mirror of https://gitee.com/openkylin/linux.git
377 lines
9.3 KiB
C
377 lines
9.3 KiB
C
/*
|
|
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
|
|
*
|
|
* This file contains the lowest level x86-specific interrupt
|
|
* entry, irq-stacks and irq statistics code. All the remaining
|
|
* irq logic is done by the generic kernel/irq/ code and
|
|
* by the x86-specific irq controller code. (e.g. i8259.c and
|
|
* io_apic.c.)
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/delay.h>
|
|
|
|
#include <asm/apic.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
|
|
EXPORT_PER_CPU_SYMBOL(irq_stat);
|
|
|
|
DEFINE_PER_CPU(struct pt_regs *, irq_regs);
|
|
EXPORT_PER_CPU_SYMBOL(irq_regs);
|
|
|
|
/*
|
|
* 'what should we do if we get a hw irq event on an illegal vector'.
|
|
* each architecture has to answer this themselves.
|
|
*/
|
|
void ack_bad_irq(unsigned int irq)
|
|
{
|
|
printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
|
|
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
/*
|
|
* Currently unexpected vectors happen only on SMP and APIC.
|
|
* We _must_ ack these because every local APIC has only N
|
|
* irq slots per priority level, and a 'hanging, unacked' IRQ
|
|
* holds up an irq slot - in excessive cases (when multiple
|
|
* unexpected vectors occur) that might lock up the APIC
|
|
* completely.
|
|
* But only ack when the APIC is enabled -AK
|
|
*/
|
|
if (cpu_has_apic)
|
|
ack_APIC_irq();
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_4KSTACKS
|
|
/*
|
|
* per-CPU IRQ handling contexts (thread information and stack)
|
|
*/
|
|
union irq_ctx {
|
|
struct thread_info tinfo;
|
|
u32 stack[THREAD_SIZE/sizeof(u32)];
|
|
};
|
|
|
|
static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
|
|
static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
|
|
#endif
|
|
|
|
/*
|
|
* do_IRQ handles all normal device IRQ's (the special
|
|
* SMP cross-CPU interrupts have their own specific
|
|
* handlers).
|
|
*/
|
|
unsigned int do_IRQ(struct pt_regs *regs)
|
|
{
|
|
struct pt_regs *old_regs;
|
|
/* high bit used in ret_from_ code */
|
|
int irq = ~regs->orig_ax;
|
|
struct irq_desc *desc = irq_desc + irq;
|
|
#ifdef CONFIG_4KSTACKS
|
|
union irq_ctx *curctx, *irqctx;
|
|
u32 *isp;
|
|
#endif
|
|
|
|
if (unlikely((unsigned)irq >= NR_IRQS)) {
|
|
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
|
|
__FUNCTION__, irq);
|
|
BUG();
|
|
}
|
|
|
|
old_regs = set_irq_regs(regs);
|
|
irq_enter();
|
|
#ifdef CONFIG_DEBUG_STACKOVERFLOW
|
|
/* Debugging check for stack overflow: is there less than 1KB free? */
|
|
{
|
|
long sp;
|
|
|
|
__asm__ __volatile__("andl %%esp,%0" :
|
|
"=r" (sp) : "0" (THREAD_SIZE - 1));
|
|
if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
|
|
printk("do_IRQ: stack overflow: %ld\n",
|
|
sp - sizeof(struct thread_info));
|
|
dump_stack();
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_4KSTACKS
|
|
|
|
curctx = (union irq_ctx *) current_thread_info();
|
|
irqctx = hardirq_ctx[smp_processor_id()];
|
|
|
|
/*
|
|
* this is where we switch to the IRQ stack. However, if we are
|
|
* already using the IRQ stack (because we interrupted a hardirq
|
|
* handler) we can't do that and just have to keep using the
|
|
* current stack (which is the irq stack already after all)
|
|
*/
|
|
if (curctx != irqctx) {
|
|
int arg1, arg2, bx;
|
|
|
|
/* build the stack frame on the IRQ stack */
|
|
isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
|
|
irqctx->tinfo.task = curctx->tinfo.task;
|
|
irqctx->tinfo.previous_esp = current_stack_pointer;
|
|
|
|
/*
|
|
* Copy the softirq bits in preempt_count so that the
|
|
* softirq checks work in the hardirq context.
|
|
*/
|
|
irqctx->tinfo.preempt_count =
|
|
(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
|
|
(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
|
|
|
|
asm volatile(
|
|
" xchgl %%ebx,%%esp \n"
|
|
" call *%%edi \n"
|
|
" movl %%ebx,%%esp \n"
|
|
: "=a" (arg1), "=d" (arg2), "=b" (bx)
|
|
: "0" (irq), "1" (desc), "2" (isp),
|
|
"D" (desc->handle_irq)
|
|
: "memory", "cc"
|
|
);
|
|
} else
|
|
#endif
|
|
desc->handle_irq(irq, desc);
|
|
|
|
irq_exit();
|
|
set_irq_regs(old_regs);
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_4KSTACKS
|
|
|
|
static char softirq_stack[NR_CPUS * THREAD_SIZE]
|
|
__attribute__((__section__(".bss.page_aligned")));
|
|
|
|
static char hardirq_stack[NR_CPUS * THREAD_SIZE]
|
|
__attribute__((__section__(".bss.page_aligned")));
|
|
|
|
/*
|
|
* allocate per-cpu stacks for hardirq and for softirq processing
|
|
*/
|
|
void irq_ctx_init(int cpu)
|
|
{
|
|
union irq_ctx *irqctx;
|
|
|
|
if (hardirq_ctx[cpu])
|
|
return;
|
|
|
|
irqctx = (union irq_ctx*) &hardirq_stack[cpu*THREAD_SIZE];
|
|
irqctx->tinfo.task = NULL;
|
|
irqctx->tinfo.exec_domain = NULL;
|
|
irqctx->tinfo.cpu = cpu;
|
|
irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
|
|
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
|
|
|
|
hardirq_ctx[cpu] = irqctx;
|
|
|
|
irqctx = (union irq_ctx*) &softirq_stack[cpu*THREAD_SIZE];
|
|
irqctx->tinfo.task = NULL;
|
|
irqctx->tinfo.exec_domain = NULL;
|
|
irqctx->tinfo.cpu = cpu;
|
|
irqctx->tinfo.preempt_count = 0;
|
|
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
|
|
|
|
softirq_ctx[cpu] = irqctx;
|
|
|
|
printk("CPU %u irqstacks, hard=%p soft=%p\n",
|
|
cpu,hardirq_ctx[cpu],softirq_ctx[cpu]);
|
|
}
|
|
|
|
void irq_ctx_exit(int cpu)
|
|
{
|
|
hardirq_ctx[cpu] = NULL;
|
|
}
|
|
|
|
extern asmlinkage void __do_softirq(void);
|
|
|
|
asmlinkage void do_softirq(void)
|
|
{
|
|
unsigned long flags;
|
|
struct thread_info *curctx;
|
|
union irq_ctx *irqctx;
|
|
u32 *isp;
|
|
|
|
if (in_interrupt())
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
|
|
if (local_softirq_pending()) {
|
|
curctx = current_thread_info();
|
|
irqctx = softirq_ctx[smp_processor_id()];
|
|
irqctx->tinfo.task = curctx->task;
|
|
irqctx->tinfo.previous_esp = current_stack_pointer;
|
|
|
|
/* build the stack frame on the softirq stack */
|
|
isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
|
|
|
|
asm volatile(
|
|
" xchgl %%ebx,%%esp \n"
|
|
" call __do_softirq \n"
|
|
" movl %%ebx,%%esp \n"
|
|
: "=b"(isp)
|
|
: "0"(isp)
|
|
: "memory", "cc", "edx", "ecx", "eax"
|
|
);
|
|
/*
|
|
* Shouldnt happen, we returned above if in_interrupt():
|
|
*/
|
|
WARN_ON_ONCE(softirq_count());
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Interrupt statistics:
|
|
*/
|
|
|
|
atomic_t irq_err_count;
|
|
|
|
/*
|
|
* /proc/interrupts printing:
|
|
*/
|
|
|
|
int show_interrupts(struct seq_file *p, void *v)
|
|
{
|
|
int i = *(loff_t *) v, j;
|
|
struct irqaction * action;
|
|
unsigned long flags;
|
|
|
|
if (i == 0) {
|
|
seq_printf(p, " ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "CPU%-8d",j);
|
|
seq_putc(p, '\n');
|
|
}
|
|
|
|
if (i < NR_IRQS) {
|
|
unsigned any_count = 0;
|
|
|
|
spin_lock_irqsave(&irq_desc[i].lock, flags);
|
|
#ifndef CONFIG_SMP
|
|
any_count = kstat_irqs(i);
|
|
#else
|
|
for_each_online_cpu(j)
|
|
any_count |= kstat_cpu(j).irqs[i];
|
|
#endif
|
|
action = irq_desc[i].action;
|
|
if (!action && !any_count)
|
|
goto skip;
|
|
seq_printf(p, "%3d: ",i);
|
|
#ifndef CONFIG_SMP
|
|
seq_printf(p, "%10u ", kstat_irqs(i));
|
|
#else
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
|
|
#endif
|
|
seq_printf(p, " %8s", irq_desc[i].chip->name);
|
|
seq_printf(p, "-%-8s", irq_desc[i].name);
|
|
|
|
if (action) {
|
|
seq_printf(p, " %s", action->name);
|
|
while ((action = action->next) != NULL)
|
|
seq_printf(p, ", %s", action->name);
|
|
}
|
|
|
|
seq_putc(p, '\n');
|
|
skip:
|
|
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
|
|
} else if (i == NR_IRQS) {
|
|
seq_printf(p, "NMI: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ", nmi_count(j));
|
|
seq_printf(p, " Non-maskable interrupts\n");
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
seq_printf(p, "LOC: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ",
|
|
per_cpu(irq_stat,j).apic_timer_irqs);
|
|
seq_printf(p, " Local timer interrupts\n");
|
|
#endif
|
|
#ifdef CONFIG_SMP
|
|
seq_printf(p, "RES: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ",
|
|
per_cpu(irq_stat,j).irq_resched_count);
|
|
seq_printf(p, " Rescheduling interrupts\n");
|
|
seq_printf(p, "CAL: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ",
|
|
per_cpu(irq_stat,j).irq_call_count);
|
|
seq_printf(p, " function call interrupts\n");
|
|
seq_printf(p, "TLB: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ",
|
|
per_cpu(irq_stat,j).irq_tlb_count);
|
|
seq_printf(p, " TLB shootdowns\n");
|
|
#endif
|
|
seq_printf(p, "TRM: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ",
|
|
per_cpu(irq_stat,j).irq_thermal_count);
|
|
seq_printf(p, " Thermal event interrupts\n");
|
|
seq_printf(p, "SPU: ");
|
|
for_each_online_cpu(j)
|
|
seq_printf(p, "%10u ",
|
|
per_cpu(irq_stat,j).irq_spurious_count);
|
|
seq_printf(p, " Spurious interrupts\n");
|
|
seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
|
|
#if defined(CONFIG_X86_IO_APIC)
|
|
seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
|
|
#endif
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
#include <mach_apic.h>
|
|
|
|
void fixup_irqs(cpumask_t map)
|
|
{
|
|
unsigned int irq;
|
|
static int warned;
|
|
|
|
for (irq = 0; irq < NR_IRQS; irq++) {
|
|
cpumask_t mask;
|
|
if (irq == 2)
|
|
continue;
|
|
|
|
cpus_and(mask, irq_desc[irq].affinity, map);
|
|
if (any_online_cpu(mask) == NR_CPUS) {
|
|
printk("Breaking affinity for irq %i\n", irq);
|
|
mask = map;
|
|
}
|
|
if (irq_desc[irq].chip->set_affinity)
|
|
irq_desc[irq].chip->set_affinity(irq, mask);
|
|
else if (irq_desc[irq].action && !(warned++))
|
|
printk("Cannot set affinity for irq %i\n", irq);
|
|
}
|
|
|
|
#if 0
|
|
barrier();
|
|
/* Ingo Molnar says: "after the IO-APIC masks have been redirected
|
|
[note the nop - the interrupt-enable boundary on x86 is two
|
|
instructions from sti] - to flush out pending hardirqs and
|
|
IPIs. After this point nothing is supposed to reach this CPU." */
|
|
__asm__ __volatile__("sti; nop; cli");
|
|
barrier();
|
|
#else
|
|
/* That doesn't seem sufficient. Give it 1ms. */
|
|
local_irq_enable();
|
|
mdelay(1);
|
|
local_irq_disable();
|
|
#endif
|
|
}
|
|
#endif
|
|
|