Commit b333a99e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'powerpc-5.11-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 

Pull powerpc fix from Michael Ellerman:
 "One fix for a bug in our soft interrupt masking, which could lead to
  interrupt replaying recursing, causing spurious interrupts.

  Thanks to Nicholas Piggin"

* tag 'powerpc-5.11-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt
parents 1188866d 4025c784

arch/powerpc/kernel/irq.c

+16 −12
Original line number Diff line number Diff line
@@ -180,13 +180,18 @@ void notrace restore_interrupts(void) 


void replay_soft_interrupts(void)

{

	struct pt_regs regs;



	/*

	 * We use local_paca rather than get_paca() to avoid all

	 * the debug_smp_processor_id() business in this low level

	 * function

	 * Be careful here, calling these interrupt handlers can cause

	 * softirqs to be raised, which they may run when calling irq_exit,

	 * which will cause local_irq_enable() to be run, which can then

	 * recurse into this function. Don't keep any state across

	 * interrupt handler calls which may change underneath us.

	 *

	 * We use local_paca rather than get_paca() to avoid all the

	 * debug_smp_processor_id() business in this low level function.

	 */

	unsigned char happened = local_paca->irq_happened;

	struct pt_regs regs;



	ppc_save_regs(&regs);

	regs.softe = IRQS_ENABLED;
@@ -209,7 +214,7 @@ void replay_soft_interrupts(void) 
	 * This is a higher priority interrupt than the others, so

	 * replay it first.

	 */

	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (happened & PACA_IRQ_HMI)) {

	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_HMI)) {

		local_paca->irq_happened &= ~PACA_IRQ_HMI;

		regs.trap = 0xe60;

		handle_hmi_exception(&regs);
@@ -217,7 +222,7 @@ void replay_soft_interrupts(void) 
			hard_irq_disable();

	}



	if (happened & PACA_IRQ_DEC) {

	if (local_paca->irq_happened & PACA_IRQ_DEC) {

		local_paca->irq_happened &= ~PACA_IRQ_DEC;

		regs.trap = 0x900;

		timer_interrupt(&regs);
@@ -225,7 +230,7 @@ void replay_soft_interrupts(void) 
			hard_irq_disable();

	}



	if (happened & PACA_IRQ_EE) {

	if (local_paca->irq_happened & PACA_IRQ_EE) {

		local_paca->irq_happened &= ~PACA_IRQ_EE;

		regs.trap = 0x500;

		do_IRQ(&regs);
@@ -233,7 +238,7 @@ void replay_soft_interrupts(void) 
			hard_irq_disable();

	}



	if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (happened & PACA_IRQ_DBELL)) {

	if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (local_paca->irq_happened & PACA_IRQ_DBELL)) {

		local_paca->irq_happened &= ~PACA_IRQ_DBELL;

		if (IS_ENABLED(CONFIG_PPC_BOOK3E))

			regs.trap = 0x280;
@@ -245,7 +250,7 @@ void replay_soft_interrupts(void) 
	}



	/* Book3E does not support soft-masking PMI interrupts */

	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (happened & PACA_IRQ_PMI)) {

	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_PMI)) {

		local_paca->irq_happened &= ~PACA_IRQ_PMI;

		regs.trap = 0xf00;

		performance_monitor_exception(&regs);
@@ -253,8 +258,7 @@ void replay_soft_interrupts(void) 
			hard_irq_disable();

	}



	happened = local_paca->irq_happened;

	if (happened & ~PACA_IRQ_HARD_DIS) {

	if (local_paca->irq_happened & ~PACA_IRQ_HARD_DIS) {

		/*

		 * We are responding to the next interrupt, so interrupt-off

		 * latencies should be reset here.