x86/mce/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type

Currently, bank 4 is reserved on Fam17h, so we chose not to initialize
bank 4 in the smca_banks array. This means that when we check if a bank
is initialized, like during boot or resume, we will see that bank 4 is
not initialized and try to initialize it.

This will cause a call trace, when resuming from suspend, due to
rdmsr_*on_cpu() calls in the init path. The rdmsr_*on_cpu() calls issue
an IPI but we're running with interrupts disabled. This triggers:

  WARNING: CPU: 0 PID: 11523 at kernel/smp.c:291 smp_call_function_single+0xdc/0xe0
  ...

Reserved banks will be read-as-zero, so their MCA_IPID register will be
zero. So, like the smca_banks array, the threshold_banks array will not
have an entry for a reserved bank since all its MCA_MISC* registers will
be zero.

Enumerate a "Reserved" bank type that matches on a HWID_MCATYPE of 0,0.

Use the "Reserved" type when checking if a bank is reserved. It's
possible that other bank numbers may be reserved on future systems.

Don't try to find the block address on reserved banks.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.14.x
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180221101900.10326-7-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index a11a671c7a38..2ab4d61ee47e 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -854,21 +854,24 @@ static void decode_mc6_mce(struct mce *m)
 static void decode_smca_error(struct mce *m)
 {
 	struct smca_hwid *hwid;
-	unsigned int bank_type;
+	enum smca_bank_types bank_type;
 	const char *ip_name;
 	u8 xec = XEC(m->status, xec_mask);
 
 	if (m->bank >= ARRAY_SIZE(smca_banks))
 		return;
 
-	if (x86_family(m->cpuid) >= 0x17 && m->bank == 4)
-		pr_emerg(HW_ERR "Bank 4 is reserved on Fam17h.\n");
-
 	hwid = smca_banks[m->bank].hwid;
 	if (!hwid)
 		return;
 
 	bank_type = hwid->bank_type;
+
+	if (bank_type == SMCA_RESERVED) {
+		pr_emerg(HW_ERR "Bank %d is reserved.\n", m->bank);
+		return;
+	}
+
 	ip_name = smca_get_long_name(bank_type);
 
 	pr_emerg(HW_ERR "%s Extended Error Code: %d\n", ip_name, xec);