Commit 0bdad33d authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64: Refactor interrupt exit irq disabling sequence 



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: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429062421.1675400-1-npiggin@gmail.com
parent 18594f9b

arch/powerpc/kernel/syscall_64.c

+28 −30
Original line number Diff line number Diff line
@@ -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();

CRA Git | Maintained and supported by SUSTech CRA and CCSE