[PATCH v5 10/20] x86/mce: Do 'UNKNOWN' vendor check early

[Yazen Ghannam <yazen.ghannam@amd.com>]

The 'UNKNOWN' vendor check is handled as a quirk that is run on each
online CPU. However, all CPUs are expected to have the same vendor.

Move the 'UNKNOWN' vendor check to the BSP-only init so it is done early
and once. Remove the unnecessary return value from the quirks check.

Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---

Notes:
    Link:
    https://lore.kernel.org/r/20250624-wip-mca-updates-v4-13-236dd74f645f@amd.com
    
    v4->v5:
    * No change.
    
    v3->v4:
    * No change.
    
    v2->v3:
    * Add tags from Qiuxu and Tony.
    
    v1->v2:
    * New in v2.

 arch/x86/kernel/cpu/mce/core.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 18a8e8f97482..14456f6c2f7b 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1979,14 +1979,11 @@ static void apply_quirks_zhaoxin(struct cpuinfo_x86 *c)
 }
 
 /* Add per CPU specific workarounds here */
-static bool __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
+static void __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 {
 	struct mca_config *cfg = &mca_cfg;
 
 	switch (c->x86_vendor) {
-	case X86_VENDOR_UNKNOWN:
-		pr_info("unknown CPU type - not enabling MCE support\n");
-		return false;
 	case X86_VENDOR_AMD:
 		apply_quirks_amd(c);
 		break;
@@ -2002,8 +1999,6 @@ static bool __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 		cfg->monarch_timeout = 0;
 	if (cfg->bootlog != 0)
 		cfg->panic_timeout = 30;
-
-	return true;
 }
 
 static bool __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
@@ -2242,6 +2237,12 @@ void mca_bsp_init(struct cpuinfo_x86 *c)
 	if (!mce_available(c))
 		return;
 
+	if (c->x86_vendor == X86_VENDOR_UNKNOWN) {
+		mca_cfg.disabled = 1;
+		pr_info("unknown CPU type - not enabling MCE support\n");
+		return;
+	}
+
 	mce_flags.overflow_recov = cpu_feature_enabled(X86_FEATURE_OVERFLOW_RECOV);
 	mce_flags.succor	 = cpu_feature_enabled(X86_FEATURE_SUCCOR);
 	mce_flags.smca		 = cpu_feature_enabled(X86_FEATURE_SMCA);
@@ -2276,10 +2277,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 
 	__mcheck_cpu_cap_init();
 
-	if (!__mcheck_cpu_apply_quirks(c)) {
-		mca_cfg.disabled = 1;
-		return;
-	}
+	__mcheck_cpu_apply_quirks(c);
 
 	if (!mce_gen_pool_init()) {
 		mca_cfg.disabled = 1;

-- 
2.51.0