- 根目录:
- arch
- x86
- kernel
- irq.c
/*
* Common interrupt code for 32 and 64 bit
*/
#include <linux/cpu.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/of.h>
#include <linux/seq_file.h>
#include <linux/smp.h>
#include <linux/ftrace.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <asm/apic.h>
#include <asm/io_apic.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/mce.h>
#include <asm/hw_irq.h>
#include <asm/desc.h>
#define CREATE_TRACE_POINTS
#include <asm/trace/irq_vectors.h>
atomic_t irq_err_count;
/* Function pointer for generic interrupt vector handling */
void (*x86_platform_ipi_callback)(void) = NULL;
/*
* '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)
{
if (printk_ratelimit())
pr_err("unexpected IRQ trap at vector %02x\n", irq);
/*
* 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
*/
ack_APIC_irq();
}
#define irq_stats(x) (&per_cpu(irq_stat, x))
/*
* /proc/interrupts printing for arch specific interrupts
*/
int arch_show_interrupts(struct seq_file *p, int prec)
{
int j;
seq_printf(p, "%*s: ", prec, "NMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
seq_puts(p, " Non-maskable interrupts\n");
#ifdef CONFIG_X86_LOCAL_APIC
seq_printf(p, "%*s: ", prec, "LOC");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
seq_puts(p, " Local timer interrupts\n");
seq_printf(p, "%*s: ", prec, "SPU");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
seq_puts(p, " Spurious interrupts\n");
seq_printf(p, "%*s: ", prec, "PMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
seq_puts(p, " Performance monitoring interrupts\n");
seq_printf(p, "%*s: ", prec, "IWI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
seq_puts(p, " IRQ work interrupts\n");
seq_printf(p, "%*s: ", prec, "RTR");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
seq_puts(p, " APIC ICR read retries\n");
#endif
if (x86_platform_ipi_callback) {
seq_printf(p, "%*s: ", prec, "PLT");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
seq_puts(p, " Platform interrupts\n");
}
#ifdef CONFIG_SMP
seq_printf(p, "%*s: ", prec, "RES");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
seq_puts(p, " Rescheduling interrupts\n");
seq_printf(p, "%*s: ", prec, "CAL");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
irq_stats(j)->irq_tlb_count);
seq_puts(p, " Function call interrupts\n");
seq_printf(p, "%*s: ", prec, "TLB");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
seq_puts(p, " TLB shootdowns\n");
#endif
#ifdef CONFIG_X86_THERMAL_VECTOR
seq_printf(p, "%*s: ", prec, "TRM");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
seq_puts(p, " Thermal event interrupts\n");
#endif
#ifdef CONFIG_X86_MCE_THRESHOLD
seq_printf(p, "%*s: ", prec, "THR");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
seq_puts(p, " Threshold APIC interrupts\n");
#endif
#ifdef CONFIG_X86_MCE
seq_printf(p, "%*s: ", prec, "MCE");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
seq_puts(p, " Machine check exceptions\n");
seq_printf(p, "%*s: ", prec, "MCP");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
seq_puts(p, " Machine check polls\n");
#endif
#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
seq_printf(p, "%*s: ", prec, "HYP");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_hv_callback_count);
seq_puts(p, " Hypervisor callback interrupts\n");
#endif
seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
#if defined(CONFIG_X86_IO_APIC)
seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
#endif
return 0;
}
/*
* /proc/stat helpers
*/
u64 arch_irq_stat_cpu(unsigned int cpu)
{
u64 sum = irq_stats(cpu)->__nmi_count;
#ifdef CONFIG_X86_LOCAL_APIC
sum += irq_stats(cpu)->apic_timer_irqs;
sum += irq_stats(cpu)->irq_spurious_count;
sum += irq_stats(cpu)->apic_perf_irqs;
sum += irq_stats(cpu)->apic_irq_work_irqs;
sum += irq_stats(cpu)->icr_read_retry_count;
#endif
if (x86_platform_ipi_callback)
sum += irq_stats(cpu)->x86_platform_ipis;
#ifdef CONFIG_SMP
sum += irq_stats(cpu)->irq_resched_count;
sum += irq_stats(cpu)->irq_call_count;
#endif
#ifdef CONFIG_X86_THERMAL_VECTOR
sum += irq_stats(cpu)->irq_thermal_count;
#endif
#ifdef CONFIG_X86_MCE_THRESHOLD
sum += irq_stats(cpu)->irq_threshold_count;
#endif
#ifdef CONFIG_X86_MCE
sum += per_cpu(mce_exception_count, cpu);
sum += per_cpu(mce_poll_count, cpu);
#endif
return sum;
}
u64 arch_irq_stat(void)
{
u64 sum = atomic_read(&irq_err_count);
return sum;
}
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
__visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
/* high bit used in ret_from_ code */
unsigned vector = ~regs->orig_ax;
unsigned irq;
irq_enter();
exit_idle();
irq = __this_cpu_read(vector_irq[vector]);
if (!handle_irq(irq, regs)) {
ack_APIC_irq();
if (irq != VECTOR_RETRIGGERED) {
pr_emerg_ratelimited("%s: %d.%d No irq handler for vector (irq %d)\n",
__func__, smp_processor_id(),
vector, irq);
} else {
__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
}
}
irq_exit();
set_irq_regs(old_regs);
return 1;
}
/*
* Handler for X86_PLATFORM_IPI_VECTOR.
*/
void __smp_x86_platform_ipi(void)
{
inc_irq_stat(x86_platform_ipis);
if (x86_platform_ipi_callback)
x86_platform_ipi_callback();
}
__visible void smp_x86_platform_ipi(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
entering_ack_irq();
__smp_x86_platform_ipi();
exiting_irq();
set_irq_regs(old_regs);
}
#ifdef CONFIG_HAVE_KVM
/*
* Handler for POSTED_INTERRUPT_VECTOR.
*/
__visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
ack_APIC_irq();
irq_enter();
exit_idle();
inc_irq_stat(kvm_posted_intr_ipis);
irq_exit();
set_irq_regs(old_regs);
}
#endif
__visible void smp_trace_x86_platform_ipi(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
entering_ack_irq();
trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
__smp_x86_platform_ipi();
trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
exiting_irq();
set_irq_regs(old_regs);
}
EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
#ifdef CONFIG_HOTPLUG_CPU
/* These two declarations are only used in check_irq_vectors_for_cpu_disable()
* below, which is protected by stop_machine(). Putting them on the stack
* results in a stack frame overflow. Dynamically allocating could result in a
* failure so declare these two cpumasks as global.
*/
static struct cpumask affinity_new, online_new;
/*
* This cpu is going to be removed and its vectors migrated to the remaining
* online cpus. Check to see if there are enough vectors in the remaining cpus.
* This function is protected by stop_machine().
*/
int check_irq_vectors_for_cpu_disable(void)
{
int irq, cpu;
unsigned int this_cpu, vector, this_count, count;
struct irq_desc *desc;
struct irq_data *data;
this_cpu = smp_processor_id();
cpumask_copy(&online_new, cpu_online_mask);
cpumask_clear_cpu(this_cpu, &online_new);
this_count = 0;
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
irq = __this_cpu_read(vector_irq[vector]);
if (irq >= 0) {
desc = irq_to_desc(irq);
if (!desc)
continue;
data = irq_desc_get_irq_data(desc);
cpumask_copy(&affinity_new, data->affinity);
cpumask_clear_cpu(this_cpu, &affinity_new);
/* Do not count inactive or per-cpu irqs. */
if (!irq_has_action(irq) || irqd_is_per_cpu(data))
continue;
/*
* A single irq may be mapped to multiple
* cpu's vector_irq[] (for example IOAPIC cluster
* mode). In this case we have two
* possibilities:
*
* 1) the resulting affinity mask is empty; that is
* this the down'd cpu is the last cpu in the irq's
* affinity mask, or
*
* 2) the resulting affinity mask is no longer
* a subset of the online cpus but the affinity
* mask is not zero; that is the down'd cpu is the
* last online cpu in a user set affinity mask.
*/
if (cpumask_empty(&affinity_new) ||
!cpumask_subset(&affinity_new, &online_new))
this_count++;
}
}
count = 0;
for_each_online_cpu(cpu) {
if (cpu == this_cpu)
continue;
/*
* We scan from FIRST_EXTERNAL_VECTOR to first system
* vector. If the vector is marked in the used vectors
* bitmap or an irq is assigned to it, we don't count
* it as available.
*/
for (vector = FIRST_EXTERNAL_VECTOR;
vector < first_system_vector; vector++) {
if (!test_bit(vector, used_vectors) &&
per_cpu(vector_irq, cpu)[vector] < 0)
count++;
}
}
if (count < this_count) {
pr_warn("CPU %d disable failed: CPU has %u vectors assigned and there are only %u available.\n",
this_cpu, this_count, count);
return -ERANGE;
}
return 0;
}
/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
void fixup_irqs(void)
{
unsigned int irq, vector;
static int warned;
struct irq_desc *desc;
struct irq_data *data;
struct irq_chip *chip;
int ret;
for_each_irq_desc(irq, desc) {
int break_affinity = 0;
int set_affinity = 1;
const struct cpumask *affinity;
if (!desc)
continue;
if (irq == 2)
continue;
/* interrupt's are disabled at this point */
raw_spin_lock(&desc->lock);
data = irq_desc_get_irq_data(desc);
affinity = data->affinity;
if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
cpumask_subset(affinity, cpu_online_mask)) {
raw_spin_unlock(&desc->lock);
continue;
}
/*
* Complete the irq move. This cpu is going down and for
* non intr-remapping case, we can't wait till this interrupt
* arrives at this cpu before completing the irq move.
*/
irq_force_complete_move(irq);
if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
break_affinity = 1;
affinity = cpu_online_mask;
}
chip = irq_data_get_irq_chip(data);
if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
chip->irq_mask(data);
if (chip->irq_set_affinity) {
ret = chip->irq_set_affinity(data, affinity, true);
if (ret == -ENOSPC)
pr_crit("IRQ %d set affinity failed because there are no available vectors. The device assigned to this IRQ is unstable.\n", irq);
} else {
if (!(warned++))
set_affinity = 0;
}
/*
* We unmask if the irq was not marked masked by the
* core code. That respects the lazy irq disable
* behaviour.
*/
if (!irqd_can_move_in_process_context(data) &&
!irqd_irq_masked(data) && chip->irq_unmask)
chip->irq_unmask(data);
raw_spin_unlock(&desc->lock);
if (break_affinity && set_affinity)
pr_notice("Broke affinity for irq %i\n", irq);
else if (!set_affinity)
pr_notice("Cannot set affinity for irq %i\n", irq);
}
/*
* We can remove mdelay() and then send spuriuous interrupts to
* new cpu targets for all the irqs that were handled previously by
* this cpu. While it works, I have seen spurious interrupt messages
* (nothing wrong but still...).
*
* So for now, retain mdelay(1) and check the IRR and then send those
* interrupts to new targets as this cpu is already offlined...
*/
mdelay(1);
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
unsigned int irr;
if (__this_cpu_read(vector_irq[vector]) <= VECTOR_UNDEFINED)
continue;
irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
if (irr & (1 << (vector % 32))) {
irq = __this_cpu_read(vector_irq[vector]);
desc = irq_to_desc(irq);
data = irq_desc_get_irq_data(desc);
chip = irq_data_get_irq_chip(data);
raw_spin_lock(&desc->lock);
if (chip->irq_retrigger) {
chip->irq_retrigger(data);
__this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
}
raw_spin_unlock(&desc->lock);
}
if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
}
}
#endif