linux_dsm_epyc7002/arch/x86/kernel/irqinit.c
Prarit Bhargava 9345005f4e x86/irq: Fix do_IRQ() interrupt warning for cpu hotplug retriggered irqs
During heavy CPU-hotplug operations the following spurious kernel warnings
can trigger:

  do_IRQ: No ... irq handler for vector (irq -1)

  [ See: https://bugzilla.kernel.org/show_bug.cgi?id=64831 ]

When downing a cpu it is possible that there are unhandled irqs
left in the APIC IRR register.  The following code path shows
how the problem can occur:

 1. CPU 5 is to go down.

 2. cpu_disable() on CPU 5 executes with interrupt flag cleared
    by local_irq_save() via stop_machine().

 3. IRQ 12 asserts on CPU 5, setting IRR but not ISR because
    interrupt flag is cleared (CPU unabled to handle the irq)

 4. IRQs are migrated off of CPU 5, and the vectors' irqs are set
    to -1. 5. stop_machine() finishes cpu_disable()

 6. cpu_die() for CPU 5 executes in normal context.

 7. CPU 5 attempts to handle IRQ 12 because the IRR is set for
    IRQ 12.  The code attempts to find the vector's IRQ and cannot
    because it has been set to -1. 8. do_IRQ() warning displays
    warning about CPU 5 IRQ 12.

I added a debug printk to output which CPU & vector was
retriggered and discovered that that we are getting bogus
events.  I see a 100% correlation between this debug printk in
fixup_irqs() and the do_IRQ() warning.

This patchset resolves this by adding definitions for
VECTOR_UNDEFINED(-1) and VECTOR_RETRIGGERED(-2) and modifying
the code to use them.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=64831
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Rui Wang <rui.y.wang@intel.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Yang Zhang <yang.z.zhang@Intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: janet.morgan@Intel.com
Cc: tony.luck@Intel.com
Cc: ruiv.wang@gmail.com
Link: http://lkml.kernel.org/r/1388938252-16627-1-git-send-email-prarit@redhat.com
[ Cleaned up the code a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-12 13:13:02 +01:00

219 lines
5.5 KiB
C

#include <linux/linkage.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/random.h>
#include <linux/kprobes.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/device.h>
#include <linux/bitops.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <asm/timer.h>
#include <asm/hw_irq.h>
#include <asm/pgtable.h>
#include <asm/desc.h>
#include <asm/apic.h>
#include <asm/setup.h>
#include <asm/i8259.h>
#include <asm/traps.h>
#include <asm/prom.h>
/*
* ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
* (these are usually mapped to vectors 0x30-0x3f)
*/
/*
* The IO-APIC gives us many more interrupt sources. Most of these
* are unused but an SMP system is supposed to have enough memory ...
* sometimes (mostly wrt. hw bugs) we get corrupted vectors all
* across the spectrum, so we really want to be prepared to get all
* of these. Plus, more powerful systems might have more than 64
* IO-APIC registers.
*
* (these are usually mapped into the 0x30-0xff vector range)
*/
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction irq2 = {
.handler = no_action,
.name = "cascade",
.flags = IRQF_NO_THREAD,
};
DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
[0 ... NR_VECTORS - 1] = VECTOR_UNDEFINED,
};
int vector_used_by_percpu_irq(unsigned int vector)
{
int cpu;
for_each_online_cpu(cpu) {
if (per_cpu(vector_irq, cpu)[vector] > VECTOR_UNDEFINED)
return 1;
}
return 0;
}
void __init init_ISA_irqs(void)
{
struct irq_chip *chip = legacy_pic->chip;
const char *name = chip->name;
int i;
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
init_bsp_APIC();
#endif
legacy_pic->init(0);
for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
irq_set_chip_and_handler_name(i, chip, handle_level_irq, name);
}
void __init init_IRQ(void)
{
int i;
/*
* We probably need a better place for this, but it works for
* now ...
*/
x86_add_irq_domains();
/*
* On cpu 0, Assign IRQ0_VECTOR..IRQ15_VECTOR's to IRQ 0..15.
* If these IRQ's are handled by legacy interrupt-controllers like PIC,
* then this configuration will likely be static after the boot. If
* these IRQ's are handled by more mordern controllers like IO-APIC,
* then this vector space can be freed and re-used dynamically as the
* irq's migrate etc.
*/
for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i;
x86_init.irqs.intr_init();
}
/*
* Setup the vector to irq mappings.
*/
void setup_vector_irq(int cpu)
{
#ifndef CONFIG_X86_IO_APIC
int irq;
/*
* On most of the platforms, legacy PIC delivers the interrupts on the
* boot cpu. But there are certain platforms where PIC interrupts are
* delivered to multiple cpu's. If the legacy IRQ is handled by the
* legacy PIC, for the new cpu that is coming online, setup the static
* legacy vector to irq mapping:
*/
for (irq = 0; irq < legacy_pic->nr_legacy_irqs; irq++)
per_cpu(vector_irq, cpu)[IRQ0_VECTOR + irq] = irq;
#endif
__setup_vector_irq(cpu);
}
static void __init smp_intr_init(void)
{
#ifdef CONFIG_SMP
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
/*
* The reschedule interrupt is a CPU-to-CPU reschedule-helper
* IPI, driven by wakeup.
*/
alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
/* IPI for generic function call */
alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
/* IPI for generic single function call */
alloc_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,
call_function_single_interrupt);
/* Low priority IPI to cleanup after moving an irq */
set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
/* IPI used for rebooting/stopping */
alloc_intr_gate(REBOOT_VECTOR, reboot_interrupt);
#endif
#endif /* CONFIG_SMP */
}
static void __init apic_intr_init(void)
{
smp_intr_init();
#ifdef CONFIG_X86_THERMAL_VECTOR
alloc_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
#endif
#ifdef CONFIG_X86_MCE_THRESHOLD
alloc_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
#endif
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
/* self generated IPI for local APIC timer */
alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
/* IPI for X86 platform specific use */
alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi);
#ifdef CONFIG_HAVE_KVM
/* IPI for KVM to deliver posted interrupt */
alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi);
#endif
/* IPI vectors for APIC spurious and error interrupts */
alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
/* IRQ work interrupts: */
# ifdef CONFIG_IRQ_WORK
alloc_intr_gate(IRQ_WORK_VECTOR, irq_work_interrupt);
# endif
#endif
}
void __init native_init_IRQ(void)
{
int i;
/* Execute any quirks before the call gates are initialised: */
x86_init.irqs.pre_vector_init();
apic_intr_init();
/*
* Cover the whole vector space, no vector can escape
* us. (some of these will be overridden and become
* 'special' SMP interrupts)
*/
i = FIRST_EXTERNAL_VECTOR;
for_each_clear_bit_from(i, used_vectors, NR_VECTORS) {
/* IA32_SYSCALL_VECTOR could be used in trap_init already. */
set_intr_gate(i, interrupt[i - FIRST_EXTERNAL_VECTOR]);
}
if (!acpi_ioapic && !of_ioapic)
setup_irq(2, &irq2);
#ifdef CONFIG_X86_32
irq_ctx_init(smp_processor_id());
#endif
}