diff options
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 4753958cd509..b716f666e48a 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -149,6 +149,7 @@ static int pnv_smp_cpu_disable(void) static void pnv_smp_cpu_kill_self(void) { unsigned int cpu; + unsigned long srr1; /* Standard hot unplug procedure */ local_irq_disable(); @@ -165,13 +166,25 @@ static void pnv_smp_cpu_kill_self(void) mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); while (!generic_check_cpu_restart(cpu)) { ppc64_runlatch_off(); - power7_nap(1); + srr1 = power7_nap(1); ppc64_runlatch_on(); - /* Clear the IPI that woke us up */ - icp_native_flush_interrupt(); - local_paca->irq_happened &= PACA_IRQ_HARD_DIS; - mb(); + /* + * If the SRR1 value indicates that we woke up due to + * an external interrupt, then clear the interrupt. + * We clear the interrupt before checking for the + * reason, so as to avoid a race where we wake up for + * some other reason, find nothing and clear the interrupt + * just as some other cpu is sending us an interrupt. + * If we returned from power7_nap as a result of + * having finished executing in a KVM guest, then srr1 + * contains 0. + */ + if ((srr1 & SRR1_WAKEMASK) == SRR1_WAKEEE) { + icp_native_flush_interrupt(); + local_paca->irq_happened &= PACA_IRQ_HARD_DIS; + smp_mb(); + } if (cpu_core_split_required()) continue; |