| Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame] | 1 | #include <stdint.h> |
| 2 | #include <string.h> |
| 3 | #include <cpu.h> |
| 4 | |
| 5 | /** @file |
| 6 | * |
| 7 | * CPU identification |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | /** |
| 12 | * Test to see if CPU flag is changeable |
| 13 | * |
| 14 | * @v flag Flag to test |
| 15 | * @ret can_change Flag is changeable |
| 16 | */ |
| 17 | static inline int flag_is_changeable ( unsigned int flag ) { |
| 18 | uint32_t f1, f2; |
| 19 | |
| 20 | __asm__ ( "pushfl\n\t" |
| 21 | "pushfl\n\t" |
| 22 | "popl %0\n\t" |
| 23 | "movl %0,%1\n\t" |
| 24 | "xorl %2,%0\n\t" |
| 25 | "pushl %0\n\t" |
| 26 | "popfl\n\t" |
| 27 | "pushfl\n\t" |
| 28 | "popl %0\n\t" |
| 29 | "popfl\n\t" |
| 30 | : "=&r" ( f1 ), "=&r" ( f2 ) |
| 31 | : "ir" ( flag ) ); |
| 32 | |
| 33 | return ( ( ( f1 ^ f2 ) & flag ) != 0 ); |
| 34 | } |
| 35 | |
| 36 | /** |
| 37 | * Get CPU information |
| 38 | * |
| 39 | * @v cpu CPU information structure to fill in |
| 40 | */ |
| 41 | void get_cpuinfo ( struct cpuinfo_x86 *cpu ) { |
| 42 | unsigned int cpuid_level; |
| 43 | unsigned int cpuid_extlevel; |
| 44 | unsigned int discard_1, discard_2, discard_3; |
| 45 | |
| 46 | memset ( cpu, 0, sizeof ( *cpu ) ); |
| 47 | |
| 48 | /* Check for CPUID instruction */ |
| 49 | if ( ! flag_is_changeable ( X86_EFLAGS_ID ) ) { |
| 50 | DBG ( "CPUID not supported\n" ); |
| 51 | return; |
| 52 | } |
| 53 | |
| 54 | /* Get features, if present */ |
| 55 | cpuid ( 0x00000000, &cpuid_level, &discard_1, |
| 56 | &discard_2, &discard_3 ); |
| 57 | if ( cpuid_level >= 0x00000001 ) { |
| 58 | cpuid ( 0x00000001, &discard_1, &discard_2, |
| 59 | &discard_3, &cpu->features ); |
| 60 | } else { |
| 61 | DBG ( "CPUID cannot return capabilities\n" ); |
| 62 | } |
| 63 | |
| 64 | /* Get 64-bit features, if present */ |
| 65 | cpuid ( 0x80000000, &cpuid_extlevel, &discard_1, |
| 66 | &discard_2, &discard_3 ); |
| 67 | if ( ( cpuid_extlevel & 0xffff0000 ) == 0x80000000 ) { |
| 68 | if ( cpuid_extlevel >= 0x80000001 ) { |
| 69 | cpuid ( 0x80000001, &discard_1, &discard_2, |
| 70 | &discard_3, &cpu->amd_features ); |
| 71 | } |
| 72 | } |
| 73 | } |