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 	size_t len = SMEM_FLASH_PTABLE_HDR_LEN;
62 	int ret, i, j, tmpparts, numparts = 0;
63 	struct smem_flash_pentry *pentry;
64 	struct smem_flash_ptable *ptable;
65 	struct mtd_partition *parts;
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 		if (PTR_ERR(ptable) != -EPROBE_DEFER)
79 			pr_err("Error reading partition table header\n");
80 		return PTR_ERR(ptable);
81 	}
82 
83 	/* Verify ptable magic */
84 	if (le32_to_cpu(ptable->magic1) != SMEM_FLASH_PART_MAGIC1 ||
85 	    le32_to_cpu(ptable->magic2) != SMEM_FLASH_PART_MAGIC2) {
86 		pr_err("Partition table magic verification failed\n");
87 		return -EINVAL;
88 	}
89 
90 	/* Ensure that # of partitions is less than the max we have allocated */
91 	tmpparts = le32_to_cpu(ptable->numparts);
92 	if (tmpparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
93 		pr_err("Partition numbers exceed the max limit\n");
94 		return -EINVAL;
95 	}
96 
97 	/* Find out length of partition data based on table version */
98 	if (le32_to_cpu(ptable->version) <= SMEM_FLASH_PTABLE_V3) {
99 		len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V3 *
100 			sizeof(struct smem_flash_pentry);
101 	} else if (le32_to_cpu(ptable->version) == SMEM_FLASH_PTABLE_V4) {
102 		len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V4 *
103 			sizeof(struct smem_flash_pentry);
104 	} else {
105 		pr_err("Unknown ptable version (%d)", le32_to_cpu(ptable->version));
106 		return -EINVAL;
107 	}
108 
109 	/*
110 	 * Now that the partition table header has been parsed, verified
111 	 * and the length of the partition table calculated, read the
112 	 * complete partition table
113 	 */
114 	ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
115 	if (IS_ERR(ptable)) {
116 		pr_err("Error reading partition table\n");
117 		return PTR_ERR(ptable);
118 	}
119 
120 	for (i = 0; i < tmpparts; i++) {
121 		pentry = &ptable->pentry[i];
122 		if (pentry->name[0] != '\0')
123 			numparts++;
124 	}
125 
126 	parts = kcalloc(numparts, sizeof(*parts), GFP_KERNEL);
127 	if (!parts)
128 		return -ENOMEM;
129 
130 	for (i = 0, j = 0; i < tmpparts; i++) {
131 		pentry = &ptable->pentry[i];
132 		if (pentry->name[0] == '\0')
133 			continue;
134 
135 		name = kstrdup(pentry->name, GFP_KERNEL);
136 		if (!name) {
137 			ret = -ENOMEM;
138 			goto out_free_parts;
139 		}
140 
141 		/* Convert name to lower case */
142 		for (c = name; *c != '\0'; c++)
143 			*c = tolower(*c);
144 
145 		parts[j].name = name;
146 		parts[j].offset = le32_to_cpu(pentry->offset) * mtd->erasesize;
147 		parts[j].mask_flags = pentry->attr;
148 		parts[j].size = le32_to_cpu(pentry->length) * mtd->erasesize;
149 		pr_debug("%d: %s offs=0x%08x size=0x%08x attr:0x%08x\n",
150 			 i, pentry->name, le32_to_cpu(pentry->offset),
151 			 le32_to_cpu(pentry->length), pentry->attr);
152 		j++;
153 	}
154 
155 	pr_debug("SMEM partition table found: ver: %d len: %d\n",
156 		 le32_to_cpu(ptable->version), tmpparts);
157 	*pparts = parts;
158 
159 	return numparts;
160 
161 out_free_parts:
162 	while (--j >= 0)
163 		kfree(parts[j].name);
164 	kfree(parts);
165 	*pparts = NULL;
166 
167 	return ret;
168 }
169 
170 static void parse_qcomsmem_cleanup(const struct mtd_partition *pparts,
171 				   int nr_parts)
172 {
173 	int i;
174 
175 	for (i = 0; i < nr_parts; i++)
176 		kfree(pparts[i].name);
177 
178 	kfree(pparts);
179 }
180 
181 static const struct of_device_id qcomsmem_of_match_table[] = {
182 	{ .compatible = "qcom,smem-part" },
183 	{},
184 };
185 MODULE_DEVICE_TABLE(of, qcomsmem_of_match_table);
186 
187 static struct mtd_part_parser mtd_parser_qcomsmem = {
188 	.parse_fn = parse_qcomsmem_part,
189 	.cleanup = parse_qcomsmem_cleanup,
190 	.name = "qcomsmem",
191 	.of_match_table = qcomsmem_of_match_table,
192 };
193 module_mtd_part_parser(mtd_parser_qcomsmem);
194 
195 MODULE_LICENSE("GPL v2");
196 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
197 MODULE_DESCRIPTION("Qualcomm SMEM NAND flash partition parser");
198