Commit d1e50966 authored Apr 28, 2015 by Ingo Molnar

x86/fpu, crypto x86/sha1_ssse3: Simplify the sha1_ssse3_mod_init() xfeature checks



Use the new 'cpu_has_xfeatures()' function to query AVX CPU support.

This has the following advantages to the driver:

 - Decouples the driver from FPU internals: it's now only using <asm/fpu/api.h>.

 - Removes detection complexity from the driver, no more raw XGETBV instruction

 - Shrinks the code a bit.

 - Standardizes feature name error message printouts across drivers

There are also advantages to the x86 FPU code: once all drivers
are decoupled from internals we can move them out of common
headers and we'll also be able to remove xcr.h.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 1debf7db

arch/x86/crypto/sha1_ssse3_glue.c

+3 −11

Original line number	Diff line number	Diff line
		@@ -30,8 +30,6 @@
		#include <crypto/sha.h>
		#include <crypto/sha1_base.h>
		#include <asm/fpu/api.h>
		#include <asm/xcr.h>
		#include <asm/fpu/xstate.h>


		asmlinkage void sha1_transform_ssse3(u32 digest, const char data,
		@@ -123,15 +121,9 @@ static struct shash_alg alg = {
		#ifdef CONFIG_AS_AVX
		static bool __init avx_usable(void)
		{
		u64 xcr0;

		if (!cpu_has_avx \|\| !cpu_has_osxsave)
		return false;

		xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
		if ((xcr0 & (XSTATE_SSE \| XSTATE_YMM)) != (XSTATE_SSE \| XSTATE_YMM)) {
		if (!cpu_has_xfeatures(XSTATE_SSE \| XSTATE_YMM, NULL)) {
		if (cpu_has_avx)
		pr_info("AVX detected but unusable.\n");

		return false;
		}