[PATCH V3] tmp patch to fix hotplug issue in CMCI storm

[Chen Gong <gong.chen@linux.intel.com>]

v3->v1
Thanks very much for Thomas' suggestion to simply the whole logic.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
---
 arch/x86/kernel/cpu/mcheck/mce-internal.h |    2 ++
 arch/x86/kernel/cpu/mcheck/mce.c          |    1 +
 arch/x86/kernel/cpu/mcheck/mce_intel.c    |   11 +++++++++++
 3 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index 2cd73ce..6a05c1d 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -31,9 +31,11 @@ extern struct mce_bank *mce_banks;
 #ifdef CONFIG_X86_MCE_INTEL
 unsigned long mce_intel_adjust_timer(unsigned long interval);
 void mce_intel_cmci_poll(void);
+void mce_intel_hcpu_update(unsigned long cpu);
 #else
 # define mce_intel_adjust_timer mce_adjust_timer_default
 static inline void mce_intel_cmci_poll(void) { }
+static inline void mce_intel_hcpu_update(unsigned long cpu) { }
 #endif
 
 void mce_timer_kick(unsigned long interval);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index e3f8b94..5e22d99 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2306,6 +2306,7 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		if (threshold_cpu_callback)
 			threshold_cpu_callback(action, cpu);
 		mce_device_remove(cpu);
+		mce_intel_hcpu_update(cpu);
 		break;
 	case CPU_DOWN_PREPARE:
 		smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 92d8b5c..693bc7d 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -77,6 +77,14 @@ void mce_intel_cmci_poll(void)
 	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
 }
 
+void mce_intel_hcpu_update(unsigned long cpu)
+{
+	if (per_cpu(cmci_storm_state, cpu) == CMCI_STORM_ACTIVE)
+		atomic_dec(&cmci_storm_on_cpus);
+
+	per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE;
+}
+
 unsigned long mce_intel_adjust_timer(unsigned long interval)
 {
 	if (interval < CMCI_POLL_INTERVAL)
@@ -119,6 +127,9 @@ static bool cmci_storm_detect(void)
 	unsigned long ts = __this_cpu_read(cmci_time_stamp);
 	unsigned long now = jiffies;
 
+	if (__this_cpu_read(cmci_storm_state) != CMCI_STORM_NONE)
+		return true;
+
 	if (time_before_eq(now, ts + CMCI_STORM_INTERVAL)) {
 		cnt++;
 	} else {
-- 
1.7.1