1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PowerNV OPAL Firmware Update Interface
4  *
5  * Copyright 2013 IBM Corp.
6  */
7 
8 #define DEBUG
9 
10 #include <linux/kernel.h>
11 #include <linux/reboot.h>
12 #include <linux/init.h>
13 #include <linux/kobject.h>
14 #include <linux/sysfs.h>
15 #include <linux/slab.h>
16 #include <linux/mm.h>
17 #include <linux/vmalloc.h>
18 #include <linux/pagemap.h>
19 #include <linux/delay.h>
20 
21 #include <asm/opal.h>
22 
23 /* FLASH status codes */
24 #define FLASH_NO_OP		-1099	/* No operation initiated by user */
25 #define FLASH_NO_AUTH		-9002	/* Not a service authority partition */
26 
27 /* Validate image status values */
28 #define VALIDATE_IMG_READY	-1001	/* Image ready for validation */
29 #define VALIDATE_IMG_INCOMPLETE	-1002	/* User copied < VALIDATE_BUF_SIZE */
30 
31 /* Manage image status values */
32 #define MANAGE_ACTIVE_ERR	-9001	/* Cannot overwrite active img */
33 
34 /* Flash image status values */
35 #define FLASH_IMG_READY		0	/* Img ready for flash on reboot */
36 #define FLASH_INVALID_IMG	-1003	/* Flash image shorter than expected */
37 #define FLASH_IMG_NULL_DATA	-1004	/* Bad data in sg list entry */
38 #define FLASH_IMG_BAD_LEN	-1005	/* Bad length in sg list entry */
39 
40 /* Manage operation tokens */
41 #define FLASH_REJECT_TMP_SIDE	0	/* Reject temporary fw image */
42 #define FLASH_COMMIT_TMP_SIDE	1	/* Commit temporary fw image */
43 
44 /* Update tokens */
45 #define FLASH_UPDATE_CANCEL	0	/* Cancel update request */
46 #define FLASH_UPDATE_INIT	1	/* Initiate update */
47 
48 /* Validate image update result tokens */
49 #define VALIDATE_TMP_UPDATE	0     /* T side will be updated */
50 #define VALIDATE_FLASH_AUTH	1     /* Partition does not have authority */
51 #define VALIDATE_INVALID_IMG	2     /* Candidate image is not valid */
52 #define VALIDATE_CUR_UNKNOWN	3     /* Current fixpack level is unknown */
53 /*
54  * Current T side will be committed to P side before being replace with new
55  * image, and the new image is downlevel from current image
56  */
57 #define VALIDATE_TMP_COMMIT_DL	4
58 /*
59  * Current T side will be committed to P side before being replaced with new
60  * image
61  */
62 #define VALIDATE_TMP_COMMIT	5
63 /*
64  * T side will be updated with a downlevel image
65  */
66 #define VALIDATE_TMP_UPDATE_DL	6
67 /*
68  * The candidate image's release date is later than the system's firmware
69  * service entitlement date - service warranty period has expired
70  */
71 #define VALIDATE_OUT_OF_WRNTY	7
72 
73 /* Validate buffer size */
74 #define VALIDATE_BUF_SIZE	4096
75 
76 /* XXX: Assume candidate image size is <= 1GB */
77 #define MAX_IMAGE_SIZE	0x40000000
78 
79 /* Image status */
80 enum {
81 	IMAGE_INVALID,
82 	IMAGE_LOADING,
83 	IMAGE_READY,
84 };
85 
86 /* Candidate image data */
87 struct image_data_t {
88 	int		status;
89 	void		*data;
90 	uint32_t	size;
91 };
92 
93 /* Candidate image header */
94 struct image_header_t {
95 	uint16_t	magic;
96 	uint16_t	version;
97 	uint32_t	size;
98 };
99 
100 struct validate_flash_t {
101 	int		status;		/* Return status */
102 	void		*buf;		/* Candidate image buffer */
103 	uint32_t	buf_size;	/* Image size */
104 	uint32_t	result;		/* Update results token */
105 };
106 
107 struct manage_flash_t {
108 	int status;		/* Return status */
109 };
110 
111 struct update_flash_t {
112 	int status;		/* Return status */
113 };
114 
115 static struct image_header_t	image_header;
116 static struct image_data_t	image_data;
117 static struct validate_flash_t	validate_flash_data;
118 static struct manage_flash_t	manage_flash_data;
119 
120 /* Initialize update_flash_data status to No Operation */
121 static struct update_flash_t	update_flash_data = {
122 	.status = FLASH_NO_OP,
123 };
124 
125 static DEFINE_MUTEX(image_data_mutex);
126 
127 /*
128  * Validate candidate image
129  */
130 static inline void opal_flash_validate(void)
131 {
132 	long ret;
133 	void *buf = validate_flash_data.buf;
134 	__be32 size = cpu_to_be32(validate_flash_data.buf_size);
135 	__be32 result;
136 
137 	ret = opal_validate_flash(__pa(buf), &size, &result);
138 
139 	validate_flash_data.status = ret;
140 	validate_flash_data.buf_size = be32_to_cpu(size);
141 	validate_flash_data.result = be32_to_cpu(result);
142 }
143 
144 /*
145  * Validate output format:
146  *     validate result token
147  *     current image version details
148  *     new image version details
149  */
150 static ssize_t validate_show(struct kobject *kobj,
151 			     struct kobj_attribute *attr, char *buf)
152 {
153 	struct validate_flash_t *args_buf = &validate_flash_data;
154 	int len;
155 
156 	/* Candidate image is not validated */
157 	if (args_buf->status < VALIDATE_TMP_UPDATE) {
158 		len = sprintf(buf, "%d\n", args_buf->status);
159 		goto out;
160 	}
161 
162 	/* Result token */
163 	len = sprintf(buf, "%d\n", args_buf->result);
164 
165 	/* Current and candidate image version details */
166 	if ((args_buf->result != VALIDATE_TMP_UPDATE) &&
167 	    (args_buf->result < VALIDATE_CUR_UNKNOWN))
168 		goto out;
169 
170 	if (args_buf->buf_size > (VALIDATE_BUF_SIZE - len)) {
171 		memcpy(buf + len, args_buf->buf, VALIDATE_BUF_SIZE - len);
172 		len = VALIDATE_BUF_SIZE;
173 	} else {
174 		memcpy(buf + len, args_buf->buf, args_buf->buf_size);
175 		len += args_buf->buf_size;
176 	}
177 out:
178 	/* Set status to default */
179 	args_buf->status = FLASH_NO_OP;
180 	return len;
181 }
182 
183 /*
184  * Validate candidate firmware image
185  *
186  * Note:
187  *   We are only interested in first 4K bytes of the
188  *   candidate image.
189  */
190 static ssize_t validate_store(struct kobject *kobj,
191 			      struct kobj_attribute *attr,
192 			      const char *buf, size_t count)
193 {
194 	struct validate_flash_t *args_buf = &validate_flash_data;
195 
196 	if (buf[0] != '1')
197 		return -EINVAL;
198 
199 	mutex_lock(&image_data_mutex);
200 
201 	if (image_data.status != IMAGE_READY ||
202 	    image_data.size < VALIDATE_BUF_SIZE) {
203 		args_buf->result = VALIDATE_INVALID_IMG;
204 		args_buf->status = VALIDATE_IMG_INCOMPLETE;
205 		goto out;
206 	}
207 
208 	/* Copy first 4k bytes of candidate image */
209 	memcpy(args_buf->buf, image_data.data, VALIDATE_BUF_SIZE);
210 
211 	args_buf->status = VALIDATE_IMG_READY;
212 	args_buf->buf_size = VALIDATE_BUF_SIZE;
213 
214 	/* Validate candidate image */
215 	opal_flash_validate();
216 
217 out:
218 	mutex_unlock(&image_data_mutex);
219 	return count;
220 }
221 
222 /*
223  * Manage flash routine
224  */
225 static inline void opal_flash_manage(uint8_t op)
226 {
227 	struct manage_flash_t *const args_buf = &manage_flash_data;
228 
229 	args_buf->status = opal_manage_flash(op);
230 }
231 
232 /*
233  * Show manage flash status
234  */
235 static ssize_t manage_show(struct kobject *kobj,
236 			   struct kobj_attribute *attr, char *buf)
237 {
238 	struct manage_flash_t *const args_buf = &manage_flash_data;
239 	int rc;
240 
241 	rc = sprintf(buf, "%d\n", args_buf->status);
242 	/* Set status to default*/
243 	args_buf->status = FLASH_NO_OP;
244 	return rc;
245 }
246 
247 /*
248  * Manage operations:
249  *   0 - Reject
250  *   1 - Commit
251  */
252 static ssize_t manage_store(struct kobject *kobj,
253 			    struct kobj_attribute *attr,
254 			    const char *buf, size_t count)
255 {
256 	uint8_t op;
257 	switch (buf[0]) {
258 	case '0':
259 		op = FLASH_REJECT_TMP_SIDE;
260 		break;
261 	case '1':
262 		op = FLASH_COMMIT_TMP_SIDE;
263 		break;
264 	default:
265 		return -EINVAL;
266 	}
267 
268 	/* commit/reject temporary image */
269 	opal_flash_manage(op);
270 	return count;
271 }
272 
273 /*
274  * OPAL update flash
275  */
276 static int opal_flash_update(int op)
277 {
278 	struct opal_sg_list *list;
279 	unsigned long addr;
280 	int64_t rc = OPAL_PARAMETER;
281 
282 	if (op == FLASH_UPDATE_CANCEL) {
283 		pr_alert("FLASH: Image update cancelled\n");
284 		addr = '\0';
285 		goto flash;
286 	}
287 
288 	list = opal_vmalloc_to_sg_list(image_data.data, image_data.size);
289 	if (!list)
290 		goto invalid_img;
291 
292 	/* First entry address */
293 	addr = __pa(list);
294 
295 flash:
296 	rc = opal_update_flash(addr);
297 
298 invalid_img:
299 	return rc;
300 }
301 
302 /* This gets called just before system reboots */
303 void opal_flash_update_print_message(void)
304 {
305 	if (update_flash_data.status != FLASH_IMG_READY)
306 		return;
307 
308 	pr_alert("FLASH: Flashing new firmware\n");
309 	pr_alert("FLASH: Image is %u bytes\n", image_data.size);
310 	pr_alert("FLASH: Performing flash and reboot/shutdown\n");
311 	pr_alert("FLASH: This will take several minutes. Do not power off!\n");
312 
313 	/* Small delay to help getting the above message out */
314 	msleep(500);
315 }
316 
317 /*
318  * Show candidate image status
319  */
320 static ssize_t update_show(struct kobject *kobj,
321 			   struct kobj_attribute *attr, char *buf)
322 {
323 	struct update_flash_t *const args_buf = &update_flash_data;
324 	return sprintf(buf, "%d\n", args_buf->status);
325 }
326 
327 /*
328  * Set update image flag
329  *  1 - Flash new image
330  *  0 - Cancel flash request
331  */
332 static ssize_t update_store(struct kobject *kobj,
333 			    struct kobj_attribute *attr,
334 			    const char *buf, size_t count)
335 {
336 	struct update_flash_t *const args_buf = &update_flash_data;
337 	int rc = count;
338 
339 	mutex_lock(&image_data_mutex);
340 
341 	switch (buf[0]) {
342 	case '0':
343 		if (args_buf->status == FLASH_IMG_READY)
344 			opal_flash_update(FLASH_UPDATE_CANCEL);
345 		args_buf->status = FLASH_NO_OP;
346 		break;
347 	case '1':
348 		/* Image is loaded? */
349 		if (image_data.status == IMAGE_READY)
350 			args_buf->status =
351 				opal_flash_update(FLASH_UPDATE_INIT);
352 		else
353 			args_buf->status = FLASH_INVALID_IMG;
354 		break;
355 	default:
356 		rc = -EINVAL;
357 	}
358 
359 	mutex_unlock(&image_data_mutex);
360 	return rc;
361 }
362 
363 /*
364  * Free image buffer
365  */
366 static void free_image_buf(void)
367 {
368 	void *addr;
369 	int size;
370 
371 	addr = image_data.data;
372 	size = PAGE_ALIGN(image_data.size);
373 	while (size > 0) {
374 		ClearPageReserved(vmalloc_to_page(addr));
375 		addr += PAGE_SIZE;
376 		size -= PAGE_SIZE;
377 	}
378 	vfree(image_data.data);
379 	image_data.data = NULL;
380 	image_data.status = IMAGE_INVALID;
381 }
382 
383 /*
384  * Allocate image buffer.
385  */
386 static int alloc_image_buf(char *buffer, size_t count)
387 {
388 	void *addr;
389 	int size;
390 
391 	if (count < sizeof(image_header)) {
392 		pr_warn("FLASH: Invalid candidate image\n");
393 		return -EINVAL;
394 	}
395 
396 	memcpy(&image_header, (void *)buffer, sizeof(image_header));
397 	image_data.size = be32_to_cpu(image_header.size);
398 	pr_debug("FLASH: Candidate image size = %u\n", image_data.size);
399 
400 	if (image_data.size > MAX_IMAGE_SIZE) {
401 		pr_warn("FLASH: Too large image\n");
402 		return -EINVAL;
403 	}
404 	if (image_data.size < VALIDATE_BUF_SIZE) {
405 		pr_warn("FLASH: Image is shorter than expected\n");
406 		return -EINVAL;
407 	}
408 
409 	image_data.data = vzalloc(PAGE_ALIGN(image_data.size));
410 	if (!image_data.data) {
411 		pr_err("%s : Failed to allocate memory\n", __func__);
412 		return -ENOMEM;
413 	}
414 
415 	/* Pin memory */
416 	addr = image_data.data;
417 	size = PAGE_ALIGN(image_data.size);
418 	while (size > 0) {
419 		SetPageReserved(vmalloc_to_page(addr));
420 		addr += PAGE_SIZE;
421 		size -= PAGE_SIZE;
422 	}
423 
424 	image_data.status = IMAGE_LOADING;
425 	return 0;
426 }
427 
428 /*
429  * Copy candidate image
430  *
431  * Parse candidate image header to get total image size
432  * and pre-allocate required memory.
433  */
434 static ssize_t image_data_write(struct file *filp, struct kobject *kobj,
435 				struct bin_attribute *bin_attr,
436 				char *buffer, loff_t pos, size_t count)
437 {
438 	int rc;
439 
440 	mutex_lock(&image_data_mutex);
441 
442 	/* New image ? */
443 	if (pos == 0) {
444 		/* Free memory, if already allocated */
445 		if (image_data.data)
446 			free_image_buf();
447 
448 		/* Cancel outstanding image update request */
449 		if (update_flash_data.status == FLASH_IMG_READY)
450 			opal_flash_update(FLASH_UPDATE_CANCEL);
451 
452 		/* Allocate memory */
453 		rc = alloc_image_buf(buffer, count);
454 		if (rc)
455 			goto out;
456 	}
457 
458 	if (image_data.status != IMAGE_LOADING) {
459 		rc = -ENOMEM;
460 		goto out;
461 	}
462 
463 	if ((pos + count) > image_data.size) {
464 		rc = -EINVAL;
465 		goto out;
466 	}
467 
468 	memcpy(image_data.data + pos, (void *)buffer, count);
469 	rc = count;
470 
471 	/* Set image status */
472 	if ((pos + count) == image_data.size) {
473 		pr_debug("FLASH: Candidate image loaded....\n");
474 		image_data.status = IMAGE_READY;
475 	}
476 
477 out:
478 	mutex_unlock(&image_data_mutex);
479 	return rc;
480 }
481 
482 /*
483  * sysfs interface :
484  *  OPAL uses below sysfs files for code update.
485  *  We create these files under /sys/firmware/opal.
486  *
487  *   image		: Interface to load candidate firmware image
488  *   validate_flash	: Validate firmware image
489  *   manage_flash	: Commit/Reject firmware image
490  *   update_flash	: Flash new firmware image
491  *
492  */
493 static const struct bin_attribute image_data_attr = {
494 	.attr = {.name = "image", .mode = 0200},
495 	.size = MAX_IMAGE_SIZE,	/* Limit image size */
496 	.write = image_data_write,
497 };
498 
499 static struct kobj_attribute validate_attribute =
500 	__ATTR(validate_flash, 0600, validate_show, validate_store);
501 
502 static struct kobj_attribute manage_attribute =
503 	__ATTR(manage_flash, 0600, manage_show, manage_store);
504 
505 static struct kobj_attribute update_attribute =
506 	__ATTR(update_flash, 0600, update_show, update_store);
507 
508 static struct attribute *image_op_attrs[] = {
509 	&validate_attribute.attr,
510 	&manage_attribute.attr,
511 	&update_attribute.attr,
512 	NULL	/* need to NULL terminate the list of attributes */
513 };
514 
515 static struct attribute_group image_op_attr_group = {
516 	.attrs = image_op_attrs,
517 };
518 
519 void __init opal_flash_update_init(void)
520 {
521 	int ret;
522 
523 	/* Allocate validate image buffer */
524 	validate_flash_data.buf = kzalloc(VALIDATE_BUF_SIZE, GFP_KERNEL);
525 	if (!validate_flash_data.buf) {
526 		pr_err("%s : Failed to allocate memory\n", __func__);
527 		return;
528 	}
529 
530 	/* Make sure /sys/firmware/opal directory is created */
531 	if (!opal_kobj) {
532 		pr_warn("FLASH: opal kobject is not available\n");
533 		goto nokobj;
534 	}
535 
536 	/* Create the sysfs files */
537 	ret = sysfs_create_group(opal_kobj, &image_op_attr_group);
538 	if (ret) {
539 		pr_warn("FLASH: Failed to create sysfs files\n");
540 		goto nokobj;
541 	}
542 
543 	ret = sysfs_create_bin_file(opal_kobj, &image_data_attr);
544 	if (ret) {
545 		pr_warn("FLASH: Failed to create sysfs files\n");
546 		goto nosysfs_file;
547 	}
548 
549 	/* Set default status */
550 	validate_flash_data.status = FLASH_NO_OP;
551 	manage_flash_data.status = FLASH_NO_OP;
552 	update_flash_data.status = FLASH_NO_OP;
553 	image_data.status = IMAGE_INVALID;
554 	return;
555 
556 nosysfs_file:
557 	sysfs_remove_group(opal_kobj, &image_op_attr_group);
558 
559 nokobj:
560 	kfree(validate_flash_data.buf);
561 	return;
562 }
563