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 */
 42int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
 43{
 44	const char *name = rproc->firmware;
 45	struct device *dev = &rproc->dev;
 46	struct elf32_hdr *ehdr;
 47	char class;
 48
 49	if (!fw) {
 50		dev_err(dev, "failed to load %s\n", name);
 51		return -EINVAL;
 52	}
 53
 54	if (fw->size < sizeof(struct elf32_hdr)) {
 55		dev_err(dev, "Image is too small\n");
 56		return -EINVAL;
 57	}
 58
 59	ehdr = (struct elf32_hdr *)fw->data;
 60
 61	/* We only support ELF32 at this point */
 62	class = ehdr->e_ident[EI_CLASS];
 63	if (class != ELFCLASS32) {
 64		dev_err(dev, "Unsupported class: %d\n", class);
 65		return -EINVAL;
 66	}
 67
 68	/* We assume the firmware has the same endianness as the host */
 69# ifdef __LITTLE_ENDIAN
 70	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
 71# else /* BIG ENDIAN */
 72	if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
 73# endif
 74		dev_err(dev, "Unsupported firmware endianness\n");
 75		return -EINVAL;
 76	}
 77
 78	if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
 79		dev_err(dev, "Image is too small\n");
 80		return -EINVAL;
 81	}
 82
 83	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
 84		dev_err(dev, "Image is corrupted (bad magic)\n");
 85		return -EINVAL;
 86	}
 87
 88	if (ehdr->e_phnum == 0) {
 89		dev_err(dev, "No loadable segments\n");
 90		return -EINVAL;
 91	}
 92
 93	if (ehdr->e_phoff > fw->size) {
 94		dev_err(dev, "Firmware size is too small\n");
 95		return -EINVAL;
 96	}
 97
 98	return 0;
 99}
100EXPORT_SYMBOL(rproc_elf_sanity_check);
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 */
113u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
114{
115	struct elf32_hdr *ehdr  = (struct elf32_hdr *)fw->data;
116
117	return ehdr->e_entry;
118}
119EXPORT_SYMBOL(rproc_elf_get_boot_addr);
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 */
145int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
146{
147	struct device *dev = &rproc->dev;
148	struct elf32_hdr *ehdr;
149	struct elf32_phdr *phdr;
150	int i, ret = 0;
151	const u8 *elf_data = fw->data;
152
153	ehdr = (struct elf32_hdr *)elf_data;
154	phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
155
156	/* go through the available ELF segments */
157	for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
158		u32 da = phdr->p_paddr;
159		u32 memsz = phdr->p_memsz;
160		u32 filesz = phdr->p_filesz;
161		u32 offset = phdr->p_offset;
162		void *ptr;
163
164		if (phdr->p_type != PT_LOAD)
165			continue;
166
167		dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
168			phdr->p_type, da, memsz, filesz);
169
170		if (filesz > memsz) {
171			dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
172				filesz, memsz);
173			ret = -EINVAL;
174			break;
175		}
176
177		if (offset + filesz > fw->size) {
178			dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
179				offset + filesz, fw->size);
180			ret = -EINVAL;
181			break;
182		}
183
184		/* grab the kernel address for this device address */
185		ptr = rproc_da_to_va(rproc, da, memsz);
186		if (!ptr) {
187			dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
188			ret = -EINVAL;
189			break;
190		}
191
192		/* put the segment where the remote processor expects it */
193		if (phdr->p_filesz)
194			memcpy(ptr, elf_data + phdr->p_offset, filesz);
195
196		/*
197		 * Zero out remaining memory for this segment.
198		 *
199		 * This isn't strictly required since dma_alloc_coherent already
200		 * did this for us. albeit harmless, we may consider removing
201		 * this.
202		 */
203		if (memsz > filesz)
204			memset(ptr + filesz, 0, memsz - filesz);
205	}
206
207	return ret;
208}
209EXPORT_SYMBOL(rproc_elf_load_segments);
210
211static struct elf32_shdr *
212find_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_load_rsc_table() - load the resource table
272 * @rproc: the rproc handle
273 * @fw: the ELF firmware image
274 *
275 * This function finds the resource table inside the remote processor's
276 * firmware, load it into the @cached_table and update @table_ptr.
277 *
278 * Return: 0 on success, negative errno on failure.
279 */
280int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
281{
282	struct elf32_hdr *ehdr;
283	struct elf32_shdr *shdr;
284	struct device *dev = &rproc->dev;
285	struct resource_table *table = NULL;
286	const u8 *elf_data = fw->data;
287	size_t tablesz;
288
289	ehdr = (struct elf32_hdr *)elf_data;
290
291	shdr = find_table(dev, ehdr, fw->size);
292	if (!shdr)
293		return -EINVAL;
294
295	table = (struct resource_table *)(elf_data + shdr->sh_offset);
296	tablesz = shdr->sh_size;
297
298	/*
299	 * Create a copy of the resource table. When a virtio device starts
300	 * and calls vring_new_virtqueue() the address of the allocated vring
301	 * will be stored in the cached_table. Before the device is started,
302	 * cached_table will be copied into device memory.
303	 */
304	rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
305	if (!rproc->cached_table)
306		return -ENOMEM;
307
308	rproc->table_ptr = rproc->cached_table;
309	rproc->table_sz = tablesz;
310
311	return 0;
312}
313EXPORT_SYMBOL(rproc_elf_load_rsc_table);
314
315/**
316 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
317 * @rproc: the rproc handle
318 * @fw: the ELF firmware image
319 *
320 * This function finds the location of the loaded resource table. Don't
321 * call this function if the table wasn't loaded yet - it's a bug if you do.
322 *
323 * Returns the pointer to the resource table if it is found or NULL otherwise.
324 * If the table wasn't loaded yet the result is unspecified.
325 */
326struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
327						       const struct firmware *fw)
328{
329	struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
330	struct elf32_shdr *shdr;
331
332	shdr = find_table(&rproc->dev, ehdr, fw->size);
333	if (!shdr)
334		return NULL;
335
336	return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
337}
338EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);