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x86/apic: Move pending interrupt check code into it's own function

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[ Upstream commit 9b217f33017715903d0956dfc58f82d2a2d00e63 ]

The pending interrupt check code is mixed with the local APIC setup code,
that looks messy.

Extract the related code, move it into a new function named
apic_pending_intr_clear().

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20180301055930.2396-2-douly.fnst@cn.fujitsu.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dou Liyang 2018-03-01 13:59:28 +08:00 committed by Greg Kroah-Hartman
parent f69f2d6119
commit fe241fe90a
1 changed files with 55 additions and 45 deletions

100
arch/x86/kernel/apic/apic.c

@ -1362,6 +1362,56 @@ static void lapic_setup_esr(void)
oldvalue, value);
}
static void apic_pending_intr_clear(void)
{
long long max_loops = cpu_khz ? cpu_khz : 1000000;
unsigned long long tsc = 0, ntsc;
unsigned int value, queued;
int i, j, acked = 0;
if (boot_cpu_has(X86_FEATURE_TSC))
tsc = rdtsc();
/*
* After a crash, we no longer service the interrupts and a pending
* interrupt from previous kernel might still have ISR bit set.
*
* Most probably by now CPU has serviced that pending interrupt and
* it might not have done the ack_APIC_irq() because it thought,
* interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
* does not clear the ISR bit and cpu thinks it has already serivced
* the interrupt. Hence a vector might get locked. It was noticed
* for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
*/
do {
queued = 0;
for (i = APIC_ISR_NR - 1; i >= 0; i--)
queued |= apic_read(APIC_IRR + i*0x10);
for (i = APIC_ISR_NR - 1; i >= 0; i--) {
value = apic_read(APIC_ISR + i*0x10);
for (j = 31; j >= 0; j--) {
if (value & (1<<j)) {
ack_APIC_irq();
acked++;
}
}
}
if (acked > 256) {
printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
acked);
break;
}
if (queued) {
if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
ntsc = rdtsc();
max_loops = (cpu_khz << 10) - (ntsc - tsc);
} else
max_loops--;
}
} while (queued && max_loops > 0);
WARN_ON(max_loops <= 0);
}
/**
* setup_local_APIC - setup the local APIC
*
@ -1371,13 +1421,11 @@ static void lapic_setup_esr(void)
void setup_local_APIC(void)
{
int cpu = smp_processor_id();
unsigned int value, queued;
int i, j, acked = 0;
unsigned long long tsc = 0, ntsc;
long long max_loops = cpu_khz ? cpu_khz : 1000000;
unsigned int value;
#ifdef CONFIG_X86_32
int i;
#endif
if (boot_cpu_has(X86_FEATURE_TSC))
tsc = rdtsc();
if (disable_apic) {
disable_ioapic_support();
@ -1437,45 +1485,7 @@ void setup_local_APIC(void)
value &= ~APIC_TPRI_MASK;
apic_write(APIC_TASKPRI, value);
/*
* After a crash, we no longer service the interrupts and a pending
* interrupt from previous kernel might still have ISR bit set.
*
* Most probably by now CPU has serviced that pending interrupt and
* it might not have done the ack_APIC_irq() because it thought,
* interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
* does not clear the ISR bit and cpu thinks it has already serivced
* the interrupt. Hence a vector might get locked. It was noticed
* for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
*/
do {
queued = 0;
for (i = APIC_ISR_NR - 1; i >= 0; i--)
queued |= apic_read(APIC_IRR + i*0x10);
for (i = APIC_ISR_NR - 1; i >= 0; i--) {
value = apic_read(APIC_ISR + i*0x10);
for (j = 31; j >= 0; j--) {
if (value & (1<<j)) {
ack_APIC_irq();
acked++;
}
}
}
if (acked > 256) {
printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
acked);
break;
}
if (queued) {
if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
ntsc = rdtsc();
max_loops = (cpu_khz << 10) - (ntsc - tsc);
} else
max_loops--;
}
} while (queued && max_loops > 0);
WARN_ON(max_loops <= 0);
apic_pending_intr_clear();
/*
* Now that we are all set up, enable the APIC