[PATCH v3 08/17] x86/mce: Define BSP-only SMCA init

[Yazen Ghannam]

Currently on AMD systems, MCA interrupt handler functions are set during
CPU init. However, the functions only need to be set once for the whole
system.

Assign the handlers only during BSP init. Do so only for SMCA systems to
maintain the old behavior for legacy systems.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---

Notes:
    Link:
    https://lore.kernel.org/r/20250213-wip-mca-updates-v2-8-3636547fe05f@xxxxxxx
    
    v2->v3:
    * No change.
    
    v1->v2:
    * New in v2.

 arch/x86/kernel/cpu/mce/amd.c      | 6 ++++++
 arch/x86/kernel/cpu/mce/core.c     | 3 +++
 arch/x86/kernel/cpu/mce/internal.h | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 206973d7dbcc..0d84b171b851 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -687,6 +687,12 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 		deferred_error_interrupt_enable(c);
 }
 
+void mce_smca_cpu_init(void)
+{
+	mce_threshold_vector	  = amd_threshold_interrupt;
+	deferred_error_int_vector = amd_deferred_error_interrupt;
+}
+
 /*
  * DRAM ECC errors are reported in the Northbridge (bank 4) with
  * Extended Error Code 8.
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index d0a29e22cab0..444d006366fd 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -2243,6 +2243,9 @@ void cpu_mca_init(struct cpuinfo_x86 *c)
 	mce_flags.succor	 = cpu_feature_enabled(X86_FEATURE_SUCCOR);
 	mce_flags.smca		 = cpu_feature_enabled(X86_FEATURE_SMCA);
 
+	if (mce_flags.smca)
+		mce_smca_cpu_init();
+
 	rdmsrl(MSR_IA32_MCG_CAP, cap);
 
 	/* Use accurate RIP reporting if available. */
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 64ac25b95360..87b69935d57d 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -294,12 +294,14 @@ static __always_inline void smca_extract_err_addr(struct mce *m)
 	m->addr &= GENMASK_ULL(55, lsb);
 }
 
+void mce_smca_cpu_init(void);
 #else
 static inline void mce_threshold_create_device(unsigned int cpu)	{ }
 static inline void mce_threshold_remove_device(unsigned int cpu)	{ }
 static inline bool amd_filter_mce(struct mce *m) { return false; }
 static inline bool amd_mce_usable_address(struct mce *m) { return false; }
 static inline void smca_extract_err_addr(struct mce *m) { }
+static inline void mce_smca_cpu_init(void) {}
 #endif
 
 #ifdef CONFIG_X86_ANCIENT_MCE

-- 
2.49.0