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 static int
  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 };