drivers/soc/qcom/mdt_loader.c

   1 /*
   2  * Qualcomm Peripheral Image Loader
   3  *
   4  * Copyright (C) 2016 Linaro Ltd
   5  * Copyright (C) 2015 Sony Mobile Communications Inc
   6  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/device.h>
  19 #include <linux/elf.h>
  20 #include <linux/firmware.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/qcom_scm.h>
  24 #include <linux/sizes.h>
  25 #include <linux/slab.h>
  26 #include <linux/soc/qcom/mdt_loader.h>
  27
  28 static bool mdt_phdr_valid(const struct elf32_phdr *phdr)
  29 {
  30         if (phdr->p_type != PT_LOAD)
  31                 return false;
  32
  33         if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
  34                 return false;
  35
  36         if (!phdr->p_memsz)
  37                 return false;
  38
  39         return true;
  40 }
  41
  42 /**
  43  * qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
  44  * @fw:         firmware object for the mdt file
  45  *
  46  * Returns size of the loaded firmware blob, or -EINVAL on failure.
  47  */
  48 ssize_t qcom_mdt_get_size(const struct firmware *fw)
  49 {
  50         const struct elf32_phdr *phdrs;
  51         const struct elf32_phdr *phdr;
  52         const struct elf32_hdr *ehdr;
  53         phys_addr_t min_addr = (phys_addr_t)ULLONG_MAX;
  54         phys_addr_t max_addr = 0;
  55         int i;
  56
  57         ehdr = (struct elf32_hdr *)fw->data;
  58         phdrs = (struct elf32_phdr *)(ehdr + 1);
  59
  60         for (i = 0; i < ehdr->e_phnum; i++) {
  61                 phdr = &phdrs[i];
  62
  63                 if (!mdt_phdr_valid(phdr))
  64                         continue;
  65
  66                 if (phdr->p_paddr < min_addr)
  67                         min_addr = phdr->p_paddr;
  68
  69                 if (phdr->p_paddr + phdr->p_memsz > max_addr)
  70                         max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
  71         }
  72
  73         return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
  74 }
  75 EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
  76
  77 /**
  78  * qcom_mdt_load() - load the firmware which header is loaded as fw
  79  * @dev:        device handle to associate resources with
  80  * @fw:         firmware object for the mdt file
  81  * @firmware:   name of the firmware, for construction of segment file names
  82  * @pas_id:     PAS identifier
  83  * @mem_region: allocated memory region to load firmware into
  84  * @mem_phys:   physical address of allocated memory region
  85  * @mem_size:   size of the allocated memory region
  86  *
  87  * Returns 0 on success, negative errno otherwise.
  88  */
  89 int qcom_mdt_load(struct device *dev, const struct firmware *fw,
  90                   const char *firmware, int pas_id, void *mem_region,
  91                   phys_addr_t mem_phys, size_t mem_size)
  92 {
  93         const struct elf32_phdr *phdrs;
  94         const struct elf32_phdr *phdr;
  95         const struct elf32_hdr *ehdr;
  96         const struct firmware *seg_fw;
  97         phys_addr_t mem_reloc;
  98         phys_addr_t min_addr = (phys_addr_t)ULLONG_MAX;
  99         phys_addr_t max_addr = 0;
 100         size_t fw_name_len;
 101         ssize_t offset;
 102         char *fw_name;
 103         bool relocate = false;
 104         void *ptr;
 105         int ret;
 106         int i;
 107
 108         if (!fw || !mem_region || !mem_phys || !mem_size)
 109                 return -EINVAL;
 110
 111         ehdr = (struct elf32_hdr *)fw->data;
 112         phdrs = (struct elf32_phdr *)(ehdr + 1);
 113
 114         fw_name_len = strlen(firmware);
 115         if (fw_name_len <= 4)
 116                 return -EINVAL;
 117
 118         fw_name = kstrdup(firmware, GFP_KERNEL);
 119         if (!fw_name)
 120                 return -ENOMEM;
 121
 122         ret = qcom_scm_pas_init_image(pas_id, fw->data, fw->size);
 123         if (ret) {
 124                 dev_err(dev, "invalid firmware metadata\n");
 125                 goto out;
 126         }
 127
 128         for (i = 0; i < ehdr->e_phnum; i++) {
 129                 phdr = &phdrs[i];
 130
 131                 if (!mdt_phdr_valid(phdr))
 132                         continue;
 133
 134                 if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
 135                         relocate = true;
 136
 137                 if (phdr->p_paddr < min_addr)
 138                         min_addr = phdr->p_paddr;
 139
 140                 if (phdr->p_paddr + phdr->p_memsz > max_addr)
 141                         max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
 142         }
 143
 144         if (relocate) {
 145                 ret = qcom_scm_pas_mem_setup(pas_id, mem_phys, max_addr - min_addr);
 146                 if (ret) {
 147                         dev_err(dev, "unable to setup relocation\n");
 148                         goto out;
 149                 }
 150
 151                 /*
 152                  * The image is relocatable, so offset each segment based on
 153                  * the lowest segment address.
 154                  */
 155                 mem_reloc = min_addr;
 156         } else {
 157                 /*
 158                  * Image is not relocatable, so offset each segment based on
 159                  * the allocated physical chunk of memory.
 160                  */
 161                 mem_reloc = mem_phys;
 162         }
 163
 164         for (i = 0; i < ehdr->e_phnum; i++) {
 165                 phdr = &phdrs[i];
 166
 167                 if (!mdt_phdr_valid(phdr))
 168                         continue;
 169
 170                 offset = phdr->p_paddr - mem_reloc;
 171                 if (offset < 0 || offset + phdr->p_memsz > mem_size) {
 172                         dev_err(dev, "segment outside memory range\n");
 173                         ret = -EINVAL;
 174                         break;
 175                 }
 176
 177                 ptr = mem_region + offset;
 178
 179                 if (phdr->p_filesz) {
 180                         sprintf(fw_name + fw_name_len - 3, "b%02d", i);
 181                         ret = request_firmware(&seg_fw, fw_name, dev);
 182                         if (ret) {
 183                                 dev_err(dev, "failed to load %s\n", fw_name);
 184                                 break;
 185                         }
 186
 187                         memcpy(ptr, seg_fw->data, seg_fw->size);
 188
 189                         release_firmware(seg_fw);
 190                 }
 191
 192                 if (phdr->p_memsz > phdr->p_filesz)
 193                         memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
 194         }
 195
 196 out:
 197         kfree(fw_name);
 198
 199         return ret;
 200 }
 201 EXPORT_SYMBOL_GPL(qcom_mdt_load);
 202
 203 MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
 204 MODULE_LICENSE("GPL v2");