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author | Nicholas Piggin | 2017-06-13 15:05:46 +0200 |
---|---|---|
committer | Michael Ellerman | 2017-06-19 11:46:26 +0200 |
commit | 2525db04d1cc53e1951143d1829aa75a78cc7f76 (patch) | |
tree | 8819d4117525b024be704ddc34ee0b5a560a4aff /arch/powerpc | |
parent | powerpc/64s/idle: Move soft interrupt mask logic into C code (diff) | |
download | kernel-qcow2-linux-2525db04d1cc53e1951143d1829aa75a78cc7f76.tar.gz kernel-qcow2-linux-2525db04d1cc53e1951143d1829aa75a78cc7f76.tar.xz kernel-qcow2-linux-2525db04d1cc53e1951143d1829aa75a78cc7f76.zip |
powerpc/powernv: Simplify lazy IRQ handling in CPU offline
Rather than concern ourselves with any soft-mask logic in the CPU
hotplug handler, just hard disable interrupts. This ensures there
are no lazy-irqs pending, which means we can call directly to idle
instruction in order to sleep.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r-- | arch/powerpc/platforms/powernv/idle.c | 23 | ||||
-rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 29 |
2 files changed, 29 insertions, 23 deletions
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index f875879ff1eb..f188d84d9c59 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -352,25 +352,31 @@ void power9_idle(void) /* * pnv_cpu_offline: A function that puts the CPU into the deepest * available platform idle state on a CPU-Offline. + * interrupts hard disabled and no lazy irq pending. */ unsigned long pnv_cpu_offline(unsigned int cpu) { unsigned long srr1; - u32 idle_states = pnv_get_supported_cpuidle_states(); + ppc64_runlatch_off(); + if (cpu_has_feature(CPU_FTR_ARCH_300) && deepest_stop_found) { - srr1 = __power9_idle_type(pnv_deepest_stop_psscr_val, - pnv_deepest_stop_psscr_mask); + unsigned long psscr; + + psscr = mfspr(SPRN_PSSCR); + psscr = (psscr & ~pnv_deepest_stop_psscr_mask) | + pnv_deepest_stop_psscr_val; + srr1 = power9_idle_stop(psscr); + } else if (idle_states & OPAL_PM_WINKLE_ENABLED) { - srr1 = __power7_idle_type(PNV_THREAD_WINKLE); + srr1 = power7_idle_insn(PNV_THREAD_WINKLE); } else if ((idle_states & OPAL_PM_SLEEP_ENABLED) || (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { - srr1 = __power7_idle_type(PNV_THREAD_SLEEP); + srr1 = power7_idle_insn(PNV_THREAD_SLEEP); } else if (idle_states & OPAL_PM_NAP_ENABLED) { - srr1 = __power7_idle_type(PNV_THREAD_NAP); + srr1 = power7_idle_insn(PNV_THREAD_NAP); } else { - ppc64_runlatch_off(); /* This is the fallback method. We emulate snooze */ while (!generic_check_cpu_restart(cpu)) { HMT_low(); @@ -378,9 +384,10 @@ unsigned long pnv_cpu_offline(unsigned int cpu) } srr1 = 0; HMT_medium(); - ppc64_runlatch_on(); } + ppc64_runlatch_on(); + return srr1; } #endif diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index f8752795decf..c04c87adad94 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -144,7 +144,14 @@ static void pnv_smp_cpu_kill_self(void) unsigned long srr1, wmask; /* Standard hot unplug procedure */ - local_irq_disable(); + /* + * This hard disables local interurpts, ensuring we have no lazy + * irqs pending. + */ + WARN_ON(irqs_disabled()); + hard_irq_disable(); + WARN_ON(lazy_irq_pending()); + idle_task_exit(); current->active_mm = NULL; /* for sanity */ cpu = smp_processor_id(); @@ -162,16 +169,6 @@ static void pnv_smp_cpu_kill_self(void) */ mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); - /* - * Hard-disable interrupts, and then clear irq_happened flags - * that we can safely ignore while off-line, since they - * are for things for which we do no processing when off-line - * (or in the case of HMI, all the processing we need to do - * is done in lower-level real-mode code). - */ - hard_irq_disable(); - local_paca->irq_happened &= ~(PACA_IRQ_DEC | PACA_IRQ_HMI); - while (!generic_check_cpu_restart(cpu)) { /* * Clear IPI flag, since we don't handle IPIs while @@ -184,6 +181,8 @@ static void pnv_smp_cpu_kill_self(void) srr1 = pnv_cpu_offline(cpu); + WARN_ON(lazy_irq_pending()); + /* * If the SRR1 value indicates that we woke up due to * an external interrupt, then clear the interrupt. @@ -196,8 +195,7 @@ static void pnv_smp_cpu_kill_self(void) * contains 0. */ if (((srr1 & wmask) == SRR1_WAKEEE) || - ((srr1 & wmask) == SRR1_WAKEHVI) || - (local_paca->irq_happened & PACA_IRQ_EE)) { + ((srr1 & wmask) == SRR1_WAKEHVI)) { if (cpu_has_feature(CPU_FTR_ARCH_300)) { if (xive_enabled()) xive_flush_interrupt(); @@ -209,14 +207,15 @@ static void pnv_smp_cpu_kill_self(void) unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); asm volatile(PPC_MSGCLR(%0) : : "r" (msg)); } - local_paca->irq_happened &= ~(PACA_IRQ_EE | PACA_IRQ_DBELL); smp_mb(); if (cpu_core_split_required()) continue; if (srr1 && !generic_check_cpu_restart(cpu)) - DBG("CPU%d Unexpected exit while offline !\n", cpu); + DBG("CPU%d Unexpected exit while offline srr1=%lx!\n", + cpu, srr1); + } /* Re-enable decrementer interrupts */ |