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| author |   Sohil Mehta <sohil.mehta@intel.com> | 2024-11-07 23:30:00 +0000 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2024-12-06 10:57:44 +0100 |
| commit | 7a470e826d7521bec6af789deab31cfa4fd05af3 (patch) | |
| tree | 2eb5e47345c02b06ec954bfc7b2602a6bc513a66 | |
| parent | Merge tag 'audit-pr-20241205' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit (diff) | |
| download | wireguard-linux-7a470e826d7521bec6af789deab31cfa4fd05af3.tar.xz wireguard-linux-7a470e826d7521bec6af789deab31cfa4fd05af3.zip | |
x86/cpufeatures: Free up unused feature bits
Linux defined feature bits X86_FEATURE_P3 and X86_FEATURE_P4 are not
used anywhere. Commit f31d731e4467 ("x86: use X86_FEATURE_NOPL in
alternatives") got rid of the last usage in 2008. Remove the related
mappings and code.
Just like all X86_FEATURE bits, the raw bit numbers can be exposed to
userspace via MODULE_DEVICE_TABLE(). There is a very small theoretical
chance of userspace getting confused if these bits got reassigned and
changed logical meaning. But these bits were never used for a device
table, so it's highly unlikely this will ever happen in practice.
[ dhansen: clarify userspace visibility of these bits ]
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/20241107233000.2742619-1-sohil.mehta%40intel.com
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 5 |
2 files changed, 2 insertions, 7 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 17b6590748c0..f725ccc77b01 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -83,8 +83,8 @@ #define X86_FEATURE_CENTAUR_MCR ( 3*32+ 3) /* "centaur_mcr" Centaur MCRs (= MTRRs) */ #define X86_FEATURE_K8 ( 3*32+ 4) /* Opteron, Athlon64 */ #define X86_FEATURE_ZEN5 ( 3*32+ 5) /* CPU based on Zen5 microarchitecture */ -#define X86_FEATURE_P3 ( 3*32+ 6) /* P3 */ -#define X86_FEATURE_P4 ( 3*32+ 7) /* P4 */ +/* Free ( 3*32+ 6) */ +/* Free ( 3*32+ 7) */ #define X86_FEATURE_CONSTANT_TSC ( 3*32+ 8) /* "constant_tsc" TSC ticks at a constant rate */ #define X86_FEATURE_UP ( 3*32+ 9) /* "up" SMP kernel running on UP */ #define X86_FEATURE_ART ( 3*32+10) /* "art" Always running timer (ART) */ diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index d1de300af173..5a9fbe962135 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -597,11 +597,6 @@ static void init_intel(struct cpuinfo_x86 *c) if (p) strcpy(c->x86_model_id, p); } - - if (c->x86 == 15) - set_cpu_cap(c, X86_FEATURE_P4); - if (c->x86 == 6) - set_cpu_cap(c, X86_FEATURE_P3); #endif /* Work around errata */ |