1 #ifndef FIO_ARCH_X86_COMMON
2 #define FIO_ARCH_X86_COMMON
3
4 #include <string.h>
5
cpuid(unsigned int op,unsigned int * eax,unsigned int * ebx,unsigned int * ecx,unsigned int * edx)6 static inline void cpuid(unsigned int op,
7 unsigned int *eax, unsigned int *ebx,
8 unsigned int *ecx, unsigned int *edx)
9 {
10 *eax = op;
11 *ecx = 0;
12 do_cpuid(eax, ebx, ecx, edx);
13 }
14
15 #define ARCH_HAVE_INIT
16
17 extern int tsc_reliable;
18 extern int arch_random;
19
arch_init_intel(unsigned int level)20 static inline void arch_init_intel(unsigned int level)
21 {
22 unsigned int eax, ebx, ecx = 0, edx;
23
24 /*
25 * Check for TSC
26 */
27 eax = 1;
28 do_cpuid(&eax, &ebx, &ecx, &edx);
29 if (!(edx & (1U << 4)))
30 return;
31
32 /*
33 * Check for constant rate and synced (across cores) TSC
34 */
35 eax = 0x80000007;
36 do_cpuid(&eax, &ebx, &ecx, &edx);
37 tsc_reliable = (edx & (1U << 8)) != 0;
38
39 /*
40 * Check for FDRAND
41 */
42 eax = 0x1;
43 do_cpuid(&eax, &ebx, &ecx, &edx);
44 arch_random = (ecx & (1U << 30)) != 0;
45 }
46
arch_init_amd(unsigned int level)47 static inline void arch_init_amd(unsigned int level)
48 {
49 unsigned int eax, ebx, ecx, edx;
50
51 cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
52 if (eax < 0x80000007)
53 return;
54
55 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
56 tsc_reliable = (edx & (1U << 8)) != 0;
57 }
58
arch_init(char * envp[])59 static inline void arch_init(char *envp[])
60 {
61 unsigned int level;
62 char str[13];
63
64 arch_random = tsc_reliable = 0;
65
66 cpuid(0, &level, (unsigned int *) &str[0],
67 (unsigned int *) &str[8],
68 (unsigned int *) &str[4]);
69
70 str[12] = '\0';
71 if (!strcmp(str, "GenuineIntel"))
72 arch_init_intel(level);
73 else if (!strcmp(str, "AuthenticAMD"))
74 arch_init_amd(level);
75 }
76
77 #endif
78