xref: /openbmc/linux/arch/x86/boot/cpu.c (revision 3821a065)
1 /* -*- linux-c -*- ------------------------------------------------------- *
2  *
3  *   Copyright (C) 1991, 1992 Linus Torvalds
4  *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
5  *
6  *   This file is part of the Linux kernel, and is made available under
7  *   the terms of the GNU General Public License version 2.
8  *
9  * ----------------------------------------------------------------------- */
10 
11 /*
12  * arch/x86/boot/cpu.c
13  *
14  * Check for obligatory CPU features and abort if the features are not
15  * present.
16  */
17 
18 #include "boot.h"
19 #ifdef CONFIG_X86_FEATURE_NAMES
20 #include "cpustr.h"
21 #endif
22 
23 static char *cpu_name(int level)
24 {
25 	static char buf[6];
26 
27 	if (level == 64) {
28 		return "x86-64";
29 	} else {
30 		if (level == 15)
31 			level = 6;
32 		sprintf(buf, "i%d86", level);
33 		return buf;
34 	}
35 }
36 
37 static void show_cap_strs(u32 *err_flags)
38 {
39 	int i, j;
40 #ifdef CONFIG_X86_FEATURE_NAMES
41 	const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs;
42 	for (i = 0; i < NCAPINTS; i++) {
43 		u32 e = err_flags[i];
44 		for (j = 0; j < 32; j++) {
45 			if (msg_strs[0] < i ||
46 			    (msg_strs[0] == i && msg_strs[1] < j)) {
47 				/* Skip to the next string */
48 				msg_strs += 2;
49 				while (*msg_strs++)
50 					;
51 			}
52 			if (e & 1) {
53 				if (msg_strs[0] == i &&
54 				    msg_strs[1] == j &&
55 				    msg_strs[2])
56 					printf("%s ", msg_strs+2);
57 				else
58 					printf("%d:%d ", i, j);
59 			}
60 			e >>= 1;
61 		}
62 	}
63 #else
64 	for (i = 0; i < NCAPINTS; i++) {
65 		u32 e = err_flags[i];
66 		for (j = 0; j < 32; j++) {
67 			if (e & 1)
68 				printf("%d:%d ", i, j);
69 			e >>= 1;
70 		}
71 	}
72 #endif
73 }
74 
75 int validate_cpu(void)
76 {
77 	u32 *err_flags;
78 	int cpu_level, req_level;
79 
80 	check_cpu(&cpu_level, &req_level, &err_flags);
81 
82 	if (cpu_level < req_level) {
83 		printf("This kernel requires an %s CPU, ",
84 		       cpu_name(req_level));
85 		printf("but only detected an %s CPU.\n",
86 		       cpu_name(cpu_level));
87 		return -1;
88 	}
89 
90 	if (err_flags) {
91 		puts("This kernel requires the following features "
92 		     "not present on the CPU:\n");
93 		show_cap_strs(err_flags);
94 		putchar('\n');
95 		return -1;
96 	} else {
97 		return 0;
98 	}
99 }
100