[PATCH] x86/mce: Kill drain_mcelog_buffer()

From: Borislav Petkov
Date: Thu Jun 18 2015 - 09:10:56 EST


From: Borislav Petkov <bp@xxxxxxx>
Subject: [PATCH] x86/mce: Kill drain_mcelog_buffer()

This used to flush out MCEs logged during early boot and which were in
the MCA registers from a previous system run. No need for that now,
since we're moving to a genpool.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Suggested-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/include/asm/mce.h | 2 +-
arch/x86/kernel/cpu/mcheck/mce.c | 44 ++--------------------------------------
drivers/acpi/acpi_extlog.c | 2 +-
drivers/edac/i7core_edac.c | 2 +-
drivers/edac/mce_amd.c | 2 +-
drivers/edac/sb_edac.c | 2 +-
6 files changed, 7 insertions(+), 47 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index dfaa4de1dbb4..982dfc3679ad 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -140,7 +140,7 @@ struct mce_vendor_flags {
extern struct mce_vendor_flags mce_flags;

extern struct mca_config mca_cfg;
-extern void mce_register_decode_chain(struct notifier_block *nb, bool drain);
+extern void mce_register_decode_chain(struct notifier_block *nb);
extern void mce_unregister_decode_chain(struct notifier_block *nb);

#include <linux/percpu.h>
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index a3660cd1fda3..72b4acef36f4 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -196,55 +196,15 @@ 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 = ACCESS_ONCE(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("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);
-}
-
static struct notifier_block mce_srao_nb;

-void mce_register_decode_chain(struct notifier_block *nb, bool drain)
+void mce_register_decode_chain(struct notifier_block *nb)
{
/* Ensure SRAO notifier has the highest priority in the decode chain. */
if (nb != &mce_srao_nb && nb->priority == INT_MAX)
nb->priority -= 1;

atomic_notifier_chain_register(&x86_mce_decoder_chain, nb);
-
- if (drain)
- drain_mcelog_buffer();
}
EXPORT_SYMBOL_GPL(mce_register_decode_chain);

@@ -2031,7 +1991,7 @@ __setup("mce", mcheck_enable);
int __init mcheck_init(void)
{
mcheck_intel_therm_init();
- mce_register_decode_chain(&mce_srao_nb, false);
+ mce_register_decode_chain(&mce_srao_nb);
mcheck_vendor_init_severity();

return 0;
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index 07e012e74c1b..b3842ffc19ba 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -286,7 +286,7 @@ static int __init extlog_init(void)
*/
old_edac_report_status = get_edac_report_status();
set_edac_report_status(EDAC_REPORTING_DISABLED);
- mce_register_decode_chain(&extlog_mce_dec, true);
+ mce_register_decode_chain(&extlog_mce_dec);
/* enable OS to be involved to take over management from BIOS */
((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;

diff --git a/drivers/edac/i7core_edac.c b/drivers/edac/i7core_edac.c
index 13d77f4a892c..01087a38da22 100644
--- a/drivers/edac/i7core_edac.c
+++ b/drivers/edac/i7core_edac.c
@@ -2424,7 +2424,7 @@ static int __init i7core_init(void)
pci_rc = pci_register_driver(&i7core_driver);

if (pci_rc >= 0) {
- mce_register_decode_chain(&i7_mce_dec, true);
+ mce_register_decode_chain(&i7_mce_dec);
return 0;
}

diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index aca31a237073..58586d59bf8e 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -895,7 +895,7 @@ static int __init mce_amd_init(void)

pr_info("MCE: In-kernel MCE decoding enabled.\n");

- mce_register_decode_chain(&amd_mce_dec_nb, true);
+ mce_register_decode_chain(&amd_mce_dec_nb);

return 0;
}
diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 494a23e4f7e6..1acf57ba4c86 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -2556,7 +2556,7 @@ static int __init sbridge_init(void)

pci_rc = pci_register_driver(&sbridge_driver);
if (pci_rc >= 0) {
- mce_register_decode_chain(&sbridge_mce_dec, true);
+ mce_register_decode_chain(&sbridge_mce_dec);
if (get_edac_report_status() == EDAC_REPORTING_DISABLED)
sbridge_printk(KERN_WARNING, "Loading driver, error reporting disabled.\n");
return 0;
--
2.3.5

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.
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