Merge tag 'x86-urgent-2024-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Miscellaneous topology parsing fixes:

   - Fix topology parsing regression on older CPUs in the new AMD/Hygon
     parser

   - Fix boot crash on odd Intel Quark and similar CPUs that do not fill
     out cpuinfo_x86::x86_clflush_size and zero out
     cpuinfo_x86::x86_cache_alignment as a result.

     Provide 32 bytes as a general fallback value.

   - Fix topology enumeration on certain rare CPUs where the BIOS locks
     certain CPUID leaves and the kernel unlocked them late, which broke
     with the new topology parsing code. Factor out this unlocking logic
     and move it earlier in the parsing sequence"

* tag 'x86-urgent-2024-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/topology/intel: Unlock CPUID before evaluating anything
  x86/cpu: Provide default cache line size if not enumerated
  x86/topology/amd: Evaluate SMT in CPUID leaf 0x8000001e only on family 0x17 and greater

4 files changed, 26 insertions, 12 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 2b170da84f97..d4e539d4e158 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1075,6 +1075,10 @@ void get_cpu_address_sizes(struct cpuinfo_x86 *c)
 
 		c->x86_virt_bits = (eax >> 8) & 0xff;
 		c->x86_phys_bits = eax & 0xff;
+
+		/* Provide a sane default if not enumerated: */
+		if (!c->x86_clflush_size)
+			c->x86_clflush_size = 32;
 	}
 
 	c->x86_cache_bits = c->x86_phys_bits;
@@ -1585,6 +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);
@@ -1744,7 +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);
diff --git a/arch/x86/kernel/cpu/topology_amd.c b/arch/x86/kernel/cpu/topology_amd.c
index d419deed6a48..7d476fa697ca 100644
--- a/arch/x86/kernel/cpu/topology_amd.c
+++ b/arch/x86/kernel/cpu/topology_amd.c
@@ -84,9 +84,9 @@ static bool parse_8000_001e(struct topo_scan *tscan, bool has_topoext)
 
 	/*
 	 * If leaf 0xb is available, then the domain shifts are set
-	 * already and nothing to do here.
+	 * already and nothing to do here. Only valid for family >= 0x17.
 	 */
-	if (!has_topoext) {
+	if (!has_topoext && tscan->c->x86 >= 0x17) {
 		/*
 		 * Leaf 0x80000008 set the CORE domain shift already.
 		 * Update the SMT domain, but do not propagate it.