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xtensa: SMP: rework IPI processing 

Don't skip current CPU in send_ipi_message: callers of this function
take care of it and it's harmless anyway.
Don't clear IPI bits one by one, clear all that were read at once.
Check IPI register in a loop in case new IPI was posted while previous
was being handled.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
hifive-unleashed-5.1
Max Filippov 2019-01-18 18:45:17 -08:00
parent 05bdebd546
commit 815af8fff1
1 changed files with 23 additions and 15 deletions
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38
arch/xtensa/kernel/smp.c
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@ -372,8 +372,7 @@ static void send_ipi_message(const struct cpumask *callmask,
unsigned long mask = 0;
for_each_cpu(index, callmask)
if (index != smp_processor_id())
mask |= 1 << index;
mask |= 1 << index;
set_er(mask, MIPISET(msg_id));
}
@ -412,22 +411,31 @@ irqreturn_t ipi_interrupt(int irq, void *dev_id)
{
unsigned int cpu = smp_processor_id();
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
unsigned int msg;
unsigned i;
msg = get_er(MIPICAUSE(cpu));
for (i = 0; i < IPI_MAX; i++)
if (msg & (1 << i)) {
set_er(1 << i, MIPICAUSE(cpu));
++ipi->ipi_count[i];
for (;;) {
unsigned int msg;
msg = get_er(MIPICAUSE(cpu));
set_er(msg, MIPICAUSE(cpu));
if (!msg)
break;
if (msg & (1 << IPI_CALL_FUNC)) {
++ipi->ipi_count[IPI_CALL_FUNC];
generic_smp_call_function_interrupt();
}
if (msg & (1 << IPI_RESCHEDULE))
scheduler_ipi();
if (msg & (1 << IPI_CALL_FUNC))
generic_smp_call_function_interrupt();
if (msg & (1 << IPI_CPU_STOP))
ipi_cpu_stop(cpu);
if (msg & (1 << IPI_RESCHEDULE)) {
++ipi->ipi_count[IPI_RESCHEDULE];
scheduler_ipi();
}
if (msg & (1 << IPI_CPU_STOP)) {
++ipi->ipi_count[IPI_CPU_STOP];
ipi_cpu_stop(cpu);
}
}
return IRQ_HANDLED;
}