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65117f1a KHL |
1 | /* |
2 | * EFI capsule loader driver. | |
3 | * | |
4 | * Copyright 2015 Intel Corporation | |
5 | * | |
6 | * This file is part of the Linux kernel, and is made available under | |
7 | * the terms of the GNU General Public License version 2. | |
8 | */ | |
9 | ||
10 | #define pr_fmt(fmt) "efi: " fmt | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/miscdevice.h> | |
15 | #include <linux/highmem.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/efi.h> | |
6862e6ad | 19 | #include <linux/vmalloc.h> |
65117f1a KHL |
20 | |
21 | #define NO_FURTHER_WRITE_ACTION -1 | |
22 | ||
2a457fb3 AB |
23 | #ifndef phys_to_page |
24 | #define phys_to_page(x) pfn_to_page((x) >> PAGE_SHIFT) | |
25 | #endif | |
26 | ||
65117f1a KHL |
27 | /** |
28 | * efi_free_all_buff_pages - free all previous allocated buffer pages | |
29 | * @cap_info: pointer to current instance of capsule_info structure | |
30 | * | |
31 | * In addition to freeing buffer pages, it flags NO_FURTHER_WRITE_ACTION | |
32 | * to cease processing data in subsequent write(2) calls until close(2) | |
33 | * is called. | |
34 | **/ | |
35 | static void efi_free_all_buff_pages(struct capsule_info *cap_info) | |
36 | { | |
37 | while (cap_info->index > 0) | |
2a457fb3 | 38 | __free_page(phys_to_page(cap_info->pages[--cap_info->index])); |
65117f1a KHL |
39 | |
40 | cap_info->index = NO_FURTHER_WRITE_ACTION; | |
41 | } | |
42 | ||
3fabd628 | 43 | int __efi_capsule_setup_info(struct capsule_info *cap_info) |
65117f1a | 44 | { |
65117f1a KHL |
45 | size_t pages_needed; |
46 | int ret; | |
47 | void *temp_page; | |
48 | ||
3fabd628 | 49 | pages_needed = ALIGN(cap_info->total_size, PAGE_SIZE) / PAGE_SIZE; |
65117f1a KHL |
50 | |
51 | if (pages_needed == 0) { | |
5dce14b9 | 52 | pr_err("invalid capsule size"); |
65117f1a KHL |
53 | return -EINVAL; |
54 | } | |
55 | ||
56 | /* Check if the capsule binary supported */ | |
82c3768b AB |
57 | ret = efi_capsule_supported(cap_info->header.guid, |
58 | cap_info->header.flags, | |
59 | cap_info->header.imagesize, | |
65117f1a KHL |
60 | &cap_info->reset_type); |
61 | if (ret) { | |
5dce14b9 | 62 | pr_err("capsule not supported\n"); |
65117f1a KHL |
63 | return ret; |
64 | } | |
65 | ||
65117f1a KHL |
66 | temp_page = krealloc(cap_info->pages, |
67 | pages_needed * sizeof(void *), | |
68 | GFP_KERNEL | __GFP_ZERO); | |
7367633f | 69 | if (!temp_page) |
65117f1a | 70 | return -ENOMEM; |
65117f1a KHL |
71 | |
72 | cap_info->pages = temp_page; | |
65117f1a KHL |
73 | |
74 | return 0; | |
75 | } | |
76 | ||
3fabd628 AB |
77 | /** |
78 | * efi_capsule_setup_info - obtain the efi capsule header in the binary and | |
79 | * setup capsule_info structure | |
80 | * @cap_info: pointer to current instance of capsule_info structure | |
81 | * @kbuff: a mapped first page buffer pointer | |
82 | * @hdr_bytes: the total received number of bytes for efi header | |
83 | * | |
84 | * Platforms with non-standard capsule update mechanisms can override | |
85 | * this __weak function so they can perform any required capsule | |
86 | * image munging. See quark_quirk_function() for an example. | |
87 | **/ | |
88 | int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff, | |
89 | size_t hdr_bytes) | |
90 | { | |
91 | /* Only process data block that is larger than efi header size */ | |
92 | if (hdr_bytes < sizeof(efi_capsule_header_t)) | |
93 | return 0; | |
94 | ||
95 | memcpy(&cap_info->header, kbuff, sizeof(cap_info->header)); | |
96 | cap_info->total_size = cap_info->header.imagesize; | |
97 | ||
98 | return __efi_capsule_setup_info(cap_info); | |
99 | } | |
100 | ||
65117f1a KHL |
101 | /** |
102 | * efi_capsule_submit_update - invoke the efi_capsule_update API once binary | |
103 | * upload done | |
104 | * @cap_info: pointer to current instance of capsule_info structure | |
105 | **/ | |
106 | static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info) | |
107 | { | |
108 | int ret; | |
65117f1a | 109 | |
82c3768b | 110 | ret = efi_capsule_update(&cap_info->header, cap_info->pages); |
65117f1a | 111 | if (ret) { |
5dce14b9 | 112 | pr_err("capsule update failed\n"); |
65117f1a KHL |
113 | return ret; |
114 | } | |
115 | ||
116 | /* Indicate capsule binary uploading is done */ | |
117 | cap_info->index = NO_FURTHER_WRITE_ACTION; | |
5dce14b9 JK |
118 | pr_info("Successfully upload capsule file with reboot type '%s'\n", |
119 | !cap_info->reset_type ? "RESET_COLD" : | |
65117f1a KHL |
120 | cap_info->reset_type == 1 ? "RESET_WARM" : |
121 | "RESET_SHUTDOWN"); | |
122 | return 0; | |
123 | } | |
124 | ||
125 | /** | |
126 | * efi_capsule_write - store the capsule binary and pass it to | |
127 | * efi_capsule_update() API | |
128 | * @file: file pointer | |
129 | * @buff: buffer pointer | |
130 | * @count: number of bytes in @buff | |
131 | * @offp: not used | |
132 | * | |
133 | * Expectation: | |
134 | * - A user space tool should start at the beginning of capsule binary and | |
135 | * pass data in sequentially. | |
136 | * - Users should close and re-open this file note in order to upload more | |
137 | * capsules. | |
138 | * - After an error returned, user should close the file and restart the | |
139 | * operation for the next try otherwise -EIO will be returned until the | |
140 | * file is closed. | |
141 | * - An EFI capsule header must be located at the beginning of capsule | |
142 | * binary file and passed in as first block data of write operation. | |
143 | **/ | |
144 | static ssize_t efi_capsule_write(struct file *file, const char __user *buff, | |
145 | size_t count, loff_t *offp) | |
146 | { | |
147 | int ret = 0; | |
148 | struct capsule_info *cap_info = file->private_data; | |
149 | struct page *page; | |
150 | void *kbuff = NULL; | |
151 | size_t write_byte; | |
152 | ||
153 | if (count == 0) | |
154 | return 0; | |
155 | ||
156 | /* Return error while NO_FURTHER_WRITE_ACTION is flagged */ | |
157 | if (cap_info->index < 0) | |
158 | return -EIO; | |
159 | ||
160 | /* Only alloc a new page when previous page is full */ | |
161 | if (!cap_info->page_bytes_remain) { | |
162 | page = alloc_page(GFP_KERNEL); | |
163 | if (!page) { | |
65117f1a KHL |
164 | ret = -ENOMEM; |
165 | goto failed; | |
166 | } | |
167 | ||
2a457fb3 | 168 | cap_info->pages[cap_info->index++] = page_to_phys(page); |
65117f1a | 169 | cap_info->page_bytes_remain = PAGE_SIZE; |
2a457fb3 AB |
170 | } else { |
171 | page = phys_to_page(cap_info->pages[cap_info->index - 1]); | |
65117f1a KHL |
172 | } |
173 | ||
65117f1a | 174 | kbuff = kmap(page); |
65117f1a KHL |
175 | kbuff += PAGE_SIZE - cap_info->page_bytes_remain; |
176 | ||
177 | /* Copy capsule binary data from user space to kernel space buffer */ | |
178 | write_byte = min_t(size_t, count, cap_info->page_bytes_remain); | |
179 | if (copy_from_user(kbuff, buff, write_byte)) { | |
65117f1a KHL |
180 | ret = -EFAULT; |
181 | goto fail_unmap; | |
182 | } | |
183 | cap_info->page_bytes_remain -= write_byte; | |
184 | ||
185 | /* Setup capsule binary info structure */ | |
82c3768b | 186 | if (cap_info->header.headersize == 0) { |
3fabd628 | 187 | ret = efi_capsule_setup_info(cap_info, kbuff - cap_info->count, |
65117f1a KHL |
188 | cap_info->count + write_byte); |
189 | if (ret) | |
190 | goto fail_unmap; | |
191 | } | |
192 | ||
193 | cap_info->count += write_byte; | |
194 | kunmap(page); | |
195 | ||
196 | /* Submit the full binary to efi_capsule_update() API */ | |
82c3768b | 197 | if (cap_info->header.headersize > 0 && |
65117f1a KHL |
198 | cap_info->count >= cap_info->total_size) { |
199 | if (cap_info->count > cap_info->total_size) { | |
5dce14b9 | 200 | pr_err("capsule upload size exceeded header defined size\n"); |
65117f1a KHL |
201 | ret = -EINVAL; |
202 | goto failed; | |
203 | } | |
204 | ||
205 | ret = efi_capsule_submit_update(cap_info); | |
206 | if (ret) | |
207 | goto failed; | |
208 | } | |
209 | ||
210 | return write_byte; | |
211 | ||
212 | fail_unmap: | |
213 | kunmap(page); | |
214 | failed: | |
215 | efi_free_all_buff_pages(cap_info); | |
216 | return ret; | |
217 | } | |
218 | ||
219 | /** | |
220 | * efi_capsule_flush - called by file close or file flush | |
221 | * @file: file pointer | |
222 | * @id: not used | |
223 | * | |
224 | * If a capsule is being partially uploaded then calling this function | |
225 | * will be treated as upload termination and will free those completed | |
226 | * buffer pages and -ECANCELED will be returned. | |
227 | **/ | |
228 | static int efi_capsule_flush(struct file *file, fl_owner_t id) | |
229 | { | |
230 | int ret = 0; | |
231 | struct capsule_info *cap_info = file->private_data; | |
232 | ||
233 | if (cap_info->index > 0) { | |
5dce14b9 | 234 | pr_err("capsule upload not complete\n"); |
65117f1a KHL |
235 | efi_free_all_buff_pages(cap_info); |
236 | ret = -ECANCELED; | |
237 | } | |
238 | ||
239 | return ret; | |
240 | } | |
241 | ||
242 | /** | |
243 | * efi_capsule_release - called by file close | |
244 | * @inode: not used | |
245 | * @file: file pointer | |
246 | * | |
247 | * We will not free successfully submitted pages since efi update | |
248 | * requires data to be maintained across system reboot. | |
249 | **/ | |
250 | static int efi_capsule_release(struct inode *inode, struct file *file) | |
251 | { | |
252 | struct capsule_info *cap_info = file->private_data; | |
253 | ||
254 | kfree(cap_info->pages); | |
255 | kfree(file->private_data); | |
256 | file->private_data = NULL; | |
257 | return 0; | |
258 | } | |
259 | ||
260 | /** | |
261 | * efi_capsule_open - called by file open | |
262 | * @inode: not used | |
263 | * @file: file pointer | |
264 | * | |
265 | * Will allocate each capsule_info memory for each file open call. | |
266 | * This provided the capability to support multiple file open feature | |
267 | * where user is not needed to wait for others to finish in order to | |
268 | * upload their capsule binary. | |
269 | **/ | |
270 | static int efi_capsule_open(struct inode *inode, struct file *file) | |
271 | { | |
272 | struct capsule_info *cap_info; | |
273 | ||
274 | cap_info = kzalloc(sizeof(*cap_info), GFP_KERNEL); | |
275 | if (!cap_info) | |
276 | return -ENOMEM; | |
277 | ||
278 | cap_info->pages = kzalloc(sizeof(void *), GFP_KERNEL); | |
279 | if (!cap_info->pages) { | |
280 | kfree(cap_info); | |
281 | return -ENOMEM; | |
282 | } | |
283 | ||
284 | file->private_data = cap_info; | |
285 | ||
286 | return 0; | |
287 | } | |
288 | ||
289 | static const struct file_operations efi_capsule_fops = { | |
290 | .owner = THIS_MODULE, | |
291 | .open = efi_capsule_open, | |
292 | .write = efi_capsule_write, | |
293 | .flush = efi_capsule_flush, | |
294 | .release = efi_capsule_release, | |
295 | .llseek = no_llseek, | |
296 | }; | |
297 | ||
298 | static struct miscdevice efi_capsule_misc = { | |
299 | .minor = MISC_DYNAMIC_MINOR, | |
300 | .name = "efi_capsule_loader", | |
301 | .fops = &efi_capsule_fops, | |
302 | }; | |
303 | ||
304 | static int __init efi_capsule_loader_init(void) | |
305 | { | |
306 | int ret; | |
307 | ||
308 | if (!efi_enabled(EFI_RUNTIME_SERVICES)) | |
309 | return -ENODEV; | |
310 | ||
311 | ret = misc_register(&efi_capsule_misc); | |
312 | if (ret) | |
5dce14b9 | 313 | pr_err("Unable to register capsule loader device\n"); |
65117f1a KHL |
314 | |
315 | return ret; | |
316 | } | |
317 | module_init(efi_capsule_loader_init); | |
318 | ||
319 | static void __exit efi_capsule_loader_exit(void) | |
320 | { | |
321 | misc_deregister(&efi_capsule_misc); | |
322 | } | |
323 | module_exit(efi_capsule_loader_exit); | |
324 | ||
325 | MODULE_DESCRIPTION("EFI capsule firmware binary loader"); | |
326 | MODULE_LICENSE("GPL v2"); |