&sem->wait);
}
int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
tsk->state = TASK_INTERRUPTIBLE;
add_wait_queue_exclusive(&sem->wait, &wait);
spin_lock_irq(&semaphore_lock);
sem->sleepers ++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into
* the trylock failure case - we won't be
* sleeping, and we* can't get the lock as
* it has contention. Just correct the count
* and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock. The
* "-1" is because we're still hoping to get
* the lock.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irq(&semaphore_lock);
schedule();
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irq(&semaphore_lock);
}
spin_unlock_irq(&semaphore_lock);
tsk->state = TASK_RUNNING;
remove_wait_queue(&sem->wait, &wait);
wake_up(&sem->wait);
return retval;
}
/*
* Trylock failed - make sure we correct for
* having decremented the count.
*/
int __down_trylock(struct semaphore * sem)
{
unsigned long flags;
int sleepers;
spin_lock_irqsave(&semaphore_lock, flags);
sleepers = sem->sleepers + 1;
sem->sleepers = 0;
/*
* Add "everybody else" and us into it. They aren't
* playing, because we own the spinlock.
*/
if (!atomic_add_negative(sleepers, &sem->count))
wake_up(&sem->wait);
spin_unlock_irqrestore(&semaphore_lock, flags);
return 1;
}

7
arch/v850/kernel/v850_ksyms.c
View File

@ -11,7 +11,6 @@
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/semaphore.h>
#include <asm/checksum.h>
#include <asm/current.h>
@ -34,12 +33,6 @@ EXPORT_SYMBOL (memset);
EXPORT_SYMBOL (memcpy);
EXPORT_SYMBOL (memmove);
/* semaphores */
EXPORT_SYMBOL (__down);
EXPORT_SYMBOL (__down_interruptible);
EXPORT_SYMBOL (__down_trylock);
EXPORT_SYMBOL (__up);
/*
* libgcc functions - functions that are used internally by the
* compiler... (prototypes are not correct though, but that

3
arch/x86/Kconfig
View File

@ -53,9 +53,6 @@ config STACKTRACE_SUPPORT
config HAVE_LATENCYTOP_SUPPORT
def_bool y
config SEMAPHORE_SLEEPERS
def_bool y
config FAST_CMPXCHG_LOCAL
bool
default y

5
arch/x86/kernel/i386_ksyms_32.c
View File

@ -1,13 +1,8 @@
#include <linux/module.h>
#include <asm/semaphore.h>
#include <asm/checksum.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__down_failed_trylock);
EXPORT_SYMBOL(__up_wakeup);
/* Networking helper routines. */
EXPORT_SYMBOL(csum_partial_copy_generic);

6
arch/x86/kernel/x8664_ksyms_64.c
View File

@ -4,7 +4,6 @@
#include <linux/module.h>
#include <linux/smp.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@ -12,11 +11,6 @@
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(__down_failed);
EXPORT_SYMBOL(__down_failed_interruptible);
EXPORT_SYMBOL(__down_failed_trylock);
EXPORT_SYMBOL(__up_wakeup);
EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);
EXPORT_SYMBOL(__get_user_4);

83
arch/x86/lib/semaphore_32.S
View File

@ -30,89 +30,6 @@
* value or just clobbered..
*/
.section .sched.text, "ax"
ENTRY(__down_failed)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __down
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
ENDPROC(__down_failed)
ENTRY(__down_failed_interruptible)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __down_interruptible
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
ENDPROC(__down_failed_interruptible)
ENTRY(__down_failed_trylock)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __down_trylock
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
ENDPROC(__down_failed_trylock)
ENTRY(__up_wakeup)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __up
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
ENDPROC(__up_wakeup)
/*
* rw spinlock fallbacks

5
arch/x86/lib/thunk_64.S
View File

@ -41,11 +41,6 @@
thunk rwsem_downgrade_thunk,rwsem_downgrade_wake
#endif
thunk __down_failed,__down
thunk_retrax __down_failed_interruptible,__down_interruptible
thunk_retrax __down_failed_trylock,__down_trylock
thunk __up_wakeup,__up
#ifdef CONFIG_TRACE_IRQFLAGS
thunk trace_hardirqs_on_thunk,trace_hardirqs_on
thunk trace_hardirqs_off_thunk,trace_hardirqs_off

2
arch/xtensa/kernel/Makefile
View File

@ -5,7 +5,7 @@
extra-y := head.o vmlinux.lds
obj-y := align.o entry.o irq.o coprocessor.o process.o ptrace.o semaphore.o \
obj-y := align.o entry.o irq.o coprocessor.o process.o ptrace.o \
setup.o signal.o syscall.o time.o traps.o vectors.o platform.o \
pci-dma.o init_task.o io.o

226
arch/xtensa/kernel/semaphore.c
View File

@ -1,226 +0,0 @@
/*
* arch/xtensa/kernel/semaphore.c
*
* Generic semaphore code. Buyer beware. Do your own specific changes
* in <asm/semaphore-helper.h>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Chris Zankel <chris@zankel.net>
* Marc Gauthier<marc@tensilica.com, marc@alumni.uwaterloo.ca>
* Kevin Chea
*/
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/init.h>
#include <asm/semaphore.h>
#include <asm/errno.h>
/*
* These two _must_ execute atomically wrt each other.
*/
static __inline__ void wake_one_more(struct semaphore * sem)
{
atomic_inc((atomic_t *)&sem->sleepers);
}
static __inline__ int waking_non_zero(struct semaphore *sem)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->sleepers > 0) {
sem->sleepers--;
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*
* We must undo the sem->count down_interruptible() increment while we are
* protected by the spinlock in order to make atomic this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static __inline__ int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->sleepers > 0) {
sem->sleepers--;
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*
* We must undo the sem->count down_trylock() increment while we are
* protected by the spinlock in order to make atomic this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static __inline__ int waking_non_zero_trylock(struct semaphore *sem)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->sleepers <= 0)
atomic_inc(&sem->count);
else {
sem->sleepers--;
ret = 0;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
DEFINE_SPINLOCK(semaphore_wake_lock);
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to sleep, while the "waking" variable is
* incremented when the "up()" code goes to wake up waiting
* processes.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* waking_non_zero() (from asm/semaphore.h) must execute
* atomically.
*
* When __up() is called, the count was negative before
* incrementing it, and we need to wake up somebody.
*
* This routine adds one to the count of processes that need to
* wake up and exit. ALL waiting processes actually wake up but
* only the one that gets to the "waking" field first will gate
* through and acquire the semaphore. The others will go back
* to sleep.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
void __up(struct semaphore *sem)
{
wake_one_more(sem);
wake_up(&sem->wait);
}
/*
* Perform the "down" function. Return zero for semaphore acquired,
* return negative for signalled out of the function.
*
* If called from __down, the return is ignored and the wait loop is
* not interruptible. This means that a task waiting on a semaphore
* using "down()" cannot be killed until someone does an "up()" on
* the semaphore.
*
* If called from __down_interruptible, the return value gets checked
* upon return. If the return value is negative then the task continues
* with the negative value in the return register (it can be tested by
* the caller).
*
* Either form may be used in conjunction with "up()".
*
*/
#define DOWN_VAR \
struct task_struct *tsk = current; \
wait_queue_t wait; \
init_waitqueue_entry(&wait, tsk);
#define DOWN_HEAD(task_state) \
\
\
tsk->state = (task_state); \
add_wait_queue(&sem->wait, &wait); \
\
/* \
* Ok, we're set up. sem->count is known to be less than zero \
* so we must wait. \
* \
* We can let go the lock for purposes of waiting. \
* We re-acquire it after awaking so as to protect \
* all semaphore operations. \
* \
* If "up()" is called before we call waking_non_zero() then \
* we will catch it right away. If it is called later then \
* we will have to go through a wakeup cycle to catch it. \
* \
* Multiple waiters contend for the semaphore lock to see \
* who gets to gate through and who has to wait some more. \
*/ \
for (;;) {
#define DOWN_TAIL(task_state) \
tsk->state = (task_state); \
} \
tsk->state = TASK_RUNNING; \
remove_wait_queue(&sem->wait, &wait);
void __sched __down(struct semaphore * sem)
{
DOWN_VAR
DOWN_HEAD(TASK_UNINTERRUPTIBLE)
if (waking_non_zero(sem))
break;
schedule();
DOWN_TAIL(TASK_UNINTERRUPTIBLE)
}
int __sched __down_interruptible(struct semaphore * sem)
{
int ret = 0;
DOWN_VAR
DOWN_HEAD(TASK_INTERRUPTIBLE)
ret = waking_non_zero_interruptible(sem, tsk);
if (ret)
{
if (ret == 1)
/* ret != 0 only if we get interrupted -arca */
ret = 0;
break;
}
schedule();
DOWN_TAIL(TASK_INTERRUPTIBLE)
return ret;
}
int __down_trylock(struct semaphore * sem)
{
return waking_non_zero_trylock(sem);
}

9
arch/xtensa/kernel/xtensa_ksyms.c
View File

@ -26,7 +26,6 @@
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/semaphore.h>
#ifdef CONFIG_BLK_DEV_FD
#include <asm/floppy.h>
#endif
@ -71,14 +70,6 @@ EXPORT_SYMBOL(__umodsi3);
EXPORT_SYMBOL(__udivdi3);
EXPORT_SYMBOL(__umoddi3);
/*
* Semaphore operations
*/
EXPORT_SYMBOL(__down);
EXPORT_SYMBOL(__down_interruptible);
EXPORT_SYMBOL(__down_trylock);
EXPORT_SYMBOL(__up);
#ifdef CONFIG_NET
/*
* Networking support

150
include/asm-alpha/semaphore.h
View File

@ -1,149 +1 @@
#ifndef _ALPHA_SEMAPHORE_H
#define _ALPHA_SEMAPHORE_H
/*
* SMP- and interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
* (C) Copyright 1996, 2000 Richard Henderson
*/
#include <asm/current.h>
#include <asm/system.h>
#include <asm/atomic.h>
#include <linux/compiler.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
struct semaphore {
atomic_t count;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init(struct semaphore *sem, int val)
{
/*
* Logically,
* *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
* except that gcc produces better initializing by parts yet.
*/
atomic_set(&sem->count, val);
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void down(struct semaphore *);
extern void __down_failed(struct semaphore *);
extern int down_interruptible(struct semaphore *);
extern int __down_failed_interruptible(struct semaphore *);
extern int down_trylock(struct semaphore *);
extern void up(struct semaphore *);
extern void __up_wakeup(struct semaphore *);
/*
* Hidden out of line code is fun, but extremely messy. Rely on newer
* compilers to do a respectable job with this. The contention cases
* are handled out of line in arch/alpha/kernel/semaphore.c.
*/
static inline void __down(struct semaphore *sem)
{
long count;
might_sleep();
count = atomic_dec_return(&sem->count);
if (unlikely(count < 0))
__down_failed(sem);
}
static inline int __down_interruptible(struct semaphore *sem)
{
long count;
might_sleep();
count = atomic_dec_return(&sem->count);
if (unlikely(count < 0))
return __down_failed_interruptible(sem);
return 0;
}
/*
* down_trylock returns 0 on success, 1 if we failed to get the lock.
*/
static inline int __down_trylock(struct semaphore *sem)
{
long ret;
/* "Equivalent" C:
do {
ret = ldl_l;
--ret;
if (ret < 0)
break;
ret = stl_c = ret;
} while (ret == 0);
*/
__asm__ __volatile__(
"1: ldl_l %0,%1\n"
" subl %0,1,%0\n"
" blt %0,2f\n"
" stl_c %0,%1\n"
" beq %0,3f\n"
" mb\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: "=&r" (ret), "=m" (sem->count)
: "m" (sem->count));
return ret < 0;
}
static inline void __up(struct semaphore *sem)
{
if (unlikely(atomic_inc_return(&sem->count) <= 0))
__up_wakeup(sem);
}
#if !defined(CONFIG_DEBUG_SEMAPHORE)
extern inline void down(struct semaphore *sem)
{
__down(sem);
}
extern inline int down_interruptible(struct semaphore *sem)
{
return __down_interruptible(sem);
}
extern inline int down_trylock(struct semaphore *sem)
{
return __down_trylock(sem);
}
extern inline void up(struct semaphore *sem)
{
__up(sem);
}
#endif
#endif
#include <linux/semaphore.h>

84
include/asm-arm/semaphore-helper.h
View File

@ -1,84 +0,0 @@
#ifndef ASMARM_SEMAPHORE_HELPER_H
#define ASMARM_SEMAPHORE_HELPER_H
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore * sem)
{
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (atomic_read(&sem->count) <= 0)
sem->waking++;
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
}
static inline int waking_non_zero(struct semaphore *sem)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->waking > 0) {
sem->waking--;
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking non zero interruptible
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*
* We must undo the sem->count down_interruptible() increment while we are
* protected by the spinlock in order to make this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->waking > 0) {
sem->waking--;
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_try_lock:
* 1 failed to lock
* 0 got the lock
*
* We must undo the sem->count down_interruptible() increment while we are
* protected by the spinlock in order to make this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->waking <= 0)
atomic_inc(&sem->count);
else {
sem->waking--;
ret = 0;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif

99
include/asm-arm/semaphore.h
View File

@ -1,98 +1 @@
/*
* linux/include/asm-arm/semaphore.h
*/
#ifndef __ASM_ARM_SEMAPHORE_H
#define __ASM_ARM_SEMAPHORE_H
#include <linux/linkage.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
#include <asm/atomic.h>
#include <asm/locks.h>
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INIT(name, cnt) \
{ \
.count = ATOMIC_INIT(cnt), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INIT(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init(struct semaphore *sem, int val)
{
atomic_set(&sem->count, val);
sem->sleepers = 0;
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX(struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED(struct semaphore *sem)
{
sema_init(sem, 0);
}
/*
* special register calling convention
*/
asmlinkage void __down_failed(void);
asmlinkage int __down_interruptible_failed(void);
asmlinkage int __down_trylock_failed(void);
asmlinkage void __up_wakeup(void);
extern void __down(struct semaphore * sem);
extern int __down_interruptible(struct semaphore * sem);
extern int __down_trylock(struct semaphore * sem);
extern void __up(struct semaphore * sem);
/*
* This is ugly, but we want the default case to fall through.
* "__down" is the actual routine that waits...
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
__down_op(sem, __down_failed);
}
/*
* This is ugly, but we want the default case to fall through.
* "__down_interruptible" is the actual routine that waits...
*/
static inline int down_interruptible (struct semaphore * sem)
{
might_sleep();
return __down_op_ret(sem, __down_interruptible_failed);
}
static inline int down_trylock(struct semaphore *sem)
{
return __down_op_ret(sem, __down_trylock_failed);
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
__up_op(sem, __up_wakeup);
}
#endif
#include <linux/semaphore.h>

109
include/asm-avr32/semaphore.h
View File

@ -1,108 +1 @@
/*
* SMP- and interrupt-safe semaphores.
*
* Copyright (C) 2006 Atmel Corporation
*
* Based on include/asm-i386/semaphore.h
* Copyright (C) 1996 Linus Torvalds
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_SEMAPHORE_H
#define __ASM_AVR32_SEMAPHORE_H
#include <linux/linkage.h>
#include <asm/system.h>
#include <asm/atomic.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
atomic_set(&sem->count, val);
sem->sleepers = 0;
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
void __down(struct semaphore * sem);
int __down_interruptible(struct semaphore * sem);
void __up(struct semaphore * sem);
/*
* This is ugly, but we want the default case to fall through.
* "__down_failed" is a special asm handler that calls the C
* routine that actually waits. See arch/i386/kernel/semaphore.c
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
if (unlikely(atomic_dec_return (&sem->count) < 0))
__down (sem);
}
/*
* Interruptible try to acquire a semaphore. If we obtained
* it, return zero. If we were interrupted, returns -EINTR
*/
static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
might_sleep();
if (unlikely(atomic_dec_return (&sem->count) < 0))
ret = __down_interruptible (sem);
return ret;
}
/*
* Non-blockingly attempt to down() a semaphore.
* Returns zero if we acquired it
*/
static inline int down_trylock(struct semaphore * sem)
{
return atomic_dec_if_positive(&sem->count) < 0;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
if (unlikely(atomic_inc_return (&sem->count) <= 0))
__up (sem);
}
#endif /*__ASM_AVR32_SEMAPHORE_H */
#include <linux/semaphore.h>

82
include/asm-blackfin/semaphore-helper.h
View File

@ -1,82 +0,0 @@
/* Based on M68K version, Lineo Inc. May 2001 */
#ifndef _BFIN_SEMAPHORE_HELPER_H
#define _BFIN_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
*
*/
#include <asm/errno.h>
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore *sem)
{
atomic_inc(&sem->waking);
}
static inline int waking_non_zero(struct semaphore *sem)
{
int ret;
unsigned long flags = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*/
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
int ret = 0;
unsigned long flags = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*/
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
int ret = 1;
unsigned long flags = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 0;
} else
atomic_inc(&sem->count);
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif /* _BFIN_SEMAPHORE_HELPER_H */

106
include/asm-blackfin/semaphore.h
View File

@ -1,105 +1 @@
#ifndef _BFIN_SEMAPHORE_H
#define _BFIN_SEMAPHORE_H
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <asm/atomic.h>
/*
* Interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
*
* BFIN version by akbar hussain Lineo Inc April 2001
*
*/
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.sleepers = 0, \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init(struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void init_MUTEX(struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED(struct semaphore *sem)
{
sema_init(sem, 0);
}
asmlinkage void __down(struct semaphore *sem);
asmlinkage int __down_interruptible(struct semaphore *sem);
asmlinkage int __down_trylock(struct semaphore *sem);
asmlinkage void __up(struct semaphore *sem);
extern spinlock_t semaphore_wake_lock;
/*
* This is ugly, but we want the default case to fall through.
* "down_failed" is a special asm handler that calls the C
* routine that actually waits.
*/
static inline void down(struct semaphore *sem)
{
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
static inline int down_interruptible(struct semaphore *sem)
{
int ret = 0;
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return (ret);
}
static inline int down_trylock(struct semaphore *sem)
{
int ret = 0;
if (atomic_dec_return(&sem->count) < 0)
ret = __down_trylock(sem);
return ret;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore *sem)
{
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
}
#endif /* __ASSEMBLY__ */
#endif /* _BFIN_SEMAPHORE_H */
#include <linux/semaphore.h>

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/* $Id: semaphore-helper.h,v 1.3 2001/03/26 15:00:33 orjanf Exp $
*
* SMP- and interrupt-safe semaphores helper functions. Generic versions, no
* optimizations whatsoever...
*
*/
#ifndef _ASM_SEMAPHORE_HELPER_H
#define _ASM_SEMAPHORE_HELPER_H
#include <asm/atomic.h>
#include <linux/errno.h>
#define read(a) ((a)->counter)
#define inc(a) (((a)->counter)++)
#define dec(a) (((a)->counter)--)
#define count_inc(a) ((*(a))++)
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore * sem)
{
atomic_inc(&sem->waking);
}
static inline int waking_non_zero(struct semaphore *sem)
{
unsigned long flags;
int ret = 0;
local_irq_save(flags);
if (read(&sem->waking) > 0) {
dec(&sem->waking);
ret = 1;
}
local_irq_restore(flags);
return ret;
}
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
int ret = 0;
unsigned long flags;
local_irq_save(flags);
if (read(&sem->waking) > 0) {
dec(&sem->waking);
ret = 1;
} else if (signal_pending(tsk)) {
inc(&sem->count);
ret = -EINTR;
}
local_irq_restore(flags);
return ret;
}
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
int ret = 1;
unsigned long flags;
local_irq_save(flags);
if (read(&sem->waking) <= 0)
inc(&sem->count);
else {
dec(&sem->waking);
ret = 0;
}
local_irq_restore(flags);
return ret;
}
#endif /* _ASM_SEMAPHORE_HELPER_H */

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@ -1,133 +1 @@
/* $Id: semaphore.h,v 1.3 2001/05/08 13:54:09 bjornw Exp $ */
/* On the i386 these are coded in asm, perhaps we should as well. Later.. */
#ifndef _CRIS_SEMAPHORE_H
#define _CRIS_SEMAPHORE_H
#define RW_LOCK_BIAS 0x01000000
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <asm/system.h>
#include <asm/atomic.h>
/*
* CRIS semaphores, implemented in C-only so far.
*/
struct semaphore {
atomic_t count;
atomic_t waking;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.waking = ATOMIC_INIT(0), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init(struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void __down(struct semaphore * sem);
extern int __down_interruptible(struct semaphore * sem);
extern int __down_trylock(struct semaphore * sem);
extern void __up(struct semaphore * sem);
/* notice - we probably can do cli/sti here instead of saving */
static inline void down(struct semaphore * sem)
{
unsigned long flags;
int failed;
might_sleep();
/* atomically decrement the semaphores count, and if its negative, we wait */
cris_atomic_save(sem, flags);
failed = --(sem->count.counter) < 0;
cris_atomic_restore(sem, flags);
if(failed) {
__down(sem);
}
}
/*
* This version waits in interruptible state so that the waiting
* process can be killed. The down_interruptible routine
* returns negative for signalled and zero for semaphore acquired.
*/
static inline int down_interruptible(struct semaphore * sem)
{
unsigned long flags;
int failed;
might_sleep();
/* atomically decrement the semaphores count, and if its negative, we wait */
cris_atomic_save(sem, flags);
failed = --(sem->count.counter) < 0;
cris_atomic_restore(sem, flags);
if(failed)
failed = __down_interruptible(sem);
return(failed);
}
static inline int down_trylock(struct semaphore * sem)
{
unsigned long flags;
int failed;
cris_atomic_save(sem, flags);
failed = --(sem->count.counter) < 0;
cris_atomic_restore(sem, flags);
if(failed)
failed = __down_trylock(sem);
return(failed);
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
unsigned long flags;
int wakeup;
/* atomically increment the semaphores count, and if it was negative, we wake people */
cris_atomic_save(sem, flags);
wakeup = ++(sem->count.counter) <= 0;
cris_atomic_restore(sem, flags);
if(wakeup) {
__up(sem);
}
}
#endif
#include <linux/semaphore.h>

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@ -1,155 +1 @@
/* semaphore.h: semaphores for the FR-V
*
* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_SEMAPHORE_H
#define _ASM_SEMAPHORE_H
#define RW_LOCK_BIAS 0x01000000
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
/*
* the semaphore definition
* - if counter is >0 then there are tokens available on the semaphore for down to collect
* - if counter is <=0 then there are no spare tokens, and anyone that wants one must wait
* - if wait_list is not empty, then there are processes waiting for the semaphore
*/
struct semaphore {
unsigned counter;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_SEMAPHORE
unsigned __magic;
#endif
};
#ifdef CONFIG_DEBUG_SEMAPHORE
# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
#else
# define __SEM_DEBUG_INIT(name)
#endif
#define __SEMAPHORE_INITIALIZER(name,count) \
{ count, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __SEM_DEBUG_INIT(name) }
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void __down(struct semaphore *sem, unsigned long flags);
extern int __down_interruptible(struct semaphore *sem, unsigned long flags);
extern void __up(struct semaphore *sem);
static inline void down(struct semaphore *sem)
{
unsigned long flags;
#ifdef CONFIG_DEBUG_SEMAPHORE
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
if (likely(sem->counter > 0)) {
sem->counter--;
spin_unlock_irqrestore(&sem->wait_lock, flags);
}
else {
__down(sem, flags);
}
}
static inline int down_interruptible(struct semaphore *sem)
{
unsigned long flags;
int ret = 0;
#ifdef CONFIG_DEBUG_SEMAPHORE
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
if (likely(sem->counter > 0)) {
sem->counter--;
spin_unlock_irqrestore(&sem->wait_lock, flags);
}
else {
ret = __down_interruptible(sem, flags);
}
return ret;
}
/*
* non-blockingly attempt to down() a semaphore.
* - returns zero if we acquired it
*/
static inline int down_trylock(struct semaphore *sem)
{
unsigned long flags;
int success = 0;
#ifdef CONFIG_DEBUG_SEMAPHORE
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->counter > 0) {
sem->counter--;
success = 1;
}
spin_unlock_irqrestore(&sem->wait_lock, flags);
return !success;
}
static inline void up(struct semaphore *sem)
{
unsigned long flags;
#ifdef CONFIG_DEBUG_SEMAPHORE
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
if (!list_empty(&sem->wait_list))
__up(sem);
else
sem->counter++;
spin_unlock_irqrestore(&sem->wait_lock, flags);
}
static inline int sem_getcount(struct semaphore *sem)
{
return sem->counter;
}
#endif /* __ASSEMBLY__ */
#endif
#include <linux/semaphore.h>

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#ifndef _H8300_SEMAPHORE_HELPER_H
#define _H8300_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
*
* based on
* m68k version by Andreas Schwab
*/
#include <linux/errno.h>
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore * sem)
{
atomic_inc((atomic_t *)&sem->sleepers);
}
static inline int waking_non_zero(struct semaphore *sem)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (sem->sleepers > 0) {
sem->sleepers--;
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*/
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (sem->sleepers > 0) {
sem->sleepers--;
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*/
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 1;
if (sem->sleepers <= 0)
atomic_inc(&sem->count);
else {
sem->sleepers--;
ret = 0;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif

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@ -1,190 +1 @@
#ifndef _H8300_SEMAPHORE_H
#define _H8300_SEMAPHORE_H
#define RW_LOCK_BIAS 0x01000000
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <asm/system.h>
#include <asm/atomic.h>
/*
* Interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
*
* H8/300 version by Yoshinori Sato
*/
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.sleepers = 0, \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
asmlinkage void __down_failed(void /* special register calling convention */);
asmlinkage int __down_failed_interruptible(void /* params in registers */);
asmlinkage int __down_failed_trylock(void /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
extern spinlock_t semaphore_wake_lock;
/*
* This is ugly, but we want the default case to fall through.
* "down_failed" is a special asm handler that calls the C
* routine that actually waits. See arch/m68k/lib/semaphore.S
*/
static inline void down(struct semaphore * sem)
{
register atomic_t *count asm("er0");
might_sleep();
count = &(sem->count);
__asm__ __volatile__(
"stc ccr,r3l\n\t"
"orc #0x80,ccr\n\t"
"mov.l %2, er1\n\t"
"dec.l #1,er1\n\t"
"mov.l er1,%0\n\t"
"bpl 1f\n\t"
"ldc r3l,ccr\n\t"
"mov.l %1,er0\n\t"
"jsr @___down\n\t"
"bra 2f\n"
"1:\n\t"
"ldc r3l,ccr\n"
"2:"
: "=m"(*count)
: "g"(sem),"m"(*count)
: "cc", "er1", "er2", "er3");
}
static inline int down_interruptible(struct semaphore * sem)
{
register atomic_t *count asm("er0");
might_sleep();
count = &(sem->count);
__asm__ __volatile__(
"stc ccr,r1l\n\t"
"orc #0x80,ccr\n\t"
"mov.l %3, er2\n\t"
"dec.l #1,er2\n\t"
"mov.l er2,%1\n\t"
"bpl 1f\n\t"
"ldc r1l,ccr\n\t"
"mov.l %2,er0\n\t"
"jsr @___down_interruptible\n\t"
"bra 2f\n"
"1:\n\t"
"ldc r1l,ccr\n\t"
"sub.l %0,%0\n\t"
"2:\n\t"
: "=r" (count),"=m" (*count)
: "g"(sem),"m"(*count)
: "cc", "er1", "er2", "er3");
return (int)count;
}
static inline int down_trylock(struct semaphore * sem)
{
register atomic_t *count asm("er0");
count = &(sem->count);
__asm__ __volatile__(
"stc ccr,r3l\n\t"
"orc #0x80,ccr\n\t"
"mov.l %3,er2\n\t"
"dec.l #1,er2\n\t"
"mov.l er2,%0\n\t"
"bpl 1f\n\t"
"ldc r3l,ccr\n\t"
"jmp @3f\n\t"
LOCK_SECTION_START(".align 2\n\t")
"3:\n\t"
"mov.l %2,er0\n\t"
"jsr @___down_trylock\n\t"
"jmp @2f\n\t"
LOCK_SECTION_END
"1:\n\t"
"ldc r3l,ccr\n\t"
"sub.l %1,%1\n"
"2:"
: "=m" (*count),"=r"(count)
: "g"(sem),"m"(*count)
: "cc", "er1","er2", "er3");
return (int)count;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
register atomic_t *count asm("er0");
count = &(sem->count);
__asm__ __volatile__(
"stc ccr,r3l\n\t"
"orc #0x80,ccr\n\t"
"mov.l %2,er1\n\t"
"inc.l #1,er1\n\t"
"mov.l er1,%0\n\t"
"ldc r3l,ccr\n\t"
"sub.l er2,er2\n\t"
"cmp.l er2,er1\n\t"
"bgt 1f\n\t"
"mov.l %1,er0\n\t"
"jsr @___up\n"
"1:"
: "=m"(*count)
: "g"(sem),"m"(*count)
: "cc", "er1", "er2", "er3");
}
#endif /* __ASSEMBLY__ */
#endif
#include <linux/semaphore.h>

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include/asm-ia64/semaphore.h
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@ -1,99 +1 @@
#ifndef _ASM_IA64_SEMAPHORE_H
#define _ASM_IA64_SEMAPHORE_H
/*
* Copyright (C) 1998-2000 Hewlett-Packard Co
* Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/wait.h>
#include <linux/rwsem.h>
#include <asm/atomic.h>
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.sleepers = 0, \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1)
static inline void
sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void
init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void
init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void __down (struct semaphore * sem);
extern int __down_interruptible (struct semaphore * sem);
extern int __down_trylock (struct semaphore * sem);
extern void __up (struct semaphore * sem);
/*
* Atomically decrement the semaphore's count. If it goes negative,
* block the calling thread in the TASK_UNINTERRUPTIBLE state.
*/
static inline void
down (struct semaphore *sem)
{
might_sleep();
if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1)
__down(sem);
}
/*
* Atomically decrement the semaphore's count. If it goes negative,
* block the calling thread in the TASK_INTERRUPTIBLE state.
*/
static inline int
down_interruptible (struct semaphore * sem)
{
int ret = 0;
might_sleep();
if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1)
ret = __down_interruptible(sem);
return ret;
}
static inline int
down_trylock (struct semaphore *sem)
{
int ret = 0;
if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1)
ret = __down_trylock(sem);
return ret;
}
static inline void
up (struct semaphore * sem)
{
if (ia64_fetchadd(1, &sem->count.counter, rel) <= -1)
__up(sem);
}
#endif /* _ASM_IA64_SEMAPHORE_H */
#include <linux/semaphore.h>

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#ifndef _ASM_M32R_SEMAPHORE_H
#define _ASM_M32R_SEMAPHORE_H
#include <linux/linkage.h>
#ifdef __KERNEL__
/*
* SMP- and interrupt-safe semaphores..
*
* Copyright (C) 1996 Linus Torvalds
* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/
#include <linux/wait.h>
#include <linux/rwsem.h>
#include <asm/assembler.h>
#include <asm/system.h>
#include <asm/atomic.h>
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.sleepers = 0, \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
/*
* *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
*
* i'd rather use the more flexible initialization above, but sadly
* GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well.
*/
atomic_set(&sem->count, val);
sem->sleepers = 0;
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
asmlinkage void __down_failed(void /* special register calling convention */);
asmlinkage int __down_failed_interruptible(void /* params in registers */);
asmlinkage int __down_failed_trylock(void /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
/*
* Atomically decrement the semaphore's count. If it goes negative,
* block the calling thread in the TASK_UNINTERRUPTIBLE state.
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
if (unlikely(atomic_dec_return(&sem->count) < 0))
__down(sem);
}
/*
* Interruptible try to acquire a semaphore. If we obtained
* it, return zero. If we were interrupted, returns -EINTR
*/
static inline int down_interruptible(struct semaphore * sem)
{
int result = 0;
might_sleep();
if (unlikely(atomic_dec_return(&sem->count) < 0))
result = __down_interruptible(sem);
return result;
}
/*
* Non-blockingly attempt to down() a semaphore.
* Returns zero if we acquired it
*/
static inline int down_trylock(struct semaphore * sem)
{
unsigned long flags;
long count;
int result = 0;
local_irq_save(flags);
__asm__ __volatile__ (
"# down_trylock \n\t"
DCACHE_CLEAR("%0", "r4", "%1")
M32R_LOCK" %0, @%1; \n\t"
"addi %0, #-1; \n\t"
M32R_UNLOCK" %0, @%1; \n\t"
: "=&r" (count)
: "r" (&sem->count)
: "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r4"
#endif /* CONFIG_CHIP_M32700_TS1 */
);
local_irq_restore(flags);
if (unlikely(count < 0))
result = __down_trylock(sem);
return result;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
if (unlikely(atomic_inc_return(&sem->count) <= 0))
__up(sem);
}
#endif /* __KERNEL__ */
#endif /* _ASM_M32R_SEMAPHORE_H */
#include <linux/semaphore.h>

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@ -1,142 +0,0 @@
#ifndef _M68K_SEMAPHORE_HELPER_H
#define _M68K_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
#include <linux/errno.h>
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore * sem)
{
atomic_inc(&sem->waking);
}
#ifndef CONFIG_RMW_INSNS
extern spinlock_t semaphore_wake_lock;
#endif
static inline int waking_non_zero(struct semaphore *sem)
{
int ret;
#ifndef CONFIG_RMW_INSNS
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
#else
int tmp1, tmp2;
__asm__ __volatile__
("1: movel %1,%2\n"
" jle 2f\n"
" subql #1,%2\n"
" casl %1,%2,%3\n"
" jne 1b\n"
" moveq #1,%0\n"
"2:"
: "=d" (ret), "=d" (tmp1), "=d" (tmp2)
: "m" (sem->waking), "0" (0), "1" (sem->waking));
#endif
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*/
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
int ret;
#ifndef CONFIG_RMW_INSNS
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
#else
int tmp1, tmp2;
__asm__ __volatile__
("1: movel %1,%2\n"
" jle 2f\n"
" subql #1,%2\n"
" casl %1,%2,%3\n"
" jne 1b\n"
" moveq #1,%0\n"
" jra %a4\n"
"2:"
: "=d" (ret), "=d" (tmp1), "=d" (tmp2)
: "m" (sem->waking), "i" (&&next), "0" (0), "1" (sem->waking));
if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
next:
#endif
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*/
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
int ret;
#ifndef CONFIG_RMW_INSNS
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 1;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 0;
} else
atomic_inc(&sem->count);
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
#else
int tmp1, tmp2;
__asm__ __volatile__
("1: movel %1,%2\n"
" jle 2f\n"
" subql #1,%2\n"
" casl %1,%2,%3\n"
" jne 1b\n"
" moveq #0,%0\n"
"2:"
: "=d" (ret), "=d" (tmp1), "=d" (tmp2)
: "m" (sem->waking), "0" (1), "1" (sem->waking));
if (ret)
atomic_inc(&sem->count);
#endif
return ret;
}
#endif

164
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@ -1,163 +1 @@
#ifndef _M68K_SEMAPHORE_H
#define _M68K_SEMAPHORE_H
#define RW_LOCK_BIAS 0x01000000
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/stringify.h>
#include <asm/system.h>
#include <asm/atomic.h>
/*
* Interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
struct semaphore {
atomic_t count;
atomic_t waking;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.waking = ATOMIC_INIT(0), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init(struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
asmlinkage void __down_failed(void /* special register calling convention */);
asmlinkage int __down_failed_interruptible(void /* params in registers */);
asmlinkage int __down_failed_trylock(void /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
/*
* This is ugly, but we want the default case to fall through.
* "down_failed" is a special asm handler that calls the C
* routine that actually waits. See arch/m68k/lib/semaphore.S
*/
static inline void down(struct semaphore *sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"subql #1,%0@\n\t"
"jmi 2f\n\t"
"1:\n"
LOCK_SECTION_START(".even\n\t")
"2:\tpea 1b\n\t"
"jbra __down_failed\n"
LOCK_SECTION_END
: /* no outputs */
: "a" (sem1)
: "memory");
}
static inline int down_interruptible(struct semaphore *sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
register int result __asm__ ("%d0");
might_sleep();
__asm__ __volatile__(
"| atomic interruptible down operation\n\t"
"subql #1,%1@\n\t"
"jmi 2f\n\t"
"clrl %0\n"
"1:\n"
LOCK_SECTION_START(".even\n\t")
"2:\tpea 1b\n\t"
"jbra __down_failed_interruptible\n"
LOCK_SECTION_END
: "=d" (result)
: "a" (sem1)
: "memory");
return result;
}
static inline int down_trylock(struct semaphore *sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
register int result __asm__ ("%d0");
__asm__ __volatile__(
"| atomic down trylock operation\n\t"
"subql #1,%1@\n\t"
"jmi 2f\n\t"
"clrl %0\n"
"1:\n"
LOCK_SECTION_START(".even\n\t")
"2:\tpea 1b\n\t"
"jbra __down_failed_trylock\n"
LOCK_SECTION_END
: "=d" (result)
: "a" (sem1)
: "memory");
return result;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore *sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
__asm__ __volatile__(
"| atomic up operation\n\t"
"addql #1,%0@\n\t"
"jle 2f\n"
"1:\n"
LOCK_SECTION_START(".even\n\t")
"2:\t"
"pea 1b\n\t"
"jbra __up_wakeup\n"
LOCK_SECTION_END
: /* no outputs */
: "a" (sem1)
: "memory");
}
#endif /* __ASSEMBLY__ */
#endif
#include <linux/semaphore.h>

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#ifndef _M68K_SEMAPHORE_HELPER_H
#define _M68K_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
/*
* These two _must_ execute atomically wrt each other.
*/
static inline void wake_one_more(struct semaphore * sem)
{
atomic_inc(&sem->waking);
}
static inline int waking_non_zero(struct semaphore *sem)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*/
static inline int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 0;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*/
static inline int waking_non_zero_trylock(struct semaphore *sem)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&semaphore_wake_lock, flags);
ret = 1;
if (atomic_read(&sem->waking) > 0) {
atomic_dec(&sem->waking);
ret = 0;
} else
atomic_inc(&sem->count);
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif

154
include/asm-m68knommu/semaphore.h
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@ -1,153 +1 @@
#ifndef _M68K_SEMAPHORE_H
#define _M68K_SEMAPHORE_H
#define RW_LOCK_BIAS 0x01000000
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <asm/system.h>
#include <asm/atomic.h>
/*
* Interrupt-safe semaphores..
*
* (C) Copyright 1996 Linus Torvalds
*
* m68k version by Andreas Schwab
*/
struct semaphore {
atomic_t count;
atomic_t waking;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.waking = ATOMIC_INIT(0), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
asmlinkage void __down_failed(void /* special register calling convention */);
asmlinkage int __down_failed_interruptible(void /* params in registers */);
asmlinkage int __down_failed_trylock(void /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
extern spinlock_t semaphore_wake_lock;
/*
* This is ugly, but we want the default case to fall through.
* "down_failed" is a special asm handler that calls the C
* routine that actually waits. See arch/m68k/lib/semaphore.S
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"movel %0, %%a1\n\t"
"lea %%pc@(1f), %%a0\n\t"
"subql #1, %%a1@\n\t"
"jmi __down_failed\n"
"1:"
: /* no outputs */
: "g" (sem)
: "cc", "%a0", "%a1", "memory");
}
static inline int down_interruptible(struct semaphore * sem)
{
int ret;
might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"movel %1, %%a1\n\t"
"lea %%pc@(1f), %%a0\n\t"
"subql #1, %%a1@\n\t"
"jmi __down_failed_interruptible\n\t"
"clrl %%d0\n"
"1: movel %%d0, %0\n"
: "=d" (ret)
: "g" (sem)
: "cc", "%d0", "%a0", "%a1", "memory");
return(ret);
}
static inline int down_trylock(struct semaphore * sem)
{
register struct semaphore *sem1 __asm__ ("%a1") = sem;
register int result __asm__ ("%d0");
__asm__ __volatile__(
"| atomic down trylock operation\n\t"
"subql #1,%1@\n\t"
"jmi 2f\n\t"
"clrl %0\n"
"1:\n"
".section .text.lock,\"ax\"\n"
".even\n"
"2:\tpea 1b\n\t"
"jbra __down_failed_trylock\n"
".previous"
: "=d" (result)
: "a" (sem1)
: "memory");
return result;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
__asm__ __volatile__(
"| atomic up operation\n\t"
"movel %0, %%a1\n\t"
"lea %%pc@(1f), %%a0\n\t"
"addql #1, %%a1@\n\t"
"jle __up_wakeup\n"
"1:"
: /* no outputs */
: "g" (sem)
: "cc", "%a0", "%a1", "memory");
}
#endif /* __ASSEMBLY__ */
#endif
#include <linux/semaphore.h>

109
include/asm-mips/semaphore.h
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@ -1,108 +1 @@
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996 Linus Torvalds
* Copyright (C) 1998, 99, 2000, 01, 04 Ralf Baechle
* Copyright (C) 1999, 2000, 01 Silicon Graphics, Inc.
* Copyright (C) 2000, 01 MIPS Technologies, Inc.
*
* In all honesty, little of the old MIPS code left - the PPC64 variant was
* just looking nice and portable so I ripped it. Credits to whoever wrote
* it.
*/
#ifndef __ASM_SEMAPHORE_H
#define __ASM_SEMAPHORE_H
/*
* Remove spinlock-based RW semaphores; RW semaphore definitions are
* now in rwsem.h and we use the generic lib/rwsem.c implementation.
* Rework semaphores to use atomic_dec_if_positive.
* -- Paul Mackerras (paulus@samba.org)
*/
#ifdef __KERNEL__
#include <asm/atomic.h>
#include <asm/system.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
struct semaphore {
/*
* Note that any negative value of count is equivalent to 0,
* but additionally indicates that some process(es) might be
* sleeping on `wait'.
*/
atomic_t count;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name, count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1)
static inline void sema_init(struct semaphore *sem, int val)
{
atomic_set(&sem->count, val);
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX(struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED(struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void __down(struct semaphore * sem);
extern int __down_interruptible(struct semaphore * sem);
extern void __up(struct semaphore * sem);
static inline void down(struct semaphore * sem)
{
might_sleep();
/*
* Try to get the semaphore, take the slow path if we fail.
*/
if (unlikely(atomic_dec_return(&sem->count) < 0))
__down(sem);
}
static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
might_sleep();
if (unlikely(atomic_dec_return(&sem->count) < 0))
ret = __down_interruptible(sem);
return ret;
}
static inline int down_trylock(struct semaphore * sem)
{
return atomic_dec_if_positive(&sem->count) < 0;
}
static inline void up(struct semaphore * sem)
{
if (unlikely(atomic_inc_return(&sem->count) <= 0))
__up(sem);
}
#endif /* __KERNEL__ */
#endif /* __ASM_SEMAPHORE_H */
#include <linux/semaphore.h>

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@ -1,169 +1 @@
/* MN10300 Semaphores
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_SEMAPHORE_H
#define _ASM_SEMAPHORE_H
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#define SEMAPHORE_DEBUG 0
/*
* the semaphore definition
* - if count is >0 then there are tokens available on the semaphore for down
* to collect
* - if count is <=0 then there are no spare tokens, and anyone that wants one
* must wait
* - if wait_list is not empty, then there are processes waiting for the
* semaphore
*/
struct semaphore {
atomic_t count; /* it's not really atomic, it's
* just that certain modules
* expect to be able to access
* it directly */
spinlock_t wait_lock;
struct list_head wait_list;
#if SEMAPHORE_DEBUG
unsigned __magic;
#endif
};
#if SEMAPHORE_DEBUG
# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
#else
# define __SEM_DEBUG_INIT(name)
#endif
#define __SEMAPHORE_INITIALIZER(name, init_count) \
{ \
.count = ATOMIC_INIT(init_count), \
.wait_lock = __SPIN_LOCK_UNLOCKED((name).wait_lock), \
.wait_list = LIST_HEAD_INIT((name).wait_list) \
__SEM_DEBUG_INIT(name) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1)
#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name, 0)
static inline void sema_init(struct semaphore *sem, int val)
{
*sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
}
static inline void init_MUTEX(struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED(struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void __down(struct semaphore *sem, unsigned long flags);
extern int __down_interruptible(struct semaphore *sem, unsigned long flags);
extern void __up(struct semaphore *sem);
static inline void down(struct semaphore *sem)
{
unsigned long flags;
int count;
#if SEMAPHORE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
count = atomic_read(&sem->count);
if (likely(count > 0)) {
atomic_set(&sem->count, count - 1);
spin_unlock_irqrestore(&sem->wait_lock, flags);
} else {
__down(sem, flags);
}
}
static inline int down_interruptible(struct semaphore *sem)
{
unsigned long flags;
int count, ret = 0;
#if SEMAPHORE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
count = atomic_read(&sem->count);
if (likely(count > 0)) {
atomic_set(&sem->count, count - 1);
spin_unlock_irqrestore(&sem->wait_lock, flags);
} else {
ret = __down_interruptible(sem, flags);
}
return ret;
}
/*
* non-blockingly attempt to down() a semaphore.
* - returns zero if we acquired it
*/
static inline int down_trylock(struct semaphore *sem)
{
unsigned long flags;
int count, success = 0;
#if SEMAPHORE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
count = atomic_read(&sem->count);
if (likely(count > 0)) {
atomic_set(&sem->count, count - 1);
success = 1;
}
spin_unlock_irqrestore(&sem->wait_lock, flags);
return !success;
}
static inline void up(struct semaphore *sem)
{
unsigned long flags;
#if SEMAPHORE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
spin_lock_irqsave(&sem->wait_lock, flags);
if (!list_empty(&sem->wait_list))
__up(sem);
else
atomic_set(&sem->count, atomic_read(&sem->count) + 1);
spin_unlock_irqrestore(&sem->wait_lock, flags);
}
static inline int sem_getcount(struct semaphore *sem)
{
return atomic_read(&sem->count);
}
#endif /* __ASSEMBLY__ */
#endif
#include <linux/semaphore.h>

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include/asm-parisc/semaphore-helper.h
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@ -1,89 +0,0 @@
#ifndef _ASM_PARISC_SEMAPHORE_HELPER_H
#define _ASM_PARISC_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
* (C) Copyright 1999 Andrea Arcangeli
*/
/*
* These two _must_ execute atomically wrt each other.
*
* This is trivially done with load_locked/store_cond,
* which we have. Let the rest of the losers suck eggs.
*/
static __inline__ void wake_one_more(struct semaphore * sem)
{
atomic_inc((atomic_t *)&sem->waking);
}
static __inline__ int waking_non_zero(struct semaphore *sem)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->waking > 0) {
sem->waking--;
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*
* We must undo the sem->count down_interruptible() increment while we are
* protected by the spinlock in order to make atomic this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static __inline__ int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->waking > 0) {
sem->waking--;
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*
* We must undo the sem->count down_trylock() increment while we are
* protected by the spinlock in order to make atomic this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static __inline__ int waking_non_zero_trylock(struct semaphore *sem)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->waking <= 0)
atomic_inc(&sem->count);
else {
sem->waking--;
ret = 0;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif /* _ASM_PARISC_SEMAPHORE_HELPER_H */

146
include/asm-parisc/semaphore.h
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@ -1,145 +1 @@
/* SMP- and interrupt-safe semaphores.
* PA-RISC version by Matthew Wilcox
*
* Linux/PA-RISC Project (http://www.parisc-linux.org/)
* Copyright (C) 1996 Linus Torvalds
* Copyright (C) 1999-2001 Matthew Wilcox < willy at debian d0T org >
* Copyright (C) 2000 Grant Grundler < grundler a debian org >
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _ASM_PARISC_SEMAPHORE_H
#define _ASM_PARISC_SEMAPHORE_H
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
#include <asm/system.h>
/*
* The `count' is initialised to the number of people who are allowed to
* take the lock. (Normally we want a mutex, so this is `1'). if
* `count' is positive, the lock can be taken. if it's 0, no-one is
* waiting on it. if it's -1, at least one task is waiting.
*/
struct semaphore {
spinlock_t sentry;
int count;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.sentry = SPIN_LOCK_UNLOCKED, \
.count = n, \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
static inline int sem_getcount(struct semaphore *sem)
{
return sem->count;
}
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
/* Semaphores can be `tried' from irq context. So we have to disable
* interrupts while we're messing with the semaphore. Sorry.
*/
static inline void down(struct semaphore * sem)
{
might_sleep();
spin_lock_irq(&sem->sentry);
if (sem->count > 0) {
sem->count--;
} else {
__down(sem);
}
spin_unlock_irq(&sem->sentry);
}
static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
might_sleep();
spin_lock_irq(&sem->sentry);
if (sem->count > 0) {
sem->count--;
} else {
ret = __down_interruptible(sem);
}
spin_unlock_irq(&sem->sentry);
return ret;
}
/*
* down_trylock returns 0 on success, 1 if we failed to get the lock.
* May not sleep, but must preserve irq state
*/
static inline int down_trylock(struct semaphore * sem)
{
unsigned long flags;
int count;
spin_lock_irqsave(&sem->sentry, flags);
count = sem->count - 1;
if (count >= 0)
sem->count = count;
spin_unlock_irqrestore(&sem->sentry, flags);
return (count < 0);
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
*/
static inline void up(struct semaphore * sem)
{
unsigned long flags;
spin_lock_irqsave(&sem->sentry, flags);
if (sem->count < 0) {
__up(sem);
} else {
sem->count++;
}
spin_unlock_irqrestore(&sem->sentry, flags);
}
#endif /* _ASM_PARISC_SEMAPHORE_H */
#include <linux/semaphore.h>

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include/asm-powerpc/semaphore.h
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@ -1,94 +1 @@
#ifndef _ASM_POWERPC_SEMAPHORE_H
#define _ASM_POWERPC_SEMAPHORE_H
/*
* Remove spinlock-based RW semaphores; RW semaphore definitions are
* now in rwsem.h and we use the generic lib/rwsem.c implementation.
* Rework semaphores to use atomic_dec_if_positive.
* -- Paul Mackerras (paulus@samba.org)
*/
#ifdef __KERNEL__
#include <asm/atomic.h>
#include <asm/system.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
struct semaphore {
/*
* Note that any negative value of count is equivalent to 0,
* but additionally indicates that some process(es) might be
* sleeping on `wait'.
*/
atomic_t count;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name, count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1)
static inline void sema_init (struct semaphore *sem, int val)
{
atomic_set(&sem->count, val);
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
extern void __down(struct semaphore * sem);
extern int __down_interruptible(struct semaphore * sem);
extern void __up(struct semaphore * sem);
static inline void down(struct semaphore * sem)
{
might_sleep();
/*
* Try to get the semaphore, take the slow path if we fail.
*/
if (unlikely(atomic_dec_return(&sem->count) < 0))
__down(sem);
}
static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
might_sleep();
if (unlikely(atomic_dec_return(&sem->count) < 0))
ret = __down_interruptible(sem);
return ret;
}
static inline int down_trylock(struct semaphore * sem)
{
return atomic_dec_if_positive(&sem->count) < 0;
}
static inline void up(struct semaphore * sem)
{
if (unlikely(atomic_inc_return(&sem->count) <= 0))
__up(sem);
}
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SEMAPHORE_H */
#include <linux/semaphore.h>

108
include/asm-s390/semaphore.h
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@ -1,107 +1 @@
/*
* include/asm-s390/semaphore.h
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
*
* Derived from "include/asm-i386/semaphore.h"
* (C) Copyright 1996 Linus Torvalds
*/
#ifndef _S390_SEMAPHORE_H
#define _S390_SEMAPHORE_H
#include <asm/system.h>
#include <asm/atomic.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
struct semaphore {
/*
* Note that any negative value of count is equivalent to 0,
* but additionally indicates that some process(es) might be
* sleeping on `wait'.
*/
atomic_t count;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name,count) \
{ ATOMIC_INIT(count), __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) }
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
atomic_set(&sem->count, val);
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
static inline void down(struct semaphore * sem)
{
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
}
static inline int down_trylock(struct semaphore * sem)
{
int old_val, new_val;
/*
* This inline assembly atomically implements the equivalent
* to the following C code:
* old_val = sem->count.counter;
* if ((new_val = old_val) > 0)
* sem->count.counter = --new_val;
* In the ppc code this is called atomic_dec_if_positive.
*/
asm volatile(
" l %0,0(%3)\n"
"0: ltr %1,%0\n"
" jle 1f\n"
" ahi %1,-1\n"
" cs %0,%1,0(%3)\n"
" jl 0b\n"
"1:"
: "=&d" (old_val), "=&d" (new_val), "=m" (sem->count.counter)
: "a" (&sem->count.counter), "m" (sem->count.counter)
: "cc", "memory");
return old_val <= 0;
}
static inline void up(struct semaphore * sem)
{
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
}
#endif
#include <linux/semaphore.h>

89
include/asm-sh/semaphore-helper.h
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@ -1,89 +0,0 @@
#ifndef __ASM_SH_SEMAPHORE_HELPER_H
#define __ASM_SH_SEMAPHORE_HELPER_H
/*
* SMP- and interrupt-safe semaphores helper functions.
*
* (C) Copyright 1996 Linus Torvalds
* (C) Copyright 1999 Andrea Arcangeli
*/
/*
* These two _must_ execute atomically wrt each other.
*
* This is trivially done with load_locked/store_cond,
* which we have. Let the rest of the losers suck eggs.
*/
static __inline__ void wake_one_more(struct semaphore * sem)
{
atomic_inc((atomic_t *)&sem->sleepers);
}
static __inline__ int waking_non_zero(struct semaphore *sem)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->sleepers > 0) {
sem->sleepers--;
ret = 1;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_interruptible:
* 1 got the lock
* 0 go to sleep
* -EINTR interrupted
*
* We must undo the sem->count down_interruptible() increment while we are
* protected by the spinlock in order to make atomic this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static __inline__ int waking_non_zero_interruptible(struct semaphore *sem,
struct task_struct *tsk)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->sleepers > 0) {
sem->sleepers--;
ret = 1;
} else if (signal_pending(tsk)) {
atomic_inc(&sem->count);
ret = -EINTR;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
/*
* waking_non_zero_trylock:
* 1 failed to lock
* 0 got the lock
*
* We must undo the sem->count down_trylock() increment while we are
* protected by the spinlock in order to make atomic this atomic_inc() with the
* atomic_read() in wake_one_more(), otherwise we can race. -arca
*/
static __inline__ int waking_non_zero_trylock(struct semaphore *sem)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&semaphore_wake_lock, flags);
if (sem->sleepers <= 0)
atomic_inc(&sem->count);
else {
sem->sleepers--;
ret = 0;
}
spin_unlock_irqrestore(&semaphore_wake_lock, flags);
return ret;
}
#endif /* __ASM_SH_SEMAPHORE_HELPER_H */

116
include/asm-sh/semaphore.h
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@ -1,115 +1 @@
#ifndef __ASM_SH_SEMAPHORE_H
#define __ASM_SH_SEMAPHORE_H
#include <linux/linkage.h>
#ifdef __KERNEL__
/*
* SMP- and interrupt-safe semaphores.
*
* (C) Copyright 1996 Linus Torvalds
*
* SuperH verison by Niibe Yutaka
* (Currently no asm implementation but generic C code...)
*/
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/wait.h>
#include <asm/system.h>
#include <asm/atomic.h>
struct semaphore {
atomic_t count;
int sleepers;
wait_queue_head_t wait;
};
#define __SEMAPHORE_INITIALIZER(name, n) \
{ \
.count = ATOMIC_INIT(n), \
.sleepers = 0, \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
}
#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
static inline void sema_init (struct semaphore *sem, int val)
{
/*
* *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
*
* i'd rather use the more flexible initialization above, but sadly
* GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well.
*/
atomic_set(&sem->count, val);
sem->sleepers = 0;
init_waitqueue_head(&sem->wait);
}
static inline void init_MUTEX (struct semaphore *sem)
{
sema_init(sem, 1);
}
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
sema_init(sem, 0);
}
#if 0
asmlinkage void __down_failed(void /* special register calling convention */);
asmlinkage int __down_failed_interruptible(void /* params in registers */);
asmlinkage int __down_failed_trylock(void /* params in registers */);
asmlinkage void __up_wakeup(void /* special register calling convention */);
#endif
asmlinkage void __down(struct semaphore * sem);
asmlinkage int __down_interruptible(struct semaphore * sem);
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
extern spinlock_t semaphore_wake_lock;
static inline void down(struct semaphore * sem)
{
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
}
static inline int down_trylock(struct semaphore * sem)
{
int ret = 0;
if (atomic_dec_return(&sem->count) < 0)
ret = __down_trylock(sem);
return ret;
}
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
*/
static inline void up(struct semaphore * sem)
{
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
}
#endif
#endif /* __ASM_SH_SEMAPHORE_H */
#include <linux/semaphore.h>

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