drivers/remoteproc/remoteproc_elf_loader.c

   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 int 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 }
 100 EXPORT_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  */
 113 u32 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 }
 119 EXPORT_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  */
 145 int 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 }
 209 EXPORT_SYMBOL(rproc_elf_load_segments);
 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_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  */
 280 int 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 }
 313 EXPORT_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  */
 326 struct 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 }
 338 EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);