Commit e78a7614f3876 ("idle: Prevent late-arriving interrupts from
disrupting offline") changes arch_cpu_idle_dead to be called with
interrupts disabled, which triggers the WARN in pnv_smp_cpu_kill_self.
Fix this by fixing up irq_happened after hard disabling, rather than
requiring there are no pending interrupts, similarly to what was done
done until commit 2525db04d1cc5 ("powerpc/powernv: Simplify lazy IRQ
handling in CPU offline").
Fixes: e78a7614f3876 ("idle: Prevent late-arriving interrupts from disrupting
offline")
Reported-by: Paul Mackerras <pau...@samba.org>
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/platforms/powernv/smp.c | 50 +++++++++++++++++++---------
1 file changed, 35 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/smp.c
b/arch/powerpc/platforms/powernv/smp.c
index fbd6e6b7bbf2..241cfee744d9 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -146,6 +146,18 @@ static int pnv_smp_cpu_disable(void)
return 0;
}
+static void pnv_flush_interrupts(void)
+{
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ if (xive_enabled())
+ xive_flush_interrupt();
+ else
+ icp_opal_flush_interrupt();
+ } else {
+ icp_native_flush_interrupt();
+ }
+}
+
static void pnv_smp_cpu_kill_self(void)
{
unsigned int cpu;
@@ -153,13 +165,6 @@ static void pnv_smp_cpu_kill_self(void)
u64 lpcr_val;
/* Standard hot unplug procedure */
- /*
- * 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 */
@@ -172,6 +177,26 @@ static void pnv_smp_cpu_kill_self(void)
if (cpu_has_feature(CPU_FTR_ARCH_207S))
wmask = SRR1_WAKEMASK_P8;
+ /*
+ * This turns the irq soft-disabled state we're called with, into a
+ * hard-disabled state with pending irq_happened interrupts cleared.
+ *
+ * PACA_IRQ_DEC - Decrementer should be ignored.
+ * PACA_IRQ_HMI - Can be ignored, processing is done in real mode.
+ * PACA_IRQ_DBELL, EE, PMI - Unexpected.
+ */
+ hard_irq_disable();
+ if (generic_check_cpu_restart(cpu))
+ goto out;
+ if (local_paca->irq_happened &
+ (PACA_IRQ_DBELL | PACA_IRQ_EE | PACA_IRQ_PMI)) {
+ if (local_paca->irq_happened & PACA_IRQ_EE)
+ pnv_flush_interrupts();
+ DBG("CPU%d Unexpected exit while offline irq_happened=%lx!\n",
+ cpu, local_paca->irq_happened);
+ }
+ local_paca->irq_happened = PACA_IRQ_HARD_DIS;
+
/*
* We don't want to take decrementer interrupts while we are
* offline, so clear LPCR:PECE1. We keep PECE2 (and
@@ -197,6 +222,7 @@ static void pnv_smp_cpu_kill_self(void)
srr1 = pnv_cpu_offline(cpu);
+ WARN_ON(!irqs_disabled());
WARN_ON(lazy_irq_pending());
/*
@@ -212,13 +238,7 @@ static void pnv_smp_cpu_kill_self(void)
*/
if (((srr1 & wmask) == SRR1_WAKEEE) ||
((srr1 & wmask) == SRR1_WAKEHVI)) {
- if (cpu_has_feature(CPU_FTR_ARCH_300)) {
- if (xive_enabled())
- xive_flush_interrupt();
- else
- icp_opal_flush_interrupt();
- } else
- icp_native_flush_interrupt();
+ pnv_flush_interrupts();
} else if ((srr1 & wmask) == SRR1_WAKEHDBELL) {
unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
asm volatile(PPC_MSGCLR(%0) : : "r" (msg));
@@ -266,7 +286,7 @@ static void pnv_smp_cpu_kill_self(void)
*/
lpcr_val = mfspr(SPRN_LPCR) | (u64)LPCR_PECE1;
pnv_program_cpu_hotplug_lpcr(cpu, lpcr_val);
-
+out:
DBG("CPU%d coming online...\n", cpu);
}
--
2.23.0
