1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * BCM63XX CFE image tag parser
4 *
5 * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
6 *			  Mike Albon <malbon@openwrt.org>
7 * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
8 * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/bcm963xx_nvram.h>
14#include <linux/bcm963xx_tag.h>
15#include <linux/crc32.h>
16#include <linux/module.h>
17#include <linux/kernel.h>
18#include <linux/sizes.h>
19#include <linux/slab.h>
20#include <linux/vmalloc.h>
21#include <linux/mtd/mtd.h>
22#include <linux/mtd/partitions.h>
23#include <linux/of.h>
24
25#ifdef CONFIG_MIPS
26#include <asm/bootinfo.h>
27#include <asm/fw/cfe/cfe_api.h>
28#endif /* CONFIG_MIPS */
29
30#define BCM963XX_CFE_BLOCK_SIZE		SZ_64K	/* always at least 64KiB */
31
32#define BCM963XX_CFE_MAGIC_OFFSET	0x4e0
33#define BCM963XX_CFE_VERSION_OFFSET	0x570
34#define BCM963XX_NVRAM_OFFSET		0x580
35
36/* Ensure strings read from flash structs are null terminated */
37#define STR_NULL_TERMINATE(x) \
38	do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
39
40static inline int bcm63xx_detect_cfe(void)
41{
42	int ret = 0;
43
44#ifdef CONFIG_MIPS
45	ret = (fw_arg3 == CFE_EPTSEAL);
46#endif /* CONFIG_MIPS */
47
48	return ret;
49}
50
51static int bcm63xx_read_nvram(struct mtd_info *master,
52	struct bcm963xx_nvram *nvram)
53{
54	u32 actual_crc, expected_crc;
55	size_t retlen;
56	int ret;
57
58	/* extract nvram data */
59	ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
60			&retlen, (void *)nvram);
61	if (ret)
62		return ret;
63
64	ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
65	if (ret)
66		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
67			expected_crc, actual_crc);
68
69	if (!nvram->psi_size)
70		nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
71
72	return 0;
73}
74
75static const char * const bcm63xx_cfe_part_types[] = {
76	"bcm963xx-imagetag",
77	NULL,
78};
79
80static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
81	const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
82{
83	struct mtd_partition *parts;
84	int nrparts = 3, curpart = 0;
85	unsigned int cfelen, nvramlen;
86	unsigned int cfe_erasesize;
87	int i;
88
89	cfe_erasesize = max_t(uint32_t, master->erasesize,
90			      BCM963XX_CFE_BLOCK_SIZE);
91
92	cfelen = cfe_erasesize;
93	nvramlen = nvram->psi_size * SZ_1K;
94	nvramlen = roundup(nvramlen, cfe_erasesize);
95
96	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
97	if (!parts)
98		return -ENOMEM;
99
100	/* Start building partition list */
101	parts[curpart].name = "CFE";
102	parts[curpart].offset = 0;
103	parts[curpart].size = cfelen;
104	curpart++;
105
106	parts[curpart].name = "nvram";
107	parts[curpart].offset = master->size - nvramlen;
108	parts[curpart].size = nvramlen;
109	curpart++;
110
111	/* Global partition "linux" to make easy firmware upgrade */
112	parts[curpart].name = "linux";
113	parts[curpart].offset = cfelen;
114	parts[curpart].size = master->size - cfelen - nvramlen;
115	parts[curpart].types = bcm63xx_cfe_part_types;
116
117	for (i = 0; i < nrparts; i++)
118		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
119			parts[i].name, parts[i].offset,	parts[i].size);
120
121	*pparts = parts;
122
123	return nrparts;
124}
125
126static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
127					const struct mtd_partition **pparts,
128					struct mtd_part_parser_data *data)
129{
130	struct bcm963xx_nvram *nvram = NULL;
131	int ret;
132
133	if (!bcm63xx_detect_cfe())
134		return -EINVAL;
135
136	nvram = vzalloc(sizeof(*nvram));
137	if (!nvram)
138		return -ENOMEM;
139
140	ret = bcm63xx_read_nvram(master, nvram);
141	if (ret)
142		goto out;
143
144	if (!mtd_type_is_nand(master))
145		ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
146	else
147		ret = -EINVAL;
148
149out:
150	vfree(nvram);
151	return ret;
152};
153
154static const struct of_device_id parse_bcm63xx_cfe_match_table[] = {
155	{ .compatible = "brcm,bcm963xx-cfe-nor-partitions" },
156	{},
157};
158MODULE_DEVICE_TABLE(of, parse_bcm63xx_cfe_match_table);
159
160static struct mtd_part_parser bcm63xx_cfe_parser = {
161	.parse_fn = bcm63xx_parse_cfe_partitions,
162	.name = "bcm63xxpart",
163	.of_match_table = parse_bcm63xx_cfe_match_table,
164};
165module_mtd_part_parser(bcm63xx_cfe_parser);
166
167MODULE_LICENSE("GPL");
168MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
169MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
170MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
171MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
172MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
173