xref: /openbmc/linux/fs/pstore/ram.c (revision f9a82c48)
1 /*
2  * RAM Oops/Panic logger
3  *
4  * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
5  * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19  * 02110-1301 USA
20  *
21  */
22 
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 
25 #include <linux/kernel.h>
26 #include <linux/err.h>
27 #include <linux/module.h>
28 #include <linux/version.h>
29 #include <linux/pstore.h>
30 #include <linux/io.h>
31 #include <linux/ioport.h>
32 #include <linux/platform_device.h>
33 #include <linux/slab.h>
34 #include <linux/compiler.h>
35 #include <linux/pstore_ram.h>
36 #include <linux/of.h>
37 #include <linux/of_address.h>
38 
39 #define RAMOOPS_KERNMSG_HDR "===="
40 #define MIN_MEM_SIZE 4096UL
41 
42 static ulong record_size = MIN_MEM_SIZE;
43 module_param(record_size, ulong, 0400);
44 MODULE_PARM_DESC(record_size,
45 		"size of each dump done on oops/panic");
46 
47 static ulong ramoops_console_size = MIN_MEM_SIZE;
48 module_param_named(console_size, ramoops_console_size, ulong, 0400);
49 MODULE_PARM_DESC(console_size, "size of kernel console log");
50 
51 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
52 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
53 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
54 
55 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
56 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
57 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
58 
59 static unsigned long long mem_address;
60 module_param_hw(mem_address, ullong, other, 0400);
61 MODULE_PARM_DESC(mem_address,
62 		"start of reserved RAM used to store oops/panic logs");
63 
64 static ulong mem_size;
65 module_param(mem_size, ulong, 0400);
66 MODULE_PARM_DESC(mem_size,
67 		"size of reserved RAM used to store oops/panic logs");
68 
69 static unsigned int mem_type;
70 module_param(mem_type, uint, 0600);
71 MODULE_PARM_DESC(mem_type,
72 		"set to 1 to try to use unbuffered memory (default 0)");
73 
74 static int dump_oops = 1;
75 module_param(dump_oops, int, 0600);
76 MODULE_PARM_DESC(dump_oops,
77 		"set to 1 to dump oopses, 0 to only dump panics (default 1)");
78 
79 static int ramoops_ecc;
80 module_param_named(ecc, ramoops_ecc, int, 0600);
81 MODULE_PARM_DESC(ramoops_ecc,
82 		"if non-zero, the option enables ECC support and specifies "
83 		"ECC buffer size in bytes (1 is a special value, means 16 "
84 		"bytes ECC)");
85 
86 struct ramoops_context {
87 	struct persistent_ram_zone **dprzs;	/* Oops dump zones */
88 	struct persistent_ram_zone *cprz;	/* Console zone */
89 	struct persistent_ram_zone **fprzs;	/* Ftrace zones */
90 	struct persistent_ram_zone *mprz;	/* PMSG zone */
91 	phys_addr_t phys_addr;
92 	unsigned long size;
93 	unsigned int memtype;
94 	size_t record_size;
95 	size_t console_size;
96 	size_t ftrace_size;
97 	size_t pmsg_size;
98 	int dump_oops;
99 	u32 flags;
100 	struct persistent_ram_ecc_info ecc_info;
101 	unsigned int max_dump_cnt;
102 	unsigned int dump_write_cnt;
103 	/* _read_cnt need clear on ramoops_pstore_open */
104 	unsigned int dump_read_cnt;
105 	unsigned int console_read_cnt;
106 	unsigned int max_ftrace_cnt;
107 	unsigned int ftrace_read_cnt;
108 	unsigned int pmsg_read_cnt;
109 	struct pstore_info pstore;
110 };
111 
112 static struct platform_device *dummy;
113 
114 static int ramoops_pstore_open(struct pstore_info *psi)
115 {
116 	struct ramoops_context *cxt = psi->data;
117 
118 	cxt->dump_read_cnt = 0;
119 	cxt->console_read_cnt = 0;
120 	cxt->ftrace_read_cnt = 0;
121 	cxt->pmsg_read_cnt = 0;
122 	return 0;
123 }
124 
125 static struct persistent_ram_zone *
126 ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
127 		     struct pstore_record *record)
128 {
129 	struct persistent_ram_zone *prz;
130 
131 	/* Give up if we never existed or have hit the end. */
132 	if (!przs)
133 		return NULL;
134 
135 	prz = przs[id];
136 	if (!prz)
137 		return NULL;
138 
139 	/* Update old/shadowed buffer. */
140 	if (prz->type == PSTORE_TYPE_DMESG)
141 		persistent_ram_save_old(prz);
142 
143 	if (!persistent_ram_old_size(prz))
144 		return NULL;
145 
146 	record->type = prz->type;
147 	record->id = id;
148 
149 	return prz;
150 }
151 
152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
153 				  bool *compressed)
154 {
155 	char data_type;
156 	int header_length = 0;
157 
158 	if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
159 		   (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
160 		   &header_length) == 3) {
161 		if (data_type == 'C')
162 			*compressed = true;
163 		else
164 			*compressed = false;
165 	} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
166 			  (time64_t *)&time->tv_sec, &time->tv_nsec,
167 			  &header_length) == 2) {
168 		*compressed = false;
169 	} else {
170 		time->tv_sec = 0;
171 		time->tv_nsec = 0;
172 		*compressed = false;
173 	}
174 	return header_length;
175 }
176 
177 static bool prz_ok(struct persistent_ram_zone *prz)
178 {
179 	return !!prz && !!(persistent_ram_old_size(prz) +
180 			   persistent_ram_ecc_string(prz, NULL, 0));
181 }
182 
183 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
184 				  struct persistent_ram_zone *src)
185 {
186 	size_t dest_size, src_size, total, dest_off, src_off;
187 	size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
188 	void *merged_buf;
189 	struct pstore_ftrace_record *drec, *srec, *mrec;
190 	size_t record_size = sizeof(struct pstore_ftrace_record);
191 
192 	dest_off = dest->old_log_size % record_size;
193 	dest_size = dest->old_log_size - dest_off;
194 
195 	src_off = src->old_log_size % record_size;
196 	src_size = src->old_log_size - src_off;
197 
198 	total = dest_size + src_size;
199 	merged_buf = kmalloc(total, GFP_KERNEL);
200 	if (!merged_buf)
201 		return -ENOMEM;
202 
203 	drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
204 	srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
205 	mrec = (struct pstore_ftrace_record *)(merged_buf);
206 
207 	while (dest_size > 0 && src_size > 0) {
208 		if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
209 		    pstore_ftrace_read_timestamp(&srec[src_idx])) {
210 			mrec[merged_idx++] = drec[dest_idx++];
211 			dest_size -= record_size;
212 		} else {
213 			mrec[merged_idx++] = srec[src_idx++];
214 			src_size -= record_size;
215 		}
216 	}
217 
218 	while (dest_size > 0) {
219 		mrec[merged_idx++] = drec[dest_idx++];
220 		dest_size -= record_size;
221 	}
222 
223 	while (src_size > 0) {
224 		mrec[merged_idx++] = srec[src_idx++];
225 		src_size -= record_size;
226 	}
227 
228 	kfree(dest->old_log);
229 	dest->old_log = merged_buf;
230 	dest->old_log_size = total;
231 
232 	return 0;
233 }
234 
235 static ssize_t ramoops_pstore_read(struct pstore_record *record)
236 {
237 	ssize_t size = 0;
238 	struct ramoops_context *cxt = record->psi->data;
239 	struct persistent_ram_zone *prz = NULL;
240 	int header_length = 0;
241 	bool free_prz = false;
242 
243 	/*
244 	 * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
245 	 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
246 	 * valid time stamps, so it is initialized to zero.
247 	 */
248 	record->time.tv_sec = 0;
249 	record->time.tv_nsec = 0;
250 	record->compressed = false;
251 
252 	/* Find the next valid persistent_ram_zone for DMESG */
253 	while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
254 		prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
255 					   record);
256 		if (!prz_ok(prz))
257 			continue;
258 		header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
259 						      &record->time,
260 						      &record->compressed);
261 		/* Clear and skip this DMESG record if it has no valid header */
262 		if (!header_length) {
263 			persistent_ram_free_old(prz);
264 			persistent_ram_zap(prz);
265 			prz = NULL;
266 		}
267 	}
268 
269 	if (!prz_ok(prz) && !cxt->console_read_cnt++)
270 		prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
271 
272 	if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
273 		prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
274 
275 	/* ftrace is last since it may want to dynamically allocate memory. */
276 	if (!prz_ok(prz)) {
277 		if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
278 		    !cxt->ftrace_read_cnt++) {
279 			prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
280 						   record);
281 		} else {
282 			/*
283 			 * Build a new dummy record which combines all the
284 			 * per-cpu records including metadata and ecc info.
285 			 */
286 			struct persistent_ram_zone *tmp_prz, *prz_next;
287 
288 			tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
289 					  GFP_KERNEL);
290 			if (!tmp_prz)
291 				return -ENOMEM;
292 			prz = tmp_prz;
293 			free_prz = true;
294 
295 			while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
296 				prz_next = ramoops_get_next_prz(cxt->fprzs,
297 						cxt->ftrace_read_cnt++, record);
298 
299 				if (!prz_ok(prz_next))
300 					continue;
301 
302 				tmp_prz->ecc_info = prz_next->ecc_info;
303 				tmp_prz->corrected_bytes +=
304 						prz_next->corrected_bytes;
305 				tmp_prz->bad_blocks += prz_next->bad_blocks;
306 				size = ftrace_log_combine(tmp_prz, prz_next);
307 				if (size)
308 					goto out;
309 			}
310 			record->id = 0;
311 		}
312 	}
313 
314 	if (!prz_ok(prz)) {
315 		size = 0;
316 		goto out;
317 	}
318 
319 	size = persistent_ram_old_size(prz) - header_length;
320 
321 	/* ECC correction notice */
322 	record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
323 
324 	record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
325 	if (record->buf == NULL) {
326 		size = -ENOMEM;
327 		goto out;
328 	}
329 
330 	memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
331 	       size);
332 
333 	persistent_ram_ecc_string(prz, record->buf + size,
334 				  record->ecc_notice_size + 1);
335 
336 out:
337 	if (free_prz) {
338 		kfree(prz->old_log);
339 		kfree(prz);
340 	}
341 
342 	return size;
343 }
344 
345 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
346 				     struct pstore_record *record)
347 {
348 	char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
349 	size_t len;
350 
351 	len = scnprintf(hdr, sizeof(hdr),
352 		RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
353 		(time64_t)record->time.tv_sec,
354 		record->time.tv_nsec / 1000,
355 		record->compressed ? 'C' : 'D');
356 	persistent_ram_write(prz, hdr, len);
357 
358 	return len;
359 }
360 
361 static int notrace ramoops_pstore_write(struct pstore_record *record)
362 {
363 	struct ramoops_context *cxt = record->psi->data;
364 	struct persistent_ram_zone *prz;
365 	size_t size, hlen;
366 
367 	if (record->type == PSTORE_TYPE_CONSOLE) {
368 		if (!cxt->cprz)
369 			return -ENOMEM;
370 		persistent_ram_write(cxt->cprz, record->buf, record->size);
371 		return 0;
372 	} else if (record->type == PSTORE_TYPE_FTRACE) {
373 		int zonenum;
374 
375 		if (!cxt->fprzs)
376 			return -ENOMEM;
377 		/*
378 		 * Choose zone by if we're using per-cpu buffers.
379 		 */
380 		if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
381 			zonenum = smp_processor_id();
382 		else
383 			zonenum = 0;
384 
385 		persistent_ram_write(cxt->fprzs[zonenum], record->buf,
386 				     record->size);
387 		return 0;
388 	} else if (record->type == PSTORE_TYPE_PMSG) {
389 		pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
390 		return -EINVAL;
391 	}
392 
393 	if (record->type != PSTORE_TYPE_DMESG)
394 		return -EINVAL;
395 
396 	/*
397 	 * Out of the various dmesg dump types, ramoops is currently designed
398 	 * to only store crash logs, rather than storing general kernel logs.
399 	 */
400 	if (record->reason != KMSG_DUMP_OOPS &&
401 	    record->reason != KMSG_DUMP_PANIC)
402 		return -EINVAL;
403 
404 	/* Skip Oopes when configured to do so. */
405 	if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
406 		return -EINVAL;
407 
408 	/*
409 	 * Explicitly only take the first part of any new crash.
410 	 * If our buffer is larger than kmsg_bytes, this can never happen,
411 	 * and if our buffer is smaller than kmsg_bytes, we don't want the
412 	 * report split across multiple records.
413 	 */
414 	if (record->part != 1)
415 		return -ENOSPC;
416 
417 	if (!cxt->dprzs)
418 		return -ENOSPC;
419 
420 	prz = cxt->dprzs[cxt->dump_write_cnt];
421 
422 	/* Build header and append record contents. */
423 	hlen = ramoops_write_kmsg_hdr(prz, record);
424 	if (!hlen)
425 		return -ENOMEM;
426 
427 	size = record->size;
428 	if (size + hlen > prz->buffer_size)
429 		size = prz->buffer_size - hlen;
430 	persistent_ram_write(prz, record->buf, size);
431 
432 	cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
433 
434 	return 0;
435 }
436 
437 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
438 					     const char __user *buf)
439 {
440 	if (record->type == PSTORE_TYPE_PMSG) {
441 		struct ramoops_context *cxt = record->psi->data;
442 
443 		if (!cxt->mprz)
444 			return -ENOMEM;
445 		return persistent_ram_write_user(cxt->mprz, buf, record->size);
446 	}
447 
448 	return -EINVAL;
449 }
450 
451 static int ramoops_pstore_erase(struct pstore_record *record)
452 {
453 	struct ramoops_context *cxt = record->psi->data;
454 	struct persistent_ram_zone *prz;
455 
456 	switch (record->type) {
457 	case PSTORE_TYPE_DMESG:
458 		if (record->id >= cxt->max_dump_cnt)
459 			return -EINVAL;
460 		prz = cxt->dprzs[record->id];
461 		break;
462 	case PSTORE_TYPE_CONSOLE:
463 		prz = cxt->cprz;
464 		break;
465 	case PSTORE_TYPE_FTRACE:
466 		if (record->id >= cxt->max_ftrace_cnt)
467 			return -EINVAL;
468 		prz = cxt->fprzs[record->id];
469 		break;
470 	case PSTORE_TYPE_PMSG:
471 		prz = cxt->mprz;
472 		break;
473 	default:
474 		return -EINVAL;
475 	}
476 
477 	persistent_ram_free_old(prz);
478 	persistent_ram_zap(prz);
479 
480 	return 0;
481 }
482 
483 static struct ramoops_context oops_cxt = {
484 	.pstore = {
485 		.owner	= THIS_MODULE,
486 		.name	= "ramoops",
487 		.open	= ramoops_pstore_open,
488 		.read	= ramoops_pstore_read,
489 		.write	= ramoops_pstore_write,
490 		.write_user	= ramoops_pstore_write_user,
491 		.erase	= ramoops_pstore_erase,
492 	},
493 };
494 
495 static void ramoops_free_przs(struct ramoops_context *cxt)
496 {
497 	int i;
498 
499 	/* Free dump PRZs */
500 	if (cxt->dprzs) {
501 		for (i = 0; i < cxt->max_dump_cnt; i++)
502 			persistent_ram_free(cxt->dprzs[i]);
503 
504 		kfree(cxt->dprzs);
505 		cxt->max_dump_cnt = 0;
506 	}
507 
508 	/* Free ftrace PRZs */
509 	if (cxt->fprzs) {
510 		for (i = 0; i < cxt->max_ftrace_cnt; i++)
511 			persistent_ram_free(cxt->fprzs[i]);
512 		kfree(cxt->fprzs);
513 		cxt->max_ftrace_cnt = 0;
514 	}
515 }
516 
517 static int ramoops_init_przs(const char *name,
518 			     struct device *dev, struct ramoops_context *cxt,
519 			     struct persistent_ram_zone ***przs,
520 			     phys_addr_t *paddr, size_t mem_sz,
521 			     ssize_t record_size,
522 			     unsigned int *cnt, u32 sig, u32 flags)
523 {
524 	int err = -ENOMEM;
525 	int i;
526 	size_t zone_sz;
527 	struct persistent_ram_zone **prz_ar;
528 
529 	/* Allocate nothing for 0 mem_sz or 0 record_size. */
530 	if (mem_sz == 0 || record_size == 0) {
531 		*cnt = 0;
532 		return 0;
533 	}
534 
535 	/*
536 	 * If we have a negative record size, calculate it based on
537 	 * mem_sz / *cnt. If we have a positive record size, calculate
538 	 * cnt from mem_sz / record_size.
539 	 */
540 	if (record_size < 0) {
541 		if (*cnt == 0)
542 			return 0;
543 		record_size = mem_sz / *cnt;
544 		if (record_size == 0) {
545 			dev_err(dev, "%s record size == 0 (%zu / %u)\n",
546 				name, mem_sz, *cnt);
547 			goto fail;
548 		}
549 	} else {
550 		*cnt = mem_sz / record_size;
551 		if (*cnt == 0) {
552 			dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
553 				name, mem_sz, record_size);
554 			goto fail;
555 		}
556 	}
557 
558 	if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
559 		dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
560 			name,
561 			mem_sz, (unsigned long long)*paddr,
562 			cxt->size, (unsigned long long)cxt->phys_addr);
563 		goto fail;
564 	}
565 
566 	zone_sz = mem_sz / *cnt;
567 	if (!zone_sz) {
568 		dev_err(dev, "%s zone size == 0\n", name);
569 		goto fail;
570 	}
571 
572 	prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
573 	if (!prz_ar)
574 		goto fail;
575 
576 	for (i = 0; i < *cnt; i++) {
577 		char *label;
578 
579 		if (*cnt == 1)
580 			label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
581 		else
582 			label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
583 					  name, i, *cnt - 1);
584 		prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
585 					       &cxt->ecc_info,
586 					       cxt->memtype, flags, label);
587 		if (IS_ERR(prz_ar[i])) {
588 			err = PTR_ERR(prz_ar[i]);
589 			dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
590 				name, record_size,
591 				(unsigned long long)*paddr, err);
592 
593 			while (i > 0) {
594 				i--;
595 				persistent_ram_free(prz_ar[i]);
596 			}
597 			kfree(prz_ar);
598 			goto fail;
599 		}
600 		*paddr += zone_sz;
601 		prz_ar[i]->type = pstore_name_to_type(name);
602 	}
603 
604 	*przs = prz_ar;
605 	return 0;
606 
607 fail:
608 	*cnt = 0;
609 	return err;
610 }
611 
612 static int ramoops_init_prz(const char *name,
613 			    struct device *dev, struct ramoops_context *cxt,
614 			    struct persistent_ram_zone **prz,
615 			    phys_addr_t *paddr, size_t sz, u32 sig)
616 {
617 	char *label;
618 
619 	if (!sz)
620 		return 0;
621 
622 	if (*paddr + sz - cxt->phys_addr > cxt->size) {
623 		dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
624 			name, sz, (unsigned long long)*paddr,
625 			cxt->size, (unsigned long long)cxt->phys_addr);
626 		return -ENOMEM;
627 	}
628 
629 	label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
630 	*prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
631 				  cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
632 	if (IS_ERR(*prz)) {
633 		int err = PTR_ERR(*prz);
634 
635 		dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
636 			name, sz, (unsigned long long)*paddr, err);
637 		return err;
638 	}
639 
640 	*paddr += sz;
641 	(*prz)->type = pstore_name_to_type(name);
642 
643 	return 0;
644 }
645 
646 static int ramoops_parse_dt_size(struct platform_device *pdev,
647 				 const char *propname, u32 *value)
648 {
649 	u32 val32 = 0;
650 	int ret;
651 
652 	ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
653 	if (ret < 0 && ret != -EINVAL) {
654 		dev_err(&pdev->dev, "failed to parse property %s: %d\n",
655 			propname, ret);
656 		return ret;
657 	}
658 
659 	if (val32 > INT_MAX) {
660 		dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
661 		return -EOVERFLOW;
662 	}
663 
664 	*value = val32;
665 	return 0;
666 }
667 
668 static int ramoops_parse_dt(struct platform_device *pdev,
669 			    struct ramoops_platform_data *pdata)
670 {
671 	struct device_node *of_node = pdev->dev.of_node;
672 	struct resource *res;
673 	u32 value;
674 	int ret;
675 
676 	dev_dbg(&pdev->dev, "using Device Tree\n");
677 
678 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
679 	if (!res) {
680 		dev_err(&pdev->dev,
681 			"failed to locate DT /reserved-memory resource\n");
682 		return -EINVAL;
683 	}
684 
685 	pdata->mem_size = resource_size(res);
686 	pdata->mem_address = res->start;
687 	pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
688 	pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
689 
690 #define parse_size(name, field) {					\
691 		ret = ramoops_parse_dt_size(pdev, name, &value);	\
692 		if (ret < 0)						\
693 			return ret;					\
694 		field = value;						\
695 	}
696 
697 	parse_size("record-size", pdata->record_size);
698 	parse_size("console-size", pdata->console_size);
699 	parse_size("ftrace-size", pdata->ftrace_size);
700 	parse_size("pmsg-size", pdata->pmsg_size);
701 	parse_size("ecc-size", pdata->ecc_info.ecc_size);
702 	parse_size("flags", pdata->flags);
703 
704 #undef parse_size
705 
706 	return 0;
707 }
708 
709 static int ramoops_probe(struct platform_device *pdev)
710 {
711 	struct device *dev = &pdev->dev;
712 	struct ramoops_platform_data *pdata = dev->platform_data;
713 	struct ramoops_platform_data pdata_local;
714 	struct ramoops_context *cxt = &oops_cxt;
715 	size_t dump_mem_sz;
716 	phys_addr_t paddr;
717 	int err = -EINVAL;
718 
719 	/*
720 	 * Only a single ramoops area allowed at a time, so fail extra
721 	 * probes.
722 	 */
723 	if (cxt->max_dump_cnt) {
724 		pr_err("already initialized\n");
725 		goto fail_out;
726 	}
727 
728 	if (dev_of_node(dev) && !pdata) {
729 		pdata = &pdata_local;
730 		memset(pdata, 0, sizeof(*pdata));
731 
732 		err = ramoops_parse_dt(pdev, pdata);
733 		if (err < 0)
734 			goto fail_out;
735 	}
736 
737 	/* Make sure we didn't get bogus platform data pointer. */
738 	if (!pdata) {
739 		pr_err("NULL platform data\n");
740 		goto fail_out;
741 	}
742 
743 	if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
744 			!pdata->ftrace_size && !pdata->pmsg_size)) {
745 		pr_err("The memory size and the record/console size must be "
746 			"non-zero\n");
747 		goto fail_out;
748 	}
749 
750 	if (pdata->record_size && !is_power_of_2(pdata->record_size))
751 		pdata->record_size = rounddown_pow_of_two(pdata->record_size);
752 	if (pdata->console_size && !is_power_of_2(pdata->console_size))
753 		pdata->console_size = rounddown_pow_of_two(pdata->console_size);
754 	if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
755 		pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
756 	if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
757 		pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
758 
759 	cxt->size = pdata->mem_size;
760 	cxt->phys_addr = pdata->mem_address;
761 	cxt->memtype = pdata->mem_type;
762 	cxt->record_size = pdata->record_size;
763 	cxt->console_size = pdata->console_size;
764 	cxt->ftrace_size = pdata->ftrace_size;
765 	cxt->pmsg_size = pdata->pmsg_size;
766 	cxt->dump_oops = pdata->dump_oops;
767 	cxt->flags = pdata->flags;
768 	cxt->ecc_info = pdata->ecc_info;
769 
770 	paddr = cxt->phys_addr;
771 
772 	dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
773 			- cxt->pmsg_size;
774 	err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
775 				dump_mem_sz, cxt->record_size,
776 				&cxt->max_dump_cnt, 0, 0);
777 	if (err)
778 		goto fail_out;
779 
780 	err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
781 			       cxt->console_size, 0);
782 	if (err)
783 		goto fail_init_cprz;
784 
785 	cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
786 				? nr_cpu_ids
787 				: 1;
788 	err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
789 				cxt->ftrace_size, -1,
790 				&cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
791 				(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
792 					? PRZ_FLAG_NO_LOCK : 0);
793 	if (err)
794 		goto fail_init_fprz;
795 
796 	err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
797 				cxt->pmsg_size, 0);
798 	if (err)
799 		goto fail_init_mprz;
800 
801 	cxt->pstore.data = cxt;
802 	/*
803 	 * Since bufsize is only used for dmesg crash dumps, it
804 	 * must match the size of the dprz record (after PRZ header
805 	 * and ECC bytes have been accounted for).
806 	 */
807 	cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
808 	cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
809 	if (!cxt->pstore.buf) {
810 		pr_err("cannot allocate pstore crash dump buffer\n");
811 		err = -ENOMEM;
812 		goto fail_clear;
813 	}
814 
815 	cxt->pstore.flags = PSTORE_FLAGS_DMESG;
816 	if (cxt->console_size)
817 		cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
818 	if (cxt->ftrace_size)
819 		cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
820 	if (cxt->pmsg_size)
821 		cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
822 
823 	err = pstore_register(&cxt->pstore);
824 	if (err) {
825 		pr_err("registering with pstore failed\n");
826 		goto fail_buf;
827 	}
828 
829 	/*
830 	 * Update the module parameter variables as well so they are visible
831 	 * through /sys/module/ramoops/parameters/
832 	 */
833 	mem_size = pdata->mem_size;
834 	mem_address = pdata->mem_address;
835 	record_size = pdata->record_size;
836 	dump_oops = pdata->dump_oops;
837 	ramoops_console_size = pdata->console_size;
838 	ramoops_pmsg_size = pdata->pmsg_size;
839 	ramoops_ftrace_size = pdata->ftrace_size;
840 
841 	pr_info("using 0x%lx@0x%llx, ecc: %d\n",
842 		cxt->size, (unsigned long long)cxt->phys_addr,
843 		cxt->ecc_info.ecc_size);
844 
845 	return 0;
846 
847 fail_buf:
848 	kfree(cxt->pstore.buf);
849 fail_clear:
850 	cxt->pstore.bufsize = 0;
851 	persistent_ram_free(cxt->mprz);
852 fail_init_mprz:
853 fail_init_fprz:
854 	persistent_ram_free(cxt->cprz);
855 fail_init_cprz:
856 	ramoops_free_przs(cxt);
857 fail_out:
858 	return err;
859 }
860 
861 static int ramoops_remove(struct platform_device *pdev)
862 {
863 	struct ramoops_context *cxt = &oops_cxt;
864 
865 	pstore_unregister(&cxt->pstore);
866 
867 	kfree(cxt->pstore.buf);
868 	cxt->pstore.bufsize = 0;
869 
870 	persistent_ram_free(cxt->mprz);
871 	persistent_ram_free(cxt->cprz);
872 	ramoops_free_przs(cxt);
873 
874 	return 0;
875 }
876 
877 static const struct of_device_id dt_match[] = {
878 	{ .compatible = "ramoops" },
879 	{}
880 };
881 
882 static struct platform_driver ramoops_driver = {
883 	.probe		= ramoops_probe,
884 	.remove		= ramoops_remove,
885 	.driver		= {
886 		.name		= "ramoops",
887 		.of_match_table	= dt_match,
888 	},
889 };
890 
891 static inline void ramoops_unregister_dummy(void)
892 {
893 	platform_device_unregister(dummy);
894 	dummy = NULL;
895 }
896 
897 static void __init ramoops_register_dummy(void)
898 {
899 	struct ramoops_platform_data pdata;
900 
901 	/*
902 	 * Prepare a dummy platform data structure to carry the module
903 	 * parameters. If mem_size isn't set, then there are no module
904 	 * parameters, and we can skip this.
905 	 */
906 	if (!mem_size)
907 		return;
908 
909 	pr_info("using module parameters\n");
910 
911 	memset(&pdata, 0, sizeof(pdata));
912 	pdata.mem_size = mem_size;
913 	pdata.mem_address = mem_address;
914 	pdata.mem_type = mem_type;
915 	pdata.record_size = record_size;
916 	pdata.console_size = ramoops_console_size;
917 	pdata.ftrace_size = ramoops_ftrace_size;
918 	pdata.pmsg_size = ramoops_pmsg_size;
919 	pdata.dump_oops = dump_oops;
920 	pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
921 
922 	/*
923 	 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
924 	 * (using 1 byte for ECC isn't much of use anyway).
925 	 */
926 	pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
927 
928 	dummy = platform_device_register_data(NULL, "ramoops", -1,
929 			&pdata, sizeof(pdata));
930 	if (IS_ERR(dummy)) {
931 		pr_info("could not create platform device: %ld\n",
932 			PTR_ERR(dummy));
933 		dummy = NULL;
934 		ramoops_unregister_dummy();
935 	}
936 }
937 
938 static int __init ramoops_init(void)
939 {
940 	int ret;
941 
942 	ramoops_register_dummy();
943 	ret = platform_driver_register(&ramoops_driver);
944 	if (ret != 0)
945 		ramoops_unregister_dummy();
946 
947 	return ret;
948 }
949 postcore_initcall(ramoops_init);
950 
951 static void __exit ramoops_exit(void)
952 {
953 	platform_driver_unregister(&ramoops_driver);
954 	ramoops_unregister_dummy();
955 }
956 module_exit(ramoops_exit);
957 
958 MODULE_LICENSE("GPL");
959 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
960 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
961