3 files changed, 20 insertions, 10 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e31293c9609f..d4e539d4e158 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1589,6 +1589,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 	if (have_cpuid_p()) {
 		cpu_detect(c);
 		get_cpu_vendor(c);
+		intel_unlock_cpuid_leafs(c);
 		get_cpu_cap(c);
 		setup_force_cpu_cap(X86_FEATURE_CPUID);
 		get_cpu_address_sizes(c);
@@ -1748,7 +1749,7 @@ static void generic_identify(struct cpuinfo_x86 *c)
 	cpu_detect(c);
 
 	get_cpu_vendor(c);
-
+	intel_unlock_cpuid_leafs(c);
 	get_cpu_cap(c);
 
 	get_cpu_address_sizes(c);
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index ea9e07d57c8d..1beccefbaff9 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -61,9 +61,11 @@ extern __ro_after_init enum tsx_ctrl_states tsx_ctrl_state;
 
 extern void __init tsx_init(void);
 void tsx_ap_init(void);
+void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c);
 #else
 static inline void tsx_init(void) { }
 static inline void tsx_ap_init(void) { }
+static inline void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c) { }
 #endif /* CONFIG_CPU_SUP_INTEL */
 
 extern void init_spectral_chicken(struct cpuinfo_x86 *c);
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 3c3e7e5695ba..fdf3489d92a4 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -269,19 +269,26 @@ detect_keyid_bits:
 	c->x86_phys_bits -= keyid_bits;
 }
 
+void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c)
+{
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+		return;
+
+	if (c->x86 < 6 || (c->x86 == 6 && c->x86_model < 0xd))
+		return;
+
+	/*
+	 * The BIOS can have limited CPUID to leaf 2, which breaks feature
+	 * enumeration. Unlock it and update the maximum leaf info.
+	 */
+	if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0)
+		c->cpuid_level = cpuid_eax(0);
+}
+
 static void early_init_intel(struct cpuinfo_x86 *c)
 {
 	u64 misc_enable;
 
-	/* Unmask CPUID levels if masked: */
-	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
-		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
-				  MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
-			c->cpuid_level = cpuid_eax(0);
-			get_cpu_cap(c);
-		}
-	}
-
 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);