[PATCH v9 5/5] x86/xsave: Remove the explicit clearing of XSAVE dependend features

Andi Kleen
2017-10-07T00:03:38Z

From: Andi Kleen <ak@linux.intel.com>

Clearing a CPU feature with setup_clear_cpu_cap() clears all features
which depend on it. Expressing feature dependencies in one place is
easier to maintain than keeping functions like
fpu__xstate_clear_all_cpu_caps() up to date.

The features which depend on XSAVE have their dependency expressed in the
dependency table, so its sufficient to clear X86_FEATURE_XSAVE.

Remove the explicit clearing of XSAVE dependend features.

v2: Use Thomas Gleixner's new description
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kernel/fpu/xstate.c | 20 --------------------
1 file changed, 20 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 924bd895b5ee..bfe8c0c1033d 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -73,26 +73,6 @@ unsigned int fpu_user_xstate_size;
void fpu__xstate_clear_all_cpu_caps(void)
{
setup_clear_cpu_cap(X86_FEATURE_XSAVE);
- setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
- setup_clear_cpu_cap(X86_FEATURE_XSAVEC);
- setup_clear_cpu_cap(X86_FEATURE_XSAVES);
- setup_clear_cpu_cap(X86_FEATURE_AVX);
- setup_clear_cpu_cap(X86_FEATURE_AVX2);
- setup_clear_cpu_cap(X86_FEATURE_AVX512F);
- setup_clear_cpu_cap(X86_FEATURE_AVX512IFMA);
- setup_clear_cpu_cap(X86_FEATURE_AVX512PF);
- setup_clear_cpu_cap(X86_FEATURE_AVX512ER);
- setup_clear_cpu_cap(X86_FEATURE_AVX512CD);
- setup_clear_cpu_cap(X86_FEATURE_AVX512DQ);
- setup_clear_cpu_cap(X86_FEATURE_AVX512BW);
- setup_clear_cpu_cap(X86_FEATURE_AVX512VL);
- setup_clear_cpu_cap(X86_FEATURE_MPX);
- setup_clear_cpu_cap(X86_FEATURE_XGETBV1);
- setup_clear_cpu_cap(X86_FEATURE_AVX512VBMI);
- setup_clear_cpu_cap(X86_FEATURE_PKU);
- setup_clear_cpu_cap(X86_FEATURE_AVX512_4VNNIW);
- setup_clear_cpu_cap(X86_FEATURE_AVX512_4FMAPS);
- setup_clear_cpu_cap(X86_FEATURE_AVX512_VPOPCNTDQ);
}

/*
--
2.13.6