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powerpc/64: Refactor interrupt exit irq disabling sequence

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The same complicated sequence for juggling EE, RI, soft mask, and
irq tracing is repeated 3 times, tidy these up into one function.

This differs qiute a bit between sub architectures, so this makes
the ppc32 port cleaner as well.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429062421.1675400-1-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2020-04-29 16:24:21 +10:00 committed by Michael Ellerman
parent 18594f9b8c
commit 0bdad33d6b
1 changed files with 28 additions and 30 deletions
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58
arch/powerpc/kernel/syscall_64.c
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@ -101,6 +101,31 @@ notrace long system_call_exception(long r3, long r4, long r5,
return f(r3, r4, r5, r6, r7, r8);
}
/*
* local irqs must be disabled. Returns false if the caller must re-enable
* them, check for new work, and try again.
*/
static notrace inline bool prep_irq_for_enabled_exit(void)
{
/* This must be done with RI=1 because tracing may touch vmaps */
trace_hardirqs_on();
/* This pattern matches prep_irq_for_idle */
__hard_EE_RI_disable();
if (unlikely(lazy_irq_pending_nocheck())) {
/* Took an interrupt, may have more exit work to do. */
__hard_RI_enable();
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
return false;
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
return true;
}
/*
* This should be called after a syscall returns, with r3 the return value
* from the syscall. If this function returns non-zero, the system call
@ -186,21 +211,10 @@ again:
}
}
/* This must be done with RI=1 because tracing may touch vmaps */
trace_hardirqs_on();
/* This pattern matches prep_irq_for_idle */
__hard_EE_RI_disable();
if (unlikely(lazy_irq_pending_nocheck())) {
__hard_RI_enable();
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
if (unlikely(!prep_irq_for_enabled_exit())) {
local_irq_enable();
/* Took an interrupt, may have more exit work to do. */
goto again;
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
local_paca->tm_scratch = regs->msr;
@ -264,19 +278,11 @@ again:
}
}
trace_hardirqs_on();
__hard_EE_RI_disable();
if (unlikely(lazy_irq_pending_nocheck())) {
__hard_RI_enable();
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
if (unlikely(!prep_irq_for_enabled_exit())) {
local_irq_enable();
local_irq_disable();
/* Took an interrupt, may have more exit work to do. */
goto again;
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
#ifdef CONFIG_PPC_BOOK3E
if (unlikely(ts->debug.dbcr0 & DBCR0_IDM)) {
@ -334,13 +340,7 @@ again:
}
}
trace_hardirqs_on();
__hard_EE_RI_disable();
if (unlikely(lazy_irq_pending_nocheck())) {
__hard_RI_enable();
irq_soft_mask_set(IRQS_ALL_DISABLED);
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
if (unlikely(!prep_irq_for_enabled_exit())) {
/*
* Can't local_irq_restore to replay if we were in
* interrupt context. Must replay directly.
@ -354,8 +354,6 @@ again:
/* Took an interrupt, may have more exit work to do. */
goto again;
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
} else {
/* Returning to a kernel context with local irqs disabled. */
__hard_EE_RI_disable();