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Diffstat (limited to 'arch/arch-x86-common.h')
-rw-r--r--arch/arch-x86-common.h33
1 files changed, 19 insertions, 14 deletions
diff --git a/arch/arch-x86-common.h b/arch/arch-x86-common.h
index 31aa79f1..cbf66b8d 100644
--- a/arch/arch-x86-common.h
+++ b/arch/arch-x86-common.h
@@ -15,8 +15,9 @@ static inline void cpuid(unsigned int op,
#define ARCH_HAVE_INIT
extern int tsc_reliable;
+extern int arch_random;
-static inline int arch_init_intel(unsigned int level)
+static inline void arch_init_intel(unsigned int level)
{
unsigned int eax, ebx, ecx = 0, edx;
@@ -26,47 +27,51 @@ static inline int arch_init_intel(unsigned int level)
eax = 1;
do_cpuid(&eax, &ebx, &ecx, &edx);
if (!(edx & (1U << 4)))
- return 0;
+ return;
/*
* Check for constant rate and synced (across cores) TSC
*/
eax = 0x80000007;
do_cpuid(&eax, &ebx, &ecx, &edx);
- return edx & (1U << 8);
+ tsc_reliable = (edx & (1U << 8)) != 0;
+
+ /*
+ * Check for FDRAND
+ */
+ eax = 0x1;
+ do_cpuid(&eax, &ebx, &ecx, &edx);
+ arch_random = (ecx & (1U << 30)) != 0;
}
-static inline int arch_init_amd(unsigned int level)
+static inline void arch_init_amd(unsigned int level)
{
unsigned int eax, ebx, ecx, edx;
cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
if (eax < 0x80000007)
- return 0;
+ return;
cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
- if (edx & (1 << 8))
- return 1;
-
- return 0;
+ tsc_reliable = (edx & (1U << 8)) != 0;
}
-static inline int arch_init(char *envp[])
+static inline void arch_init(char *envp[])
{
unsigned int level;
char str[13];
+ arch_random = tsc_reliable = 0;
+
cpuid(0, &level, (unsigned int *) &str[0],
(unsigned int *) &str[8],
(unsigned int *) &str[4]);
str[12] = '\0';
if (!strcmp(str, "GenuineIntel"))
- tsc_reliable = arch_init_intel(level);
+ arch_init_intel(level);
else if (!strcmp(str, "AuthenticAMD"))
- tsc_reliable = arch_init_amd(level);
-
- return 0;
+ arch_init_amd(level);
}
#endif