x86/mce: Define mce_severity function pointer

Rename mce_severity() to mce_severity_intel() and assign the
mce_severity function pointer to mce_severity_amd() during init on AMD.
This way, we can avoid a test to call mce_severity_amd every time we get
into mce_severity(). And it's cleaner to do it this way.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Suggested-by: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1427125373-2918-3-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>

arch/x86/include/asm/mce.h

@@ -134,9 +134,11 @@ extern int mce_p5_enabled;
 #ifdef CONFIG_X86_MCE
 int mcheck_init(void);
 void mcheck_cpu_init(struct cpuinfo_x86 *c);
+void mcheck_vendor_init_severity(void);
 #else
 static inline int mcheck_init(void) { return 0; }
 static inline void mcheck_cpu_init(struct cpuinfo_x86 *c) {}
+static inline void mcheck_vendor_init_severity(void) {}
 #endif
 
 #ifdef CONFIG_X86_ANCIENT_MCE

arch/x86/kernel/cpu/mcheck/mce-internal.h

@@ -24,7 +24,7 @@ struct mce_bank {
 	char			attrname[ATTR_LEN];	/* attribute name */
 };
 
-int mce_severity(struct mce *a, int tolerant, char **msg, bool is_excp);
+extern int (*mce_severity)(struct mce *a, int tolerant, char **msg, bool is_excp);
 struct dentry *mce_get_debugfs_dir(void);
 
 extern struct mce_bank *mce_banks;

arch/x86/kernel/cpu/mcheck/mce-severity.c

@@ -190,8 +190,10 @@ static int error_context(struct mce *m)
  * See AMD Error Scope Hierarchy table in a newer BKDG. For example
  * 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features"
  */
-static int mce_severity_amd(struct mce *m, enum context ctx)
+static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_excp)
 {
+	enum context ctx = error_context(m);
+
 	/* Processor Context Corrupt, no need to fumble too much, die! */
 	if (m->status & MCI_STATUS_PCC)
 		return MCE_PANIC_SEVERITY;
@@ -239,15 +241,12 @@ static int mce_severity_amd(struct mce *m, enum context ctx)
 	return MCE_KEEP_SEVERITY;
 }
 
-int mce_severity(struct mce *m, int tolerant, char **msg, bool is_excp)
+static int mce_severity_intel(struct mce *m, int tolerant, char **msg, bool is_excp)
 {
 	enum exception excp = (is_excp ? EXCP_CONTEXT : NO_EXCP);
 	enum context ctx = error_context(m);
 	struct severity *s;
 
-	if (m->cpuvendor == X86_VENDOR_AMD)
-		return mce_severity_amd(m, ctx);
-
 	for (s = severities;; s++) {
 		if ((m->status & s->mask) != s->result)
 			continue;
@@ -272,6 +271,16 @@ int mce_severity(struct mce *m, int tolerant, char **msg, bool is_excp)
 	}
 }
 
+/* Default to mce_severity_intel */
+int (*mce_severity)(struct mce *m, int tolerant, char **msg, bool is_excp) =
+		    mce_severity_intel;
+
+void __init mcheck_vendor_init_severity(void)
+{
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+		mce_severity = mce_severity_amd;
+}
+
 #ifdef CONFIG_DEBUG_FS
 static void *s_start(struct seq_file *f, loff_t *pos)
 {

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

@@ -2026,6 +2026,7 @@ __setup("mce", mcheck_enable);
 int __init mcheck_init(void)
 {
 	mcheck_intel_therm_init();
+	mcheck_vendor_init_severity();
 
 	return 0;
 }