mtd: bcm63xxpart: merge sparelen calculation
[deliverable/linux.git] / drivers / mtd / bcm63xxpart.c
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1/*
2 * BCM63XX CFE image tag parser
3 *
4 * Copyright © 2006-2008 Florian Fainelli <florian@openwrt.org>
5 * Mike Albon <malbon@openwrt.org>
6 * Copyright © 2009-2010 Daniel Dickinson <openwrt@cshore.neomailbox.net>
5329d67c 7 * Copyright © 2011-2012 Jonas Gorski <jonas.gorski@gmail.com>
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8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 */
24
25#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26
f98872fc 27#include <linux/crc32.h>
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28#include <linux/module.h>
29#include <linux/kernel.h>
30#include <linux/slab.h>
31#include <linux/vmalloc.h>
32#include <linux/mtd/mtd.h>
33#include <linux/mtd/partitions.h>
34
35#include <asm/mach-bcm63xx/bcm963xx_tag.h>
f2d9739b 36#include <asm/mach-bcm63xx/board_bcm963xx.h>
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37
38#define BCM63XX_EXTENDED_SIZE 0xBFC00000 /* Extended flash address */
39
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40#define BCM63XX_MIN_CFE_SIZE 0x10000 /* always at least 64KiB */
41#define BCM63XX_MIN_NVRAM_SIZE 0x10000 /* always at least 64KiB */
42
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43#define BCM63XX_CFE_MAGIC_OFFSET 0x4e0
44
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45static int bcm63xx_detect_cfe(struct mtd_info *master)
46{
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47 char buf[9];
48 int ret;
49 size_t retlen;
50
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51 ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
52 (void *)buf);
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53 buf[retlen] = 0;
54
55 if (ret)
56 return ret;
57
58 if (strncmp("cfe-v", buf, 5) == 0)
59 return 0;
60
61 /* very old CFE's do not have the cfe-v string, so check for magic */
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62 ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
63 (void *)buf);
70a3c167 64 buf[retlen] = 0;
70a3c167 65
f2d9739b 66 return strncmp("CFE1CFE1", buf, 8);
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67}
68
69static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
70 struct mtd_partition **pparts,
71 struct mtd_part_parser_data *data)
72{
73 /* CFE, NVRAM and global Linux are always present */
74 int nrparts = 3, curpart = 0;
75 struct bcm_tag *buf;
76 struct mtd_partition *parts;
77 int ret;
78 size_t retlen;
79 unsigned int rootfsaddr, kerneladdr, spareaddr;
80 unsigned int rootfslen, kernellen, sparelen, totallen;
678eb9bb 81 unsigned int cfelen, nvramlen;
70a3c167 82 int i;
f98872fc 83 u32 computed_crc;
5329d67c 84 bool rootfs_first = false;
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85
86 if (bcm63xx_detect_cfe(master))
87 return -EINVAL;
88
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89 cfelen = max_t(uint32_t, master->erasesize, BCM63XX_MIN_CFE_SIZE);
90 nvramlen = max_t(uint32_t, master->erasesize, BCM63XX_MIN_NVRAM_SIZE);
91
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92 /* Allocate memory for buffer */
93 buf = vmalloc(sizeof(struct bcm_tag));
94 if (!buf)
95 return -ENOMEM;
96
97 /* Get the tag */
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98 ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
99 (void *)buf);
678eb9bb 100
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101 if (retlen != sizeof(struct bcm_tag)) {
102 vfree(buf);
103 return -EIO;
104 }
105
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106 computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
107 offsetof(struct bcm_tag, header_crc));
108 if (computed_crc == buf->header_crc) {
109 char *boardid = &(buf->board_id[0]);
110 char *tagversion = &(buf->tag_version[0]);
111
5329d67c 112 sscanf(buf->flash_image_start, "%u", &rootfsaddr);
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113 sscanf(buf->kernel_address, "%u", &kerneladdr);
114 sscanf(buf->kernel_length, "%u", &kernellen);
115 sscanf(buf->total_length, "%u", &totallen);
116
117 pr_info("CFE boot tag found with version %s and board type %s\n",
118 tagversion, boardid);
119
120 kerneladdr = kerneladdr - BCM63XX_EXTENDED_SIZE;
5329d67c 121 rootfsaddr = rootfsaddr - BCM63XX_EXTENDED_SIZE;
f98872fc 122 spareaddr = roundup(totallen, master->erasesize) + cfelen;
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123
124 if (rootfsaddr < kerneladdr) {
125 /* default Broadcom layout */
126 rootfslen = kerneladdr - rootfsaddr;
127 rootfs_first = true;
128 } else {
129 /* OpenWrt layout */
130 rootfsaddr = kerneladdr + kernellen;
131 rootfslen = spareaddr - rootfsaddr;
132 }
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133 } else {
134 pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
135 buf->header_crc, computed_crc);
136 kernellen = 0;
137 rootfslen = 0;
138 rootfsaddr = 0;
139 spareaddr = cfelen;
f98872fc 140 }
e190401b 141 sparelen = master->size - spareaddr - nvramlen;
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142
143 /* Determine number of partitions */
fafc3d68 144 if (rootfslen > 0)
70a3c167 145 nrparts++;
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146
147 if (kernellen > 0)
70a3c167 148 nrparts++;
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149
150 /* Ask kernel for more memory */
151 parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
152 if (!parts) {
153 vfree(buf);
154 return -ENOMEM;
155 }
156
157 /* Start building partition list */
158 parts[curpart].name = "CFE";
159 parts[curpart].offset = 0;
678eb9bb 160 parts[curpart].size = cfelen;
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161 curpart++;
162
163 if (kernellen > 0) {
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164 int kernelpart = curpart;
165
166 if (rootfslen > 0 && rootfs_first)
167 kernelpart++;
168 parts[kernelpart].name = "kernel";
169 parts[kernelpart].offset = kerneladdr;
170 parts[kernelpart].size = kernellen;
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171 curpart++;
172 }
173
174 if (rootfslen > 0) {
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175 int rootfspart = curpart;
176
177 if (kernellen > 0 && rootfs_first)
178 rootfspart--;
179 parts[rootfspart].name = "rootfs";
180 parts[rootfspart].offset = rootfsaddr;
181 parts[rootfspart].size = rootfslen;
182 if (sparelen > 0 && !rootfs_first)
183 parts[rootfspart].size += sparelen;
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184 curpart++;
185 }
186
187 parts[curpart].name = "nvram";
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188 parts[curpart].offset = master->size - nvramlen;
189 parts[curpart].size = nvramlen;
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190
191 /* Global partition "linux" to make easy firmware upgrade */
192 curpart++;
193 parts[curpart].name = "linux";
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194 parts[curpart].offset = cfelen;
195 parts[curpart].size = master->size - cfelen - nvramlen;
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196
197 for (i = 0; i < nrparts; i++)
198 pr_info("Partition %d is %s offset %lx and length %lx\n", i,
199 parts[i].name, (long unsigned int)(parts[i].offset),
200 (long unsigned int)(parts[i].size));
201
202 pr_info("Spare partition is offset %x and length %x\n", spareaddr,
203 sparelen);
204
205 *pparts = parts;
206 vfree(buf);
207
208 return nrparts;
209};
210
211static struct mtd_part_parser bcm63xx_cfe_parser = {
212 .owner = THIS_MODULE,
213 .parse_fn = bcm63xx_parse_cfe_partitions,
214 .name = "bcm63xxpart",
215};
216
217static int __init bcm63xx_cfe_parser_init(void)
218{
219 return register_mtd_parser(&bcm63xx_cfe_parser);
220}
221
222static void __exit bcm63xx_cfe_parser_exit(void)
223{
224 deregister_mtd_parser(&bcm63xx_cfe_parser);
225}
226
227module_init(bcm63xx_cfe_parser_init);
228module_exit(bcm63xx_cfe_parser_exit);
229
230MODULE_LICENSE("GPL");
231MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
232MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
233MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
234MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
235MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
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