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| author | Yu-cheng Yu <yu-cheng.yu@intel.com> | 2019-12-12 13:08:53 -0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-01-06 17:31:11 +0100 |
| commit | 8c9e607376968865456b33d9a2efdee2c7e1030d (patch) | |
| tree | 4dbead3699cd01e57f5fe70357def03c24ec3bfc /arch/x86 | |
| parent | c79f46a282390e0f5b306007bf7b11a46d529538 (diff) | |
| download | linux-stable-8c9e607376968865456b33d9a2efdee2c7e1030d.tar.gz linux-stable-8c9e607376968865456b33d9a2efdee2c7e1030d.tar.bz2 linux-stable-8c9e607376968865456b33d9a2efdee2c7e1030d.zip | |
x86/fpu/xstate: Fix small issues
In response to earlier comments, fix small issues before introducing
XSAVES supervisor states:
- Fix comments of xfeature_is_supervisor().
- Replace ((u64)1 << 63) with XCOMP_BV_COMPACTED_FORMAT.
No functional changes.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191212210855.19260-2-yu-cheng.yu@intel.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index fa31470bbf24..4588fc57203e 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -110,12 +110,9 @@ EXPORT_SYMBOL_GPL(cpu_has_xfeatures); static int xfeature_is_supervisor(int xfeature_nr) { /* - * We currently do not support supervisor states, but if - * we did, we could find out like this. - * - * SDM says: If state component 'i' is a user state component, - * ECX[0] return 0; if state component i is a supervisor - * state component, ECX[0] returns 1. + * Extended State Enumeration Sub-leaves (EAX = 0DH, ECX = n, n > 1) + * returns ECX[0] set to (1) for a supervisor state, and cleared (0) + * for a user state. */ u32 eax, ebx, ecx, edx; @@ -419,7 +416,8 @@ static void __init setup_init_fpu_buf(void) print_xstate_features(); if (boot_cpu_has(X86_FEATURE_XSAVES)) - init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask; + init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | + xfeatures_mask; /* * Init all the features state with header.xfeatures being 0x0 |