[PATCH v7 052/120] x86/microcode/intel: Explain CPUID parser APIs unavailability
From: Ahmed S. Darwish
Date: Thu May 28 2026 - 11:56:24 EST
intel_cpuid_vfm() is defined so that it can be used before cpuinfo_x86
structures are populated.
Explain why it should not use the CPUID parser APIs as well.
Signed-off-by: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/microcode/intel.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 18d2eff7a4b7..a3d0f8197d4d 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -123,8 +123,8 @@ static inline unsigned int exttable_size(struct extended_sigtable *et)
/*
- * Use CPUID to generate a "vfm" value. Useful before cpuinfo_x86
- * structures are populated.
+ * Use a direct CPUID query to generate a "vfm" value. To be used before
+ * the CPUID parser is initialized; e.g. head's load_ucode_bsp() stage.
*/
static u32 intel_cpuid_vfm(void)
{
--
2.54.0