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
cpu_name(int level)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
show_cap_strs(u32 * err_flags)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
validate_cpu(void)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