1 // SPDX-License-Identifier: GPL-2.0-only 2 /* -*- linux-c -*- ------------------------------------------------------- * 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * Copyright 2007-2008 rPath, Inc. - All Rights Reserved 6 * 7 * ----------------------------------------------------------------------- */ 8 9 /* 10 * arch/x86/boot/cpu.c 11 * 12 * Check for obligatory CPU features and abort if the features are not 13 * present. 14 */ 15 16 #include "boot.h" 17 #ifdef CONFIG_X86_FEATURE_NAMES 18 #include "cpustr.h" 19 #endif 20 21 static char *cpu_name(int level) 22 { 23 static char buf[6]; 24 25 if (level == 64) { 26 return "x86-64"; 27 } else { 28 if (level == 15) 29 level = 6; 30 sprintf(buf, "i%d86", level); 31 return buf; 32 } 33 } 34 35 static void show_cap_strs(u32 *err_flags) 36 { 37 int i, j; 38 #ifdef CONFIG_X86_FEATURE_NAMES 39 const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs; 40 for (i = 0; i < NCAPINTS; i++) { 41 u32 e = err_flags[i]; 42 for (j = 0; j < 32; j++) { 43 if (msg_strs[0] < i || 44 (msg_strs[0] == i && msg_strs[1] < j)) { 45 /* Skip to the next string */ 46 msg_strs += 2; 47 while (*msg_strs++) 48 ; 49 } 50 if (e & 1) { 51 if (msg_strs[0] == i && 52 msg_strs[1] == j && 53 msg_strs[2]) 54 printf("%s ", msg_strs+2); 55 else 56 printf("%d:%d ", i, j); 57 } 58 e >>= 1; 59 } 60 } 61 #else 62 for (i = 0; i < NCAPINTS; i++) { 63 u32 e = err_flags[i]; 64 for (j = 0; j < 32; j++) { 65 if (e & 1) 66 printf("%d:%d ", i, j); 67 e >>= 1; 68 } 69 } 70 #endif 71 } 72 73 int validate_cpu(void) 74 { 75 u32 *err_flags; 76 int cpu_level, req_level; 77 78 check_cpu(&cpu_level, &req_level, &err_flags); 79 80 if (cpu_level < req_level) { 81 printf("This kernel requires an %s CPU, ", 82 cpu_name(req_level)); 83 printf("but only detected an %s CPU.\n", 84 cpu_name(cpu_level)); 85 return -1; 86 } 87 88 if (err_flags) { 89 puts("This kernel requires the following features " 90 "not present on the CPU:\n"); 91 show_cap_strs(err_flags); 92 putchar('\n'); 93 return -1; 94 } else if (check_knl_erratum()) { 95 return -1; 96 } else { 97 return 0; 98 } 99 } 100