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linux/arch/ppc64/kernel/irq.c

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/*
* arch/ppc/kernel/irq.c
*
* Derived from arch/i386/kernel/irq.c
* Copyright (C) 1992 Linus Torvalds
* Adapted from arch/i386 by Gary Thomas
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
* Updated and modified by Cort Dougan (cort@cs.nmt.edu)
* Copyright (C) 1996 Cort Dougan
* Adapted for Power Macintosh by Paul Mackerras
* Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* 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 file contains the code used by various IRQ handling routines:
* asking for different IRQ's should be done through these routines
* instead of just grabbing them. Thus setups with different IRQ numbers
* shouldn't result in any weird surprises, and installing new handlers
* should be easier.
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/threads.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/random.h>
#include <linux/kallsyms.h>
#include <linux/profile.h>
#include <linux/bitops.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/cache.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/iSeries/ItLpQueue.h>
#include <asm/machdep.h>
#include <asm/paca.h>
#ifdef CONFIG_SMP
extern void iSeries_smp_message_recv( struct pt_regs * );
#endif
extern irq_desc_t irq_desc[NR_IRQS];
EXPORT_SYMBOL(irq_desc);
int distribute_irqs = 1;
int __irq_offset_value;
int ppc_spurious_interrupts;
u64 ppc64_interrupt_controller;
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
struct irqaction * action;
irq_desc_t *desc;
unsigned long flags;
if (i == 0) {
seq_printf(p, " ");
for (j=0; j<NR_CPUS; j++) {
if (cpu_online(j))
seq_printf(p, "CPU%d ",j);
}
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
desc = get_irq_desc(i);
spin_lock_irqsave(&desc->lock, flags);
action = desc->action;
if (!action || !action->handler)
goto skip;
seq_printf(p, "%3d: ", i);
#ifdef CONFIG_SMP
for (j = 0; j < NR_CPUS; j++) {
if (cpu_online(j))
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
}
#else
seq_printf(p, "%10u ", kstat_irqs(i));
#endif /* CONFIG_SMP */
if (desc->handler)
seq_printf(p, " %s ", desc->handler->typename );
else
seq_printf(p, " None ");
seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge ");
seq_printf(p, " %s",action->name);
for (action=action->next; action; action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
skip:
spin_unlock_irqrestore(&desc->lock, flags);
} else if (i == NR_IRQS)
seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(cpumask_t map)
{
unsigned int irq;
static int warned;
for_each_irq(irq) {
cpumask_t mask;
if (irq_desc[irq].status & IRQ_PER_CPU)
continue;
cpus_and(mask, irq_affinity[irq], map);
if (any_online_cpu(mask) == NR_CPUS) {
printk("Breaking affinity for irq %i\n", irq);
mask = map;
}
if (irq_desc[irq].handler->set_affinity)
irq_desc[irq].handler->set_affinity(irq, mask);
else if (irq_desc[irq].action && !(warned++))
printk("Cannot set affinity for irq %i\n", irq);
}
local_irq_enable();
mdelay(1);
local_irq_disable();
}
#endif
extern int noirqdebug;
/*
* Eventually, this should take an array of interrupts and an array size
* so it can dispatch multiple interrupts.
*/
void ppc_irq_dispatch_handler(struct pt_regs *regs, int irq)
{
int status;
struct irqaction *action;
int cpu = smp_processor_id();
irq_desc_t *desc = get_irq_desc(irq);
irqreturn_t action_ret;
#ifdef CONFIG_IRQSTACKS
struct thread_info *curtp, *irqtp;
#endif
kstat_cpu(cpu).irqs[irq]++;
if (desc->status & IRQ_PER_CPU) {
/* no locking required for CPU-local interrupts: */
ack_irq(irq);
action_ret = handle_IRQ_event(irq, regs, desc->action);
desc->handler->end(irq);
return;
}
spin_lock(&desc->lock);
ack_irq(irq);
/*
REPLAY is when Linux resends an IRQ that was dropped earlier
WAITING is used by probe to mark irqs that are being tested
*/
status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
status |= IRQ_PENDING; /* we _want_ to handle it */
/*
* If the IRQ is disabled for whatever reason, we cannot
* use the action we have.
*/
action = NULL;
if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
action = desc->action;
if (!action || !action->handler) {
ppc_spurious_interrupts++;
printk(KERN_DEBUG "Unhandled interrupt %x, disabled\n", irq);
/* We can't call disable_irq here, it would deadlock */
if (!desc->depth)
desc->depth = 1;
desc->status |= IRQ_DISABLED;
/* This is not a real spurrious interrupt, we
* have to eoi it, so we jump to out
*/
mask_irq(irq);
goto out;
}
status &= ~IRQ_PENDING; /* we commit to handling */
status |= IRQ_INPROGRESS; /* we are handling it */
}
desc->status = status;
/*
* If there is no IRQ handler or it was disabled, exit early.
Since we set PENDING, if another processor is handling
a different instance of this same irq, the other processor
will take care of it.
*/
if (unlikely(!action))
goto out;
/*
* Edge triggered interrupts need to remember
* pending events.
* This applies to any hw interrupts that allow a second
* instance of the same irq to arrive while we are in do_IRQ
* or in the handler. But the code here only handles the _second_
* instance of the irq, not the third or fourth. So it is mostly
* useful for irq hardware that does not mask cleanly in an
* SMP environment.
*/
for (;;) {
spin_unlock(&desc->lock);
#ifdef CONFIG_IRQSTACKS
/* Switch to the irq stack to handle this */
curtp = current_thread_info();
irqtp = hardirq_ctx[smp_processor_id()];
if (curtp != irqtp) {
irqtp->task = curtp->task;
irqtp->flags = 0;
action_ret = call_handle_IRQ_event(irq, regs, action, irqtp);
irqtp->task = NULL;
if (irqtp->flags)
set_bits(irqtp->flags, &curtp->flags);
} else
#endif
action_ret = handle_IRQ_event(irq, regs, action);
spin_lock(&desc->lock);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret, regs);
if (likely(!(desc->status & IRQ_PENDING)))
break;
desc->status &= ~IRQ_PENDING;
}
out:
desc->status &= ~IRQ_INPROGRESS;
/*
* The ->end() handler has to deal with interrupts which got
* disabled while the handler was running.
*/
if (desc->handler) {
if (desc->handler->end)
desc->handler->end(irq);
else if (desc->handler->enable)
desc->handler->enable(irq);
}
spin_unlock(&desc->lock);
}
#ifdef CONFIG_PPC_ISERIES
void do_IRQ(struct pt_regs *regs)
{
struct paca_struct *lpaca;
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 2KB free? */
{
long sp;
sp = __get_SP() & (THREAD_SIZE-1);
if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
printk("do_IRQ: stack overflow: %ld\n",
sp - sizeof(struct thread_info));
dump_stack();
}
}
#endif
lpaca = get_paca();
#ifdef CONFIG_SMP
if (lpaca->lppaca.int_dword.fields.ipi_cnt) {
lpaca->lppaca.int_dword.fields.ipi_cnt = 0;
iSeries_smp_message_recv(regs);
}
#endif /* CONFIG_SMP */
if (hvlpevent_is_pending())
process_hvlpevents(regs);
irq_exit();
if (lpaca->lppaca.int_dword.fields.decr_int) {
lpaca->lppaca.int_dword.fields.decr_int = 0;
/* Signal a fake decrementer interrupt */
timer_interrupt(regs);
}
}
#else /* CONFIG_PPC_ISERIES */
void do_IRQ(struct pt_regs *regs)
{
int irq;
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 2KB free? */
{
long sp;
sp = __get_SP() & (THREAD_SIZE-1);
if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
printk("do_IRQ: stack overflow: %ld\n",
sp - sizeof(struct thread_info));
dump_stack();
}
}
#endif
irq = ppc_md.get_irq(regs);
if (irq >= 0)
ppc_irq_dispatch_handler(regs, irq);
else
/* That's not SMP safe ... but who cares ? */
ppc_spurious_interrupts++;
irq_exit();
}
#endif /* CONFIG_PPC_ISERIES */
void __init init_IRQ(void)
{
static int once = 0;
if (once)
return;
once++;
ppc_md.init_IRQ();
irq_ctx_init();
}
#ifndef CONFIG_PPC_ISERIES
/*
* Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
*/
#define UNDEFINED_IRQ 0xffffffff
unsigned int virt_irq_to_real_map[NR_IRQS];
/*
* Don't use virtual irqs 0, 1, 2 for devices.
* The pcnet32 driver considers interrupt numbers < 2 to be invalid,
* and 2 is the XICS IPI interrupt.
* We limit virtual irqs to 17 less than NR_IRQS so that when we
* offset them by 16 (to reserve the first 16 for ISA interrupts)
* we don't end up with an interrupt number >= NR_IRQS.
*/
#define MIN_VIRT_IRQ 3
#define MAX_VIRT_IRQ (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
#define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
void
virt_irq_init(void)
{
int i;
for (i = 0; i < NR_IRQS; i++)
virt_irq_to_real_map[i] = UNDEFINED_IRQ;
}
/* Create a mapping for a real_irq if it doesn't already exist.
* Return the virtual irq as a convenience.
*/
int virt_irq_create_mapping(unsigned int real_irq)
{
unsigned int virq, first_virq;
static int warned;
if (ppc64_interrupt_controller == IC_OPEN_PIC)
return real_irq; /* no mapping for openpic (for now) */
if (ppc64_interrupt_controller == IC_BPA_IIC)
return real_irq; /* no mapping for iic either */
/* don't map interrupts < MIN_VIRT_IRQ */
if (real_irq < MIN_VIRT_IRQ) {
virt_irq_to_real_map[real_irq] = real_irq;
return real_irq;
}
/* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
virq = real_irq;
if (virq > MAX_VIRT_IRQ)
virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
/* search for this number or a free slot */
first_virq = virq;
while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
if (virt_irq_to_real_map[virq] == real_irq)
return virq;
if (++virq > MAX_VIRT_IRQ)
virq = MIN_VIRT_IRQ;
if (virq == first_virq)
goto nospace; /* oops, no free slots */
}
virt_irq_to_real_map[virq] = real_irq;
return virq;
nospace:
if (!warned) {
printk(KERN_CRIT "Interrupt table is full\n");
printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
"in your kernel sources and rebuild.\n", NR_IRQS);
warned = 1;
}
return NO_IRQ;
}
/*
* In most cases will get a hit on the very first slot checked in the
* virt_irq_to_real_map. Only when there are a large number of
* IRQs will this be expensive.
*/
unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
{
unsigned int virq;
unsigned int first_virq;
virq = real_irq;
if (virq > MAX_VIRT_IRQ)
virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
first_virq = virq;
do {
if (virt_irq_to_real_map[virq] == real_irq)
return virq;
virq++;
if (virq >= MAX_VIRT_IRQ)
virq = 0;
} while (first_virq != virq);
return NO_IRQ;
}
#endif /* CONFIG_PPC_ISERIES */
#ifdef CONFIG_IRQSTACKS
struct thread_info *softirq_ctx[NR_CPUS];
struct thread_info *hardirq_ctx[NR_CPUS];
void irq_ctx_init(void)
{
struct thread_info *tp;
int i;
for_each_cpu(i) {
memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
tp = softirq_ctx[i];
tp->cpu = i;
tp->preempt_count = SOFTIRQ_OFFSET;
memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
tp = hardirq_ctx[i];
tp->cpu = i;
tp->preempt_count = HARDIRQ_OFFSET;
}
}
void do_softirq(void)
{
unsigned long flags;
struct thread_info *curtp, *irqtp;
if (in_interrupt())
return;
local_irq_save(flags);
if (local_softirq_pending()) {
curtp = current_thread_info();
irqtp = softirq_ctx[smp_processor_id()];
irqtp->task = curtp->task;
call_do_softirq(irqtp);
irqtp->task = NULL;
}
local_irq_restore(flags);
}
EXPORT_SYMBOL(do_softirq);
#endif /* CONFIG_IRQSTACKS */
static int __init setup_noirqdistrib(char *str)
{
distribute_irqs = 0;
return 1;
}
__setup("noirqdistrib", setup_noirqdistrib);
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