1 /*
2 * Remote Processor Framework Elf loader
3 *
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Copyright (C) 2011 Google, Inc.
6 *
7 * Ohad Ben-Cohen <ohad@wizery.com>
8 * Brian Swetland <swetland@google.com>
9 * Mark Grosen <mgrosen@ti.com>
10 * Fernando Guzman Lugo <fernando.lugo@ti.com>
11 * Suman Anna <s-anna@ti.com>
12 * Robert Tivy <rtivy@ti.com>
13 * Armando Uribe De Leon <x0095078@ti.com>
14 * Sjur Brændeland <sjur.brandeland@stericsson.com>
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * version 2 as published by the Free Software Foundation.
19 *
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
24 */
25
26 #define pr_fmt(fmt) "%s: " fmt, __func__
27
28 #include <linux/module.h>
29 #include <linux/firmware.h>
30 #include <linux/remoteproc.h>
31 #include <linux/elf.h>
32
33 #include "remoteproc_internal.h"
34
35 /**
36 * rproc_elf_sanity_check() - Sanity Check ELF firmware image
37 * @rproc: the remote processor handle
38 * @fw: the ELF firmware image
39 *
40 * Make sure this fw image is sane.
41 */
42 static int
rproc_elf_sanity_check(struct rproc * rproc,const struct firmware * fw)43 rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
44 {
45 const char *name = rproc->firmware;
46 struct device *dev = &rproc->dev;
47 struct elf32_hdr *ehdr;
48 char class;
49
50 if (!fw) {
51 dev_err(dev, "failed to load %s\n", name);
52 return -EINVAL;
53 }
54
55 if (fw->size < sizeof(struct elf32_hdr)) {
56 dev_err(dev, "Image is too small\n");
57 return -EINVAL;
58 }
59
60 ehdr = (struct elf32_hdr *)fw->data;
61
62 /* We only support ELF32 at this point */
63 class = ehdr->e_ident[EI_CLASS];
64 if (class != ELFCLASS32) {
65 dev_err(dev, "Unsupported class: %d\n", class);
66 return -EINVAL;
67 }
68
69 /* We assume the firmware has the same endianness as the host */
70 # ifdef __LITTLE_ENDIAN
71 if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
72 # else /* BIG ENDIAN */
73 if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
74 # endif
75 dev_err(dev, "Unsupported firmware endianness\n");
76 return -EINVAL;
77 }
78
79 if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
80 dev_err(dev, "Image is too small\n");
81 return -EINVAL;
82 }
83
84 if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
85 dev_err(dev, "Image is corrupted (bad magic)\n");
86 return -EINVAL;
87 }
88
89 if (ehdr->e_phnum == 0) {
90 dev_err(dev, "No loadable segments\n");
91 return -EINVAL;
92 }
93
94 if (ehdr->e_phoff > fw->size) {
95 dev_err(dev, "Firmware size is too small\n");
96 return -EINVAL;
97 }
98
99 return 0;
100 }
101
102 /**
103 * rproc_elf_get_boot_addr() - Get rproc's boot address.
104 * @rproc: the remote processor handle
105 * @fw: the ELF firmware image
106 *
107 * This function returns the entry point address of the ELF
108 * image.
109 *
110 * Note that the boot address is not a configurable property of all remote
111 * processors. Some will always boot at a specific hard-coded address.
112 */
113 static
114 u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
115 {
116 struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
117
118 return ehdr->e_entry;
119 }
120
121 /**
122 * rproc_elf_load_segments() - load firmware segments to memory
123 * @rproc: remote processor which will be booted using these fw segments
124 * @fw: the ELF firmware image
125 *
126 * This function loads the firmware segments to memory, where the remote
127 * processor expects them.
128 *
129 * Some remote processors will expect their code and data to be placed
130 * in specific device addresses, and can't have them dynamically assigned.
131 *
132 * We currently support only those kind of remote processors, and expect
133 * the program header's paddr member to contain those addresses. We then go
134 * through the physically contiguous "carveout" memory regions which we
135 * allocated (and mapped) earlier on behalf of the remote processor,
136 * and "translate" device address to kernel addresses, so we can copy the
137 * segments where they are expected.
138 *
139 * Currently we only support remote processors that required carveout
140 * allocations and got them mapped onto their iommus. Some processors
141 * might be different: they might not have iommus, and would prefer to
142 * directly allocate memory for every segment/resource. This is not yet
143 * supported, though.
144 */
145 static int
146 rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
147 {
148 struct device *dev = &rproc->dev;
149 struct elf32_hdr *ehdr;
150 struct elf32_phdr *phdr;
151 int i, ret = 0;
152 const u8 *elf_data = fw->data;
153
154 ehdr = (struct elf32_hdr *)elf_data;
155 phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
156
157 /* go through the available ELF segments */
158 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
159 u32 da = phdr->p_paddr;
160 u32 memsz = phdr->p_memsz;
161 u32 filesz = phdr->p_filesz;
162 u32 offset = phdr->p_offset;
163 void *ptr;
164
165 if (phdr->p_type != PT_LOAD)
166 continue;
167
168 dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
169 phdr->p_type, da, memsz, filesz);
170
171 if (filesz > memsz) {
172 dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
173 filesz, memsz);
174 ret = -EINVAL;
175 break;
176 }
177
178 if (offset + filesz > fw->size) {
179 dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
180 offset + filesz, fw->size);
181 ret = -EINVAL;
182 break;
183 }
184
185 /* grab the kernel address for this device address */
186 ptr = rproc_da_to_va(rproc, da, memsz);
187 if (!ptr) {
188 dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
189 ret = -EINVAL;
190 break;
191 }
192
193 /* put the segment where the remote processor expects it */
194 if (phdr->p_filesz)
195 memcpy(ptr, elf_data + phdr->p_offset, filesz);
196
197 /*
198 * Zero out remaining memory for this segment.
199 *
200 * This isn't strictly required since dma_alloc_coherent already
201 * did this for us. albeit harmless, we may consider removing
202 * this.
203 */
204 if (memsz > filesz)
205 memset(ptr + filesz, 0, memsz - filesz);
206 }
207
208 return ret;
209 }
210
211 static struct elf32_shdr *
212 find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
213 {
214 struct elf32_shdr *shdr;
215 int i;
216 const char *name_table;
217 struct resource_table *table = NULL;
218 const u8 *elf_data = (void *)ehdr;
219
220 /* look for the resource table and handle it */
221 shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
222 name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset;
223
224 for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
225 u32 size = shdr->sh_size;
226 u32 offset = shdr->sh_offset;
227
228 if (strcmp(name_table + shdr->sh_name, ".resource_table"))
229 continue;
230
231 table = (struct resource_table *)(elf_data + offset);
232
233 /* make sure we have the entire table */
234 if (offset + size > fw_size || offset + size < size) {
235 dev_err(dev, "resource table truncated\n");
236 return NULL;
237 }
238
239 /* make sure table has at least the header */
240 if (sizeof(struct resource_table) > size) {
241 dev_err(dev, "header-less resource table\n");
242 return NULL;
243 }
244
245 /* we don't support any version beyond the first */
246 if (table->ver != 1) {
247 dev_err(dev, "unsupported fw ver: %d\n", table->ver);
248 return NULL;
249 }
250
251 /* make sure reserved bytes are zeroes */
252 if (table->reserved[0] || table->reserved[1]) {
253 dev_err(dev, "non zero reserved bytes\n");
254 return NULL;
255 }
256
257 /* make sure the offsets array isn't truncated */
258 if (table->num * sizeof(table->offset[0]) +
259 sizeof(struct resource_table) > size) {
260 dev_err(dev, "resource table incomplete\n");
261 return NULL;
262 }
263
264 return shdr;
265 }
266
267 return NULL;
268 }
269
270 /**
271 * rproc_elf_find_rsc_table() - find the resource table
272 * @rproc: the rproc handle
273 * @fw: the ELF firmware image
274 * @tablesz: place holder for providing back the table size
275 *
276 * This function finds the resource table inside the remote processor's
277 * firmware. It is used both upon the registration of @rproc (in order
278 * to look for and register the supported virito devices), and when the
279 * @rproc is booted.
280 *
281 * Returns the pointer to the resource table if it is found, and write its
282 * size into @tablesz. If a valid table isn't found, NULL is returned
283 * (and @tablesz isn't set).
284 */
285 static struct resource_table *
286 rproc_elf_find_rsc_table(struct rproc *rproc, const struct firmware *fw,
287 int *tablesz)
288 {
289 struct elf32_hdr *ehdr;
290 struct elf32_shdr *shdr;
291 struct device *dev = &rproc->dev;
292 struct resource_table *table = NULL;
293 const u8 *elf_data = fw->data;
294
295 ehdr = (struct elf32_hdr *)elf_data;
296
297 shdr = find_table(dev, ehdr, fw->size);
298 if (!shdr)
299 return NULL;
300
301 table = (struct resource_table *)(elf_data + shdr->sh_offset);
302 *tablesz = shdr->sh_size;
303
304 return table;
305 }
306
307 /**
308 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
309 * @rproc: the rproc handle
310 * @fw: the ELF firmware image
311 *
312 * This function finds the location of the loaded resource table. Don't
313 * call this function if the table wasn't loaded yet - it's a bug if you do.
314 *
315 * Returns the pointer to the resource table if it is found or NULL otherwise.
316 * If the table wasn't loaded yet the result is unspecified.
317 */
318 static struct resource_table *
319 rproc_elf_find_loaded_rsc_table(struct rproc *rproc, const struct firmware *fw)
320 {
321 struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
322 struct elf32_shdr *shdr;
323
324 shdr = find_table(&rproc->dev, ehdr, fw->size);
325 if (!shdr)
326 return NULL;
327
328 return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
329 }
330
331 const struct rproc_fw_ops rproc_elf_fw_ops = {
332 .load = rproc_elf_load_segments,
333 .find_rsc_table = rproc_elf_find_rsc_table,
334 .find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
335 .sanity_check = rproc_elf_sanity_check,
336 .get_boot_addr = rproc_elf_get_boot_addr
337 };
338