1 /*
2 * Intel CPU Microcode Update Driver for Linux
3 *
4 * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
5 * H Peter Anvin" <hpa@zytor.com>
6 *
7 * This driver allows to upgrade microcode on Intel processors
8 * belonging to IA-32 family - PentiumPro, Pentium II,
9 * Pentium III, Xeon, Pentium 4, etc.
10 *
11 * Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
12 * Software Developer's Manual
13 * Order Number 253668 or free download from:
14 *
15 * http://developer.intel.com/Assets/PDF/manual/253668.pdf
16 *
17 * For more information, go to http://www.urbanmyth.org/microcode
18 *
19 * This program is free software; you can redistribute it and/or
20 * modify it under the terms of the GNU General Public License
21 * as published by the Free Software Foundation; either version
22 * 2 of the License, or (at your option) any later version.
23 *
24 */
25 #include <linux/firmware.h>
26 #include <linux/uaccess.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29
30 #include <asm/microcode_intel.h>
31 #include <asm/processor.h>
32 #include <asm/msr.h>
33
34 static inline int
update_match_cpu(unsigned int csig,unsigned int cpf,unsigned int sig,unsigned int pf)35 update_match_cpu(unsigned int csig, unsigned int cpf,
36 unsigned int sig, unsigned int pf)
37 {
38 return (!sigmatch(sig, csig, pf, cpf)) ? 0 : 1;
39 }
40
microcode_sanity_check(void * mc,int print_err)41 int microcode_sanity_check(void *mc, int print_err)
42 {
43 unsigned long total_size, data_size, ext_table_size;
44 struct microcode_header_intel *mc_header = mc;
45 struct extended_sigtable *ext_header = NULL;
46 int sum, orig_sum, ext_sigcount = 0, i;
47 struct extended_signature *ext_sig;
48
49 total_size = get_totalsize(mc_header);
50 data_size = get_datasize(mc_header);
51
52 if (data_size + MC_HEADER_SIZE > total_size) {
53 if (print_err)
54 pr_err("error! Bad data size in microcode data file\n");
55 return -EINVAL;
56 }
57
58 if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
59 if (print_err)
60 pr_err("error! Unknown microcode update format\n");
61 return -EINVAL;
62 }
63 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
64 if (ext_table_size) {
65 if ((ext_table_size < EXT_HEADER_SIZE)
66 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
67 if (print_err)
68 pr_err("error! Small exttable size in microcode data file\n");
69 return -EINVAL;
70 }
71 ext_header = mc + MC_HEADER_SIZE + data_size;
72 if (ext_table_size != exttable_size(ext_header)) {
73 if (print_err)
74 pr_err("error! Bad exttable size in microcode data file\n");
75 return -EFAULT;
76 }
77 ext_sigcount = ext_header->count;
78 }
79
80 /* check extended table checksum */
81 if (ext_table_size) {
82 int ext_table_sum = 0;
83 int *ext_tablep = (int *)ext_header;
84
85 i = ext_table_size / DWSIZE;
86 while (i--)
87 ext_table_sum += ext_tablep[i];
88 if (ext_table_sum) {
89 if (print_err)
90 pr_warn("aborting, bad extended signature table checksum\n");
91 return -EINVAL;
92 }
93 }
94
95 /* calculate the checksum */
96 orig_sum = 0;
97 i = (MC_HEADER_SIZE + data_size) / DWSIZE;
98 while (i--)
99 orig_sum += ((int *)mc)[i];
100 if (orig_sum) {
101 if (print_err)
102 pr_err("aborting, bad checksum\n");
103 return -EINVAL;
104 }
105 if (!ext_table_size)
106 return 0;
107 /* check extended signature checksum */
108 for (i = 0; i < ext_sigcount; i++) {
109 ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
110 EXT_SIGNATURE_SIZE * i;
111 sum = orig_sum
112 - (mc_header->sig + mc_header->pf + mc_header->cksum)
113 + (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
114 if (sum) {
115 if (print_err)
116 pr_err("aborting, bad checksum\n");
117 return -EINVAL;
118 }
119 }
120 return 0;
121 }
122 EXPORT_SYMBOL_GPL(microcode_sanity_check);
123
124 /*
125 * Returns 1 if update has been found, 0 otherwise.
126 */
get_matching_sig(unsigned int csig,int cpf,int rev,void * mc)127 int get_matching_sig(unsigned int csig, int cpf, int rev, void *mc)
128 {
129 struct microcode_header_intel *mc_header = mc;
130 struct extended_sigtable *ext_header;
131 unsigned long total_size = get_totalsize(mc_header);
132 int ext_sigcount, i;
133 struct extended_signature *ext_sig;
134
135 if (update_match_cpu(csig, cpf, mc_header->sig, mc_header->pf))
136 return 1;
137
138 /* Look for ext. headers: */
139 if (total_size <= get_datasize(mc_header) + MC_HEADER_SIZE)
140 return 0;
141
142 ext_header = mc + get_datasize(mc_header) + MC_HEADER_SIZE;
143 ext_sigcount = ext_header->count;
144 ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
145
146 for (i = 0; i < ext_sigcount; i++) {
147 if (update_match_cpu(csig, cpf, ext_sig->sig, ext_sig->pf))
148 return 1;
149 ext_sig++;
150 }
151 return 0;
152 }
153
154 /*
155 * Returns 1 if update has been found, 0 otherwise.
156 */
get_matching_microcode(unsigned int csig,int cpf,int rev,void * mc)157 int get_matching_microcode(unsigned int csig, int cpf, int rev, void *mc)
158 {
159 struct microcode_header_intel *mc_hdr = mc;
160
161 if (!revision_is_newer(mc_hdr, rev))
162 return 0;
163
164 return get_matching_sig(csig, cpf, rev, mc);
165 }
166 EXPORT_SYMBOL_GPL(get_matching_microcode);
167