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Diffstat (limited to 'arch/x86/include/asm/archrandom.h')
-rw-r--r--arch/x86/include/asm/archrandom.h42
1 files changed, 41 insertions, 1 deletions
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h
index e6a92455740e..69f1366f1aa3 100644
--- a/arch/x86/include/asm/archrandom.h
+++ b/arch/x86/include/asm/archrandom.h
@@ -1,7 +1,7 @@
/*
* This file is part of the Linux kernel.
*
- * Copyright (c) 2011, Intel Corporation
+ * Copyright (c) 2011-2014, Intel Corporation
* Authors: Fenghua Yu <fenghua.yu@intel.com>,
* H. Peter Anvin <hpa@linux.intel.com>
*
@@ -31,10 +31,13 @@
#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
#ifdef CONFIG_ARCH_RANDOM
@@ -53,6 +56,16 @@ static inline int rdrand_long(unsigned long *v)
return ok;
}
+/* A single attempt at RDSEED */
+static inline bool rdseed_long(unsigned long *v)
+{
+ unsigned char ok;
+ asm volatile(RDSEED_LONG "\n\t"
+ "setc %0"
+ : "=qm" (ok), "=a" (*v));
+ return ok;
+}
+
#define GET_RANDOM(name, type, rdrand, nop) \
static inline int name(type *v) \
{ \
@@ -70,18 +83,40 @@ static inline int name(type *v) \
return ok; \
}
+#define GET_SEED(name, type, rdseed, nop) \
+static inline int name(type *v) \
+{ \
+ unsigned char ok; \
+ alternative_io("movb $0, %0\n\t" \
+ nop, \
+ rdseed "\n\t" \
+ "setc %0", \
+ X86_FEATURE_RDSEED, \
+ ASM_OUTPUT2("=q" (ok), "=a" (*v))); \
+ return ok; \
+}
+
#ifdef CONFIG_X86_64
GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP5);
GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP4);
+GET_SEED(arch_get_random_seed_long, unsigned long, RDSEED_LONG, ASM_NOP5);
+GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4);
+
#else
GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP3);
GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP3);
+GET_SEED(arch_get_random_seed_long, unsigned long, RDSEED_LONG, ASM_NOP4);
+GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4);
+
#endif /* CONFIG_X86_64 */
+#define arch_has_random() static_cpu_has(X86_FEATURE_RDRAND)
+#define arch_has_random_seed() static_cpu_has(X86_FEATURE_RDSEED)
+
#else
static inline int rdrand_long(unsigned long *v)
@@ -89,6 +124,11 @@ static inline int rdrand_long(unsigned long *v)
return 0;
}
+static inline bool rdseed_long(unsigned long *v)
+{
+ return 0;
+}
+
#endif /* CONFIG_ARCH_RANDOM */
extern void x86_init_rdrand(struct cpuinfo_x86 *c);