x86: EDAC: MCE: Fix MCE decoding callback logic
Make decoding of MCEs happen only on AMD hardware by registering a
non-default callback only on CPU families which support it.
While looking at the interaction of decode_mce() with the other MCE
code i also noticed a few other things and made the following
cleanups/fixes:
- Fixed the mce_decode() weak alias - a weak alias is really not
good here, it should be a proper callback. A weak alias will be
overriden if a piece of code is built into the kernel - not
good, obviously.
- The patch initializes the callback on AMD family 10h and 11h.
- Added the more correct fallback printk of:
No support for human readable MCE decoding on this CPU type.
Transcribe the message and run it through 'mcelog --ascii' to decode.
On CPUs that dont have a decoder.
- Made the surrounding code more readable.
Note that the callback allows us to have a default fallback -
without having to check the CPU versions during the printout
itself. When an EDAC module registers itself, it can install the
decode-print function.
(there's no unregister needed as this is core code.)
version -v2 by Borislav Petkov:
- add K8 to the set of supported CPUs
- always build in edac_mce_amd since we use an early_initcall now
- fix checkpatch warnings
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <20091001141432.GA11410@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 183c345..b1598a9 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -85,6 +85,18 @@
static DEFINE_PER_CPU(struct mce, mces_seen);
static int cpu_missing;
+static void default_decode_mce(struct mce *m)
+{
+ pr_emerg("No human readable MCE decoding support on this CPU type.\n");
+ pr_emerg("Run the message through 'mcelog --ascii' to decode.\n");
+}
+
+/*
+ * 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);
/* MCA banks polled by the period polling timer for corrected events */
DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = {
@@ -165,46 +177,46 @@
set_bit(0, &mce_need_notify);
}
-void __weak decode_mce(struct mce *m)
-{
- return;
-}
-
static void print_mce(struct mce *m)
{
- printk(KERN_EMERG
- "CPU %d: Machine Check Exception: %16Lx Bank %d: %016Lx\n",
+ pr_emerg("CPU %d: Machine Check Exception: %16Lx Bank %d: %016Lx\n",
m->extcpu, m->mcgstatus, m->bank, m->status);
+
if (m->ip) {
- printk(KERN_EMERG "RIP%s %02x:<%016Lx> ",
- !(m->mcgstatus & MCG_STATUS_EIPV) ? " !INEXACT!" : "",
- m->cs, m->ip);
+ pr_emerg("RIP%s %02x:<%016Lx> ",
+ !(m->mcgstatus & MCG_STATUS_EIPV) ? " !INEXACT!" : "",
+ m->cs, m->ip);
+
if (m->cs == __KERNEL_CS)
print_symbol("{%s}", m->ip);
- printk(KERN_CONT "\n");
+ pr_cont("\n");
}
- printk(KERN_EMERG "TSC %llx ", m->tsc);
- if (m->addr)
- printk(KERN_CONT "ADDR %llx ", m->addr);
- if (m->misc)
- printk(KERN_CONT "MISC %llx ", m->misc);
- printk(KERN_CONT "\n");
- printk(KERN_EMERG "PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x\n",
- m->cpuvendor, m->cpuid, m->time, m->socketid,
- m->apicid);
- decode_mce(m);
+ pr_emerg("TSC %llx ", m->tsc);
+ if (m->addr)
+ pr_cont("ADDR %llx ", m->addr);
+ if (m->misc)
+ pr_cont("MISC %llx ", m->misc);
+
+ pr_cont("\n");
+ pr_emerg("PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x\n",
+ m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid);
+
+ /*
+ * Print out human-readable details about the MCE error,
+ * (if the CPU has an implementation for that):
+ */
+ x86_mce_decode_callback(m);
}
static void print_mce_head(void)
{
- printk(KERN_EMERG "\nHARDWARE ERROR\n");
+ pr_emerg("\nHARDWARE ERROR\n");
}
static void print_mce_tail(void)
{
- printk(KERN_EMERG "This is not a software problem!\n"
- "Run through mcelog --ascii to decode and contact your hardware vendor\n");
+ pr_emerg("This is not a software problem!\n");
}
#define PANIC_TIMEOUT 5 /* 5 seconds */
@@ -218,6 +230,7 @@
static void wait_for_panic(void)
{
long timeout = PANIC_TIMEOUT*USEC_PER_SEC;
+
preempt_disable();
local_irq_enable();
while (timeout-- > 0)
@@ -285,6 +298,7 @@
static int msr_to_offset(u32 msr)
{
unsigned bank = __get_cpu_var(injectm.bank);
+
if (msr == rip_msr)
return offsetof(struct mce, ip);
if (msr == MSR_IA32_MCx_STATUS(bank))
