drivers/soc/qcom/mdt_loader.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Qualcomm Peripheral Image Loader
   4  *
   5  * Copyright (C) 2016 Linaro Ltd
   6  * Copyright (C) 2015 Sony Mobile Communications Inc
   7  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/elf.h>
  12 #include <linux/firmware.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/qcom_scm.h>
  16 #include <linux/sizes.h>
  17 #include <linux/slab.h>
  18 #include <linux/soc/qcom/mdt_loader.h>
  19
  20 static bool mdt_phdr_valid(const struct elf32_phdr *phdr)
  21 {
  22         if (phdr->p_type != PT_LOAD)
  23                 return false;
  24
  25         if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
  26                 return false;
  27
  28         if (!phdr->p_memsz)
  29                 return false;
  30
  31         return true;
  32 }
  33
  34 /**
  35  * qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
  36  * @fw:         firmware object for the mdt file
  37  *
  38  * Returns size of the loaded firmware blob, or -EINVAL on failure.
  39  */
  40 ssize_t qcom_mdt_get_size(const struct firmware *fw)
  41 {
  42         const struct elf32_phdr *phdrs;
  43         const struct elf32_phdr *phdr;
  44         const struct elf32_hdr *ehdr;
  45         phys_addr_t min_addr = PHYS_ADDR_MAX;
  46         phys_addr_t max_addr = 0;
  47         int i;
  48
  49         ehdr = (struct elf32_hdr *)fw->data;
  50         phdrs = (struct elf32_phdr *)(ehdr + 1);
  51
  52         for (i = 0; i < ehdr->e_phnum; i++) {
  53                 phdr = &phdrs[i];
  54
  55                 if (!mdt_phdr_valid(phdr))
  56                         continue;
  57
  58                 if (phdr->p_paddr < min_addr)
  59                         min_addr = phdr->p_paddr;
  60
  61                 if (phdr->p_paddr + phdr->p_memsz > max_addr)
  62                         max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
  63         }
  64
  65         return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
  66 }
  67 EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
  68
  69 /**
  70  * qcom_mdt_read_metadata() - read header and metadata from mdt or mbn
  71  * @fw:         firmware of mdt header or mbn
  72  * @data_len:   length of the read metadata blob
  73  *
  74  * The mechanism that performs the authentication of the loading firmware
  75  * expects an ELF header directly followed by the segment of hashes, with no
  76  * padding inbetween. This function allocates a chunk of memory for this pair
  77  * and copy the two pieces into the buffer.
  78  *
  79  * In the case of split firmware the hash is found directly following the ELF
  80  * header, rather than at p_offset described by the second program header.
  81  *
  82  * The caller is responsible to free (kfree()) the returned pointer.
  83  *
  84  * Return: pointer to data, or ERR_PTR()
  85  */
  86 void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
  87 {
  88         const struct elf32_phdr *phdrs;
  89         const struct elf32_hdr *ehdr;
  90         size_t hash_offset;
  91         size_t hash_size;
  92         size_t ehdr_size;
  93         void *data;
  94
  95         ehdr = (struct elf32_hdr *)fw->data;
  96         phdrs = (struct elf32_phdr *)(ehdr + 1);
  97
  98         if (ehdr->e_phnum < 2)
  99                 return ERR_PTR(-EINVAL);
 100
 101         if (phdrs[0].p_type == PT_LOAD || phdrs[1].p_type == PT_LOAD)
 102                 return ERR_PTR(-EINVAL);
 103
 104         if ((phdrs[1].p_flags & QCOM_MDT_TYPE_MASK) != QCOM_MDT_TYPE_HASH)
 105                 return ERR_PTR(-EINVAL);
 106
 107         ehdr_size = phdrs[0].p_filesz;
 108         hash_size = phdrs[1].p_filesz;
 109
 110         data = kmalloc(ehdr_size + hash_size, GFP_KERNEL);
 111         if (!data)
 112                 return ERR_PTR(-ENOMEM);
 113
 114         /* Is the header and hash already packed */
 115         if (ehdr_size + hash_size == fw->size)
 116                 hash_offset = phdrs[0].p_filesz;
 117         else
 118                 hash_offset = phdrs[1].p_offset;
 119
 120         memcpy(data, fw->data, ehdr_size);
 121         memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
 122
 123         *data_len = ehdr_size + hash_size;
 124
 125         return data;
 126 }
 127 EXPORT_SYMBOL_GPL(qcom_mdt_read_metadata);
 128
 129 static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
 130                            const char *firmware, int pas_id, void *mem_region,
 131                            phys_addr_t mem_phys, size_t mem_size,
 132                            phys_addr_t *reloc_base, bool pas_init)
 133 {
 134         const struct elf32_phdr *phdrs;
 135         const struct elf32_phdr *phdr;
 136         const struct elf32_hdr *ehdr;
 137         const struct firmware *seg_fw;
 138         phys_addr_t mem_reloc;
 139         phys_addr_t min_addr = PHYS_ADDR_MAX;
 140         phys_addr_t max_addr = 0;
 141         size_t metadata_len;
 142         size_t fw_name_len;
 143         ssize_t offset;
 144         void *metadata;
 145         char *fw_name;
 146         bool relocate = false;
 147         void *ptr;
 148         int ret = 0;
 149         int i;
 150
 151         if (!fw || !mem_region || !mem_phys || !mem_size)
 152                 return -EINVAL;
 153
 154         ehdr = (struct elf32_hdr *)fw->data;
 155         phdrs = (struct elf32_phdr *)(ehdr + 1);
 156
 157         fw_name_len = strlen(firmware);
 158         if (fw_name_len <= 4)
 159                 return -EINVAL;
 160
 161         fw_name = kstrdup(firmware, GFP_KERNEL);
 162         if (!fw_name)
 163                 return -ENOMEM;
 164
 165         if (pas_init) {
 166                 metadata = qcom_mdt_read_metadata(fw, &metadata_len);
 167                 if (IS_ERR(metadata)) {
 168                         ret = PTR_ERR(metadata);
 169                         goto out;
 170                 }
 171
 172                 ret = qcom_scm_pas_init_image(pas_id, metadata, metadata_len);
 173
 174                 kfree(metadata);
 175                 if (ret) {
 176                         dev_err(dev, "invalid firmware metadata\n");
 177                         goto out;
 178                 }
 179         }
 180
 181         for (i = 0; i < ehdr->e_phnum; i++) {
 182                 phdr = &phdrs[i];
 183
 184                 if (!mdt_phdr_valid(phdr))
 185                         continue;
 186
 187                 if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
 188                         relocate = true;
 189
 190                 if (phdr->p_paddr < min_addr)
 191                         min_addr = phdr->p_paddr;
 192
 193                 if (phdr->p_paddr + phdr->p_memsz > max_addr)
 194                         max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
 195         }
 196
 197         if (relocate) {
 198                 if (pas_init) {
 199                         ret = qcom_scm_pas_mem_setup(pas_id, mem_phys,
 200                                                      max_addr - min_addr);
 201                         if (ret) {
 202                                 dev_err(dev, "unable to setup relocation\n");
 203                                 goto out;
 204                         }
 205                 }
 206
 207                 /*
 208                  * The image is relocatable, so offset each segment based on
 209                  * the lowest segment address.
 210                  */
 211                 mem_reloc = min_addr;
 212         } else {
 213                 /*
 214                  * Image is not relocatable, so offset each segment based on
 215                  * the allocated physical chunk of memory.
 216                  */
 217                 mem_reloc = mem_phys;
 218         }
 219
 220         for (i = 0; i < ehdr->e_phnum; i++) {
 221                 phdr = &phdrs[i];
 222
 223                 if (!mdt_phdr_valid(phdr))
 224                         continue;
 225
 226                 offset = phdr->p_paddr - mem_reloc;
 227                 if (offset < 0 || offset + phdr->p_memsz > mem_size) {
 228                         dev_err(dev, "segment outside memory range\n");
 229                         ret = -EINVAL;
 230                         break;
 231                 }
 232
 233                 ptr = mem_region + offset;
 234
 235                 if (phdr->p_filesz && phdr->p_offset < fw->size) {
 236                         /* Firmware is large enough to be non-split */
 237                         if (phdr->p_offset + phdr->p_filesz > fw->size) {
 238                                 dev_err(dev,
 239                                         "failed to load segment %d from truncated file %s\n",
 240                                         i, firmware);
 241                                 ret = -EINVAL;
 242                                 break;
 243                         }
 244
 245                         memcpy(ptr, fw->data + phdr->p_offset, phdr->p_filesz);
 246                 } else if (phdr->p_filesz) {
 247                         /* Firmware not large enough, load split-out segments */
 248                         sprintf(fw_name + fw_name_len - 3, "b%02d", i);
 249                         ret = request_firmware_into_buf(&seg_fw, fw_name, dev,
 250                                                         ptr, phdr->p_filesz);
 251                         if (ret) {
 252                                 dev_err(dev, "failed to load %s\n", fw_name);
 253                                 break;
 254                         }
 255
 256                         release_firmware(seg_fw);
 257                 }
 258
 259                 if (phdr->p_memsz > phdr->p_filesz)
 260                         memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
 261         }
 262
 263         if (reloc_base)
 264                 *reloc_base = mem_reloc;
 265
 266 out:
 267         kfree(fw_name);
 268
 269         return ret;
 270 }
 271
 272 /**
 273  * qcom_mdt_load() - load the firmware which header is loaded as fw
 274  * @dev:        device handle to associate resources with
 275  * @fw:         firmware object for the mdt file
 276  * @firmware:   name of the firmware, for construction of segment file names
 277  * @pas_id:     PAS identifier
 278  * @mem_region: allocated memory region to load firmware into
 279  * @mem_phys:   physical address of allocated memory region
 280  * @mem_size:   size of the allocated memory region
 281  * @reloc_base: adjusted physical address after relocation
 282  *
 283  * Returns 0 on success, negative errno otherwise.
 284  */
 285 int qcom_mdt_load(struct device *dev, const struct firmware *fw,
 286                   const char *firmware, int pas_id, void *mem_region,
 287                   phys_addr_t mem_phys, size_t mem_size,
 288                   phys_addr_t *reloc_base)
 289 {
 290         return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
 291                                mem_size, reloc_base, true);
 292 }
 293 EXPORT_SYMBOL_GPL(qcom_mdt_load);
 294
 295 /**
 296  * qcom_mdt_load_no_init() - load the firmware which header is loaded as fw
 297  * @dev:        device handle to associate resources with
 298  * @fw:         firmware object for the mdt file
 299  * @firmware:   name of the firmware, for construction of segment file names
 300  * @pas_id:     PAS identifier
 301  * @mem_region: allocated memory region to load firmware into
 302  * @mem_phys:   physical address of allocated memory region
 303  * @mem_size:   size of the allocated memory region
 304  * @reloc_base: adjusted physical address after relocation
 305  *
 306  * Returns 0 on success, negative errno otherwise.
 307  */
 308 int qcom_mdt_load_no_init(struct device *dev, const struct firmware *fw,
 309                           const char *firmware, int pas_id,
 310                           void *mem_region, phys_addr_t mem_phys,
 311                           size_t mem_size, phys_addr_t *reloc_base)
 312 {
 313         return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
 314                                mem_size, reloc_base, false);
 315 }
 316 EXPORT_SYMBOL_GPL(qcom_mdt_load_no_init);
 317
 318 MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
 319 MODULE_LICENSE("GPL v2");