3 files changed, 55 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h
index d853d163ba47..801beba4e64b 100644
--- a/arch/powerpc/include/asm/archrandom.h
+++ b/arch/powerpc/include/asm/archrandom.h
@@ -27,6 +27,15 @@ static inline int arch_get_random_int(unsigned int *v)
 
 int powernv_get_random_long(unsigned long *v);
 
+static inline int arch_get_random_seed_long(unsigned long *v)
+{
+        return 0;
+}
+static inline int arch_get_random_seed_int(unsigned int *v)
+{
+        return 0;
+}
+
 #endif /* CONFIG_ARCH_RANDOM */
 
 #endif /* _ASM_POWERPC_ARCHRANDOM_H */
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h
index e6a92455740e..6ad7f6d3f97f 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)                                 \
 {                                                               \
@@ -70,16 +83,35 @@ 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 */
 
 #else
@@ -89,6 +121,11 @@ 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);
diff --git a/include/linux/random.h b/include/linux/random.h
index 1cfce0e24dbd..c2f08131050d 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -88,6 +88,14 @@ static inline int arch_get_random_int(unsigned int *v)
 {
         return 0;
 }
+static inline int arch_get_random_seed_long(unsigned long *v)
+{
+        return 0;
+}
+static inline int arch_get_random_seed_int(unsigned int *v)
+{
+        return 0;
+}
 #endif
 
 /* Pseudo random number generator from numerical recipes. */