x86/mce/AMD: Pass the bank number to smca_get_bank_type()

Pass the bank number to smca_get_bank_type() since that's all we need.

Also, we should compare the bank number to MAX_NR_BANKS (size of the
smca_banks array) not the number of bank types. Bank types are reused
for multiple banks, so the number of types can be different from the
number of banks in a system and thus we could return an invalid bank
type.
Signed-off-by: NYazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.14.x
Cc: <stable@vger.kernel.org> # 4.14.x: 11cf8877 x86/MCE/AMD: Define a function to get SMCA bank type
Cc: <stable@vger.kernel.org> # 4.14.x: c6708d50 x86/MCE: Report only DRAM ECC as memory errors on AMD systems
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/20180221101900.10326-6-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/mcheck/mce_amd.c

@@ -110,14 +110,14 @@ const char *smca_get_long_name(enum smca_bank_types t)
 }
 EXPORT_SYMBOL_GPL(smca_get_long_name);
 
-static enum smca_bank_types smca_get_bank_type(struct mce *m)
+static enum smca_bank_types smca_get_bank_type(unsigned int bank)
 {
 	struct smca_bank *b;
 
-	if (m->bank >= N_SMCA_BANK_TYPES)
+	if (bank >= MAX_NR_BANKS)
 		return N_SMCA_BANK_TYPES;
 
-	b = &smca_banks[m->bank];
+	b = &smca_banks[bank];
 	if (!b->hwid)
 		return N_SMCA_BANK_TYPES;
 
@@ -760,7 +760,7 @@ bool amd_mce_is_memory_error(struct mce *m)
 	u8 xec = (m->status >> 16) & 0x1f;
 
 	if (mce_flags.smca)
-		return smca_get_bank_type(m) == SMCA_UMC && xec == 0x0;
+		return smca_get_bank_type(m->bank) == SMCA_UMC && xec == 0x0;
 
 	return m->bank == 4 && xec == 0x8;
 }
@@ -1063,7 +1063,7 @@ static struct kobj_type threshold_ktype = {
 
 static const char *get_name(unsigned int bank, struct threshold_block *b)
 {
-	unsigned int bank_type;
+	enum smca_bank_types bank_type;
 
 	if (!mce_flags.smca) {
 		if (b && bank == 4)
@@ -1072,11 +1072,10 @@ static const char *get_name(unsigned int bank, struct threshold_block *b)
 		return th_names[bank];
 	}
 
-	if (!smca_banks[bank].hwid)
+	bank_type = smca_get_bank_type(bank);
+	if (bank_type >= N_SMCA_BANK_TYPES)
 		return NULL;
 
-	bank_type = smca_banks[bank].hwid->bank_type;
-
 	if (b && bank_type == SMCA_UMC) {
 		if (b->block < ARRAY_SIZE(smca_umc_block_names))
 			return smca_umc_block_names[b->block];