[PATCH v6 05/15] x86/mce: Separate global and per-CPU quirks

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

Many quirks are global configuration settings and a handful apply to
each CPU.

Move the per-CPU quirks to vendor init to execute them on each online
CPU. Set the global quirks during BSP-only init so they're only executed
once and early.

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/20250825-wip-mca-updates-v5-11-865768a2eef8@amd.com
    
    v5->v6:
    * No change.
    
    v4->v5:
    * Apply consistent naming to quirk functions.
    
    v3->v4:
    * Add newline in mce_amd_feature_init().
    * Remove __mcheck_cpu_apply_quirks().
    * Update code comment ref. __mcheck_cpu_apply_quirks().
    
    v2->v3:
    * Update code comment.
    * Add tags from Qiuxu and Tony.
    
    v1->v2:
    * New in v2.

 arch/x86/kernel/cpu/mce/amd.c   | 24 ++++++++++++
 arch/x86/kernel/cpu/mce/core.c  | 85 +++++++++++------------------------------
 arch/x86/kernel/cpu/mce/intel.c | 18 +++++++++
 3 files changed, 65 insertions(+), 62 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 7345e24bf658..b8aed0ac765c 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -646,6 +646,28 @@ static void disable_err_thresholding(struct cpuinfo_x86 *c, unsigned int bank)
 		wrmsrq(MSR_K7_HWCR, hwcr);
 }
 
+static void amd_apply_cpu_quirks(struct cpuinfo_x86 *c)
+{
+	struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
+
+	/* This should be disabled by the BIOS, but isn't always */
+	if (c->x86 == 15 && this_cpu_read(mce_num_banks) > 4) {
+		/*
+		 * disable GART TBL walk error reporting, which
+		 * trips off incorrectly with the IOMMU & 3ware
+		 * & Cerberus:
+		 */
+		clear_bit(10, (unsigned long *)&mce_banks[4].ctl);
+	}
+
+	/*
+	 * Various K7s with broken bank 0 around. Always disable
+	 * by default.
+	 */
+	if (c->x86 == 6 && this_cpu_read(mce_num_banks))
+		mce_banks[0].ctl = 0;
+}
+
 /* cpu init entry point, called from mce.c with preempt off */
 void mce_amd_feature_init(struct cpuinfo_x86 *c)
 {
@@ -653,6 +675,8 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 	u32 low = 0, high = 0, address = 0;
 	int offset = -1;
 
+	amd_apply_cpu_quirks(c);
+
 	mce_flags.amd_threshold	 = 1;
 
 	for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 515942cbfeb5..7fd86c8006ba 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1807,8 +1807,9 @@ static void __mcheck_cpu_mce_banks_init(void)
 		struct mce_bank *b = &mce_banks[i];
 
 		/*
-		 * Init them all, __mcheck_cpu_apply_quirks() is going to apply
-		 * the required vendor quirks before
+		 * Init them all by default.
+		 *
+		 * The required vendor quirks will be applied before
 		 * __mcheck_cpu_init_prepare_banks() does the final bank setup.
 		 */
 		b->ctl = -1ULL;
@@ -1880,20 +1881,8 @@ static void __mcheck_cpu_init_prepare_banks(void)
 	}
 }
 
-static void apply_quirks_amd(struct cpuinfo_x86 *c)
+static void amd_apply_global_quirks(struct cpuinfo_x86 *c)
 {
-	struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
-
-	/* This should be disabled by the BIOS, but isn't always */
-	if (c->x86 == 15 && this_cpu_read(mce_num_banks) > 4) {
-		/*
-		 * disable GART TBL walk error reporting, which
-		 * trips off incorrectly with the IOMMU & 3ware
-		 * & Cerberus:
-		 */
-		clear_bit(10, (unsigned long *)&mce_banks[4].ctl);
-	}
-
 	if (c->x86 < 0x11 && mca_cfg.bootlog < 0) {
 		/*
 		 * Lots of broken BIOS around that don't clear them
@@ -1902,13 +1891,6 @@ static void apply_quirks_amd(struct cpuinfo_x86 *c)
 		mca_cfg.bootlog = 0;
 	}
 
-	/*
-	 * Various K7s with broken bank 0 around. Always disable
-	 * by default.
-	 */
-	if (c->x86 == 6 && this_cpu_read(mce_num_banks))
-		mce_banks[0].ctl = 0;
-
 	/*
 	 * overflow_recov is supported for F15h Models 00h-0fh
 	 * even though we don't have a CPUID bit for it.
@@ -1920,25 +1902,12 @@ static void apply_quirks_amd(struct cpuinfo_x86 *c)
 		mce_flags.zen_ifu_quirk = 1;
 }
 
-static void apply_quirks_intel(struct cpuinfo_x86 *c)
+static void intel_apply_global_quirks(struct cpuinfo_x86 *c)
 {
-	struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
-
 	/* Older CPUs (prior to family 6) don't need quirks. */
 	if (c->x86_vfm < INTEL_PENTIUM_PRO)
 		return;
 
-	/*
-	 * SDM documents that on family 6 bank 0 should not be written
-	 * because it aliases to another special BIOS controlled
-	 * register.
-	 * But it's not aliased anymore on model 0x1a+
-	 * Don't ignore bank 0 completely because there could be a
-	 * valid event later, merely don't write CTL0.
-	 */
-	if (c->x86_vfm < INTEL_NEHALEM_EP && this_cpu_read(mce_num_banks))
-		mce_banks[0].init = false;
-
 	/*
 	 * All newer Intel systems support MCE broadcasting. Enable
 	 * synchronization with a one second timeout.
@@ -1964,7 +1933,7 @@ static void apply_quirks_intel(struct cpuinfo_x86 *c)
 		mce_flags.skx_repmov_quirk = 1;
 }
 
-static void apply_quirks_zhaoxin(struct cpuinfo_x86 *c)
+static void zhaoxin_apply_global_quirks(struct cpuinfo_x86 *c)
 {
 	/*
 	 * All newer Zhaoxin CPUs support MCE broadcasting. Enable
@@ -1976,29 +1945,6 @@ static void apply_quirks_zhaoxin(struct cpuinfo_x86 *c)
 	}
 }
 
-/* Add per CPU specific workarounds here */
-static void __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
-{
-	struct mca_config *cfg = &mca_cfg;
-
-	switch (c->x86_vendor) {
-	case X86_VENDOR_AMD:
-		apply_quirks_amd(c);
-		break;
-	case X86_VENDOR_INTEL:
-		apply_quirks_intel(c);
-		break;
-	case X86_VENDOR_ZHAOXIN:
-		apply_quirks_zhaoxin(c);
-		break;
-	}
-
-	if (cfg->monarch_timeout < 0)
-		cfg->monarch_timeout = 0;
-	if (cfg->bootlog != 0)
-		cfg->panic_timeout = 30;
-}
-
 static bool __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
 {
 	if (c->x86 != 5)
@@ -2256,6 +2202,23 @@ void mca_bsp_init(struct cpuinfo_x86 *c)
 
 	if (cap & MCG_SER_P)
 		mca_cfg.ser = 1;
+
+	switch (c->x86_vendor) {
+	case X86_VENDOR_AMD:
+		amd_apply_global_quirks(c);
+		break;
+	case X86_VENDOR_INTEL:
+		intel_apply_global_quirks(c);
+		break;
+	case X86_VENDOR_ZHAOXIN:
+		zhaoxin_apply_global_quirks(c);
+		break;
+	}
+
+	if (mca_cfg.monarch_timeout < 0)
+		mca_cfg.monarch_timeout = 0;
+	if (mca_cfg.bootlog != 0)
+		mca_cfg.panic_timeout = 30;
 }
 
 /*
@@ -2275,8 +2238,6 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 
 	__mcheck_cpu_cap_init();
 
-	__mcheck_cpu_apply_quirks(c);
-
 	if (!mce_gen_pool_init()) {
 		mca_cfg.disabled = 1;
 		pr_emerg("Couldn't allocate MCE records pool!\n");
diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c
index 9b149b9c4109..4655223ba560 100644
--- a/arch/x86/kernel/cpu/mce/intel.c
+++ b/arch/x86/kernel/cpu/mce/intel.c
@@ -468,8 +468,26 @@ static void intel_imc_init(struct cpuinfo_x86 *c)
 	}
 }
 
+static void intel_apply_cpu_quirks(struct cpuinfo_x86 *c)
+{
+	/*
+	 * SDM documents that on family 6 bank 0 should not be written
+	 * because it aliases to another special BIOS controlled
+	 * register.
+	 * But it's not aliased anymore on model 0x1a+
+	 * Don't ignore bank 0 completely because there could be a
+	 * valid event later, merely don't write CTL0.
+	 *
+	 * Older CPUs (prior to family 6) can't reach this point and already
+	 * return early due to the check of __mcheck_cpu_ancient_init().
+	 */
+	if (c->x86_vfm < INTEL_NEHALEM_EP && this_cpu_read(mce_num_banks))
+		this_cpu_ptr(mce_banks_array)[0].init = false;
+}
+
 void mce_intel_feature_init(struct cpuinfo_x86 *c)
 {
+	intel_apply_cpu_quirks(c);
 	intel_init_cmci();
 	intel_init_lmce();
 	intel_imc_init(c);

-- 
2.51.0