x86/ras/amd: Make sysfs names of banks more user-friendly

Currently, we append the MCA_IPID[InstanceId] to the bank name to create
the sysfs filename. The InstanceId field uniquely identifies a bank
instance but it doesn't look very nice for most banks.

Replace the InstanceId with a simpler, ascending (0, 1, ..) value.
Only use this in the sysfs name when there is more than 1 instance.
Otherwise, just use the bank's name as the sysfs name.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.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/1484322741-41884-3-git-send-email-Yazen.Ghannam@amd.com
Link: http://lkml.kernel.org/r/20170123183514.13356-4-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/mce.h

@@ -356,12 +356,13 @@ struct smca_hwid {
 	unsigned int bank_type;	/* Use with smca_bank_types for easy indexing. */
 	u32 hwid_mcatype;	/* (hwid,mcatype) tuple */
 	u32 xec_bitmap;		/* Bitmap of valid ExtErrorCodes; current max is 21. */
+	u8 count;		/* Number of instances. */
 };
 
 struct smca_bank {
 	struct smca_hwid *hwid;
-	/* Instance ID */
-	u32 id;
+	u32 id;			/* Value of MCA_IPID[InstanceId]. */
+	u8 sysfs_id;		/* Value used for sysfs name. */
 };
 
 extern struct smca_bank smca_banks[MAX_NR_BANKS];

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

@@ -192,6 +192,7 @@ static void get_smca_bank_info(unsigned int bank)
 
 			smca_banks[bank].hwid = s_hwid;
 			smca_banks[bank].id = instance_id;
+			smca_banks[bank].sysfs_id = s_hwid->count++;
 			break;
 		}
 	}
@@ -1064,9 +1065,12 @@ static const char *get_name(unsigned int bank, struct threshold_block *b)
 		return NULL;
 	}
 
+	if (smca_banks[bank].hwid->count == 1)
+		return smca_get_name(bank_type);
+
 	snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN,
 		 "%s_%x", smca_get_name(bank_type),
-			  smca_banks[bank].id);
+			  smca_banks[bank].sysfs_id);
 	return buf_mcatype;
 }