2 * EFI capsule loader driver.
4 * Copyright 2015 Intel Corporation
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.
10 #define pr_fmt(fmt) "efi: " fmt
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>
20 #define NO_FURTHER_WRITE_ACTION -1
29 size_t page_bytes_remain
;
33 * efi_free_all_buff_pages - free all previous allocated buffer pages
34 * @cap_info: pointer to current instance of capsule_info structure
36 * In addition to freeing buffer pages, it flags NO_FURTHER_WRITE_ACTION
37 * to cease processing data in subsequent write(2) calls until close(2)
40 static void efi_free_all_buff_pages(struct capsule_info
*cap_info
)
42 while (cap_info
->index
> 0)
43 __free_page(cap_info
->pages
[--cap_info
->index
]);
45 cap_info
->index
= NO_FURTHER_WRITE_ACTION
;
49 * efi_capsule_setup_info - obtain the efi capsule header in the binary and
50 * setup capsule_info structure
51 * @cap_info: pointer to current instance of capsule_info structure
52 * @kbuff: a mapped first page buffer pointer
53 * @hdr_bytes: the total received number of bytes for efi header
55 static ssize_t
efi_capsule_setup_info(struct capsule_info
*cap_info
,
56 void *kbuff
, size_t hdr_bytes
)
58 efi_capsule_header_t
*cap_hdr
;
63 /* Only process data block that is larger than efi header size */
64 if (hdr_bytes
< sizeof(efi_capsule_header_t
))
67 /* Reset back to the correct offset of header */
68 cap_hdr
= kbuff
- cap_info
->count
;
69 pages_needed
= ALIGN(cap_hdr
->imagesize
, PAGE_SIZE
) >> PAGE_SHIFT
;
71 if (pages_needed
== 0) {
72 pr_err("%s: pages count invalid\n", __func__
);
76 /* Check if the capsule binary supported */
77 ret
= efi_capsule_supported(cap_hdr
->guid
, cap_hdr
->flags
,
79 &cap_info
->reset_type
);
81 pr_err("%s: efi_capsule_supported() failed\n",
86 cap_info
->total_size
= cap_hdr
->imagesize
;
87 temp_page
= krealloc(cap_info
->pages
,
88 pages_needed
* sizeof(void *),
89 GFP_KERNEL
| __GFP_ZERO
);
91 pr_debug("%s: krealloc() failed\n", __func__
);
95 cap_info
->pages
= temp_page
;
96 cap_info
->header_obtained
= true;
102 * efi_capsule_submit_update - invoke the efi_capsule_update API once binary
104 * @cap_info: pointer to current instance of capsule_info structure
106 static ssize_t
efi_capsule_submit_update(struct capsule_info
*cap_info
)
111 cap_hdr_temp
= kmap(cap_info
->pages
[0]);
113 pr_debug("%s: kmap() failed\n", __func__
);
117 ret
= efi_capsule_update(cap_hdr_temp
, cap_info
->pages
);
118 kunmap(cap_info
->pages
[0]);
120 pr_err("%s: efi_capsule_update() failed\n", __func__
);
124 /* Indicate capsule binary uploading is done */
125 cap_info
->index
= NO_FURTHER_WRITE_ACTION
;
126 pr_info("%s: Successfully upload capsule file with reboot type '%s'\n",
127 __func__
, !cap_info
->reset_type
? "RESET_COLD" :
128 cap_info
->reset_type
== 1 ? "RESET_WARM" :
134 * efi_capsule_write - store the capsule binary and pass it to
135 * efi_capsule_update() API
136 * @file: file pointer
137 * @buff: buffer pointer
138 * @count: number of bytes in @buff
142 * - A user space tool should start at the beginning of capsule binary and
143 * pass data in sequentially.
144 * - Users should close and re-open this file note in order to upload more
146 * - After an error returned, user should close the file and restart the
147 * operation for the next try otherwise -EIO will be returned until the
149 * - An EFI capsule header must be located at the beginning of capsule
150 * binary file and passed in as first block data of write operation.
152 static ssize_t
efi_capsule_write(struct file
*file
, const char __user
*buff
,
153 size_t count
, loff_t
*offp
)
156 struct capsule_info
*cap_info
= file
->private_data
;
164 /* Return error while NO_FURTHER_WRITE_ACTION is flagged */
165 if (cap_info
->index
< 0)
168 /* Only alloc a new page when previous page is full */
169 if (!cap_info
->page_bytes_remain
) {
170 page
= alloc_page(GFP_KERNEL
);
172 pr_debug("%s: alloc_page() failed\n", __func__
);
177 cap_info
->pages
[cap_info
->index
++] = page
;
178 cap_info
->page_bytes_remain
= PAGE_SIZE
;
181 page
= cap_info
->pages
[cap_info
->index
- 1];
185 pr_debug("%s: kmap() failed\n", __func__
);
189 kbuff
+= PAGE_SIZE
- cap_info
->page_bytes_remain
;
191 /* Copy capsule binary data from user space to kernel space buffer */
192 write_byte
= min_t(size_t, count
, cap_info
->page_bytes_remain
);
193 if (copy_from_user(kbuff
, buff
, write_byte
)) {
194 pr_debug("%s: copy_from_user() failed\n", __func__
);
198 cap_info
->page_bytes_remain
-= write_byte
;
200 /* Setup capsule binary info structure */
201 if (!cap_info
->header_obtained
) {
202 ret
= efi_capsule_setup_info(cap_info
, kbuff
,
203 cap_info
->count
+ write_byte
);
208 cap_info
->count
+= write_byte
;
211 /* Submit the full binary to efi_capsule_update() API */
212 if (cap_info
->header_obtained
&&
213 cap_info
->count
>= cap_info
->total_size
) {
214 if (cap_info
->count
> cap_info
->total_size
) {
215 pr_err("%s: upload size exceeded header defined size\n",
221 ret
= efi_capsule_submit_update(cap_info
);
231 efi_free_all_buff_pages(cap_info
);
236 * efi_capsule_flush - called by file close or file flush
237 * @file: file pointer
240 * If a capsule is being partially uploaded then calling this function
241 * will be treated as upload termination and will free those completed
242 * buffer pages and -ECANCELED will be returned.
244 static int efi_capsule_flush(struct file
*file
, fl_owner_t id
)
247 struct capsule_info
*cap_info
= file
->private_data
;
249 if (cap_info
->index
> 0) {
250 pr_err("%s: capsule upload not complete\n", __func__
);
251 efi_free_all_buff_pages(cap_info
);
259 * efi_capsule_release - called by file close
261 * @file: file pointer
263 * We will not free successfully submitted pages since efi update
264 * requires data to be maintained across system reboot.
266 static int efi_capsule_release(struct inode
*inode
, struct file
*file
)
268 struct capsule_info
*cap_info
= file
->private_data
;
270 kfree(cap_info
->pages
);
271 kfree(file
->private_data
);
272 file
->private_data
= NULL
;
277 * efi_capsule_open - called by file open
279 * @file: file pointer
281 * Will allocate each capsule_info memory for each file open call.
282 * This provided the capability to support multiple file open feature
283 * where user is not needed to wait for others to finish in order to
284 * upload their capsule binary.
286 static int efi_capsule_open(struct inode
*inode
, struct file
*file
)
288 struct capsule_info
*cap_info
;
290 cap_info
= kzalloc(sizeof(*cap_info
), GFP_KERNEL
);
294 cap_info
->pages
= kzalloc(sizeof(void *), GFP_KERNEL
);
295 if (!cap_info
->pages
) {
300 file
->private_data
= cap_info
;
305 static const struct file_operations efi_capsule_fops
= {
306 .owner
= THIS_MODULE
,
307 .open
= efi_capsule_open
,
308 .write
= efi_capsule_write
,
309 .flush
= efi_capsule_flush
,
310 .release
= efi_capsule_release
,
314 static struct miscdevice efi_capsule_misc
= {
315 .minor
= MISC_DYNAMIC_MINOR
,
316 .name
= "efi_capsule_loader",
317 .fops
= &efi_capsule_fops
,
320 static int __init
efi_capsule_loader_init(void)
324 if (!efi_enabled(EFI_RUNTIME_SERVICES
))
327 ret
= misc_register(&efi_capsule_misc
);
329 pr_err("%s: Failed to register misc char file note\n",
334 module_init(efi_capsule_loader_init
);
336 static void __exit
efi_capsule_loader_exit(void)
338 misc_deregister(&efi_capsule_misc
);
340 module_exit(efi_capsule_loader_exit
);
342 MODULE_DESCRIPTION("EFI capsule firmware binary loader");
343 MODULE_LICENSE("GPL v2");