drivers/remoteproc/remoteproc_elf_loader.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Remote Processor Framework Elf loader
   4  *
   5  * Copyright (C) 2011 Texas Instruments, Inc.
   6  * Copyright (C) 2011 Google, Inc.
   7  *
   8  * Ohad Ben-Cohen <ohad@wizery.com>
   9  * Brian Swetland <swetland@google.com>
  10  * Mark Grosen <mgrosen@ti.com>
  11  * Fernando Guzman Lugo <fernando.lugo@ti.com>
  12  * Suman Anna <s-anna@ti.com>
  13  * Robert Tivy <rtivy@ti.com>
  14  * Armando Uribe De Leon <x0095078@ti.com>
  15  * Sjur Brændeland <sjur.brandeland@stericsson.com>
  16  */
  17
  18 #define pr_fmt(fmt)    "%s: " fmt, __func__
  19
  20 #include <linux/module.h>
  21 #include <linux/firmware.h>
  22 #include <linux/remoteproc.h>
  23 #include <linux/elf.h>
  24
  25 #include "remoteproc_internal.h"
  26
  27 /**
  28  * rproc_elf_sanity_check() - Sanity Check ELF firmware image
  29  * @rproc: the remote processor handle
  30  * @fw: the ELF firmware image
  31  *
  32  * Make sure this fw image is sane.
  33  */
  34 int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
  35 {
  36         const char *name = rproc->firmware;
  37         struct device *dev = &rproc->dev;
  38         struct elf32_hdr *ehdr;
  39         char class;
  40
  41         if (!fw) {
  42                 dev_err(dev, "failed to load %s\n", name);
  43                 return -EINVAL;
  44         }
  45
  46         if (fw->size < sizeof(struct elf32_hdr)) {
  47                 dev_err(dev, "Image is too small\n");
  48                 return -EINVAL;
  49         }
  50
  51         ehdr = (struct elf32_hdr *)fw->data;
  52
  53         /* We only support ELF32 at this point */
  54         class = ehdr->e_ident[EI_CLASS];
  55         if (class != ELFCLASS32) {
  56                 dev_err(dev, "Unsupported class: %d\n", class);
  57                 return -EINVAL;
  58         }
  59
  60         /* We assume the firmware has the same endianness as the host */
  61 # ifdef __LITTLE_ENDIAN
  62         if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
  63 # else /* BIG ENDIAN */
  64         if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
  65 # endif
  66                 dev_err(dev, "Unsupported firmware endianness\n");
  67                 return -EINVAL;
  68         }
  69
  70         if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
  71                 dev_err(dev, "Image is too small\n");
  72                 return -EINVAL;
  73         }
  74
  75         if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
  76                 dev_err(dev, "Image is corrupted (bad magic)\n");
  77                 return -EINVAL;
  78         }
  79
  80         if (ehdr->e_phnum == 0) {
  81                 dev_err(dev, "No loadable segments\n");
  82                 return -EINVAL;
  83         }
  84
  85         if (ehdr->e_phoff > fw->size) {
  86                 dev_err(dev, "Firmware size is too small\n");
  87                 return -EINVAL;
  88         }
  89
  90         return 0;
  91 }
  92 EXPORT_SYMBOL(rproc_elf_sanity_check);
  93
  94 /**
  95  * rproc_elf_get_boot_addr() - Get rproc's boot address.
  96  * @rproc: the remote processor handle
  97  * @fw: the ELF firmware image
  98  *
  99  * This function returns the entry point address of the ELF
 100  * image.
 101  *
 102  * Note that the boot address is not a configurable property of all remote
 103  * processors. Some will always boot at a specific hard-coded address.
 104  */
 105 u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
 106 {
 107         struct elf32_hdr *ehdr  = (struct elf32_hdr *)fw->data;
 108
 109         return ehdr->e_entry;
 110 }
 111 EXPORT_SYMBOL(rproc_elf_get_boot_addr);
 112
 113 /**
 114  * rproc_elf_load_segments() - load firmware segments to memory
 115  * @rproc: remote processor which will be booted using these fw segments
 116  * @fw: the ELF firmware image
 117  *
 118  * This function loads the firmware segments to memory, where the remote
 119  * processor expects them.
 120  *
 121  * Some remote processors will expect their code and data to be placed
 122  * in specific device addresses, and can't have them dynamically assigned.
 123  *
 124  * We currently support only those kind of remote processors, and expect
 125  * the program header's paddr member to contain those addresses. We then go
 126  * through the physically contiguous "carveout" memory regions which we
 127  * allocated (and mapped) earlier on behalf of the remote processor,
 128  * and "translate" device address to kernel addresses, so we can copy the
 129  * segments where they are expected.
 130  *
 131  * Currently we only support remote processors that required carveout
 132  * allocations and got them mapped onto their iommus. Some processors
 133  * might be different: they might not have iommus, and would prefer to
 134  * directly allocate memory for every segment/resource. This is not yet
 135  * supported, though.
 136  */
 137 int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
 138 {
 139         struct device *dev = &rproc->dev;
 140         struct elf32_hdr *ehdr;
 141         struct elf32_phdr *phdr;
 142         int i, ret = 0;
 143         const u8 *elf_data = fw->data;
 144
 145         ehdr = (struct elf32_hdr *)elf_data;
 146         phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
 147
 148         /* go through the available ELF segments */
 149         for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
 150                 u32 da = phdr->p_paddr;
 151                 u32 memsz = phdr->p_memsz;
 152                 u32 filesz = phdr->p_filesz;
 153                 u32 offset = phdr->p_offset;
 154                 void *ptr;
 155
 156                 if (phdr->p_type != PT_LOAD)
 157                         continue;
 158
 159                 dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
 160                         phdr->p_type, da, memsz, filesz);
 161
 162                 if (filesz > memsz) {
 163                         dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
 164                                 filesz, memsz);
 165                         ret = -EINVAL;
 166                         break;
 167                 }
 168
 169                 if (offset + filesz > fw->size) {
 170                         dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
 171                                 offset + filesz, fw->size);
 172                         ret = -EINVAL;
 173                         break;
 174                 }
 175
 176                 /* grab the kernel address for this device address */
 177                 ptr = rproc_da_to_va(rproc, da, memsz);
 178                 if (!ptr) {
 179                         dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
 180                         ret = -EINVAL;
 181                         break;
 182                 }
 183
 184                 /* put the segment where the remote processor expects it */
 185                 if (phdr->p_filesz)
 186                         memcpy(ptr, elf_data + phdr->p_offset, filesz);
 187
 188                 /*
 189                  * Zero out remaining memory for this segment.
 190                  *
 191                  * This isn't strictly required since dma_alloc_coherent already
 192                  * did this for us. albeit harmless, we may consider removing
 193                  * this.
 194                  */
 195                 if (memsz > filesz)
 196                         memset(ptr + filesz, 0, memsz - filesz);
 197         }
 198
 199         return ret;
 200 }
 201 EXPORT_SYMBOL(rproc_elf_load_segments);
 202
 203 static struct elf32_shdr *
 204 find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
 205 {
 206         struct elf32_shdr *shdr;
 207         int i;
 208         const char *name_table;
 209         struct resource_table *table = NULL;
 210         const u8 *elf_data = (void *)ehdr;
 211
 212         /* look for the resource table and handle it */
 213         shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
 214         name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset;
 215
 216         for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
 217                 u32 size = shdr->sh_size;
 218                 u32 offset = shdr->sh_offset;
 219
 220                 if (strcmp(name_table + shdr->sh_name, ".resource_table"))
 221                         continue;
 222
 223                 table = (struct resource_table *)(elf_data + offset);
 224
 225                 /* make sure we have the entire table */
 226                 if (offset + size > fw_size || offset + size < size) {
 227                         dev_err(dev, "resource table truncated\n");
 228                         return NULL;
 229                 }
 230
 231                 /* make sure table has at least the header */
 232                 if (sizeof(struct resource_table) > size) {
 233                         dev_err(dev, "header-less resource table\n");
 234                         return NULL;
 235                 }
 236
 237                 /* we don't support any version beyond the first */
 238                 if (table->ver != 1) {
 239                         dev_err(dev, "unsupported fw ver: %d\n", table->ver);
 240                         return NULL;
 241                 }
 242
 243                 /* make sure reserved bytes are zeroes */
 244                 if (table->reserved[0] || table->reserved[1]) {
 245                         dev_err(dev, "non zero reserved bytes\n");
 246                         return NULL;
 247                 }
 248
 249                 /* make sure the offsets array isn't truncated */
 250                 if (struct_size(table, offset, table->num) > size) {
 251                         dev_err(dev, "resource table incomplete\n");
 252                         return NULL;
 253                 }
 254
 255                 return shdr;
 256         }
 257
 258         return NULL;
 259 }
 260
 261 /**
 262  * rproc_elf_load_rsc_table() - load the resource table
 263  * @rproc: the rproc handle
 264  * @fw: the ELF firmware image
 265  *
 266  * This function finds the resource table inside the remote processor's
 267  * firmware, load it into the @cached_table and update @table_ptr.
 268  *
 269  * Return: 0 on success, negative errno on failure.
 270  */
 271 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
 272 {
 273         struct elf32_hdr *ehdr;
 274         struct elf32_shdr *shdr;
 275         struct device *dev = &rproc->dev;
 276         struct resource_table *table = NULL;
 277         const u8 *elf_data = fw->data;
 278         size_t tablesz;
 279
 280         ehdr = (struct elf32_hdr *)elf_data;
 281
 282         shdr = find_table(dev, ehdr, fw->size);
 283         if (!shdr)
 284                 return -EINVAL;
 285
 286         table = (struct resource_table *)(elf_data + shdr->sh_offset);
 287         tablesz = shdr->sh_size;
 288
 289         /*
 290          * Create a copy of the resource table. When a virtio device starts
 291          * and calls vring_new_virtqueue() the address of the allocated vring
 292          * will be stored in the cached_table. Before the device is started,
 293          * cached_table will be copied into device memory.
 294          */
 295         rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
 296         if (!rproc->cached_table)
 297                 return -ENOMEM;
 298
 299         rproc->table_ptr = rproc->cached_table;
 300         rproc->table_sz = tablesz;
 301
 302         return 0;
 303 }
 304 EXPORT_SYMBOL(rproc_elf_load_rsc_table);
 305
 306 /**
 307  * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
 308  * @rproc: the rproc handle
 309  * @fw: the ELF firmware image
 310  *
 311  * This function finds the location of the loaded resource table. Don't
 312  * call this function if the table wasn't loaded yet - it's a bug if you do.
 313  *
 314  * Returns the pointer to the resource table if it is found or NULL otherwise.
 315  * If the table wasn't loaded yet the result is unspecified.
 316  */
 317 struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
 318                                                        const struct firmware *fw)
 319 {
 320         struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
 321         struct elf32_shdr *shdr;
 322
 323         shdr = find_table(&rproc->dev, ehdr, fw->size);
 324         if (!shdr)
 325                 return NULL;
 326
 327         return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
 328 }
 329 EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);