xref: /openbmc/linux/drivers/soc/qcom/mdt_loader.c (revision d236d361)
1 /*
2  * Qualcomm Peripheral Image Loader
3  *
4  * Copyright (C) 2016 Linaro Ltd
5  * Copyright (C) 2015 Sony Mobile Communications Inc
6  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/device.h>
19 #include <linux/elf.h>
20 #include <linux/firmware.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/qcom_scm.h>
24 #include <linux/sizes.h>
25 #include <linux/slab.h>
26 #include <linux/soc/qcom/mdt_loader.h>
27 
28 static bool mdt_phdr_valid(const struct elf32_phdr *phdr)
29 {
30 	if (phdr->p_type != PT_LOAD)
31 		return false;
32 
33 	if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
34 		return false;
35 
36 	if (!phdr->p_memsz)
37 		return false;
38 
39 	return true;
40 }
41 
42 /**
43  * qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
44  * @fw:		firmware object for the mdt file
45  *
46  * Returns size of the loaded firmware blob, or -EINVAL on failure.
47  */
48 ssize_t qcom_mdt_get_size(const struct firmware *fw)
49 {
50 	const struct elf32_phdr *phdrs;
51 	const struct elf32_phdr *phdr;
52 	const struct elf32_hdr *ehdr;
53 	phys_addr_t min_addr = (phys_addr_t)ULLONG_MAX;
54 	phys_addr_t max_addr = 0;
55 	int i;
56 
57 	ehdr = (struct elf32_hdr *)fw->data;
58 	phdrs = (struct elf32_phdr *)(ehdr + 1);
59 
60 	for (i = 0; i < ehdr->e_phnum; i++) {
61 		phdr = &phdrs[i];
62 
63 		if (!mdt_phdr_valid(phdr))
64 			continue;
65 
66 		if (phdr->p_paddr < min_addr)
67 			min_addr = phdr->p_paddr;
68 
69 		if (phdr->p_paddr + phdr->p_memsz > max_addr)
70 			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
71 	}
72 
73 	return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
74 }
75 EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
76 
77 /**
78  * qcom_mdt_load() - load the firmware which header is loaded as fw
79  * @dev:	device handle to associate resources with
80  * @fw:		firmware object for the mdt file
81  * @firmware:	name of the firmware, for construction of segment file names
82  * @pas_id:	PAS identifier
83  * @mem_region:	allocated memory region to load firmware into
84  * @mem_phys:	physical address of allocated memory region
85  * @mem_size:	size of the allocated memory region
86  *
87  * Returns 0 on success, negative errno otherwise.
88  */
89 int qcom_mdt_load(struct device *dev, const struct firmware *fw,
90 		  const char *firmware, int pas_id, void *mem_region,
91 		  phys_addr_t mem_phys, size_t mem_size)
92 {
93 	const struct elf32_phdr *phdrs;
94 	const struct elf32_phdr *phdr;
95 	const struct elf32_hdr *ehdr;
96 	const struct firmware *seg_fw;
97 	phys_addr_t mem_reloc;
98 	phys_addr_t min_addr = (phys_addr_t)ULLONG_MAX;
99 	phys_addr_t max_addr = 0;
100 	size_t fw_name_len;
101 	ssize_t offset;
102 	char *fw_name;
103 	bool relocate = false;
104 	void *ptr;
105 	int ret;
106 	int i;
107 
108 	if (!fw || !mem_region || !mem_phys || !mem_size)
109 		return -EINVAL;
110 
111 	ehdr = (struct elf32_hdr *)fw->data;
112 	phdrs = (struct elf32_phdr *)(ehdr + 1);
113 
114 	fw_name_len = strlen(firmware);
115 	if (fw_name_len <= 4)
116 		return -EINVAL;
117 
118 	fw_name = kstrdup(firmware, GFP_KERNEL);
119 	if (!fw_name)
120 		return -ENOMEM;
121 
122 	ret = qcom_scm_pas_init_image(pas_id, fw->data, fw->size);
123 	if (ret) {
124 		dev_err(dev, "invalid firmware metadata\n");
125 		goto out;
126 	}
127 
128 	for (i = 0; i < ehdr->e_phnum; i++) {
129 		phdr = &phdrs[i];
130 
131 		if (!mdt_phdr_valid(phdr))
132 			continue;
133 
134 		if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
135 			relocate = true;
136 
137 		if (phdr->p_paddr < min_addr)
138 			min_addr = phdr->p_paddr;
139 
140 		if (phdr->p_paddr + phdr->p_memsz > max_addr)
141 			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
142 	}
143 
144 	if (relocate) {
145 		ret = qcom_scm_pas_mem_setup(pas_id, mem_phys, max_addr - min_addr);
146 		if (ret) {
147 			dev_err(dev, "unable to setup relocation\n");
148 			goto out;
149 		}
150 
151 		/*
152 		 * The image is relocatable, so offset each segment based on
153 		 * the lowest segment address.
154 		 */
155 		mem_reloc = min_addr;
156 	} else {
157 		/*
158 		 * Image is not relocatable, so offset each segment based on
159 		 * the allocated physical chunk of memory.
160 		 */
161 		mem_reloc = mem_phys;
162 	}
163 
164 	for (i = 0; i < ehdr->e_phnum; i++) {
165 		phdr = &phdrs[i];
166 
167 		if (!mdt_phdr_valid(phdr))
168 			continue;
169 
170 		offset = phdr->p_paddr - mem_reloc;
171 		if (offset < 0 || offset + phdr->p_memsz > mem_size) {
172 			dev_err(dev, "segment outside memory range\n");
173 			ret = -EINVAL;
174 			break;
175 		}
176 
177 		ptr = mem_region + offset;
178 
179 		if (phdr->p_filesz) {
180 			sprintf(fw_name + fw_name_len - 3, "b%02d", i);
181 			ret = request_firmware(&seg_fw, fw_name, dev);
182 			if (ret) {
183 				dev_err(dev, "failed to load %s\n", fw_name);
184 				break;
185 			}
186 
187 			memcpy(ptr, seg_fw->data, seg_fw->size);
188 
189 			release_firmware(seg_fw);
190 		}
191 
192 		if (phdr->p_memsz > phdr->p_filesz)
193 			memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
194 	}
195 
196 out:
197 	kfree(fw_name);
198 
199 	return ret;
200 }
201 EXPORT_SYMBOL_GPL(qcom_mdt_load);
202 
203 MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
204 MODULE_LICENSE("GPL v2");
205