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 */
34struct 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 */
49struct 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
57static 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
161out_free_parts:
162	while (--j >= 0)
163		kfree(parts[j].name);
164	kfree(parts);
165	*pparts = NULL;
166
167	return ret;
168}
169
170static 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
181static const struct of_device_id qcomsmem_of_match_table[] = {
182	{ .compatible = "qcom,smem-part" },
183	{},
184};
185MODULE_DEVICE_TABLE(of, qcomsmem_of_match_table);
186
187static 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};
193module_mtd_part_parser(mtd_parser_qcomsmem);
194
195MODULE_LICENSE("GPL v2");
196MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
197MODULE_DESCRIPTION("Qualcomm SMEM NAND flash partition parser");
198