remoteproc_elf_loader.c 9.32 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
/*
 * Remote Processor Framework Elf loader
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Copyright (C) 2011 Google, Inc.
 *
 * Ohad Ben-Cohen <ohad@wizery.com>
 * Brian Swetland <swetland@google.com>
 * Mark Grosen <mgrosen@ti.com>
 * Fernando Guzman Lugo <fernando.lugo@ti.com>
 * Suman Anna <s-anna@ti.com>
 * Robert Tivy <rtivy@ti.com>
 * Armando Uribe De Leon <x0095078@ti.com>
 * Sjur Brændeland <sjur.brandeland@stericsson.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt)    "%s: " fmt, __func__

#include <linux/module.h>
#include <linux/firmware.h>
#include <linux/remoteproc.h>
#include <linux/elf.h>

#include "remoteproc_internal.h"

/**
36
 * rproc_elf_sanity_check() - Sanity Check ELF firmware image
37 38 39 40 41
 * @rproc: the remote processor handle
 * @fw: the ELF firmware image
 *
 * Make sure this fw image is sane.
 */
42 43
static int
rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68
{
	const char *name = rproc->firmware;
	struct device *dev = &rproc->dev;
	struct elf32_hdr *ehdr;
	char class;

	if (!fw) {
		dev_err(dev, "failed to load %s\n", name);
		return -EINVAL;
	}

	if (fw->size < sizeof(struct elf32_hdr)) {
		dev_err(dev, "Image is too small\n");
		return -EINVAL;
	}

	ehdr = (struct elf32_hdr *)fw->data;

	/* We only support ELF32 at this point */
	class = ehdr->e_ident[EI_CLASS];
	if (class != ELFCLASS32) {
		dev_err(dev, "Unsupported class: %d\n", class);
		return -EINVAL;
	}

69
	/* We assume the firmware has the same endianness as the host */
70 71 72 73 74
# ifdef __LITTLE_ENDIAN
	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
# else /* BIG ENDIAN */
	if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
# endif
75
		dev_err(dev, "Unsupported firmware endianness\n");
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102
		return -EINVAL;
	}

	if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
		dev_err(dev, "Image is too small\n");
		return -EINVAL;
	}

	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
		dev_err(dev, "Image is corrupted (bad magic)\n");
		return -EINVAL;
	}

	if (ehdr->e_phnum == 0) {
		dev_err(dev, "No loadable segments\n");
		return -EINVAL;
	}

	if (ehdr->e_phoff > fw->size) {
		dev_err(dev, "Firmware size is too small\n");
		return -EINVAL;
	}

	return 0;
}

/**
103
 * rproc_elf_get_boot_addr() - Get rproc's boot address.
104 105 106 107 108 109 110 111 112
 * @rproc: the remote processor handle
 * @fw: the ELF firmware image
 *
 * This function returns the entry point address of the ELF
 * image.
 *
 * Note that the boot address is not a configurable property of all remote
 * processors. Some will always boot at a specific hard-coded address.
 */
113 114
static
u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
115 116 117 118 119 120 121
{
	struct elf32_hdr *ehdr  = (struct elf32_hdr *)fw->data;

	return ehdr->e_entry;
}

/**
122
 * rproc_elf_load_segments() - load firmware segments to memory
123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144
 * @rproc: remote processor which will be booted using these fw segments
 * @fw: the ELF firmware image
 *
 * This function loads the firmware segments to memory, where the remote
 * processor expects them.
 *
 * Some remote processors will expect their code and data to be placed
 * in specific device addresses, and can't have them dynamically assigned.
 *
 * We currently support only those kind of remote processors, and expect
 * the program header's paddr member to contain those addresses. We then go
 * through the physically contiguous "carveout" memory regions which we
 * allocated (and mapped) earlier on behalf of the remote processor,
 * and "translate" device address to kernel addresses, so we can copy the
 * segments where they are expected.
 *
 * Currently we only support remote processors that required carveout
 * allocations and got them mapped onto their iommus. Some processors
 * might be different: they might not have iommus, and would prefer to
 * directly allocate memory for every segment/resource. This is not yet
 * supported, though.
 */
145 146
static int
rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178
{
	struct device *dev = &rproc->dev;
	struct elf32_hdr *ehdr;
	struct elf32_phdr *phdr;
	int i, ret = 0;
	const u8 *elf_data = fw->data;

	ehdr = (struct elf32_hdr *)elf_data;
	phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);

	/* go through the available ELF segments */
	for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
		u32 da = phdr->p_paddr;
		u32 memsz = phdr->p_memsz;
		u32 filesz = phdr->p_filesz;
		u32 offset = phdr->p_offset;
		void *ptr;

		if (phdr->p_type != PT_LOAD)
			continue;

		dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
					phdr->p_type, da, memsz, filesz);

		if (filesz > memsz) {
			dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
							filesz, memsz);
			ret = -EINVAL;
			break;
		}

		if (offset + filesz > fw->size) {
179
			dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210
					offset + filesz, fw->size);
			ret = -EINVAL;
			break;
		}

		/* grab the kernel address for this device address */
		ptr = rproc_da_to_va(rproc, da, memsz);
		if (!ptr) {
			dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
			ret = -EINVAL;
			break;
		}

		/* put the segment where the remote processor expects it */
		if (phdr->p_filesz)
			memcpy(ptr, elf_data + phdr->p_offset, filesz);

		/*
		 * Zero out remaining memory for this segment.
		 *
		 * This isn't strictly required since dma_alloc_coherent already
		 * did this for us. albeit harmless, we may consider removing
		 * this.
		 */
		if (memsz > filesz)
			memset(ptr + filesz, 0, memsz - filesz);
	}

	return ret;
}

211 212
static struct elf32_shdr *
find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
213 214
{
	struct elf32_shdr *shdr;
215
	int i;
216 217
	const char *name_table;
	struct resource_table *table = NULL;
218
	const u8 *elf_data = (void *)ehdr;
219

220
	/* look for the resource table and handle it */
221 222 223 224
	shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
	name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset;

	for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
225 226
		u32 size = shdr->sh_size;
		u32 offset = shdr->sh_offset;
227 228 229 230 231 232 233

		if (strcmp(name_table + shdr->sh_name, ".resource_table"))
			continue;

		table = (struct resource_table *)(elf_data + offset);

		/* make sure we have the entire table */
234
		if (offset + size > fw_size || offset + size < size) {
235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263
			dev_err(dev, "resource table truncated\n");
			return NULL;
		}

		/* make sure table has at least the header */
		if (sizeof(struct resource_table) > size) {
			dev_err(dev, "header-less resource table\n");
			return NULL;
		}

		/* we don't support any version beyond the first */
		if (table->ver != 1) {
			dev_err(dev, "unsupported fw ver: %d\n", table->ver);
			return NULL;
		}

		/* make sure reserved bytes are zeroes */
		if (table->reserved[0] || table->reserved[1]) {
			dev_err(dev, "non zero reserved bytes\n");
			return NULL;
		}

		/* make sure the offsets array isn't truncated */
		if (table->num * sizeof(table->offset[0]) +
				sizeof(struct resource_table) > size) {
			dev_err(dev, "resource table incomplete\n");
			return NULL;
		}

264
		return shdr;
265 266
	}

267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303
	return NULL;
}

/**
 * rproc_elf_find_rsc_table() - find the resource table
 * @rproc: the rproc handle
 * @fw: the ELF firmware image
 * @tablesz: place holder for providing back the table size
 *
 * This function finds the resource table inside the remote processor's
 * firmware. It is used both upon the registration of @rproc (in order
 * to look for and register the supported virito devices), and when the
 * @rproc is booted.
 *
 * Returns the pointer to the resource table if it is found, and write its
 * size into @tablesz. If a valid table isn't found, NULL is returned
 * (and @tablesz isn't set).
 */
static struct resource_table *
rproc_elf_find_rsc_table(struct rproc *rproc, const struct firmware *fw,
			 int *tablesz)
{
	struct elf32_hdr *ehdr;
	struct elf32_shdr *shdr;
	struct device *dev = &rproc->dev;
	struct resource_table *table = NULL;
	const u8 *elf_data = fw->data;

	ehdr = (struct elf32_hdr *)elf_data;

	shdr = find_table(dev, ehdr, fw->size);
	if (!shdr)
		return NULL;

	table = (struct resource_table *)(elf_data + shdr->sh_offset);
	*tablesz = shdr->sh_size;

304 305
	return table;
}
306

307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
/**
 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
 * @rproc: the rproc handle
 * @fw: the ELF firmware image
 *
 * This function finds the location of the loaded resource table. Don't
 * call this function if the table wasn't loaded yet - it's a bug if you do.
 *
 * Returns the pointer to the resource table if it is found or NULL otherwise.
 * If the table wasn't loaded yet the result is unspecified.
 */
static struct resource_table *
rproc_elf_find_loaded_rsc_table(struct rproc *rproc, const struct firmware *fw)
{
	struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
	struct elf32_shdr *shdr;

	shdr = find_table(&rproc->dev, ehdr, fw->size);
	if (!shdr)
		return NULL;

	return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
}

331 332 333
const struct rproc_fw_ops rproc_elf_fw_ops = {
	.load = rproc_elf_load_segments,
	.find_rsc_table = rproc_elf_find_rsc_table,
334
	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
335 336 337
	.sanity_check = rproc_elf_sanity_check,
	.get_boot_addr = rproc_elf_get_boot_addr
};