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* [PATCH] x86: Use RDRAND and RDSEED mnemonics in archrandom.h
@ 2020-05-08 10:58 Uros Bizjak
  2020-05-08 16:57 ` hpa
  2020-05-18 18:06 ` [tip: x86/cpu] x86/cpu: " tip-bot2 for Uros Bizjak
  0 siblings, 2 replies; 3+ messages in thread
From: Uros Bizjak @ 2020-05-08 10:58 UTC (permalink / raw)
  To: x86, linux-kernel
  Cc: Uros Bizjak, H. Peter Anvin, Ingo Molnar, Thomas Gleixner

Current minimum required version of binutils is 2.23,
which supports RDRAND and RDSEED instruction mnemonics.

Replace the byte-wise specification of RDRAND and
RDSEED with these proper mnemonics.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/archrandom.h | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h
index 7a4bb1bd4bdb..ebc248e49549 100644
--- a/arch/x86/include/asm/archrandom.h
+++ b/arch/x86/include/asm/archrandom.h
@@ -15,16 +15,6 @@
 
 #define RDRAND_RETRY_LOOPS	10
 
-#define RDRAND_INT	".byte 0x0f,0xc7,0xf0"
-#define RDSEED_INT	".byte 0x0f,0xc7,0xf8"
-#ifdef CONFIG_X86_64
-# define RDRAND_LONG	".byte 0x48,0x0f,0xc7,0xf0"
-# define RDSEED_LONG	".byte 0x48,0x0f,0xc7,0xf8"
-#else
-# define RDRAND_LONG	RDRAND_INT
-# define RDSEED_LONG	RDSEED_INT
-#endif
-
 /* Unconditional execution of RDRAND and RDSEED */
 
 static inline bool __must_check rdrand_long(unsigned long *v)
@@ -32,9 +22,9 @@ static inline bool __must_check rdrand_long(unsigned long *v)
 	bool ok;
 	unsigned int retry = RDRAND_RETRY_LOOPS;
 	do {
-		asm volatile(RDRAND_LONG
+		asm volatile("rdrand %[out]"
 			     CC_SET(c)
-			     : CC_OUT(c) (ok), "=a" (*v));
+			     : CC_OUT(c) (ok), [out] "=r" (*v));
 		if (ok)
 			return true;
 	} while (--retry);
@@ -46,9 +36,9 @@ static inline bool __must_check rdrand_int(unsigned int *v)
 	bool ok;
 	unsigned int retry = RDRAND_RETRY_LOOPS;
 	do {
-		asm volatile(RDRAND_INT
+		asm volatile("rdrand %[out]"
 			     CC_SET(c)
-			     : CC_OUT(c) (ok), "=a" (*v));
+			     : CC_OUT(c) (ok), [out] "=r" (*v));
 		if (ok)
 			return true;
 	} while (--retry);
@@ -58,18 +48,18 @@ static inline bool __must_check rdrand_int(unsigned int *v)
 static inline bool __must_check rdseed_long(unsigned long *v)
 {
 	bool ok;
-	asm volatile(RDSEED_LONG
+	asm volatile("rdseed %[out]"
 		     CC_SET(c)
-		     : CC_OUT(c) (ok), "=a" (*v));
+		     : CC_OUT(c) (ok), [out] "=r" (*v));
 	return ok;
 }
 
 static inline bool __must_check rdseed_int(unsigned int *v)
 {
 	bool ok;
-	asm volatile(RDSEED_INT
+	asm volatile("rdseed %[out]"
 		     CC_SET(c)
-		     : CC_OUT(c) (ok), "=a" (*v));
+		     : CC_OUT(c) (ok), [out] "=r" (*v));
 	return ok;
 }
 
-- 
2.25.4


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-05-18 18:09 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-05-08 10:58 [PATCH] x86: Use RDRAND and RDSEED mnemonics in archrandom.h Uros Bizjak
2020-05-08 16:57 ` hpa
2020-05-18 18:06 ` [tip: x86/cpu] x86/cpu: " tip-bot2 for Uros Bizjak

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