projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| dd78b973 KC |
1 | #include <linux/types.h> |
| 2 | #include "bitops.h" | |
| 3 | ||
| 4 | #include <asm/processor-flags.h> | |
| 5 | #include <asm/required-features.h> | |
| 6 | #include <asm/msr-index.h> | |
| 7 | #include "cpuflags.h" | |
| 8 | ||
| 9 | struct cpu_features cpu; | |
| 10 | u32 cpu_vendor[3]; | |
| 11 | ||
| 12 | static bool loaded_flags; | |
| 13 | ||
| 14 | static int has_fpu(void) | |
| 15 | { | |
| 16 | u16 fcw = -1, fsw = -1; | |
| 17 | unsigned long cr0; | |
| 18 | ||
| 19 | asm volatile("mov %%cr0,%0" : "=r" (cr0)); | |
| 20 | if (cr0 & (X86_CR0_EM|X86_CR0_TS)) { | |
| 21 | cr0 &= ~(X86_CR0_EM|X86_CR0_TS); | |
| 22 | asm volatile("mov %0,%%cr0" : : "r" (cr0)); | |
| 23 | } | |
| 24 | ||
| 25 | asm volatile("fninit ; fnstsw %0 ; fnstcw %1" | |
| 26 | : "+m" (fsw), "+m" (fcw)); | |
| 27 | ||
| 28 | return fsw == 0 && (fcw & 0x103f) == 0x003f; | |
| 29 | } | |
| 30 | ||
| 31 | int has_eflag(unsigned long mask) | |
| 32 | { | |
| 33 | unsigned long f0, f1; | |
| 34 | ||
| 35 | asm volatile("pushf \n\t" | |
| 36 | "pushf \n\t" | |
| 37 | "pop %0 \n\t" | |
| 38 | "mov %0,%1 \n\t" | |
| 39 | "xor %2,%1 \n\t" | |
| 40 | "push %1 \n\t" | |
| 41 | "popf \n\t" | |
| 42 | "pushf \n\t" | |
| 43 | "pop %1 \n\t" | |
| 44 | "popf" | |
| 45 | : "=&r" (f0), "=&r" (f1) | |
| 46 | : "ri" (mask)); | |
| 47 | ||
| 48 | return !!((f0^f1) & mask); | |
| 49 | } | |
| 50 | ||
| 51 | /* Handle x86_32 PIC using ebx. */ | |
| 52 | #if defined(__i386__) && defined(__PIC__) | |
| 53 | # define EBX_REG "=r" | |
| 54 | #else | |
| 55 | # define EBX_REG "=b" | |
| 56 | #endif | |
| 57 | ||
| 58 | static inline void cpuid(u32 id, u32 *a, u32 *b, u32 *c, u32 *d) | |
| 59 | { | |
| 60 | asm volatile(".ifnc %%ebx,%3 ; movl %%ebx,%3 ; .endif \n\t" | |
| 61 | "cpuid \n\t" | |
| 62 | ".ifnc %%ebx,%3 ; xchgl %%ebx,%3 ; .endif \n\t" | |
| 63 | : "=a" (*a), "=c" (*c), "=d" (*d), EBX_REG (*b) | |
| 64 | : "a" (id) | |
| 65 | ); | |
| 66 | } | |
| 67 | ||
| 68 | void get_flags(void) | |
| 69 | { | |
| 70 | u32 max_intel_level, max_amd_level; | |
| 71 | u32 tfms; | |
| 72 | u32 ignored; | |
| 73 | ||
| 74 | if (loaded_flags) | |
| 75 | return; | |
| 76 | loaded_flags = true; | |
| 77 | ||
| 78 | if (has_fpu()) | |
| 79 | set_bit(X86_FEATURE_FPU, cpu.flags); | |
| 80 | ||
| 81 | if (has_eflag(X86_EFLAGS_ID)) { | |
| 82 | cpuid(0x0, &max_intel_level, &cpu_vendor[0], &cpu_vendor[2], | |
| 83 | &cpu_vendor[1]); | |
| 84 | ||
| 85 | if (max_intel_level >= 0x00000001 && | |
| 86 | max_intel_level <= 0x0000ffff) { | |
| 87 | cpuid(0x1, &tfms, &ignored, &cpu.flags[4], | |
| 88 | &cpu.flags[0]); | |
| 89 | cpu.level = (tfms >> 8) & 15; | |
| 90 | cpu.model = (tfms >> 4) & 15; | |
| 91 | if (cpu.level >= 6) | |
| 92 | cpu.model += ((tfms >> 16) & 0xf) << 4; | |
| 93 | } | |
| 94 | ||
| 95 | cpuid(0x80000000, &max_amd_level, &ignored, &ignored, | |
| 96 | &ignored); | |
| 97 | ||
| 98 | if (max_amd_level >= 0x80000001 && | |
| 99 | max_amd_level <= 0x8000ffff) { | |
| 100 | cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6], | |
| 101 | &cpu.flags[1]); | |
| 102 | } | |
| 103 | } | |
| 104 | } |