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authorLi Zhong <zhong@linux.vnet.ibm.com>2012-10-17 21:30:13 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-01-10 14:43:45 +1100
commitfb9125680d0e7c23eae7c6000acc91ea26acab9c (patch)
tree4f961ee02e1661876e6c2e565c8085558a0e9281
parent323a6bf1d6f4ec7907d9d8aacb4ae9590f755dda (diff)
powerpc: Fix a lazy irq related WARING in arch_local_irq_restore()
The pseries CPU hotplug code uses cede_processor without properly synchronizing the SW and HW interrupt enable state. This fixes it using the same helpers that were written for the idle code. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> ======================= Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/platforms/pseries/hotplug-cpu.c8
-rw-r--r--arch/powerpc/platforms/pseries/plpar_wrappers.h8
2 files changed, 16 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index a38956269fbf..217ca5c75b20 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -127,9 +127,16 @@ static void pseries_mach_cpu_die(void)
get_lppaca()->donate_dedicated_cpu = 1;
while (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
+ while (!prep_irq_for_idle()) {
+ local_irq_enable();
+ local_irq_disable();
+ }
+
extended_cede_processor(cede_latency_hint);
}
+ local_irq_disable();
+
if (!get_lppaca()->shared_proc)
get_lppaca()->donate_dedicated_cpu = 0;
get_lppaca()->idle = 0;
@@ -137,6 +144,7 @@ static void pseries_mach_cpu_die(void)
if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
unregister_slb_shadow(hwcpu);
+ hard_irq_disable();
/*
* Call to start_secondary_resume() will not return.
* Kernel stack will be reset and start_secondary()
diff --git a/arch/powerpc/platforms/pseries/plpar_wrappers.h b/arch/powerpc/platforms/pseries/plpar_wrappers.h
index e6cc34a67053..b93384929c4c 100644
--- a/arch/powerpc/platforms/pseries/plpar_wrappers.h
+++ b/arch/powerpc/platforms/pseries/plpar_wrappers.h
@@ -2,6 +2,7 @@
#define _PSERIES_PLPAR_WRAPPERS_H
#include <linux/string.h>
+#include <linux/irqflags.h>
#include <asm/hvcall.h>
#include <asm/paca.h>
@@ -41,7 +42,14 @@ static inline long extended_cede_processor(unsigned long latency_hint)
u8 old_latency_hint = get_cede_latency_hint();
set_cede_latency_hint(latency_hint);
+
rc = cede_processor();
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Ensure that H_CEDE returns with IRQs on */
+ if (WARN_ON(!(mfmsr() & MSR_EE)))
+ __hard_irq_enable();
+#endif
+
set_cede_latency_hint(old_latency_hint);
return rc;