From 6e83985b0f6e30b928eee26eb41d276814a698aa Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Mon, 20 Mar 2017 16:31:49 +1000 Subject: [PATCH] powerpc/cbe: Do not process external or decremeter interrupts from sreset Cell will wake from low power state at the system reset interrupt, with the event encoded in SRR1, rather than waking at the interrupt vector that corresponds to that event. The system reset handler for this platform decodes SRR1 event reason and calls the interrupt handler to process it directly from the system reset handlre. A subsequent change will treat the system reset interrupt as a Linux NMI with its own per-CPU stack, and this will no longer work. Remove the external and decrementer handlers from the system reset handler. - The external exception remains raised and will fire again at the EE interrupt vector when system reset returns. - The decrementer is set to 1 so it will be raised again and fire when the system reset returns. It is possible to branch to an idle handler from the system reset interrupt (like POWER does), then restore a normal stack and restore this optimisation. But simplicity wins for now. Tested-by: Michael Ellerman Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/cell/pervasive.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/platforms/cell/pervasive.c b/arch/powerpc/platforms/cell/pervasive.c index e7d0750..a88944d 100644 --- a/arch/powerpc/platforms/cell/pervasive.c +++ b/arch/powerpc/platforms/cell/pervasive.c @@ -88,11 +88,14 @@ static void cbe_power_save(void) static int cbe_system_reset_exception(struct pt_regs *regs) { switch (regs->msr & SRR1_WAKEMASK) { - case SRR1_WAKEEE: - do_IRQ(regs); - break; case SRR1_WAKEDEC: - timer_interrupt(regs); + set_dec(1); + case SRR1_WAKEEE: + /* + * Handle these when interrupts get re-enabled and we take + * them as regular exceptions. We are in an NMI context + * and can't handle these here. + */ break; case SRR1_WAKEMT: return cbe_sysreset_hack(); -- 2.7.4