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 <npig...@gmail.com>
---
arch/powerpc/platforms/powernv/idle.c | 23 +++++++++++++++--------
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 */
--
2.11.0
