[tip: x86/cpu] x86/cpuid: Carve out all CPUID functionality

From: tip-bot2 for Borislav Petkov
Date: Wed Nov 30 2022 - 06:41:22 EST


The following commit has been merged into the x86/cpu branch of tip:

Commit-ID: d800169041c0e035160c8b81f30d4b7e8f8ef777
Gitweb: https://git.kernel.org/tip/d800169041c0e035160c8b81f30d4b7e8f8ef777
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Thu, 24 Nov 2022 16:31:27 +01:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Tue, 29 Nov 2022 20:41:24 +01:00

x86/cpuid: Carve out all CPUID functionality

Carve it out into a special header, where it belongs.

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/20221124164150.3040-1-bp@xxxxxxxxx
---
arch/x86/include/asm/cpuid.h | 141 +++++++++++++++++++++++++++++-
arch/x86/include/asm/processor.h | 133 +----------------------------
2 files changed, 140 insertions(+), 134 deletions(-)

diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h
index 70b2db1..9bee3e7 100644
--- a/arch/x86/include/asm/cpuid.h
+++ b/arch/x86/include/asm/cpuid.h
@@ -1,13 +1,132 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* CPUID-related helpers/definitions
- *
- * Derived from arch/x86/kvm/cpuid.c
*/

#ifndef _ASM_X86_CPUID_H
#define _ASM_X86_CPUID_H

+#include <asm/string.h>
+
+struct cpuid_regs {
+ u32 eax, ebx, ecx, edx;
+};
+
+enum cpuid_regs_idx {
+ CPUID_EAX = 0,
+ CPUID_EBX,
+ CPUID_ECX,
+ CPUID_EDX,
+};
+
+#ifdef CONFIG_X86_32
+extern int have_cpuid_p(void);
+#else
+static inline int have_cpuid_p(void)
+{
+ return 1;
+}
+#endif
+static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ /* ecx is often an input as well as an output. */
+ asm volatile("cpuid"
+ : "=a" (*eax),
+ "=b" (*ebx),
+ "=c" (*ecx),
+ "=d" (*edx)
+ : "0" (*eax), "2" (*ecx)
+ : "memory");
+}
+
+#define native_cpuid_reg(reg) \
+static inline unsigned int native_cpuid_##reg(unsigned int op) \
+{ \
+ unsigned int eax = op, ebx, ecx = 0, edx; \
+ \
+ native_cpuid(&eax, &ebx, &ecx, &edx); \
+ \
+ return reg; \
+}
+
+/*
+ * Native CPUID functions returning a single datum.
+ */
+native_cpuid_reg(eax)
+native_cpuid_reg(ebx)
+native_cpuid_reg(ecx)
+native_cpuid_reg(edx)
+
+#ifdef CONFIG_PARAVIRT_XXL
+#include <asm/paravirt.h>
+#else
+#define __cpuid native_cpuid
+#endif
+
+/*
+ * Generic CPUID function
+ * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
+ * resulting in stale register contents being returned.
+ */
+static inline void cpuid(unsigned int op,
+ unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ *eax = op;
+ *ecx = 0;
+ __cpuid(eax, ebx, ecx, edx);
+}
+
+/* Some CPUID calls want 'count' to be placed in ecx */
+static inline void cpuid_count(unsigned int op, int count,
+ unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ *eax = op;
+ *ecx = count;
+ __cpuid(eax, ebx, ecx, edx);
+}
+
+/*
+ * CPUID functions returning a single datum
+ */
+static inline unsigned int cpuid_eax(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+
+ return eax;
+}
+
+static inline unsigned int cpuid_ebx(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+
+ return ebx;
+}
+
+static inline unsigned int cpuid_ecx(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+
+ return ecx;
+}
+
+static inline unsigned int cpuid_edx(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+
+ return edx;
+}
+
static __always_inline bool cpuid_function_is_indexed(u32 function)
{
switch (function) {
@@ -31,4 +150,22 @@ static __always_inline bool cpuid_function_is_indexed(u32 function)
return false;
}

+#define for_each_possible_hypervisor_cpuid_base(function) \
+ for (function = 0x40000000; function < 0x40010000; function += 0x100)
+
+static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
+{
+ uint32_t base, eax, signature[3];
+
+ for_each_possible_hypervisor_cpuid_base(base) {
+ cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);
+
+ if (!memcmp(sig, signature, 12) &&
+ (leaves == 0 || ((eax - base) >= leaves)))
+ return base;
+ }
+
+ return 0;
+}
+
#endif /* _ASM_X86_CPUID_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 67c9d73..6836c64 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -16,6 +16,7 @@ struct vm86;
#include <uapi/asm/sigcontext.h>
#include <asm/current.h>
#include <asm/cpufeatures.h>
+#include <asm/cpuid.h>
#include <asm/page.h>
#include <asm/pgtable_types.h>
#include <asm/percpu.h>
@@ -146,17 +147,6 @@ struct cpuinfo_x86 {
unsigned initialized : 1;
} __randomize_layout;

-struct cpuid_regs {
- u32 eax, ebx, ecx, edx;
-};
-
-enum cpuid_regs_idx {
- CPUID_EAX = 0,
- CPUID_EBX,
- CPUID_ECX,
- CPUID_EDX,
-};
-
#define X86_VENDOR_INTEL 0
#define X86_VENDOR_CYRIX 1
#define X86_VENDOR_AMD 2
@@ -205,45 +195,6 @@ extern void identify_secondary_cpu(struct cpuinfo_x86 *);
extern void print_cpu_info(struct cpuinfo_x86 *);
void print_cpu_msr(struct cpuinfo_x86 *);

-#ifdef CONFIG_X86_32
-extern int have_cpuid_p(void);
-#else
-static inline int have_cpuid_p(void)
-{
- return 1;
-}
-#endif
-static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
- unsigned int *ecx, unsigned int *edx)
-{
- /* ecx is often an input as well as an output. */
- asm volatile("cpuid"
- : "=a" (*eax),
- "=b" (*ebx),
- "=c" (*ecx),
- "=d" (*edx)
- : "0" (*eax), "2" (*ecx)
- : "memory");
-}
-
-#define native_cpuid_reg(reg) \
-static inline unsigned int native_cpuid_##reg(unsigned int op) \
-{ \
- unsigned int eax = op, ebx, ecx = 0, edx; \
- \
- native_cpuid(&eax, &ebx, &ecx, &edx); \
- \
- return reg; \
-}
-
-/*
- * Native CPUID functions returning a single datum.
- */
-native_cpuid_reg(eax)
-native_cpuid_reg(ebx)
-native_cpuid_reg(ecx)
-native_cpuid_reg(edx)
-
/*
* Friendlier CR3 helpers.
*/
@@ -578,7 +529,6 @@ static __always_inline bool on_thread_stack(void)
#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else
-#define __cpuid native_cpuid

static inline void load_sp0(unsigned long sp0)
{
@@ -589,69 +539,6 @@ static inline void load_sp0(unsigned long sp0)

unsigned long __get_wchan(struct task_struct *p);

-/*
- * Generic CPUID function
- * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
- * resulting in stale register contents being returned.
- */
-static inline void cpuid(unsigned int op,
- unsigned int *eax, unsigned int *ebx,
- unsigned int *ecx, unsigned int *edx)
-{
- *eax = op;
- *ecx = 0;
- __cpuid(eax, ebx, ecx, edx);
-}
-
-/* Some CPUID calls want 'count' to be placed in ecx */
-static inline void cpuid_count(unsigned int op, int count,
- unsigned int *eax, unsigned int *ebx,
- unsigned int *ecx, unsigned int *edx)
-{
- *eax = op;
- *ecx = count;
- __cpuid(eax, ebx, ecx, edx);
-}
-
-/*
- * CPUID functions returning a single datum
- */
-static inline unsigned int cpuid_eax(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
-
- return eax;
-}
-
-static inline unsigned int cpuid_ebx(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
-
- return ebx;
-}
-
-static inline unsigned int cpuid_ecx(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
-
- return ecx;
-}
-
-static inline unsigned int cpuid_edx(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
-
- return edx;
-}
-
extern void select_idle_routine(const struct cpuinfo_x86 *c);
extern void amd_e400_c1e_apic_setup(void);

@@ -805,24 +692,6 @@ static inline u32 amd_get_nodes_per_socket(void) { return 0; }
static inline u32 amd_get_highest_perf(void) { return 0; }
#endif

-#define for_each_possible_hypervisor_cpuid_base(function) \
- for (function = 0x40000000; function < 0x40010000; function += 0x100)
-
-static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
-{
- uint32_t base, eax, signature[3];
-
- for_each_possible_hypervisor_cpuid_base(base) {
- cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);
-
- if (!memcmp(sig, signature, 12) &&
- (leaves == 0 || ((eax - base) >= leaves)))
- return base;
- }
-
- return 0;
-}
-
extern unsigned long arch_align_stack(unsigned long sp);
void free_init_pages(const char *what, unsigned long begin, unsigned long end);
extern void free_kernel_image_pages(const char *what, void *begin, void *end);