5 files changed, 65 insertions, 16 deletions

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 0e8ae57d3656..b7c47a468fde 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -120,7 +120,8 @@ struct mce_log {
 
 #ifdef __KERNEL__
 
-extern struct atomic_notifier_head x86_mce_decoder_chain;
+extern void mce_register_decode_chain(struct notifier_block *nb);
+extern void mce_unregister_decode_chain(struct notifier_block *nb);
 
 #include <linux/percpu.h>
 #include <linux/init.h>
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 2af127d4c3d1..5be2464cce6a 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -95,13 +95,6 @@ static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait);
 static DEFINE_PER_CPU(struct mce, mces_seen);
 static int                      cpu_missing;
 
-/*
- * 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);
-
 /* MCA banks polled by the period polling timer for corrected events */
 DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = {
         [0 ... BITS_TO_LONGS(MAX_NR_BANKS)-1] = ~0UL
@@ -109,6 +102,12 @@ DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = {
 
 static DEFINE_PER_CPU(struct work_struct, mce_work);
 
+/*
+ * 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);
+
 /* Do initial initialization of a struct mce */
 void mce_setup(struct mce *m)
 {
@@ -190,6 +189,57 @@ void mce_log(struct mce *mce)
         set_bit(0, &mce_need_notify);
 }
 
+static void drain_mcelog_buffer(void)
+{
+        unsigned int next, i, prev = 0;
+
+        next = rcu_dereference_check_mce(mcelog.next);
+
+        do {
+                struct mce *m;
+
+                /* drain what was logged during boot */
+                for (i = prev; i < next; i++) {
+                        unsigned long start = jiffies;
+                        unsigned retries = 1;
+
+                        m = &mcelog.entry[i];
+
+                        while (!m->finished) {
+                                if (time_after_eq(jiffies, start + 2*retries))
+                                        retries++;
+
+                                cpu_relax();
+
+                                if (!m->finished && retries >= 4) {
+                                        pr_err("MCE: skipping error being logged currently!\n");
+                                        break;
+                                }
+                        }
+                        smp_rmb();
+                        atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
+                }
+
+                memset(mcelog.entry + prev, 0, (next - prev) * sizeof(*m));
+                prev = next;
+                next = cmpxchg(&mcelog.next, prev, 0);
+        } while (next != prev);
+}
+
+
+void mce_register_decode_chain(struct notifier_block *nb)
+{
+        atomic_notifier_chain_register(&x86_mce_decoder_chain, nb);
+        drain_mcelog_buffer();
+}
+EXPORT_SYMBOL_GPL(mce_register_decode_chain);
+
+void mce_unregister_decode_chain(struct notifier_block *nb)
+{
+        atomic_notifier_chain_unregister(&x86_mce_decoder_chain, nb);
+}
+EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
+
 static void print_mce(struct mce *m)
 {
         int ret = 0;
diff --git a/drivers/edac/i7core_edac.c b/drivers/edac/i7core_edac.c
index 70ad8923f1d7..8568d9b61875 100644
--- a/drivers/edac/i7core_edac.c
+++ b/drivers/edac/i7core_edac.c
@@ -2234,7 +2234,7 @@ static void i7core_unregister_mci(struct i7core_dev *i7core_dev)
         if (pvt->enable_scrub)
                 disable_sdram_scrub_setting(mci);
 
-        atomic_notifier_chain_unregister(&x86_mce_decoder_chain, &i7_mce_dec);
+        mce_unregister_decode_chain(&i7_mce_dec);
 
         /* Disable EDAC polling */
         i7core_pci_ctl_release(pvt);
@@ -2336,7 +2336,7 @@ static int i7core_register_mci(struct i7core_dev *i7core_dev)
         /* DCLK for scrub rate setting */
         pvt->dclk_freq = get_dclk_freq();
 
-        atomic_notifier_chain_register(&x86_mce_decoder_chain, &i7_mce_dec);
+        mce_register_decode_chain(&i7_mce_dec);
 
         return 0;
 
diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index d0864d9c38ad..bd926ea2e00c 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -884,7 +884,7 @@ static int __init mce_amd_init(void)
 
         pr_info("MCE: In-kernel MCE decoding enabled.\n");
 
-        atomic_notifier_chain_register(&x86_mce_decoder_chain, &amd_mce_dec_nb);
+        mce_register_decode_chain(&amd_mce_dec_nb);
 
         return 0;
 }
@@ -893,7 +893,7 @@ early_initcall(mce_amd_init);
 #ifdef MODULE
 static void __exit mce_amd_exit(void)
 {
-        atomic_notifier_chain_unregister(&x86_mce_decoder_chain, &amd_mce_dec_nb);
+        mce_unregister_decode_chain(&amd_mce_dec_nb);
         kfree(fam_ops);
 }
 
diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 7a402bfbee7d..965bc0cc0cf6 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -1661,8 +1661,7 @@ static void sbridge_unregister_mci(struct sbridge_dev *sbridge_dev)
         debugf0("MC: " __FILE__ ": %s(): mci = %p, dev = %p\n",
                 __func__, mci, &sbridge_dev->pdev[0]->dev);
 
-        atomic_notifier_chain_unregister(&x86_mce_decoder_chain,
-                                         &sbridge_mce_dec);
+        mce_unregister_decode_chain(&sbridge_mce_dec);
 
         /* Remove MC sysfs nodes */
         edac_mc_del_mc(mci->dev);
@@ -1731,8 +1730,7 @@ static int sbridge_register_mci(struct sbridge_dev *sbridge_dev)
                 goto fail0;
         }
 
-        atomic_notifier_chain_register(&x86_mce_decoder_chain,
-                                       &sbridge_mce_dec);
+        mce_register_decode_chain(&sbridge_mce_dec);
         return 0;
 
 fail0: