1dd78b973SKees Cook #include <linux/types.h> 2dd78b973SKees Cook #include "bitops.h" 3dd78b973SKees Cook 4dd78b973SKees Cook #include <asm/processor-flags.h> 5dd78b973SKees Cook #include <asm/required-features.h> 6dd78b973SKees Cook #include <asm/msr-index.h> 7dd78b973SKees Cook #include "cpuflags.h" 8dd78b973SKees Cook 9dd78b973SKees Cook struct cpu_features cpu; 10dd78b973SKees Cook u32 cpu_vendor[3]; 11dd78b973SKees Cook 12dd78b973SKees Cook static bool loaded_flags; 13dd78b973SKees Cook 14dd78b973SKees Cook static int has_fpu(void) 15dd78b973SKees Cook { 16dd78b973SKees Cook u16 fcw = -1, fsw = -1; 17dd78b973SKees Cook unsigned long cr0; 18dd78b973SKees Cook 19dd78b973SKees Cook asm volatile("mov %%cr0,%0" : "=r" (cr0)); 20dd78b973SKees Cook if (cr0 & (X86_CR0_EM|X86_CR0_TS)) { 21dd78b973SKees Cook cr0 &= ~(X86_CR0_EM|X86_CR0_TS); 22dd78b973SKees Cook asm volatile("mov %0,%%cr0" : : "r" (cr0)); 23dd78b973SKees Cook } 24dd78b973SKees Cook 25dd78b973SKees Cook asm volatile("fninit ; fnstsw %0 ; fnstcw %1" 26dd78b973SKees Cook : "+m" (fsw), "+m" (fcw)); 27dd78b973SKees Cook 28dd78b973SKees Cook return fsw == 0 && (fcw & 0x103f) == 0x003f; 29dd78b973SKees Cook } 30dd78b973SKees Cook 31dd78b973SKees Cook int has_eflag(unsigned long mask) 32dd78b973SKees Cook { 33dd78b973SKees Cook unsigned long f0, f1; 34dd78b973SKees Cook 35dd78b973SKees Cook asm volatile("pushf \n\t" 36dd78b973SKees Cook "pushf \n\t" 37dd78b973SKees Cook "pop %0 \n\t" 38dd78b973SKees Cook "mov %0,%1 \n\t" 39dd78b973SKees Cook "xor %2,%1 \n\t" 40dd78b973SKees Cook "push %1 \n\t" 41dd78b973SKees Cook "popf \n\t" 42dd78b973SKees Cook "pushf \n\t" 43dd78b973SKees Cook "pop %1 \n\t" 44dd78b973SKees Cook "popf" 45dd78b973SKees Cook : "=&r" (f0), "=&r" (f1) 46dd78b973SKees Cook : "ri" (mask)); 47dd78b973SKees Cook 48dd78b973SKees Cook return !!((f0^f1) & mask); 49dd78b973SKees Cook } 50dd78b973SKees Cook 51dd78b973SKees Cook /* Handle x86_32 PIC using ebx. */ 52dd78b973SKees Cook #if defined(__i386__) && defined(__PIC__) 53dd78b973SKees Cook # define EBX_REG "=r" 54dd78b973SKees Cook #else 55dd78b973SKees Cook # define EBX_REG "=b" 56dd78b973SKees Cook #endif 57dd78b973SKees Cook 58dd78b973SKees Cook static inline void cpuid(u32 id, u32 *a, u32 *b, u32 *c, u32 *d) 59dd78b973SKees Cook { 60dd78b973SKees Cook asm volatile(".ifnc %%ebx,%3 ; movl %%ebx,%3 ; .endif \n\t" 61dd78b973SKees Cook "cpuid \n\t" 62dd78b973SKees Cook ".ifnc %%ebx,%3 ; xchgl %%ebx,%3 ; .endif \n\t" 63dd78b973SKees Cook : "=a" (*a), "=c" (*c), "=d" (*d), EBX_REG (*b) 64dd78b973SKees Cook : "a" (id) 65dd78b973SKees Cook ); 66dd78b973SKees Cook } 67dd78b973SKees Cook 686e6a4932SH. Peter Anvin void get_cpuflags(void) 69dd78b973SKees Cook { 70dd78b973SKees Cook u32 max_intel_level, max_amd_level; 71dd78b973SKees Cook u32 tfms; 72dd78b973SKees Cook u32 ignored; 73dd78b973SKees Cook 74dd78b973SKees Cook if (loaded_flags) 75dd78b973SKees Cook return; 76dd78b973SKees Cook loaded_flags = true; 77dd78b973SKees Cook 78dd78b973SKees Cook if (has_fpu()) 79dd78b973SKees Cook set_bit(X86_FEATURE_FPU, cpu.flags); 80dd78b973SKees Cook 81dd78b973SKees Cook if (has_eflag(X86_EFLAGS_ID)) { 82dd78b973SKees Cook cpuid(0x0, &max_intel_level, &cpu_vendor[0], &cpu_vendor[2], 83dd78b973SKees Cook &cpu_vendor[1]); 84dd78b973SKees Cook 85dd78b973SKees Cook if (max_intel_level >= 0x00000001 && 86dd78b973SKees Cook max_intel_level <= 0x0000ffff) { 87dd78b973SKees Cook cpuid(0x1, &tfms, &ignored, &cpu.flags[4], 88dd78b973SKees Cook &cpu.flags[0]); 89dd78b973SKees Cook cpu.level = (tfms >> 8) & 15; 90dd78b973SKees Cook cpu.model = (tfms >> 4) & 15; 91dd78b973SKees Cook if (cpu.level >= 6) 92dd78b973SKees Cook cpu.model += ((tfms >> 16) & 0xf) << 4; 93dd78b973SKees Cook } 94dd78b973SKees Cook 95dd78b973SKees Cook cpuid(0x80000000, &max_amd_level, &ignored, &ignored, 96dd78b973SKees Cook &ignored); 97dd78b973SKees Cook 98dd78b973SKees Cook if (max_amd_level >= 0x80000001 && 99dd78b973SKees Cook max_amd_level <= 0x8000ffff) { 100dd78b973SKees Cook cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6], 101dd78b973SKees Cook &cpu.flags[1]); 102dd78b973SKees Cook } 103dd78b973SKees Cook } 104dd78b973SKees Cook } 105