25c7cb05fa
with 32-bit guests, seeing stale instruction bytes, to one working on a buffer, like the rest of the alternatives code does - Add a long overdue check to the X86_FEATURE flag modifying functions to warn when former get changed in a non-compatible way after alternatives have been patched because those changes will be already wrong - Other cleanups -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmZCT+kACgkQEsHwGGHe VUraaxAAl6pwAVD19vK6VtTRxgKGW8GBaGjdtSBDSFP3dhyvqd+xC1Vez5HKShMz Lmg81ZsoeAruGWDo+Av0twgGEd5OagTMHdrJsfWVQlaVXNE1IPm4tWuic4Llh+0X LSZYrBXpQH7/bsOHFTdvun8NdHVb5Ew8pvYCB06lPrlU7sjBujGsFzyQ1R6xNWmr IErYqUVtEqexNS9lo45N+1Q5Uzdb9eNnPqMDA0ZbvJEytXWHlqW3ukOjRyNls1BS HbgIqOk59xuHII/nw+GgsXant2TvJQYFJPC7CculJWp7oLZITn03rj0AMKOS7cm+ zOKDbnvQogw4mf/eVc1X6RbIq+9O5eZcBskIiRVGpFP294Axt8gEwmFcfBI2UsUF t73Z2ELHuo/iHc02Gd2y+uV98NEmluX+g4efb5ILpdMJiP9J2rl6TA0PIYUx8U3T 794We38nk1YCSZnXZOpso7y+m/lRPocALWHQdtw9Frn8UNzgjidpef8vT2O+Trp5 AYv5ucnChjcUQycMIBGFbqppwjs9vb2y1L6mh4mCB6WrxeAitUw0hjvuYQvKL+wB 0gYqOrL4Z+swYKMC+GAE5HCcQayzsURbjnyzcM4nhKGSiwpaeYKHPqAPPq+oyH18 xMc8KI3n791oeZBUhA5o1ECw5vX3FcgUfAmlYfhMTnqvo+UQALM= =gaPh -----END PGP SIGNATURE----- Merge tag 'x86_alternatives_for_v6.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm alternatives updates from Borislav Petkov: - Switch the in-place instruction patching which lead to at least one weird bug with 32-bit guests, seeing stale instruction bytes, to one working on a buffer, like the rest of the alternatives code does - Add a long overdue check to the X86_FEATURE flag modifying functions to warn when former get changed in a non-compatible way after alternatives have been patched because those changes will be already wrong - Other cleanups * tag 'x86_alternatives_for_v6.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternatives: Remove alternative_input_2() x86/alternatives: Sort local vars in apply_alternatives() x86/alternatives: Optimize optimize_nops() x86/alternatives: Get rid of __optimize_nops() x86/alternatives: Use a temporary buffer when optimizing NOPs x86/alternatives: Catch late X86_FEATURE modifiers
218 lines
8.1 KiB
C
218 lines
8.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_CPUFEATURE_H
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#define _ASM_X86_CPUFEATURE_H
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#include <asm/processor.h>
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#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
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#include <asm/asm.h>
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#include <linux/bitops.h>
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#include <asm/alternative.h>
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enum cpuid_leafs
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{
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CPUID_1_EDX = 0,
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CPUID_8000_0001_EDX,
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CPUID_8086_0001_EDX,
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CPUID_LNX_1,
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CPUID_1_ECX,
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CPUID_C000_0001_EDX,
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CPUID_8000_0001_ECX,
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CPUID_LNX_2,
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CPUID_LNX_3,
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CPUID_7_0_EBX,
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CPUID_D_1_EAX,
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CPUID_LNX_4,
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CPUID_7_1_EAX,
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CPUID_8000_0008_EBX,
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CPUID_6_EAX,
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CPUID_8000_000A_EDX,
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CPUID_7_ECX,
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CPUID_8000_0007_EBX,
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CPUID_7_EDX,
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CPUID_8000_001F_EAX,
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CPUID_8000_0021_EAX,
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CPUID_LNX_5,
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NR_CPUID_WORDS,
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};
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#define X86_CAP_FMT_NUM "%d:%d"
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#define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31)
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extern const char * const x86_cap_flags[NCAPINTS*32];
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extern const char * const x86_power_flags[32];
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#define X86_CAP_FMT "%s"
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#define x86_cap_flag(flag) x86_cap_flags[flag]
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/*
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* In order to save room, we index into this array by doing
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* X86_BUG_<name> - NCAPINTS*32.
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*/
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extern const char * const x86_bug_flags[NBUGINTS*32];
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#define test_cpu_cap(c, bit) \
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arch_test_bit(bit, (unsigned long *)((c)->x86_capability))
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/*
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* There are 32 bits/features in each mask word. The high bits
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* (selected with (bit>>5) give us the word number and the low 5
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* bits give us the bit/feature number inside the word.
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* (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
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* see if it is set in the mask word.
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*/
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#define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \
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(((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
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/*
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* {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the
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* following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all
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* header macros which use NCAPINTS need to be changed. The duplicated macro
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* use causes the compiler to issue errors for all headers so that all usage
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* sites can be corrected.
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*/
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#define REQUIRED_MASK_BIT_SET(feature_bit) \
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( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 21, feature_bit) || \
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REQUIRED_MASK_CHECK || \
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BUILD_BUG_ON_ZERO(NCAPINTS != 22))
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#define DISABLED_MASK_BIT_SET(feature_bit) \
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( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \
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CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 21, feature_bit) || \
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DISABLED_MASK_CHECK || \
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BUILD_BUG_ON_ZERO(NCAPINTS != 22))
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#define cpu_has(c, bit) \
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(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
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test_cpu_cap(c, bit))
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#define this_cpu_has(bit) \
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(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
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x86_this_cpu_test_bit(bit, cpu_info.x86_capability))
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/*
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* This macro is for detection of features which need kernel
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* infrastructure to be used. It may *not* directly test the CPU
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* itself. Use the cpu_has() family if you want true runtime
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* testing of CPU features, like in hypervisor code where you are
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* supporting a possible guest feature where host support for it
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* is not relevant.
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*/
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#define cpu_feature_enabled(bit) \
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(__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
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#define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
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#define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
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extern void setup_clear_cpu_cap(unsigned int bit);
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extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
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#define setup_force_cpu_cap(bit) do { \
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\
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if (!boot_cpu_has(bit)) \
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WARN_ON(alternatives_patched); \
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\
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set_cpu_cap(&boot_cpu_data, bit); \
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set_bit(bit, (unsigned long *)cpu_caps_set); \
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} while (0)
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#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
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/*
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* Static testing of CPU features. Used the same as boot_cpu_has(). It
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* statically patches the target code for additional performance. Use
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* static_cpu_has() only in fast paths, where every cycle counts. Which
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* means that the boot_cpu_has() variant is already fast enough for the
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* majority of cases and you should stick to using it as it is generally
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* only two instructions: a RIP-relative MOV and a TEST.
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*
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* Do not use an "m" constraint for [cap_byte] here: gcc doesn't know
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* that this is only used on a fallback path and will sometimes cause
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* it to manifest the address of boot_cpu_data in a register, fouling
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* the mainline (post-initialization) code.
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*/
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static __always_inline bool _static_cpu_has(u16 bit)
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{
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asm goto(ALTERNATIVE_TERNARY("jmp 6f", %c[feature], "", "jmp %l[t_no]")
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".pushsection .altinstr_aux,\"ax\"\n"
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"6:\n"
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" testb %[bitnum], %a[cap_byte]\n"
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" jnz %l[t_yes]\n"
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" jmp %l[t_no]\n"
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".popsection\n"
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: : [feature] "i" (bit),
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[bitnum] "i" (1 << (bit & 7)),
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[cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3])
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: : t_yes, t_no);
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t_yes:
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return true;
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t_no:
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return false;
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}
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#define static_cpu_has(bit) \
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( \
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__builtin_constant_p(boot_cpu_has(bit)) ? \
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boot_cpu_has(bit) : \
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_static_cpu_has(bit) \
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)
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#define cpu_has_bug(c, bit) cpu_has(c, (bit))
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#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
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#define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))
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#define static_cpu_has_bug(bit) static_cpu_has((bit))
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#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
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#define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit))
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#define MAX_CPU_FEATURES (NCAPINTS * 32)
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#define cpu_have_feature boot_cpu_has
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#define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
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#define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
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boot_cpu_data.x86_model
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#endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
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#endif /* _ASM_X86_CPUFEATURE_H */
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