The following commit has been merged into the x86/cpu branch of tip: Commit-ID: 02b63b33dfc9294cfbdef78b99f5e15ef9243e39 Gitweb: https://git.kernel.org/tip/02b63b33dfc9294cfbdef78b99f5e15ef9243e39 Author: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx> AuthorDate: Mon, 17 Mar 2025 23:18:20 +01:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Tue, 18 Mar 2025 09:35:57 +01:00 x86/cpuid: Refactor <asm/cpuid.h> In preparation for future commits where CPUID headers will be expanded, refactor the CPUID header <asm/cpuid.h> into: asm/cpuid/ ├── api.h └── types.h Move the CPUID data structures into <asm/cpuid/types.h> and the access APIs into <asm/cpuid/api.h>. Let <asm/cpuid.h> be just an include of <asm/cpuid/api.h> so that existing call sites do not break. Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: John Ogness <john.ogness@xxxxxxxxxxxxx> Cc: "Ahmed S. Darwish" <darwi@xxxxxxxxxxxxx> Cc: x86-cpuid@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20250317221824.3738853-2-mingo@xxxxxxxxxx --- arch/x86/include/asm/cpuid.h | 217 +---------------------------- arch/x86/include/asm/cpuid/api.h | 208 +++++++++++++++++++++++++++- arch/x86/include/asm/cpuid/types.h | 29 ++++- 3 files changed, 238 insertions(+), 216 deletions(-) create mode 100644 arch/x86/include/asm/cpuid/api.h create mode 100644 arch/x86/include/asm/cpuid/types.h diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h index a92e4b0..d5749b2 100644 --- a/arch/x86/include/asm/cpuid.h +++ b/arch/x86/include/asm/cpuid.h @@ -1,223 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 */ -/* - * CPUID-related helpers/definitions - */ #ifndef _ASM_X86_CPUID_H #define _ASM_X86_CPUID_H -#include <linux/build_bug.h> -#include <linux/types.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, -}; - -#define CPUID_LEAF_MWAIT 0x5 -#define CPUID_LEAF_DCA 0x9 -#define CPUID_LEAF_XSTATE 0x0d -#define CPUID_LEAF_TSC 0x15 -#define CPUID_LEAF_FREQ 0x16 -#define CPUID_LEAF_TILE 0x1d - -#ifdef CONFIG_X86_32 -bool have_cpuid_p(void); -#else -static inline bool have_cpuid_p(void) -{ - return true; -} -#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 inline void __cpuid_read(unsigned int leaf, unsigned int subleaf, u32 *regs) -{ - regs[CPUID_EAX] = leaf; - regs[CPUID_ECX] = subleaf; - __cpuid(regs + CPUID_EAX, regs + CPUID_EBX, regs + CPUID_ECX, regs + CPUID_EDX); -} - -#define cpuid_subleaf(leaf, subleaf, regs) { \ - static_assert(sizeof(*(regs)) == 16); \ - __cpuid_read(leaf, subleaf, (u32 *)(regs)); \ -} - -#define cpuid_leaf(leaf, regs) { \ - static_assert(sizeof(*(regs)) == 16); \ - __cpuid_read(leaf, 0, (u32 *)(regs)); \ -} - -static inline void __cpuid_read_reg(unsigned int leaf, unsigned int subleaf, - enum cpuid_regs_idx regidx, u32 *reg) -{ - u32 regs[4]; - - __cpuid_read(leaf, subleaf, regs); - *reg = regs[regidx]; -} - -#define cpuid_subleaf_reg(leaf, subleaf, regidx, reg) { \ - static_assert(sizeof(*(reg)) == 4); \ - __cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg)); \ -} - -#define cpuid_leaf_reg(leaf, regidx, reg) { \ - static_assert(sizeof(*(reg)) == 4); \ - __cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg)); \ -} - -static __always_inline bool cpuid_function_is_indexed(u32 function) -{ - switch (function) { - case 4: - case 7: - case 0xb: - case 0xd: - case 0xf: - case 0x10: - case 0x12: - case 0x14: - case 0x17: - case 0x18: - case 0x1d: - case 0x1e: - case 0x1f: - case 0x24: - case 0x8000001d: - return true; - } - - 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]); - - /* - * This must not compile to "call memcmp" because it's called - * from PVH early boot code before instrumentation is set up - * and memcmp() itself may be instrumented. - */ - if (!__builtin_memcmp(sig, signature, 12) && - (leaves == 0 || ((eax - base) >= leaves))) - return base; - } - - return 0; -} +#include <asm/cpuid/api.h> #endif /* _ASM_X86_CPUID_H */ diff --git a/arch/x86/include/asm/cpuid/api.h b/arch/x86/include/asm/cpuid/api.h new file mode 100644 index 0000000..4d1da9c --- /dev/null +++ b/arch/x86/include/asm/cpuid/api.h @@ -0,0 +1,208 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_X86_CPUID_API_H +#define _ASM_X86_CPUID_API_H + +#include <linux/build_bug.h> +#include <linux/types.h> + +#include <asm/cpuid/types.h> +#include <asm/string.h> + +/* + * Raw CPUID accessors + */ + +#ifdef CONFIG_X86_32 +bool have_cpuid_p(void); +#else +static inline bool have_cpuid_p(void) +{ + return true; +} +#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 inline void __cpuid_read(unsigned int leaf, unsigned int subleaf, u32 *regs) +{ + regs[CPUID_EAX] = leaf; + regs[CPUID_ECX] = subleaf; + __cpuid(regs + CPUID_EAX, regs + CPUID_EBX, regs + CPUID_ECX, regs + CPUID_EDX); +} + +#define cpuid_subleaf(leaf, subleaf, regs) { \ + static_assert(sizeof(*(regs)) == 16); \ + __cpuid_read(leaf, subleaf, (u32 *)(regs)); \ +} + +#define cpuid_leaf(leaf, regs) { \ + static_assert(sizeof(*(regs)) == 16); \ + __cpuid_read(leaf, 0, (u32 *)(regs)); \ +} + +static inline void __cpuid_read_reg(unsigned int leaf, unsigned int subleaf, + enum cpuid_regs_idx regidx, u32 *reg) +{ + u32 regs[4]; + + __cpuid_read(leaf, subleaf, regs); + *reg = regs[regidx]; +} + +#define cpuid_subleaf_reg(leaf, subleaf, regidx, reg) { \ + static_assert(sizeof(*(reg)) == 4); \ + __cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg)); \ +} + +#define cpuid_leaf_reg(leaf, regidx, reg) { \ + static_assert(sizeof(*(reg)) == 4); \ + __cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg)); \ +} + +static __always_inline bool cpuid_function_is_indexed(u32 function) +{ + switch (function) { + case 4: + case 7: + case 0xb: + case 0xd: + case 0xf: + case 0x10: + case 0x12: + case 0x14: + case 0x17: + case 0x18: + case 0x1d: + case 0x1e: + case 0x1f: + case 0x24: + case 0x8000001d: + return true; + } + + 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]); + + /* + * This must not compile to "call memcmp" because it's called + * from PVH early boot code before instrumentation is set up + * and memcmp() itself may be instrumented. + */ + if (!__builtin_memcmp(sig, signature, 12) && + (leaves == 0 || ((eax - base) >= leaves))) + return base; + } + + return 0; +} + +#endif /* _ASM_X86_CPUID_API_H */ diff --git a/arch/x86/include/asm/cpuid/types.h b/arch/x86/include/asm/cpuid/types.h new file mode 100644 index 0000000..724002a --- /dev/null +++ b/arch/x86/include/asm/cpuid/types.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_CPUID_TYPES_H +#define _ASM_X86_CPUID_TYPES_H + +#include <linux/types.h> + +/* + * Types for raw CPUID access + */ + +struct cpuid_regs { + u32 eax, ebx, ecx, edx; +}; + +enum cpuid_regs_idx { + CPUID_EAX = 0, + CPUID_EBX, + CPUID_ECX, + CPUID_EDX, +}; + +#define CPUID_LEAF_MWAIT 0x5 +#define CPUID_LEAF_DCA 0x9 +#define CPUID_LEAF_XSTATE 0x0d +#define CPUID_LEAF_TSC 0x15 +#define CPUID_LEAF_FREQ 0x16 +#define CPUID_LEAF_TILE 0x1d + +#endif /* _ASM_X86_CPUID_TYPES_H */
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