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1// SPDX-License-Identifier: GPL-2.02/*3 * EFI capsule loader driver.4 *5 * Copyright 2015 Intel Corporation6 */7 8#define pr_fmt(fmt) "efi: " fmt9 10#include <linux/kernel.h>11#include <linux/module.h>12#include <linux/miscdevice.h>13#include <linux/highmem.h>14#include <linux/io.h>15#include <linux/slab.h>16#include <linux/mutex.h>17#include <linux/efi.h>18#include <linux/vmalloc.h>19 20#define NO_FURTHER_WRITE_ACTION -121 22/**23 * efi_free_all_buff_pages - free all previous allocated buffer pages24 * @cap_info: pointer to current instance of capsule_info structure25 *26 * In addition to freeing buffer pages, it flags NO_FURTHER_WRITE_ACTION27 * to cease processing data in subsequent write(2) calls until close(2)28 * is called.29 **/30static void efi_free_all_buff_pages(struct capsule_info *cap_info)31{32 while (cap_info->index > 0)33 __free_page(cap_info->pages[--cap_info->index]);34 35 cap_info->index = NO_FURTHER_WRITE_ACTION;36}37 38int __efi_capsule_setup_info(struct capsule_info *cap_info)39{40 size_t pages_needed;41 int ret;42 void *temp_page;43 44 pages_needed = ALIGN(cap_info->total_size, PAGE_SIZE) / PAGE_SIZE;45 46 if (pages_needed == 0) {47 pr_err("invalid capsule size\n");48 return -EINVAL;49 }50 51 /* Check if the capsule binary supported */52 ret = efi_capsule_supported(cap_info->header.guid,53 cap_info->header.flags,54 cap_info->header.imagesize,55 &cap_info->reset_type);56 if (ret) {57 pr_err("capsule not supported\n");58 return ret;59 }60 61 temp_page = krealloc(cap_info->pages,62 pages_needed * sizeof(void *),63 GFP_KERNEL | __GFP_ZERO);64 if (!temp_page)65 return -ENOMEM;66 67 cap_info->pages = temp_page;68 69 temp_page = krealloc(cap_info->phys,70 pages_needed * sizeof(phys_addr_t *),71 GFP_KERNEL | __GFP_ZERO);72 if (!temp_page)73 return -ENOMEM;74 75 cap_info->phys = temp_page;76 77 return 0;78}79 80/**81 * efi_capsule_setup_info - obtain the efi capsule header in the binary and82 * setup capsule_info structure83 * @cap_info: pointer to current instance of capsule_info structure84 * @kbuff: a mapped first page buffer pointer85 * @hdr_bytes: the total received number of bytes for efi header86 *87 * Platforms with non-standard capsule update mechanisms can override88 * this __weak function so they can perform any required capsule89 * image munging. See quark_quirk_function() for an example.90 **/91int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,92 size_t hdr_bytes)93{94 /* Only process data block that is larger than efi header size */95 if (hdr_bytes < sizeof(efi_capsule_header_t))96 return 0;97 98 memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));99 cap_info->total_size = cap_info->header.imagesize;100 101 return __efi_capsule_setup_info(cap_info);102}103 104/**105 * efi_capsule_submit_update - invoke the efi_capsule_update API once binary106 * upload done107 * @cap_info: pointer to current instance of capsule_info structure108 **/109static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info)110{111 bool do_vunmap = false;112 int ret;113 114 /*115 * cap_info->capsule may have been assigned already by a quirk116 * handler, so only overwrite it if it is NULL117 */118 if (!cap_info->capsule) {119 cap_info->capsule = vmap(cap_info->pages, cap_info->index,120 VM_MAP, PAGE_KERNEL);121 if (!cap_info->capsule)122 return -ENOMEM;123 do_vunmap = true;124 }125 126 ret = efi_capsule_update(cap_info->capsule, cap_info->phys);127 if (do_vunmap)128 vunmap(cap_info->capsule);129 if (ret) {130 pr_err("capsule update failed\n");131 return ret;132 }133 134 /* Indicate capsule binary uploading is done */135 cap_info->index = NO_FURTHER_WRITE_ACTION;136 137 if (cap_info->header.flags & EFI_CAPSULE_PERSIST_ACROSS_RESET) {138 pr_info("Successfully uploaded capsule file with reboot type '%s'\n",139 !cap_info->reset_type ? "RESET_COLD" :140 cap_info->reset_type == 1 ? "RESET_WARM" :141 "RESET_SHUTDOWN");142 } else {143 pr_info("Successfully processed capsule file\n");144 }145 146 return 0;147}148 149/**150 * efi_capsule_write - store the capsule binary and pass it to151 * efi_capsule_update() API152 * @file: file pointer153 * @buff: buffer pointer154 * @count: number of bytes in @buff155 * @offp: not used156 *157 * Expectation:158 * - A user space tool should start at the beginning of capsule binary and159 * pass data in sequentially.160 * - Users should close and re-open this file note in order to upload more161 * capsules.162 * - After an error returned, user should close the file and restart the163 * operation for the next try otherwise -EIO will be returned until the164 * file is closed.165 * - An EFI capsule header must be located at the beginning of capsule166 * binary file and passed in as first block data of write operation.167 **/168static ssize_t efi_capsule_write(struct file *file, const char __user *buff,169 size_t count, loff_t *offp)170{171 int ret;172 struct capsule_info *cap_info = file->private_data;173 struct page *page;174 void *kbuff = NULL;175 size_t write_byte;176 177 if (count == 0)178 return 0;179 180 /* Return error while NO_FURTHER_WRITE_ACTION is flagged */181 if (cap_info->index < 0)182 return -EIO;183 184 /* Only alloc a new page when previous page is full */185 if (!cap_info->page_bytes_remain) {186 page = alloc_page(GFP_KERNEL);187 if (!page) {188 ret = -ENOMEM;189 goto failed;190 }191 192 cap_info->pages[cap_info->index] = page;193 cap_info->phys[cap_info->index] = page_to_phys(page);194 cap_info->page_bytes_remain = PAGE_SIZE;195 cap_info->index++;196 } else {197 page = cap_info->pages[cap_info->index - 1];198 }199 200 kbuff = kmap(page);201 kbuff += PAGE_SIZE - cap_info->page_bytes_remain;202 203 /* Copy capsule binary data from user space to kernel space buffer */204 write_byte = min_t(size_t, count, cap_info->page_bytes_remain);205 if (copy_from_user(kbuff, buff, write_byte)) {206 ret = -EFAULT;207 goto fail_unmap;208 }209 cap_info->page_bytes_remain -= write_byte;210 211 /* Setup capsule binary info structure */212 if (cap_info->header.headersize == 0) {213 ret = efi_capsule_setup_info(cap_info, kbuff - cap_info->count,214 cap_info->count + write_byte);215 if (ret)216 goto fail_unmap;217 }218 219 cap_info->count += write_byte;220 kunmap(page);221 222 /* Submit the full binary to efi_capsule_update() API */223 if (cap_info->header.headersize > 0 &&224 cap_info->count >= cap_info->total_size) {225 if (cap_info->count > cap_info->total_size) {226 pr_err("capsule upload size exceeded header defined size\n");227 ret = -EINVAL;228 goto failed;229 }230 231 ret = efi_capsule_submit_update(cap_info);232 if (ret)233 goto failed;234 }235 236 return write_byte;237 238fail_unmap:239 kunmap(page);240failed:241 efi_free_all_buff_pages(cap_info);242 return ret;243}244 245/**246 * efi_capsule_release - called by file close247 * @inode: not used248 * @file: file pointer249 *250 * We will not free successfully submitted pages since efi update251 * requires data to be maintained across system reboot.252 **/253static int efi_capsule_release(struct inode *inode, struct file *file)254{255 struct capsule_info *cap_info = file->private_data;256 257 if (cap_info->index > 0 &&258 (cap_info->header.headersize == 0 ||259 cap_info->count < cap_info->total_size)) {260 pr_err("capsule upload not complete\n");261 efi_free_all_buff_pages(cap_info);262 }263 264 kfree(cap_info->pages);265 kfree(cap_info->phys);266 kfree(file->private_data);267 file->private_data = NULL;268 return 0;269}270 271/**272 * efi_capsule_open - called by file open273 * @inode: not used274 * @file: file pointer275 *276 * Will allocate each capsule_info memory for each file open call.277 * This provided the capability to support multiple file open feature278 * where user is not needed to wait for others to finish in order to279 * upload their capsule binary.280 **/281static int efi_capsule_open(struct inode *inode, struct file *file)282{283 struct capsule_info *cap_info;284 285 cap_info = kzalloc(sizeof(*cap_info), GFP_KERNEL);286 if (!cap_info)287 return -ENOMEM;288 289 cap_info->pages = kzalloc(sizeof(void *), GFP_KERNEL);290 if (!cap_info->pages) {291 kfree(cap_info);292 return -ENOMEM;293 }294 295 cap_info->phys = kzalloc(sizeof(phys_addr_t), GFP_KERNEL);296 if (!cap_info->phys) {297 kfree(cap_info->pages);298 kfree(cap_info);299 return -ENOMEM;300 }301 302 file->private_data = cap_info;303 304 return 0;305}306 307static const struct file_operations efi_capsule_fops = {308 .owner = THIS_MODULE,309 .open = efi_capsule_open,310 .write = efi_capsule_write,311 .release = efi_capsule_release,312};313 314static struct miscdevice efi_capsule_misc = {315 .minor = MISC_DYNAMIC_MINOR,316 .name = "efi_capsule_loader",317 .fops = &efi_capsule_fops,318};319 320static int __init efi_capsule_loader_init(void)321{322 int ret;323 324 if (!efi_enabled(EFI_RUNTIME_SERVICES))325 return -ENODEV;326 327 ret = misc_register(&efi_capsule_misc);328 if (ret)329 pr_err("Unable to register capsule loader device\n");330 331 return ret;332}333module_init(efi_capsule_loader_init);334 335static void __exit efi_capsule_loader_exit(void)336{337 misc_deregister(&efi_capsule_misc);338}339module_exit(efi_capsule_loader_exit);340 341MODULE_DESCRIPTION("EFI capsule firmware binary loader");342MODULE_LICENSE("GPL v2");343