1 /*
2  * PowerNV OPAL Firmware Update Interface
3  *
4  * Copyright 2013 IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #define DEBUG
13 
14 #include <linux/kernel.h>
15 #include <linux/reboot.h>
16 #include <linux/init.h>
17 #include <linux/kobject.h>
18 #include <linux/sysfs.h>
19 #include <linux/slab.h>
20 #include <linux/mm.h>
21 #include <linux/vmalloc.h>
22 #include <linux/pagemap.h>
23 #include <linux/delay.h>
24 
25 #include <asm/opal.h>
26 
27 /* FLASH status codes */
28 #define FLASH_NO_OP		-1099	/* No operation initiated by user */
29 #define FLASH_NO_AUTH		-9002	/* Not a service authority partition */
30 
31 /* Validate image status values */
32 #define VALIDATE_IMG_READY	-1001	/* Image ready for validation */
33 #define VALIDATE_IMG_INCOMPLETE	-1002	/* User copied < VALIDATE_BUF_SIZE */
34 
35 /* Manage image status values */
36 #define MANAGE_ACTIVE_ERR	-9001	/* Cannot overwrite active img */
37 
38 /* Flash image status values */
39 #define FLASH_IMG_READY		0	/* Img ready for flash on reboot */
40 #define FLASH_INVALID_IMG	-1003	/* Flash image shorter than expected */
41 #define FLASH_IMG_NULL_DATA	-1004	/* Bad data in sg list entry */
42 #define FLASH_IMG_BAD_LEN	-1005	/* Bad length in sg list entry */
43 
44 /* Manage operation tokens */
45 #define FLASH_REJECT_TMP_SIDE	0	/* Reject temporary fw image */
46 #define FLASH_COMMIT_TMP_SIDE	1	/* Commit temporary fw image */
47 
48 /* Update tokens */
49 #define FLASH_UPDATE_CANCEL	0	/* Cancel update request */
50 #define FLASH_UPDATE_INIT	1	/* Initiate update */
51 
52 /* Validate image update result tokens */
53 #define VALIDATE_TMP_UPDATE	0     /* T side will be updated */
54 #define VALIDATE_FLASH_AUTH	1     /* Partition does not have authority */
55 #define VALIDATE_INVALID_IMG	2     /* Candidate image is not valid */
56 #define VALIDATE_CUR_UNKNOWN	3     /* Current fixpack level is unknown */
57 /*
58  * Current T side will be committed to P side before being replace with new
59  * image, and the new image is downlevel from current image
60  */
61 #define VALIDATE_TMP_COMMIT_DL	4
62 /*
63  * Current T side will be committed to P side before being replaced with new
64  * image
65  */
66 #define VALIDATE_TMP_COMMIT	5
67 /*
68  * T side will be updated with a downlevel image
69  */
70 #define VALIDATE_TMP_UPDATE_DL	6
71 /*
72  * The candidate image's release date is later than the system's firmware
73  * service entitlement date - service warranty period has expired
74  */
75 #define VALIDATE_OUT_OF_WRNTY	7
76 
77 /* Validate buffer size */
78 #define VALIDATE_BUF_SIZE	4096
79 
80 /* XXX: Assume candidate image size is <= 1GB */
81 #define MAX_IMAGE_SIZE	0x40000000
82 
83 /* Image status */
84 enum {
85 	IMAGE_INVALID,
86 	IMAGE_LOADING,
87 	IMAGE_READY,
88 };
89 
90 /* Candidate image data */
91 struct image_data_t {
92 	int		status;
93 	void		*data;
94 	uint32_t	size;
95 };
96 
97 /* Candidate image header */
98 struct image_header_t {
99 	uint16_t	magic;
100 	uint16_t	version;
101 	uint32_t	size;
102 };
103 
104 struct validate_flash_t {
105 	int		status;		/* Return status */
106 	void		*buf;		/* Candidate image buffer */
107 	uint32_t	buf_size;	/* Image size */
108 	uint32_t	result;		/* Update results token */
109 };
110 
111 struct manage_flash_t {
112 	int status;		/* Return status */
113 };
114 
115 struct update_flash_t {
116 	int status;		/* Return status */
117 };
118 
119 static struct image_header_t	image_header;
120 static struct image_data_t	image_data;
121 static struct validate_flash_t	validate_flash_data;
122 static struct manage_flash_t	manage_flash_data;
123 static struct update_flash_t	update_flash_data;
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 /* Return CPUs to OPAL before starting FW update */
303 static void flash_return_cpu(void *info)
304 {
305 	int cpu = smp_processor_id();
306 
307 	if (!cpu_online(cpu))
308 		return;
309 
310 	/* Disable IRQ */
311 	hard_irq_disable();
312 
313 	/* Return the CPU to OPAL */
314 	opal_return_cpu();
315 }
316 
317 /* This gets called just before system reboots */
318 void opal_flash_term_callback(void)
319 {
320 	struct cpumask mask;
321 
322 	if (update_flash_data.status != FLASH_IMG_READY)
323 		return;
324 
325 	pr_alert("FLASH: Flashing new firmware\n");
326 	pr_alert("FLASH: Image is %u bytes\n", image_data.size);
327 	pr_alert("FLASH: Performing flash and reboot/shutdown\n");
328 	pr_alert("FLASH: This will take several minutes. Do not power off!\n");
329 
330 	/* Small delay to help getting the above message out */
331 	msleep(500);
332 
333 	/* Return secondary CPUs to firmware */
334 	cpumask_copy(&mask, cpu_online_mask);
335 	cpumask_clear_cpu(smp_processor_id(), &mask);
336 	if (!cpumask_empty(&mask))
337 		smp_call_function_many(&mask,
338 				       flash_return_cpu, NULL, false);
339 	/* Hard disable interrupts */
340 	hard_irq_disable();
341 }
342 
343 /*
344  * Show candidate image status
345  */
346 static ssize_t update_show(struct kobject *kobj,
347 			   struct kobj_attribute *attr, char *buf)
348 {
349 	struct update_flash_t *const args_buf = &update_flash_data;
350 	return sprintf(buf, "%d\n", args_buf->status);
351 }
352 
353 /*
354  * Set update image flag
355  *  1 - Flash new image
356  *  0 - Cancel flash request
357  */
358 static ssize_t update_store(struct kobject *kobj,
359 			    struct kobj_attribute *attr,
360 			    const char *buf, size_t count)
361 {
362 	struct update_flash_t *const args_buf = &update_flash_data;
363 	int rc = count;
364 
365 	mutex_lock(&image_data_mutex);
366 
367 	switch (buf[0]) {
368 	case '0':
369 		if (args_buf->status == FLASH_IMG_READY)
370 			opal_flash_update(FLASH_UPDATE_CANCEL);
371 		args_buf->status = FLASH_NO_OP;
372 		break;
373 	case '1':
374 		/* Image is loaded? */
375 		if (image_data.status == IMAGE_READY)
376 			args_buf->status =
377 				opal_flash_update(FLASH_UPDATE_INIT);
378 		else
379 			args_buf->status = FLASH_INVALID_IMG;
380 		break;
381 	default:
382 		rc = -EINVAL;
383 	}
384 
385 	mutex_unlock(&image_data_mutex);
386 	return rc;
387 }
388 
389 /*
390  * Free image buffer
391  */
392 static void free_image_buf(void)
393 {
394 	void *addr;
395 	int size;
396 
397 	addr = image_data.data;
398 	size = PAGE_ALIGN(image_data.size);
399 	while (size > 0) {
400 		ClearPageReserved(vmalloc_to_page(addr));
401 		addr += PAGE_SIZE;
402 		size -= PAGE_SIZE;
403 	}
404 	vfree(image_data.data);
405 	image_data.data = NULL;
406 	image_data.status = IMAGE_INVALID;
407 }
408 
409 /*
410  * Allocate image buffer.
411  */
412 static int alloc_image_buf(char *buffer, size_t count)
413 {
414 	void *addr;
415 	int size;
416 
417 	if (count < sizeof(struct image_header_t)) {
418 		pr_warn("FLASH: Invalid candidate image\n");
419 		return -EINVAL;
420 	}
421 
422 	memcpy(&image_header, (void *)buffer, sizeof(struct image_header_t));
423 	image_data.size = be32_to_cpu(image_header.size);
424 	pr_debug("FLASH: Candidate image size = %u\n", image_data.size);
425 
426 	if (image_data.size > MAX_IMAGE_SIZE) {
427 		pr_warn("FLASH: Too large image\n");
428 		return -EINVAL;
429 	}
430 	if (image_data.size < VALIDATE_BUF_SIZE) {
431 		pr_warn("FLASH: Image is shorter than expected\n");
432 		return -EINVAL;
433 	}
434 
435 	image_data.data = vzalloc(PAGE_ALIGN(image_data.size));
436 	if (!image_data.data) {
437 		pr_err("%s : Failed to allocate memory\n", __func__);
438 		return -ENOMEM;
439 	}
440 
441 	/* Pin memory */
442 	addr = image_data.data;
443 	size = PAGE_ALIGN(image_data.size);
444 	while (size > 0) {
445 		SetPageReserved(vmalloc_to_page(addr));
446 		addr += PAGE_SIZE;
447 		size -= PAGE_SIZE;
448 	}
449 
450 	image_data.status = IMAGE_LOADING;
451 	return 0;
452 }
453 
454 /*
455  * Copy candidate image
456  *
457  * Parse candidate image header to get total image size
458  * and pre-allocate required memory.
459  */
460 static ssize_t image_data_write(struct file *filp, struct kobject *kobj,
461 				struct bin_attribute *bin_attr,
462 				char *buffer, loff_t pos, size_t count)
463 {
464 	int rc;
465 
466 	mutex_lock(&image_data_mutex);
467 
468 	/* New image ? */
469 	if (pos == 0) {
470 		/* Free memory, if already allocated */
471 		if (image_data.data)
472 			free_image_buf();
473 
474 		/* Cancel outstanding image update request */
475 		if (update_flash_data.status == FLASH_IMG_READY)
476 			opal_flash_update(FLASH_UPDATE_CANCEL);
477 
478 		/* Allocate memory */
479 		rc = alloc_image_buf(buffer, count);
480 		if (rc)
481 			goto out;
482 	}
483 
484 	if (image_data.status != IMAGE_LOADING) {
485 		rc = -ENOMEM;
486 		goto out;
487 	}
488 
489 	if ((pos + count) > image_data.size) {
490 		rc = -EINVAL;
491 		goto out;
492 	}
493 
494 	memcpy(image_data.data + pos, (void *)buffer, count);
495 	rc = count;
496 
497 	/* Set image status */
498 	if ((pos + count) == image_data.size) {
499 		pr_debug("FLASH: Candidate image loaded....\n");
500 		image_data.status = IMAGE_READY;
501 	}
502 
503 out:
504 	mutex_unlock(&image_data_mutex);
505 	return rc;
506 }
507 
508 /*
509  * sysfs interface :
510  *  OPAL uses below sysfs files for code update.
511  *  We create these files under /sys/firmware/opal.
512  *
513  *   image		: Interface to load candidate firmware image
514  *   validate_flash	: Validate firmware image
515  *   manage_flash	: Commit/Reject firmware image
516  *   update_flash	: Flash new firmware image
517  *
518  */
519 static struct bin_attribute image_data_attr = {
520 	.attr = {.name = "image", .mode = 0200},
521 	.size = MAX_IMAGE_SIZE,	/* Limit image size */
522 	.write = image_data_write,
523 };
524 
525 static struct kobj_attribute validate_attribute =
526 	__ATTR(validate_flash, 0600, validate_show, validate_store);
527 
528 static struct kobj_attribute manage_attribute =
529 	__ATTR(manage_flash, 0600, manage_show, manage_store);
530 
531 static struct kobj_attribute update_attribute =
532 	__ATTR(update_flash, 0600, update_show, update_store);
533 
534 static struct attribute *image_op_attrs[] = {
535 	&validate_attribute.attr,
536 	&manage_attribute.attr,
537 	&update_attribute.attr,
538 	NULL	/* need to NULL terminate the list of attributes */
539 };
540 
541 static struct attribute_group image_op_attr_group = {
542 	.attrs = image_op_attrs,
543 };
544 
545 void __init opal_flash_init(void)
546 {
547 	int ret;
548 
549 	/* Allocate validate image buffer */
550 	validate_flash_data.buf = kzalloc(VALIDATE_BUF_SIZE, GFP_KERNEL);
551 	if (!validate_flash_data.buf) {
552 		pr_err("%s : Failed to allocate memory\n", __func__);
553 		return;
554 	}
555 
556 	/* Make sure /sys/firmware/opal directory is created */
557 	if (!opal_kobj) {
558 		pr_warn("FLASH: opal kobject is not available\n");
559 		goto nokobj;
560 	}
561 
562 	/* Create the sysfs files */
563 	ret = sysfs_create_group(opal_kobj, &image_op_attr_group);
564 	if (ret) {
565 		pr_warn("FLASH: Failed to create sysfs files\n");
566 		goto nokobj;
567 	}
568 
569 	ret = sysfs_create_bin_file(opal_kobj, &image_data_attr);
570 	if (ret) {
571 		pr_warn("FLASH: Failed to create sysfs files\n");
572 		goto nosysfs_file;
573 	}
574 
575 	/* Set default status */
576 	validate_flash_data.status = FLASH_NO_OP;
577 	manage_flash_data.status = FLASH_NO_OP;
578 	update_flash_data.status = FLASH_NO_OP;
579 	image_data.status = IMAGE_INVALID;
580 	return;
581 
582 nosysfs_file:
583 	sysfs_remove_group(opal_kobj, &image_op_attr_group);
584 
585 nokobj:
586 	kfree(validate_flash_data.buf);
587 	return;
588 }
589