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
arch_init_intel(unsigned int level)19 static inline int arch_init_intel(unsigned int level)
20 {
21 unsigned int eax, ebx, ecx = 0, edx;
22
23 /*
24 * Check for TSC
25 */
26 eax = 1;
27 do_cpuid(&eax, &ebx, &ecx, &edx);
28 if (!(edx & (1U << 4)))
29 return 0;
30
31 /*
32 * Check for constant rate and synced (across cores) TSC
33 */
34 eax = 0x80000007;
35 do_cpuid(&eax, &ebx, &ecx, &edx);
36 return edx & (1U << 8);
37 }
38
arch_init_amd(unsigned int level)39 static inline int arch_init_amd(unsigned int level)
40 {
41 unsigned int eax, ebx, ecx, edx;
42
43 cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
44 if (eax < 0x80000007)
45 return 0;
46
47 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
48 if (edx & (1 << 8))
49 return 1;
50
51 return 0;
52 }
53
arch_init(char * envp[])54 static inline int arch_init(char *envp[])
55 {
56 unsigned int level;
57 char str[13];
58
59 cpuid(0, &level, (unsigned int *) &str[0],
60 (unsigned int *) &str[8],
61 (unsigned int *) &str[4]);
62
63 str[12] = '\0';
64 if (!strcmp(str, "GenuineIntel"))
65 tsc_reliable = arch_init_intel(level);
66 else if (!strcmp(str, "AuthenticAMD"))
67 tsc_reliable = arch_init_amd(level);
68
69 return 0;
70 }
71
72 #endif
73