[PATCH v7 114/120] x86: Route all feature queries to the CPUID tables

Use the CPUID API's cpuid_feature_*() and cpuid_word_*() helpers to route
all feature querying to the CPUID tables instead of to x86_capability[].

This allows the CPUID tables to act as a single source of truth for x86
feature state; both hardware-backed and synthetic.

Do this routing in one shot, not to fragment x86 state tracking between
CPUID tables and x86_capability[].  The latter will be fully removed.

Signed-off-by: Ahmed S. Darwish <[email protected]>
---
 arch/x86/include/asm/cpufeature.h | 12 ++++++---
 arch/x86/include/asm/elf.h        |  2 +-
 arch/x86/kernel/cpu/common.c      | 41 +++++++++++++++++--------------
 arch/x86/kernel/cpu/cpuid-deps.c  |  2 +-
 arch/x86/kernel/mpparse.c         |  2 +-
 arch/x86/kvm/cpuid.c              |  3 +--
 6 files changed, 34 insertions(+), 28 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 48643b4b1e24..58d5e4f3891c 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -10,6 +10,7 @@
 #include <linux/bitops.h>
 #include <asm/alternative.h>
 #include <asm/cpufeaturemasks.h>
+#include <asm/cpuid/api.h>
 
 enum cpuid_leafs
 {
@@ -48,7 +49,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 #define x86_bug_flag(flag) x86_bug_flags[flag]
 
 #define test_cpu_cap(c, bit)						\
-	 arch_test_bit(bit, (unsigned long *)((c)->x86_capability))
+	arch_test_bit(cpuid_feature_bit_offset(bit), cpuid_feature_bitmap(c, bit))
 
 #define cpu_has(c, bit)							\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
@@ -56,7 +57,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 
 #define this_cpu_has(bit)						\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
-	 x86_this_cpu_test_bit(bit, cpu_info.x86_capability, 0))
+	 x86_this_cpu_test_bit(cpuid_feature_bit_offset(bit), cpu_info.cpuid.leaves, cpuid_feature_byte_offset(bit)))
 
 /*
  * This is the default CPU features testing macro to use in code.
@@ -72,7 +73,8 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 
 #define boot_cpu_has(bit)	cpu_has(&boot_cpu_data, bit)
 
-#define set_cpu_cap(c, bit)	set_bit(bit, (unsigned long *)((c)->x86_capability))
+#define set_cpu_cap(c, bit)						\
+	set_bit(cpuid_feature_bit_offset(bit), cpuid_feature_bitmap(c, bit))
 
 extern void setup_clear_cpu_cap(unsigned int bit);
 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
@@ -116,7 +118,9 @@ void check_cpufeature_deps(struct cpuinfo_x86 *c);
 
 static __always_inline bool _static_cpu_has(u16 bit)
 {
-	__static_cpu_has(bit, &boot_cpu_data.x86_capability, bit);
+	__static_cpu_has(bit,
+			 cpuid_feature_bitmap(&boot_cpu_data, bit),
+			 cpuid_feature_bit_offset(bit));
 }
 
 #define static_cpu_has(bit)					\
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index c7f98977663c..abf3142bb255 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -238,7 +238,7 @@ extern int force_personality32;
    instruction set this CPU supports.  This could be done in user space,
    but it's not easy, and we've already done it here.  */
 
-#define ELF_HWCAP		(boot_cpu_data.x86_capability[CPUID_1_EDX])
+#define ELF_HWCAP		cpuid_word(&boot_cpu_data, CPUID_1_EDX)
 
 extern u32 elf_hwcap2;
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index f5e3aaed67ef..d6b3550b9f11 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -970,11 +970,9 @@ void cpu_detect(struct cpuinfo_x86 *c)
 
 static void apply_forced_caps(struct cpuinfo_x86 *c)
 {
-	int i;
-
-	for (i = 0; i < NCAPINTS + NBUGINTS; i++) {
-		c->x86_capability[i] &= ~cpu_caps_cleared[i];
-		c->x86_capability[i] |= cpu_caps_set[i];
+	for (int i = 0; i < NCAPINTS + NBUGINTS; i++) {
+		cpuid_word_clear_bits(c, i, cpu_caps_cleared[i]);
+		cpuid_word_set_bits(c, i, cpu_caps_set[i]);
 	}
 }
 
@@ -2004,8 +2002,6 @@ static void generic_identify(struct cpuinfo_x86 *c)
  */
 static void identify_cpu(struct cpuinfo_x86 *c)
 {
-	int i;
-
 	c->loops_per_jiffy = loops_per_jiffy;
 	c->x86_cache_size = 0;
 	c->x86_vendor = X86_VENDOR_UNKNOWN;
@@ -2107,13 +2103,13 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	 * executed, c == &boot_cpu_data.
 	 */
 	if (c != &boot_cpu_data) {
-		/* AND the already accumulated flags with these */
-		for (i = 0; i < NCAPINTS; i++)
-			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
+		/* Clear boot_cpu_data features that are not on this CPU */
+		for (int i = 0; i < NCAPINTS; i++)
+			cpuid_word_clear_bits(&boot_cpu_data, i, ~cpuid_word(c, i));
 
-		/* OR, i.e. replicate the bug flags */
-		for (i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++)
-			c->x86_capability[i] |= boot_cpu_data.x86_capability[i];
+		/* Replicate boot_cpu_data's bug flags to this CPU */
+		for (int i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++)
+			cpuid_word_set_bits(c, i, cpuid_word(&boot_cpu_data, i));
 	}
 
 	ppin_init(c);
@@ -2529,12 +2525,17 @@ void cpu_init(void)
  */
 void store_cpu_caps(struct cpuinfo_x86 *curr_info)
 {
+	const struct leaf_0x0_0 *l0;
+
 	/* Reload CPUID max function as it might've changed. */
-	curr_info->cpuid_level = cpuid_eax(0);
+	cpuid_refresh_leaf(curr_info, 0x0);
+	l0 = cpuid_leaf(curr_info, 0x0);
+	if (l0)
+		curr_info->cpuid_level = l0->max_std_leaf;
 
 	/* Copy all capability leafs and pick up the synthetic ones. */
-	memcpy(&curr_info->x86_capability, &boot_cpu_data.x86_capability,
-	       sizeof(curr_info->x86_capability));
+	for (int i = 0; i < NCAPINTS + NBUGINTS; i++)
+		cpuid_word_set(curr_info, i, cpuid_word(&boot_cpu_data, i));
 
 	/* Get the hardware CPUID leafs */
 	get_cpu_cap(curr_info);
@@ -2564,10 +2565,12 @@ void microcode_check(struct cpuinfo_x86 *prev_info)
 
 	store_cpu_caps(curr_info);
 
-	if (!memcmp(&prev_info->x86_capability, &curr_info->x86_capability,
-		    sizeof(prev_info->x86_capability)))
-		return;
+	for (int i = 0; i < NCAPINTS + NBUGINTS; i++)
+		if (cpuid_word(prev_info, i) != cpuid_word(curr_info, i))
+			goto err;
 
+	return;
+err:
 	pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
 	pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
 }
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 99801e844b30..da4fc649f857 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -107,7 +107,7 @@ static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
 		clear_cpu_cap(&boot_cpu_data, feature);
 		set_bit(feature, (unsigned long *)cpu_caps_cleared);
 	} else {
-		clear_bit(feature, (unsigned long *)c->x86_capability);
+		clear_bit(cpuid_feature_bit_offset(feature), cpuid_feature_bitmap(c, feature));
 	}
 }
 
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 4a1b1b28abf9..a66f22db640f 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -384,7 +384,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 	processor.cpuflag = CPU_ENABLED;
 	processor.cpufeature = (boot_cpu_data.x86 << 8) |
 	    (boot_cpu_data.x86_model << 4) | boot_cpu_data.x86_stepping;
-	processor.featureflag = boot_cpu_data.x86_capability[CPUID_1_EDX];
+	processor.featureflag = cpuid_word(&boot_cpu_data, CPUID_1_EDX);
 	processor.reserved[0] = 0;
 	processor.reserved[1] = 0;
 	for (i = 0; i < 2; i++) {
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index ad0a5410899d..018cd3078306 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -704,7 +704,6 @@ static __always_inline u32 raw_cpuid_get(struct cpuid_reg cpuid)
 do {									\
 	const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32);	\
 	const u32 __maybe_unused kvm_cpu_cap_init_in_progress = leaf;	\
-	const u32 *kernel_cpu_caps = boot_cpu_data.x86_capability;	\
 	u32 kvm_cpu_cap_passthrough = 0;				\
 	u32 kvm_cpu_cap_synthesized = 0;				\
 	u32 kvm_cpu_cap_emulated = 0;					\
@@ -715,7 +714,7 @@ do {									\
 	kvm_cpu_caps[leaf] = kvm_cpu_cap_features;			\
 									\
 	if (leaf < NCAPINTS)						\
-		kvm_cpu_caps[leaf] &= kernel_cpu_caps[leaf];		\
+		kvm_cpu_caps[leaf] &= cpuid_word(&boot_cpu_data, leaf);\
 									\
 	kvm_cpu_caps[leaf] |= kvm_cpu_cap_passthrough;			\
 	kvm_cpu_caps[leaf] &= (raw_cpuid_get(cpuid) |			\
-- 
2.54.0