1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Qualcomm SMEM NAND flash partition parser
4  *
5  * Copyright (C) 2020, Linaro Ltd.
6  */
7 
8 #include <linux/ctype.h>
9 #include <linux/module.h>
10 #include <linux/mtd/mtd.h>
11 #include <linux/mtd/partitions.h>
12 #include <linux/slab.h>
13 #include <linux/soc/qcom/smem.h>
14 
15 #define SMEM_AARM_PARTITION_TABLE	9
16 #define SMEM_APPS			0
17 
18 #define SMEM_FLASH_PART_MAGIC1		0x55ee73aa
19 #define SMEM_FLASH_PART_MAGIC2		0xe35ebddb
20 #define SMEM_FLASH_PTABLE_V3		3
21 #define SMEM_FLASH_PTABLE_V4		4
22 #define SMEM_FLASH_PTABLE_MAX_PARTS_V3	16
23 #define SMEM_FLASH_PTABLE_MAX_PARTS_V4	48
24 #define SMEM_FLASH_PTABLE_HDR_LEN	(4 * sizeof(u32))
25 #define SMEM_FLASH_PTABLE_NAME_SIZE	16
26 
27 /**
28  * struct smem_flash_pentry - SMEM Flash partition entry
29  * @name: Name of the partition
30  * @offset: Offset in blocks
31  * @length: Length of the partition in blocks
32  * @attr: Flags for this partition
33  */
34 struct smem_flash_pentry {
35 	char name[SMEM_FLASH_PTABLE_NAME_SIZE];
36 	__le32 offset;
37 	__le32 length;
38 	u8 attr;
39 } __packed __aligned(4);
40 
41 /**
42  * struct smem_flash_ptable - SMEM Flash partition table
43  * @magic1: Partition table Magic 1
44  * @magic2: Partition table Magic 2
45  * @version: Partition table version
46  * @numparts: Number of partitions in this ptable
47  * @pentry: Flash partition entries belonging to this ptable
48  */
49 struct smem_flash_ptable {
50 	__le32 magic1;
51 	__le32 magic2;
52 	__le32 version;
53 	__le32 numparts;
54 	struct smem_flash_pentry pentry[SMEM_FLASH_PTABLE_MAX_PARTS_V4];
55 } __packed __aligned(4);
56 
57 static int parse_qcomsmem_part(struct mtd_info *mtd,
58 			       const struct mtd_partition **pparts,
59 			       struct mtd_part_parser_data *data)
60 {
61 	struct smem_flash_pentry *pentry;
62 	struct smem_flash_ptable *ptable;
63 	size_t len = SMEM_FLASH_PTABLE_HDR_LEN;
64 	struct mtd_partition *parts;
65 	int ret, i, numparts;
66 	char *name, *c;
67 
68 	if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_4K_SECTORS)
69 			&& mtd->type == MTD_NORFLASH) {
70 		pr_err("%s: SMEM partition parser is incompatible with 4K sectors\n",
71 				mtd->name);
72 		return -EINVAL;
73 	}
74 
75 	pr_debug("Parsing partition table info from SMEM\n");
76 	ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
77 	if (IS_ERR(ptable)) {
78 		pr_err("Error reading partition table header\n");
79 		return PTR_ERR(ptable);
80 	}
81 
82 	/* Verify ptable magic */
83 	if (le32_to_cpu(ptable->magic1) != SMEM_FLASH_PART_MAGIC1 ||
84 	    le32_to_cpu(ptable->magic2) != SMEM_FLASH_PART_MAGIC2) {
85 		pr_err("Partition table magic verification failed\n");
86 		return -EINVAL;
87 	}
88 
89 	/* Ensure that # of partitions is less than the max we have allocated */
90 	numparts = le32_to_cpu(ptable->numparts);
91 	if (numparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
92 		pr_err("Partition numbers exceed the max limit\n");
93 		return -EINVAL;
94 	}
95 
96 	/* Find out length of partition data based on table version */
97 	if (le32_to_cpu(ptable->version) <= SMEM_FLASH_PTABLE_V3) {
98 		len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V3 *
99 			sizeof(struct smem_flash_pentry);
100 	} else if (le32_to_cpu(ptable->version) == SMEM_FLASH_PTABLE_V4) {
101 		len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V4 *
102 			sizeof(struct smem_flash_pentry);
103 	} else {
104 		pr_err("Unknown ptable version (%d)", le32_to_cpu(ptable->version));
105 		return -EINVAL;
106 	}
107 
108 	/*
109 	 * Now that the partition table header has been parsed, verified
110 	 * and the length of the partition table calculated, read the
111 	 * complete partition table
112 	 */
113 	ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
114 	if (IS_ERR(ptable)) {
115 		pr_err("Error reading partition table\n");
116 		return PTR_ERR(ptable);
117 	}
118 
119 	parts = kcalloc(numparts, sizeof(*parts), GFP_KERNEL);
120 	if (!parts)
121 		return -ENOMEM;
122 
123 	for (i = 0; i < numparts; i++) {
124 		pentry = &ptable->pentry[i];
125 		if (pentry->name[0] == '\0')
126 			continue;
127 
128 		name = kstrdup(pentry->name, GFP_KERNEL);
129 		if (!name) {
130 			ret = -ENOMEM;
131 			goto out_free_parts;
132 		}
133 
134 		/* Convert name to lower case */
135 		for (c = name; *c != '\0'; c++)
136 			*c = tolower(*c);
137 
138 		parts[i].name = name;
139 		parts[i].offset = le32_to_cpu(pentry->offset) * mtd->erasesize;
140 		parts[i].mask_flags = pentry->attr;
141 		parts[i].size = le32_to_cpu(pentry->length) * mtd->erasesize;
142 		pr_debug("%d: %s offs=0x%08x size=0x%08x attr:0x%08x\n",
143 			 i, pentry->name, le32_to_cpu(pentry->offset),
144 			 le32_to_cpu(pentry->length), pentry->attr);
145 	}
146 
147 	pr_debug("SMEM partition table found: ver: %d len: %d\n",
148 		 le32_to_cpu(ptable->version), numparts);
149 	*pparts = parts;
150 
151 	return numparts;
152 
153 out_free_parts:
154 	while (--i >= 0)
155 		kfree(parts[i].name);
156 	kfree(parts);
157 	*pparts = NULL;
158 
159 	return ret;
160 }
161 
162 static const struct of_device_id qcomsmem_of_match_table[] = {
163 	{ .compatible = "qcom,smem-part" },
164 	{},
165 };
166 MODULE_DEVICE_TABLE(of, qcomsmem_of_match_table);
167 
168 static struct mtd_part_parser mtd_parser_qcomsmem = {
169 	.parse_fn = parse_qcomsmem_part,
170 	.name = "qcomsmem",
171 	.of_match_table = qcomsmem_of_match_table,
172 };
173 module_mtd_part_parser(mtd_parser_qcomsmem);
174 
175 MODULE_LICENSE("GPL v2");
176 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
177 MODULE_DESCRIPTION("Qualcomm SMEM NAND flash partition parser");
178