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Message-ID: <20091007112038.GA2505@aftab>
Date: Wed, 7 Oct 2009 13:20:38 +0200
From: Borislav Petkov <borislav.petkov@....com>
To: Ingo Molnar <mingo@...e.hu>
CC: <x86@...ab>, <linux-kernel@...r.kernel.org>
Subject: [RESEND PATCH] mce, edac: use an atomic notifier for MCEs decoding
Add an atomic notifier which ensures proper locking when conveying MCE
info to EDAC for decoding. The actual notifier call overrides a default,
negative priority notifier.
Note: make sure we register the default decoder only once since
mcheck_init() runs on each CPU.
Signed-off-by: Borislav Petkov <borislav.petkov@....com>
LKML-Reference: <20091003065752.GA8935@...ndog.tnic>
---
arch/x86/include/asm/mce.h | 3 ++-
arch/x86/kernel/cpu/mcheck/mce.c | 30 +++++++++++++++++++++---------
drivers/edac/edac_mce_amd.c | 23 ++++++++++++++---------
3 files changed, 37 insertions(+), 19 deletions(-)
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index f1363b7..227a72d 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -108,6 +108,8 @@ struct mce_log {
#define K8_MCE_THRESHOLD_BANK_5 (MCE_THRESHOLD_BASE + 5 * 9)
#define K8_MCE_THRESHOLD_DRAM_ECC (MCE_THRESHOLD_BANK_4 + 0)
+extern struct atomic_notifier_head x86_mce_decoder_chain;
+
#ifdef __KERNEL__
#include <linux/percpu.h>
@@ -213,6 +215,5 @@ extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu);
void intel_init_thermal(struct cpuinfo_x86 *c);
void mce_log_therm_throt_event(__u64 status);
-
#endif /* __KERNEL__ */
#endif /* _ASM_X86_MCE_H */
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index b1598a9..09c2e2e 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -85,18 +85,26 @@ static DECLARE_WAIT_QUEUE_HEAD(mce_wait);
static DEFINE_PER_CPU(struct mce, mces_seen);
static int cpu_missing;
-static void default_decode_mce(struct mce *m)
+/*
+ * CPU/chipset specific EDAC code can register a notifier call here to print
+ * MCE errors in a human-readable form.
+ */
+ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain);
+EXPORT_SYMBOL_GPL(x86_mce_decoder_chain);
+
+static int default_decode_mce(struct notifier_block *nb, unsigned long val,
+ void *data)
{
pr_emerg("No human readable MCE decoding support on this CPU type.\n");
pr_emerg("Run the message through 'mcelog --ascii' to decode.\n");
+
+ return NOTIFY_STOP;
}
-/*
- * CPU/chipset specific EDAC code can register a callback here to print
- * MCE errors in a human-readable form:
- */
-void (*x86_mce_decode_callback)(struct mce *m) = default_decode_mce;
-EXPORT_SYMBOL(x86_mce_decode_callback);
+static struct notifier_block mce_dec_nb = {
+ .notifier_call = default_decode_mce,
+ .priority = -1,
+};
/* MCA banks polled by the period polling timer for corrected events */
DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = {
@@ -204,9 +212,9 @@ static void print_mce(struct mce *m)
/*
* Print out human-readable details about the MCE error,
- * (if the CPU has an implementation for that):
+ * (if the CPU has an implementation for that)
*/
- x86_mce_decode_callback(m);
+ atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
}
static void print_mce_head(void)
@@ -1420,6 +1428,10 @@ void __cpuinit mcheck_init(struct cpuinfo_x86 *c)
mce_cpu_features(c);
mce_init_timer();
INIT_WORK(&__get_cpu_var(mce_work), mce_process_work);
+
+ if (raw_smp_processor_id() == 0)
+ atomic_notifier_chain_register(&x86_mce_decoder_chain,
+ &mce_dec_nb);
}
/*
diff --git a/drivers/edac/edac_mce_amd.c b/drivers/edac/edac_mce_amd.c
index 713ed7d..6ee7529 100644
--- a/drivers/edac/edac_mce_amd.c
+++ b/drivers/edac/edac_mce_amd.c
@@ -3,7 +3,6 @@
static bool report_gart_errors;
static void (*nb_bus_decoder)(int node_id, struct err_regs *regs);
-static void (*orig_mce_callback)(struct mce *m);
void amd_report_gart_errors(bool v)
{
@@ -363,8 +362,10 @@ static inline void amd_decode_err_code(unsigned int ec)
pr_warning("Huh? Unknown MCE error 0x%x\n", ec);
}
-static void amd_decode_mce(struct mce *m)
+static int amd_decode_mce(struct notifier_block *nb, unsigned long val,
+ void *data)
{
+ struct mce *m = (struct mce *)data;
struct err_regs regs;
int node, ecc;
@@ -420,20 +421,23 @@ static void amd_decode_mce(struct mce *m)
}
amd_decode_err_code(m->status & 0xffff);
+
+ return NOTIFY_STOP;
}
+static struct notifier_block amd_mce_dec_nb = {
+ .notifier_call = amd_decode_mce,
+};
+
static int __init mce_amd_init(void)
{
/*
* We can decode MCEs for Opteron and later CPUs:
*/
if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) &&
- (boot_cpu_data.x86 >= 0xf)) {
- /* safe the default decode mce callback */
- orig_mce_callback = x86_mce_decode_callback;
-
- x86_mce_decode_callback = amd_decode_mce;
- }
+ (boot_cpu_data.x86 >= 0xf))
+ atomic_notifier_chain_register(&x86_mce_decoder_chain,
+ &amd_mce_dec_nb);
return 0;
}
@@ -442,7 +446,8 @@ early_initcall(mce_amd_init);
#ifdef MODULE
static void __exit mce_amd_exit(void)
{
- x86_mce_decode_callback = orig_mce_callback;
+ atomic_notifier_chain_unregister(&x86_mce_decoder_chain,
+ &amd_mce_dec_nb);
}
MODULE_DESCRIPTION("AMD MCE decoder");
--
1.6.4.3
--
Regards/Gruss,
Boris.
Operating | Advanced Micro Devices GmbH
System | Karl-Hammerschmidt-Str. 34, 85609 Dornach b. München, Germany
Research | Geschäftsführer: Andrew Bowd, Thomas M. McCoy, Giuliano Meroni
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