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 <l...@amacapital.net>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Fenghua Yu <fenghua...@intel.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Oleg Nesterov <o...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 arch/x86/crypto/sha1_ssse3_glue.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/x86/crypto/sha1_ssse3_glue.c 
b/arch/x86/crypto/sha1_ssse3_glue.c
index 84db12f052e8..7c48e8b20848 100644
--- a/arch/x86/crypto/sha1_ssse3_glue.c
+++ b/arch/x86/crypto/sha1_ssse3_glue.c
@@ -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)) {
-               pr_info("AVX detected but unusable.\n");
-
+       if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, NULL)) {
+               if (cpu_has_avx)
+                       pr_info("AVX detected but unusable.\n");
                return false;
        }
 
-- 
2.1.0

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