xref: /openbmc/linux/drivers/soc/qcom/mdt_loader.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Qualcomm Peripheral Image Loader
4  *
5  * Copyright (C) 2016 Linaro Ltd
6  * Copyright (C) 2015 Sony Mobile Communications Inc
7  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
8  */
9 
10 #include <linux/device.h>
11 #include <linux/elf.h>
12 #include <linux/firmware.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/qcom_scm.h>
16 #include <linux/sizes.h>
17 #include <linux/slab.h>
18 #include <linux/soc/qcom/mdt_loader.h>
19 
20 static bool mdt_phdr_valid(const struct elf32_phdr *phdr)
21 {
22 	if (phdr->p_type != PT_LOAD)
23 		return false;
24 
25 	if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
26 		return false;
27 
28 	if (!phdr->p_memsz)
29 		return false;
30 
31 	return true;
32 }
33 
34 /**
35  * qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
36  * @fw:		firmware object for the mdt file
37  *
38  * Returns size of the loaded firmware blob, or -EINVAL on failure.
39  */
40 ssize_t qcom_mdt_get_size(const struct firmware *fw)
41 {
42 	const struct elf32_phdr *phdrs;
43 	const struct elf32_phdr *phdr;
44 	const struct elf32_hdr *ehdr;
45 	phys_addr_t min_addr = PHYS_ADDR_MAX;
46 	phys_addr_t max_addr = 0;
47 	int i;
48 
49 	ehdr = (struct elf32_hdr *)fw->data;
50 	phdrs = (struct elf32_phdr *)(ehdr + 1);
51 
52 	for (i = 0; i < ehdr->e_phnum; i++) {
53 		phdr = &phdrs[i];
54 
55 		if (!mdt_phdr_valid(phdr))
56 			continue;
57 
58 		if (phdr->p_paddr < min_addr)
59 			min_addr = phdr->p_paddr;
60 
61 		if (phdr->p_paddr + phdr->p_memsz > max_addr)
62 			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
63 	}
64 
65 	return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
66 }
67 EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
68 
69 /**
70  * qcom_mdt_read_metadata() - read header and metadata from mdt or mbn
71  * @fw:		firmware of mdt header or mbn
72  * @data_len:	length of the read metadata blob
73  *
74  * The mechanism that performs the authentication of the loading firmware
75  * expects an ELF header directly followed by the segment of hashes, with no
76  * padding inbetween. This function allocates a chunk of memory for this pair
77  * and copy the two pieces into the buffer.
78  *
79  * In the case of split firmware the hash is found directly following the ELF
80  * header, rather than at p_offset described by the second program header.
81  *
82  * The caller is responsible to free (kfree()) the returned pointer.
83  *
84  * Return: pointer to data, or ERR_PTR()
85  */
86 void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
87 {
88 	const struct elf32_phdr *phdrs;
89 	const struct elf32_hdr *ehdr;
90 	size_t hash_offset;
91 	size_t hash_size;
92 	size_t ehdr_size;
93 	void *data;
94 
95 	ehdr = (struct elf32_hdr *)fw->data;
96 	phdrs = (struct elf32_phdr *)(ehdr + 1);
97 
98 	if (ehdr->e_phnum < 2)
99 		return ERR_PTR(-EINVAL);
100 
101 	if (phdrs[0].p_type == PT_LOAD || phdrs[1].p_type == PT_LOAD)
102 		return ERR_PTR(-EINVAL);
103 
104 	if ((phdrs[1].p_flags & QCOM_MDT_TYPE_MASK) != QCOM_MDT_TYPE_HASH)
105 		return ERR_PTR(-EINVAL);
106 
107 	ehdr_size = phdrs[0].p_filesz;
108 	hash_size = phdrs[1].p_filesz;
109 
110 	data = kmalloc(ehdr_size + hash_size, GFP_KERNEL);
111 	if (!data)
112 		return ERR_PTR(-ENOMEM);
113 
114 	/* Is the header and hash already packed */
115 	if (ehdr_size + hash_size == fw->size)
116 		hash_offset = phdrs[0].p_filesz;
117 	else
118 		hash_offset = phdrs[1].p_offset;
119 
120 	memcpy(data, fw->data, ehdr_size);
121 	memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
122 
123 	*data_len = ehdr_size + hash_size;
124 
125 	return data;
126 }
127 EXPORT_SYMBOL_GPL(qcom_mdt_read_metadata);
128 
129 static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
130 			   const char *firmware, int pas_id, void *mem_region,
131 			   phys_addr_t mem_phys, size_t mem_size,
132 			   phys_addr_t *reloc_base, bool pas_init)
133 {
134 	const struct elf32_phdr *phdrs;
135 	const struct elf32_phdr *phdr;
136 	const struct elf32_hdr *ehdr;
137 	const struct firmware *seg_fw;
138 	phys_addr_t mem_reloc;
139 	phys_addr_t min_addr = PHYS_ADDR_MAX;
140 	phys_addr_t max_addr = 0;
141 	size_t metadata_len;
142 	size_t fw_name_len;
143 	ssize_t offset;
144 	void *metadata;
145 	char *fw_name;
146 	bool relocate = false;
147 	void *ptr;
148 	int ret = 0;
149 	int i;
150 
151 	if (!fw || !mem_region || !mem_phys || !mem_size)
152 		return -EINVAL;
153 
154 	ehdr = (struct elf32_hdr *)fw->data;
155 	phdrs = (struct elf32_phdr *)(ehdr + 1);
156 
157 	fw_name_len = strlen(firmware);
158 	if (fw_name_len <= 4)
159 		return -EINVAL;
160 
161 	fw_name = kstrdup(firmware, GFP_KERNEL);
162 	if (!fw_name)
163 		return -ENOMEM;
164 
165 	if (pas_init) {
166 		metadata = qcom_mdt_read_metadata(fw, &metadata_len);
167 		if (IS_ERR(metadata)) {
168 			ret = PTR_ERR(metadata);
169 			goto out;
170 		}
171 
172 		ret = qcom_scm_pas_init_image(pas_id, metadata, metadata_len);
173 
174 		kfree(metadata);
175 		if (ret) {
176 			dev_err(dev, "invalid firmware metadata\n");
177 			goto out;
178 		}
179 	}
180 
181 	for (i = 0; i < ehdr->e_phnum; i++) {
182 		phdr = &phdrs[i];
183 
184 		if (!mdt_phdr_valid(phdr))
185 			continue;
186 
187 		if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
188 			relocate = true;
189 
190 		if (phdr->p_paddr < min_addr)
191 			min_addr = phdr->p_paddr;
192 
193 		if (phdr->p_paddr + phdr->p_memsz > max_addr)
194 			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
195 	}
196 
197 	if (relocate) {
198 		if (pas_init) {
199 			ret = qcom_scm_pas_mem_setup(pas_id, mem_phys,
200 						     max_addr - min_addr);
201 			if (ret) {
202 				dev_err(dev, "unable to setup relocation\n");
203 				goto out;
204 			}
205 		}
206 
207 		/*
208 		 * The image is relocatable, so offset each segment based on
209 		 * the lowest segment address.
210 		 */
211 		mem_reloc = min_addr;
212 	} else {
213 		/*
214 		 * Image is not relocatable, so offset each segment based on
215 		 * the allocated physical chunk of memory.
216 		 */
217 		mem_reloc = mem_phys;
218 	}
219 
220 	for (i = 0; i < ehdr->e_phnum; i++) {
221 		phdr = &phdrs[i];
222 
223 		if (!mdt_phdr_valid(phdr))
224 			continue;
225 
226 		offset = phdr->p_paddr - mem_reloc;
227 		if (offset < 0 || offset + phdr->p_memsz > mem_size) {
228 			dev_err(dev, "segment outside memory range\n");
229 			ret = -EINVAL;
230 			break;
231 		}
232 
233 		ptr = mem_region + offset;
234 
235 		if (phdr->p_filesz && phdr->p_offset < fw->size) {
236 			/* Firmware is large enough to be non-split */
237 			if (phdr->p_offset + phdr->p_filesz > fw->size) {
238 				dev_err(dev,
239 					"failed to load segment %d from truncated file %s\n",
240 					i, firmware);
241 				ret = -EINVAL;
242 				break;
243 			}
244 
245 			memcpy(ptr, fw->data + phdr->p_offset, phdr->p_filesz);
246 		} else if (phdr->p_filesz) {
247 			/* Firmware not large enough, load split-out segments */
248 			sprintf(fw_name + fw_name_len - 3, "b%02d", i);
249 			ret = request_firmware_into_buf(&seg_fw, fw_name, dev,
250 							ptr, phdr->p_filesz);
251 			if (ret) {
252 				dev_err(dev, "failed to load %s\n", fw_name);
253 				break;
254 			}
255 
256 			release_firmware(seg_fw);
257 		}
258 
259 		if (phdr->p_memsz > phdr->p_filesz)
260 			memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
261 	}
262 
263 	if (reloc_base)
264 		*reloc_base = mem_reloc;
265 
266 out:
267 	kfree(fw_name);
268 
269 	return ret;
270 }
271 
272 /**
273  * qcom_mdt_load() - load the firmware which header is loaded as fw
274  * @dev:	device handle to associate resources with
275  * @fw:		firmware object for the mdt file
276  * @firmware:	name of the firmware, for construction of segment file names
277  * @pas_id:	PAS identifier
278  * @mem_region:	allocated memory region to load firmware into
279  * @mem_phys:	physical address of allocated memory region
280  * @mem_size:	size of the allocated memory region
281  * @reloc_base:	adjusted physical address after relocation
282  *
283  * Returns 0 on success, negative errno otherwise.
284  */
285 int qcom_mdt_load(struct device *dev, const struct firmware *fw,
286 		  const char *firmware, int pas_id, void *mem_region,
287 		  phys_addr_t mem_phys, size_t mem_size,
288 		  phys_addr_t *reloc_base)
289 {
290 	return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
291 			       mem_size, reloc_base, true);
292 }
293 EXPORT_SYMBOL_GPL(qcom_mdt_load);
294 
295 /**
296  * qcom_mdt_load_no_init() - load the firmware which header is loaded as fw
297  * @dev:	device handle to associate resources with
298  * @fw:		firmware object for the mdt file
299  * @firmware:	name of the firmware, for construction of segment file names
300  * @pas_id:	PAS identifier
301  * @mem_region:	allocated memory region to load firmware into
302  * @mem_phys:	physical address of allocated memory region
303  * @mem_size:	size of the allocated memory region
304  * @reloc_base:	adjusted physical address after relocation
305  *
306  * Returns 0 on success, negative errno otherwise.
307  */
308 int qcom_mdt_load_no_init(struct device *dev, const struct firmware *fw,
309 			  const char *firmware, int pas_id,
310 			  void *mem_region, phys_addr_t mem_phys,
311 			  size_t mem_size, phys_addr_t *reloc_base)
312 {
313 	return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
314 			       mem_size, reloc_base, false);
315 }
316 EXPORT_SYMBOL_GPL(qcom_mdt_load_no_init);
317 
318 MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
319 MODULE_LICENSE("GPL v2");
320