cpufeature.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_X86_CPUFEATURE_H
  3#define _ASM_X86_CPUFEATURE_H
  4
  5#include <asm/processor.h>
  6
  7#if defined(__KERNEL__) && !defined(__ASSEMBLER__)
  8
  9#include <asm/asm.h>
 10#include <linux/bitops.h>
 11#include <asm/alternative.h>
 12#include <asm/cpufeaturemasks.h>
 13
 14enum cpuid_leafs
 15{
 16	CPUID_1_EDX		= 0,
 17	CPUID_8000_0001_EDX,
 18	CPUID_8086_0001_EDX,
 19	CPUID_LNX_1,
 20	CPUID_1_ECX,
 21	CPUID_C000_0001_EDX,
 22	CPUID_8000_0001_ECX,
 23	CPUID_LNX_2,
 24	CPUID_LNX_3,
 25	CPUID_7_0_EBX,
 26	CPUID_D_1_EAX,
 27	CPUID_LNX_4,
 28	CPUID_7_1_EAX,
 29	CPUID_8000_0008_EBX,
 30	CPUID_6_EAX,
 31	CPUID_8000_000A_EDX,
 32	CPUID_7_ECX,
 33	CPUID_LNX_6,
 34	CPUID_7_EDX,
 35	CPUID_8000_001F_EAX,
 36	CPUID_8000_0021_EAX,
 37	CPUID_LNX_5,
 38	NR_CPUID_WORDS,
 39};
 40
 41extern const char * const x86_cap_flags[NCAPINTS*32];
 42extern const char * const x86_power_flags[32];
 43
 44/*
 45 * In order to save room, we index into this array by doing
 46 * X86_BUG_<name> - NCAPINTS*32.
 47 */
 48extern const char * const x86_bug_flags[NBUGINTS*32];
 49#define x86_bug_flag(flag) x86_bug_flags[flag]
 50
 51#define test_cpu_cap(c, bit)						\
 52	 arch_test_bit(bit, (unsigned long *)((c)->x86_capability))
 53
 54#define cpu_has(c, bit)							\
 55	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
 56	 test_cpu_cap(c, bit))
 57
 58#define this_cpu_has(bit)						\
 59	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
 60	 x86_this_cpu_test_bit(bit, cpu_info.x86_capability))
 61
 62/*
 63 * This is the default CPU features testing macro to use in code.
 64 *
 65 * It is for detection of features which need kernel infrastructure to be
 66 * used.  It may *not* directly test the CPU itself.  Use the cpu_has() family
 67 * if you want true runtime testing of CPU features, like in hypervisor code
 68 * where you are supporting a possible guest feature where host support for it
 69 * is not relevant.
 70 */
 71#define cpu_feature_enabled(bit)	\
 72	(__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
 73
 74#define boot_cpu_has(bit)	cpu_has(&boot_cpu_data, bit)
 75
 76#define set_cpu_cap(c, bit)	set_bit(bit, (unsigned long *)((c)->x86_capability))
 77
 78extern void setup_clear_cpu_cap(unsigned int bit);
 79extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
 80void check_cpufeature_deps(struct cpuinfo_x86 *c);
 81
 82#define setup_force_cpu_cap(bit) do {			\
 83							\
 84	if (!boot_cpu_has(bit))				\
 85		WARN_ON(alternatives_patched);		\
 86							\
 87	set_cpu_cap(&boot_cpu_data, bit);		\
 88	set_bit(bit, (unsigned long *)cpu_caps_set);	\
 89} while (0)
 90
 91#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
 92
 93/*
 94 * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know
 95 * that this is only used on a fallback path and will sometimes cause
 96 * it to manifest the address of boot_cpu_data in a register, fouling
 97 * the mainline (post-initialization) code.
 98 */
 99static __always_inline bool _static_cpu_has(u16 bit)
100{
101	asm goto(ALTERNATIVE_TERNARY("jmp 6f", %c[feature], "", "jmp %l[t_no]")
102		".pushsection .altinstr_aux,\"ax\"\n"
103		"6:\n"
104		ANNOTATE_DATA_SPECIAL "\n"
105		" testb %[bitnum], %a[cap_byte]\n"
106		" jnz %l[t_yes]\n"
107		" jmp %l[t_no]\n"
108		".popsection\n"
109		 : : [feature]  "i" (bit),
110		     [bitnum]   "i" (1 << (bit & 7)),
111		     [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3])
112		 : : t_yes, t_no);
113t_yes:
114	return true;
115t_no:
116	return false;
117}
118
119#define static_cpu_has(bit)					\
120(								\
121	__builtin_constant_p(boot_cpu_has(bit)) ?		\
122		boot_cpu_has(bit) :				\
123		_static_cpu_has(bit)				\
124)
125
126#define cpu_has_bug(c, bit)		cpu_has(c, (bit))
127#define set_cpu_bug(c, bit)		set_cpu_cap(c, (bit))
128#define clear_cpu_bug(c, bit)		clear_cpu_cap(c, (bit))
129
130#define static_cpu_has_bug(bit)		static_cpu_has((bit))
131#define boot_cpu_has_bug(bit)		cpu_has_bug(&boot_cpu_data, (bit))
132#define boot_cpu_set_bug(bit)		set_cpu_cap(&boot_cpu_data, (bit))
133
134#define MAX_CPU_FEATURES		(NCAPINTS * 32)
135#define cpu_have_feature		boot_cpu_has
136
137#define CPU_FEATURE_TYPEFMT		"x86,ven%04Xfam%04Xmod%04X"
138#define CPU_FEATURE_TYPEVAL		boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
139					boot_cpu_data.x86_model
140
141#endif /* defined(__KERNEL__) && !defined(__ASSEMBLER__) */
142#endif /* _ASM_X86_CPUFEATURE_H */