Linux 5.1.15
[linux/fpc-iii.git] / drivers / firmware / efi / capsule-loader.c
blobb1395133389edb89ff549b5705c5e4b9d794981c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * EFI capsule loader driver.
5 * Copyright 2015 Intel Corporation
6 */
8 #define pr_fmt(fmt) "efi: " fmt
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/miscdevice.h>
13 #include <linux/highmem.h>
14 #include <linux/slab.h>
15 #include <linux/mutex.h>
16 #include <linux/efi.h>
17 #include <linux/vmalloc.h>
19 #define NO_FURTHER_WRITE_ACTION -1
21 /**
22 * efi_free_all_buff_pages - free all previous allocated buffer pages
23 * @cap_info: pointer to current instance of capsule_info structure
25 * In addition to freeing buffer pages, it flags NO_FURTHER_WRITE_ACTION
26 * to cease processing data in subsequent write(2) calls until close(2)
27 * is called.
28 **/
29 static void efi_free_all_buff_pages(struct capsule_info *cap_info)
31 while (cap_info->index > 0)
32 __free_page(cap_info->pages[--cap_info->index]);
34 cap_info->index = NO_FURTHER_WRITE_ACTION;
37 int __efi_capsule_setup_info(struct capsule_info *cap_info)
39 size_t pages_needed;
40 int ret;
41 void *temp_page;
43 pages_needed = ALIGN(cap_info->total_size, PAGE_SIZE) / PAGE_SIZE;
45 if (pages_needed == 0) {
46 pr_err("invalid capsule size\n");
47 return -EINVAL;
50 /* Check if the capsule binary supported */
51 ret = efi_capsule_supported(cap_info->header.guid,
52 cap_info->header.flags,
53 cap_info->header.imagesize,
54 &cap_info->reset_type);
55 if (ret) {
56 pr_err("capsule not supported\n");
57 return ret;
60 temp_page = krealloc(cap_info->pages,
61 pages_needed * sizeof(void *),
62 GFP_KERNEL | __GFP_ZERO);
63 if (!temp_page)
64 return -ENOMEM;
66 cap_info->pages = temp_page;
68 temp_page = krealloc(cap_info->phys,
69 pages_needed * sizeof(phys_addr_t *),
70 GFP_KERNEL | __GFP_ZERO);
71 if (!temp_page)
72 return -ENOMEM;
74 cap_info->phys = temp_page;
76 return 0;
79 /**
80 * efi_capsule_setup_info - obtain the efi capsule header in the binary and
81 * setup capsule_info structure
82 * @cap_info: pointer to current instance of capsule_info structure
83 * @kbuff: a mapped first page buffer pointer
84 * @hdr_bytes: the total received number of bytes for efi header
86 * Platforms with non-standard capsule update mechanisms can override
87 * this __weak function so they can perform any required capsule
88 * image munging. See quark_quirk_function() for an example.
89 **/
90 int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
91 size_t hdr_bytes)
93 /* Only process data block that is larger than efi header size */
94 if (hdr_bytes < sizeof(efi_capsule_header_t))
95 return 0;
97 memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
98 cap_info->total_size = cap_info->header.imagesize;
100 return __efi_capsule_setup_info(cap_info);
104 * efi_capsule_submit_update - invoke the efi_capsule_update API once binary
105 * upload done
106 * @cap_info: pointer to current instance of capsule_info structure
108 static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info)
110 bool do_vunmap = false;
111 int ret;
114 * cap_info->capsule may have been assigned already by a quirk
115 * handler, so only overwrite it if it is NULL
117 if (!cap_info->capsule) {
118 cap_info->capsule = vmap(cap_info->pages, cap_info->index,
119 VM_MAP, PAGE_KERNEL);
120 if (!cap_info->capsule)
121 return -ENOMEM;
122 do_vunmap = true;
125 ret = efi_capsule_update(cap_info->capsule, cap_info->phys);
126 if (do_vunmap)
127 vunmap(cap_info->capsule);
128 if (ret) {
129 pr_err("capsule update failed\n");
130 return ret;
133 /* Indicate capsule binary uploading is done */
134 cap_info->index = NO_FURTHER_WRITE_ACTION;
136 if (cap_info->header.flags & EFI_CAPSULE_PERSIST_ACROSS_RESET) {
137 pr_info("Successfully uploaded capsule file with reboot type '%s'\n",
138 !cap_info->reset_type ? "RESET_COLD" :
139 cap_info->reset_type == 1 ? "RESET_WARM" :
140 "RESET_SHUTDOWN");
141 } else {
142 pr_info("Successfully processed capsule file\n");
145 return 0;
149 * efi_capsule_write - store the capsule binary and pass it to
150 * efi_capsule_update() API
151 * @file: file pointer
152 * @buff: buffer pointer
153 * @count: number of bytes in @buff
154 * @offp: not used
156 * Expectation:
157 * - A user space tool should start at the beginning of capsule binary and
158 * pass data in sequentially.
159 * - Users should close and re-open this file note in order to upload more
160 * capsules.
161 * - After an error returned, user should close the file and restart the
162 * operation for the next try otherwise -EIO will be returned until the
163 * file is closed.
164 * - An EFI capsule header must be located at the beginning of capsule
165 * binary file and passed in as first block data of write operation.
167 static ssize_t efi_capsule_write(struct file *file, const char __user *buff,
168 size_t count, loff_t *offp)
170 int ret = 0;
171 struct capsule_info *cap_info = file->private_data;
172 struct page *page;
173 void *kbuff = NULL;
174 size_t write_byte;
176 if (count == 0)
177 return 0;
179 /* Return error while NO_FURTHER_WRITE_ACTION is flagged */
180 if (cap_info->index < 0)
181 return -EIO;
183 /* Only alloc a new page when previous page is full */
184 if (!cap_info->page_bytes_remain) {
185 page = alloc_page(GFP_KERNEL);
186 if (!page) {
187 ret = -ENOMEM;
188 goto failed;
191 cap_info->pages[cap_info->index] = page;
192 cap_info->phys[cap_info->index] = page_to_phys(page);
193 cap_info->page_bytes_remain = PAGE_SIZE;
194 cap_info->index++;
195 } else {
196 page = cap_info->pages[cap_info->index - 1];
199 kbuff = kmap(page);
200 kbuff += PAGE_SIZE - cap_info->page_bytes_remain;
202 /* Copy capsule binary data from user space to kernel space buffer */
203 write_byte = min_t(size_t, count, cap_info->page_bytes_remain);
204 if (copy_from_user(kbuff, buff, write_byte)) {
205 ret = -EFAULT;
206 goto fail_unmap;
208 cap_info->page_bytes_remain -= write_byte;
210 /* Setup capsule binary info structure */
211 if (cap_info->header.headersize == 0) {
212 ret = efi_capsule_setup_info(cap_info, kbuff - cap_info->count,
213 cap_info->count + write_byte);
214 if (ret)
215 goto fail_unmap;
218 cap_info->count += write_byte;
219 kunmap(page);
221 /* Submit the full binary to efi_capsule_update() API */
222 if (cap_info->header.headersize > 0 &&
223 cap_info->count >= cap_info->total_size) {
224 if (cap_info->count > cap_info->total_size) {
225 pr_err("capsule upload size exceeded header defined size\n");
226 ret = -EINVAL;
227 goto failed;
230 ret = efi_capsule_submit_update(cap_info);
231 if (ret)
232 goto failed;
235 return write_byte;
237 fail_unmap:
238 kunmap(page);
239 failed:
240 efi_free_all_buff_pages(cap_info);
241 return ret;
245 * efi_capsule_flush - called by file close or file flush
246 * @file: file pointer
247 * @id: not used
249 * If a capsule is being partially uploaded then calling this function
250 * will be treated as upload termination and will free those completed
251 * buffer pages and -ECANCELED will be returned.
253 static int efi_capsule_flush(struct file *file, fl_owner_t id)
255 int ret = 0;
256 struct capsule_info *cap_info = file->private_data;
258 if (cap_info->index > 0) {
259 pr_err("capsule upload not complete\n");
260 efi_free_all_buff_pages(cap_info);
261 ret = -ECANCELED;
264 return ret;
268 * efi_capsule_release - called by file close
269 * @inode: not used
270 * @file: file pointer
272 * We will not free successfully submitted pages since efi update
273 * requires data to be maintained across system reboot.
275 static int efi_capsule_release(struct inode *inode, struct file *file)
277 struct capsule_info *cap_info = file->private_data;
279 kfree(cap_info->pages);
280 kfree(cap_info->phys);
281 kfree(file->private_data);
282 file->private_data = NULL;
283 return 0;
287 * efi_capsule_open - called by file open
288 * @inode: not used
289 * @file: file pointer
291 * Will allocate each capsule_info memory for each file open call.
292 * This provided the capability to support multiple file open feature
293 * where user is not needed to wait for others to finish in order to
294 * upload their capsule binary.
296 static int efi_capsule_open(struct inode *inode, struct file *file)
298 struct capsule_info *cap_info;
300 cap_info = kzalloc(sizeof(*cap_info), GFP_KERNEL);
301 if (!cap_info)
302 return -ENOMEM;
304 cap_info->pages = kzalloc(sizeof(void *), GFP_KERNEL);
305 if (!cap_info->pages) {
306 kfree(cap_info);
307 return -ENOMEM;
310 cap_info->phys = kzalloc(sizeof(void *), GFP_KERNEL);
311 if (!cap_info->phys) {
312 kfree(cap_info->pages);
313 kfree(cap_info);
314 return -ENOMEM;
317 file->private_data = cap_info;
319 return 0;
322 static const struct file_operations efi_capsule_fops = {
323 .owner = THIS_MODULE,
324 .open = efi_capsule_open,
325 .write = efi_capsule_write,
326 .flush = efi_capsule_flush,
327 .release = efi_capsule_release,
328 .llseek = no_llseek,
331 static struct miscdevice efi_capsule_misc = {
332 .minor = MISC_DYNAMIC_MINOR,
333 .name = "efi_capsule_loader",
334 .fops = &efi_capsule_fops,
337 static int __init efi_capsule_loader_init(void)
339 int ret;
341 if (!efi_enabled(EFI_RUNTIME_SERVICES))
342 return -ENODEV;
344 ret = misc_register(&efi_capsule_misc);
345 if (ret)
346 pr_err("Unable to register capsule loader device\n");
348 return ret;
350 module_init(efi_capsule_loader_init);
352 static void __exit efi_capsule_loader_exit(void)
354 misc_deregister(&efi_capsule_misc);
356 module_exit(efi_capsule_loader_exit);
358 MODULE_DESCRIPTION("EFI capsule firmware binary loader");
359 MODULE_LICENSE("GPL v2");