mirror of https://gitee.com/openkylin/linux.git
387 lines
9.9 KiB
C
387 lines
9.9 KiB
C
/* asm/bitops.h for Linux/CRIS
|
|
*
|
|
* TODO: asm versions if speed is needed
|
|
*
|
|
* All bit operations return 0 if the bit was cleared before the
|
|
* operation and != 0 if it was not.
|
|
*
|
|
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
|
|
*/
|
|
|
|
#ifndef _CRIS_BITOPS_H
|
|
#define _CRIS_BITOPS_H
|
|
|
|
/* Currently this is unsuitable for consumption outside the kernel. */
|
|
#ifdef __KERNEL__
|
|
|
|
#include <asm/arch/bitops.h>
|
|
#include <asm/system.h>
|
|
#include <asm/atomic.h>
|
|
#include <linux/compiler.h>
|
|
|
|
/*
|
|
* Some hacks to defeat gcc over-optimizations..
|
|
*/
|
|
struct __dummy { unsigned long a[100]; };
|
|
#define ADDR (*(struct __dummy *) addr)
|
|
#define CONST_ADDR (*(const struct __dummy *) addr)
|
|
|
|
/*
|
|
* set_bit - Atomically set a bit in memory
|
|
* @nr: the bit to set
|
|
* @addr: the address to start counting from
|
|
*
|
|
* This function is atomic and may not be reordered. See __set_bit()
|
|
* if you do not require the atomic guarantees.
|
|
* Note that @nr may be almost arbitrarily large; this function is not
|
|
* restricted to acting on a single-word quantity.
|
|
*/
|
|
|
|
#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
|
|
|
|
#define __set_bit(nr, addr) (void)__test_and_set_bit(nr, addr)
|
|
|
|
/*
|
|
* clear_bit - Clears a bit in memory
|
|
* @nr: Bit to clear
|
|
* @addr: Address to start counting from
|
|
*
|
|
* clear_bit() is atomic and may not be reordered. However, it does
|
|
* not contain a memory barrier, so if it is used for locking purposes,
|
|
* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
|
|
* in order to ensure changes are visible on other processors.
|
|
*/
|
|
|
|
#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
|
|
|
|
#define __clear_bit(nr, addr) (void)__test_and_clear_bit(nr, addr)
|
|
|
|
/*
|
|
* change_bit - Toggle a bit in memory
|
|
* @nr: Bit to change
|
|
* @addr: Address to start counting from
|
|
*
|
|
* change_bit() is atomic and may not be reordered.
|
|
* Note that @nr may be almost arbitrarily large; this function is not
|
|
* restricted to acting on a single-word quantity.
|
|
*/
|
|
|
|
#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
|
|
|
|
/*
|
|
* __change_bit - Toggle a bit in memory
|
|
* @nr: the bit to change
|
|
* @addr: the address to start counting from
|
|
*
|
|
* Unlike change_bit(), this function is non-atomic and may be reordered.
|
|
* If it's called on the same region of memory simultaneously, the effect
|
|
* may be that only one operation succeeds.
|
|
*/
|
|
|
|
#define __change_bit(nr, addr) (void)__test_and_change_bit(nr, addr)
|
|
|
|
/**
|
|
* test_and_set_bit - Set a bit and return its old value
|
|
* @nr: Bit to set
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is atomic and cannot be reordered.
|
|
* It also implies a memory barrier.
|
|
*/
|
|
|
|
extern inline int test_and_set_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask, retval;
|
|
unsigned long flags;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
cris_atomic_save(addr, flags);
|
|
retval = (mask & *adr) != 0;
|
|
*adr |= mask;
|
|
cris_atomic_restore(addr, flags);
|
|
local_irq_restore(flags);
|
|
return retval;
|
|
}
|
|
|
|
extern inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask, retval;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
retval = (mask & *adr) != 0;
|
|
*adr |= mask;
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* clear_bit() doesn't provide any barrier for the compiler.
|
|
*/
|
|
#define smp_mb__before_clear_bit() barrier()
|
|
#define smp_mb__after_clear_bit() barrier()
|
|
|
|
/**
|
|
* test_and_clear_bit - Clear a bit and return its old value
|
|
* @nr: Bit to clear
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is atomic and cannot be reordered.
|
|
* It also implies a memory barrier.
|
|
*/
|
|
|
|
extern inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask, retval;
|
|
unsigned long flags;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
cris_atomic_save(addr, flags);
|
|
retval = (mask & *adr) != 0;
|
|
*adr &= ~mask;
|
|
cris_atomic_restore(addr, flags);
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* __test_and_clear_bit - Clear a bit and return its old value
|
|
* @nr: Bit to clear
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is non-atomic and can be reordered.
|
|
* If two examples of this operation race, one can appear to succeed
|
|
* but actually fail. You must protect multiple accesses with a lock.
|
|
*/
|
|
|
|
extern inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask, retval;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
retval = (mask & *adr) != 0;
|
|
*adr &= ~mask;
|
|
return retval;
|
|
}
|
|
/**
|
|
* test_and_change_bit - Change a bit and return its old value
|
|
* @nr: Bit to change
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is atomic and cannot be reordered.
|
|
* It also implies a memory barrier.
|
|
*/
|
|
|
|
extern inline int test_and_change_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask, retval;
|
|
unsigned long flags;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
cris_atomic_save(addr, flags);
|
|
retval = (mask & *adr) != 0;
|
|
*adr ^= mask;
|
|
cris_atomic_restore(addr, flags);
|
|
return retval;
|
|
}
|
|
|
|
/* WARNING: non atomic and it can be reordered! */
|
|
|
|
extern inline int __test_and_change_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask, retval;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
retval = (mask & *adr) != 0;
|
|
*adr ^= mask;
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* test_bit - Determine whether a bit is set
|
|
* @nr: bit number to test
|
|
* @addr: Address to start counting from
|
|
*
|
|
* This routine doesn't need to be atomic.
|
|
*/
|
|
|
|
extern inline int test_bit(int nr, const volatile unsigned long *addr)
|
|
{
|
|
unsigned int mask;
|
|
unsigned int *adr = (unsigned int *)addr;
|
|
|
|
adr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
return ((mask & *adr) != 0);
|
|
}
|
|
|
|
/*
|
|
* Find-bit routines..
|
|
*/
|
|
|
|
/*
|
|
* Since we define it "external", it collides with the built-in
|
|
* definition, which doesn't have the same semantics. We don't want to
|
|
* use -fno-builtin, so just hide the name ffs.
|
|
*/
|
|
#define ffs kernel_ffs
|
|
|
|
/*
|
|
* fls: find last bit set.
|
|
*/
|
|
|
|
#define fls(x) generic_fls(x)
|
|
|
|
/*
|
|
* hweightN - returns the hamming weight of a N-bit word
|
|
* @x: the word to weigh
|
|
*
|
|
* The Hamming Weight of a number is the total number of bits set in it.
|
|
*/
|
|
|
|
#define hweight32(x) generic_hweight32(x)
|
|
#define hweight16(x) generic_hweight16(x)
|
|
#define hweight8(x) generic_hweight8(x)
|
|
|
|
/**
|
|
* find_next_zero_bit - find the first zero bit in a memory region
|
|
* @addr: The address to base the search on
|
|
* @offset: The bitnumber to start searching at
|
|
* @size: The maximum size to search
|
|
*/
|
|
extern inline int find_next_zero_bit (const unsigned long * addr, int size, int offset)
|
|
{
|
|
unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
|
|
unsigned long result = offset & ~31UL;
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset &= 31UL;
|
|
if (offset) {
|
|
tmp = *(p++);
|
|
tmp |= ~0UL >> (32-offset);
|
|
if (size < 32)
|
|
goto found_first;
|
|
if (~tmp)
|
|
goto found_middle;
|
|
size -= 32;
|
|
result += 32;
|
|
}
|
|
while (size & ~31UL) {
|
|
if (~(tmp = *(p++)))
|
|
goto found_middle;
|
|
result += 32;
|
|
size -= 32;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = *p;
|
|
|
|
found_first:
|
|
tmp |= ~0UL >> size;
|
|
found_middle:
|
|
return result + ffz(tmp);
|
|
}
|
|
|
|
/**
|
|
* find_next_bit - find the first set bit in a memory region
|
|
* @addr: The address to base the search on
|
|
* @offset: The bitnumber to start searching at
|
|
* @size: The maximum size to search
|
|
*/
|
|
static __inline__ int find_next_bit(const unsigned long *addr, int size, int offset)
|
|
{
|
|
unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
|
|
unsigned long result = offset & ~31UL;
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset &= 31UL;
|
|
if (offset) {
|
|
tmp = *(p++);
|
|
tmp &= (~0UL << offset);
|
|
if (size < 32)
|
|
goto found_first;
|
|
if (tmp)
|
|
goto found_middle;
|
|
size -= 32;
|
|
result += 32;
|
|
}
|
|
while (size & ~31UL) {
|
|
if ((tmp = *(p++)))
|
|
goto found_middle;
|
|
result += 32;
|
|
size -= 32;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = *p;
|
|
|
|
found_first:
|
|
tmp &= (~0UL >> (32 - size));
|
|
if (tmp == 0UL) /* Are any bits set? */
|
|
return result + size; /* Nope. */
|
|
found_middle:
|
|
return result + __ffs(tmp);
|
|
}
|
|
|
|
/**
|
|
* find_first_zero_bit - find the first zero bit in a memory region
|
|
* @addr: The address to start the search at
|
|
* @size: The maximum size to search
|
|
*
|
|
* Returns the bit-number of the first zero bit, not the number of the byte
|
|
* containing a bit.
|
|
*/
|
|
|
|
#define find_first_zero_bit(addr, size) \
|
|
find_next_zero_bit((addr), (size), 0)
|
|
#define find_first_bit(addr, size) \
|
|
find_next_bit((addr), (size), 0)
|
|
|
|
#define ext2_set_bit test_and_set_bit
|
|
#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
|
|
#define ext2_clear_bit test_and_clear_bit
|
|
#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
|
|
#define ext2_test_bit test_bit
|
|
#define ext2_find_first_zero_bit find_first_zero_bit
|
|
#define ext2_find_next_zero_bit find_next_zero_bit
|
|
|
|
/* Bitmap functions for the minix filesystem. */
|
|
#define minix_set_bit(nr,addr) test_and_set_bit(nr,addr)
|
|
#define minix_clear_bit(nr,addr) test_and_clear_bit(nr,addr)
|
|
#define minix_test_bit(nr,addr) test_bit(nr,addr)
|
|
#define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)
|
|
|
|
extern inline int sched_find_first_bit(const unsigned long *b)
|
|
{
|
|
if (unlikely(b[0]))
|
|
return __ffs(b[0]);
|
|
if (unlikely(b[1]))
|
|
return __ffs(b[1]) + 32;
|
|
if (unlikely(b[2]))
|
|
return __ffs(b[2]) + 64;
|
|
if (unlikely(b[3]))
|
|
return __ffs(b[3]) + 96;
|
|
if (b[4])
|
|
return __ffs(b[4]) + 128;
|
|
return __ffs(b[5]) + 32 + 128;
|
|
}
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif /* _CRIS_BITOPS_H */
|