[PATCH v2 1/4] x86/MCE/AMD: Redo function to get SMCA bank type

[Yazen Ghannam]

From: Yazen Ghannam <yazen.ghannam@xxxxxxx>

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

Also, we should compare the bank number to the 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. We could return an invalid bank type.

Use smca_get_bank_type() in get_name(), and change type of bank_type
variable to match return type of smca_get_bank_type().

Cc: <stable@xxxxxxxxxxxxxxx> # 4.14.x: 11cf887728a3 x86/MCE/AMD: Define a function to get SMCA bank type
Cc: <stable@xxxxxxxxxxxxxxx> # 4.14.x: c6708d50f166 x86/MCE: Report only DRAM ECC as memory errors on AMD systems
Cc: <stable@xxxxxxxxxxxxxxx> # 4.14.x
Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lkml.kernel.org/r/20180201184813.82253-1-Yazen.Ghannam@xxxxxxx

v1->v2:
* Check bank number against MAX_NR_BANKS

 arch/x86/kernel/cpu/mcheck/mce_amd.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 0f32ad242324..7fbb19cb1859 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/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];
-- 
2.14.1