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/twofish_avx_glue.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/arch/x86/crypto/twofish_avx_glue.c
b/arch/x86/crypto/twofish_avx_glue.c
index 95434f5b705a..c2bd0ce718ee 100644
--- a/arch/x86/crypto/twofish_avx_glue.c
+++ b/arch/x86/crypto/twofish_avx_glue.c
@@ -37,8 +37,6 @@
#include <crypto/lrw.h>
#include <crypto/xts.h>
#include <asm/fpu/api.h>
-#include <asm/xcr.h>
-#include <asm/fpu/xstate.h>
#include <asm/crypto/twofish.h>
#include <asm/crypto/glue_helper.h>
#include <crypto/scatterwalk.h>
@@ -558,16 +556,10 @@ static struct crypto_alg twofish_algs[10] = { {
static int __init twofish_init(void)
{
- u64 xcr0;
+ const char *feature_name;
- if (!cpu_has_avx || !cpu_has_osxsave) {
- printk(KERN_INFO "AVX instructions are not detected.\n");
- return -ENODEV;
- }
-
- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
- if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
- printk(KERN_INFO "AVX detected but unusable.\n");
+ if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+ pr_info("CPU feature '%s' is not supported.\n", feature_name);
return -ENODEV;
}
--
2.1.0
--
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