[tip:ras/core] x86/mce: Init some CPU features early

[tip-bot for Yazen Ghannam]

Commit-ID:  5204bf17031b69fa5faa4dc80a9dc1e2446d74f9
Gitweb:     http://git.kernel.org/tip/5204bf17031b69fa5faa4dc80a9dc1e2446d74f9
Author:     Yazen Ghannam <Yazen.Ghannam@xxxxxxx>
AuthorDate: Wed, 15 Mar 2017 12:30:55 -0500
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sat, 18 Mar 2017 13:03:44 +0100

x86/mce: Init some CPU features early

When the MCA banks in __mcheck_cpu_init_generic() are polled for leftover
errors logged during boot or from the previous boot, its required to have
CPU features detected sufficiently so that the reading out and handling of
those early errors is done correctly.

If those features are not available, the decoding may miss some information
and get incomplete errors logged. For example, on SMCA systems the MCA_IPID
and MCA_SYND registers are not logged and MCA_ADDR is not masked
appropriately.

To cure that, do a subset of the basic feature detection early while the
rest happens in its usual place in __mcheck_cpu_init_vendor().

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1489599055-20756-1-git-send-email-Yazen.Ghannam@xxxxxxx
[ Massage commit message and simplify. ]
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 arch/x86/kernel/cpu/mcheck/mce.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 177472a..5e365a2 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1702,30 +1702,35 @@ static int __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
 	return 0;
 }
 
-static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
+/*
+ * Init basic CPU features needed for early decoding of MCEs.
+ */
+static void __mcheck_cpu_init_early(struct cpuinfo_x86 *c)
 {
-	switch (c->x86_vendor) {
-	case X86_VENDOR_INTEL:
-		mce_intel_feature_init(c);
-		mce_adjust_timer = cmci_intel_adjust_timer;
-		break;
-
-	case X86_VENDOR_AMD: {
+	if (c->x86_vendor == X86_VENDOR_AMD) {
 		mce_flags.overflow_recov = !!cpu_has(c, X86_FEATURE_OVERFLOW_RECOV);
 		mce_flags.succor	 = !!cpu_has(c, X86_FEATURE_SUCCOR);
 		mce_flags.smca		 = !!cpu_has(c, X86_FEATURE_SMCA);
 
-		/*
-		 * Install proper ops for Scalable MCA enabled processors
-		 */
 		if (mce_flags.smca) {
 			msr_ops.ctl	= smca_ctl_reg;
 			msr_ops.status	= smca_status_reg;
 			msr_ops.addr	= smca_addr_reg;
 			msr_ops.misc	= smca_misc_reg;
 		}
-		mce_amd_feature_init(c);
+	}
+}
 
+static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
+{
+	switch (c->x86_vendor) {
+	case X86_VENDOR_INTEL:
+		mce_intel_feature_init(c);
+		mce_adjust_timer = cmci_intel_adjust_timer;
+		break;
+
+	case X86_VENDOR_AMD: {
+		mce_amd_feature_init(c);
 		break;
 		}
 
@@ -1812,6 +1817,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 
 	machine_check_vector = do_machine_check;
 
+	__mcheck_cpu_init_early(c);
 	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_vendor(c);
 	__mcheck_cpu_init_clear_banks();