x86/MCE/AMD: Define a function to get SMCA bank type

Scalable MCA systems have various types of banks. The bank's type
can determine how we handle errors from it. For example, if a bank
represents a UMC (Unified Memory Controller) then we will need to
convert its address from a normalized address to a system physical
address before handling the error.

[ bp: Verify m->bank is within range and use bank pointer. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171207203955.118171-1-Yazen.Ghannam@amd.com

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

@@ -110,6 +110,20 @@ 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)
+{
+	struct smca_bank *b;
+
+	if (m->bank >= N_SMCA_BANK_TYPES)
+		return N_SMCA_BANK_TYPES;
+
+	b = &smca_banks[m->bank];
+	if (!b->hwid)
+		return N_SMCA_BANK_TYPES;
+
+	return b->hwid->bank_type;
+}
+
 static struct smca_hwid smca_hwid_mcatypes[] = {
 	/* { bank_type, hwid_mcatype, xec_bitmap } */