[PATCH 4.9 42/94] x86/MCE: Export memory_error()

Greg Kroah-Hartman
2017-06-05T17:04:30Z

From: Borislav Petkov <bp@suse.de>

commit 2d1f406139ec20320bf38bcd2461aa8e358084b5 upstream.

Export the function which checks whether an MCE is a memory error to
other users so that we can reuse the logic. Drop the boot_cpu_data use,
while at it, as mce.cpuvendor already has the CPU vendor in there.

Integrate a piece from a patch from Vishal Verma
<vishal.l.verma@intel.com> to export it for modules (nfit).

The main reason we're exporting it is that the nfit handler
nfit_handle_mce() needs to detect a memory error properly before doing
its recovery actions.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Link: http://lkml.kernel.org/r/20170519093915.15413-2-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/include/asm/mce.h | 1 +
arch/x86/kernel/cpu/mcheck/mce.c | 11 +++++------
2 files changed, 6 insertions(+), 6 deletions(-)

--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -257,6 +257,7 @@ static inline void mce_amd_feature_init(
#endif

int mce_available(struct cpuinfo_x86 *c);
+bool mce_is_memory_error(struct mce *m);

DECLARE_PER_CPU(unsigned, mce_exception_count);
DECLARE_PER_CPU(unsigned, mce_poll_count);
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -598,16 +598,14 @@ static void mce_read_aux(struct mce *m,
}
}

-static bool memory_error(struct mce *m)
+bool mce_is_memory_error(struct mce *m)
{
- struct cpuinfo_x86 *c = &boot_cpu_data;
-
- if (c->x86_vendor == X86_VENDOR_AMD) {
+ if (m->cpuvendor == X86_VENDOR_AMD) {
/* ErrCodeExt[20:16] */
u8 xec = (m->status >> 16) & 0x1f;

return (xec == 0x0 || xec == 0x8);
- } else if (c->x86_vendor == X86_VENDOR_INTEL) {
+ } else if (m->cpuvendor == X86_VENDOR_INTEL) {
/*
* Intel SDM Volume 3B - 15.9.2 Compound Error Codes
*
@@ -628,6 +626,7 @@ static bool memory_error(struct mce *m)

return false;
}
+EXPORT_SYMBOL_GPL(mce_is_memory_error);

DEFINE_PER_CPU(unsigned, mce_poll_count);

@@ -691,7 +690,7 @@ bool machine_check_poll(enum mcp_flags f

severity = mce_severity(&m, mca_cfg.tolerant, NULL, false);

- if (severity == MCE_DEFERRED_SEVERITY && memory_error(&m))
+ if (severity == MCE_DEFERRED_SEVERITY && mce_is_memory_error(&m))
if (m.status & MCI_STATUS_ADDRV)
m.severity = severity;