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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/time.h>
31 #include <linux/io.h>
32 #include <linux/ioport.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/compiler.h>
36 #include <linux/pstore_ram.h>
37 #include <linux/of.h>
38 #include <linux/of_address.h>
39 
40 #define RAMOOPS_KERNMSG_HDR "===="
41 #define MIN_MEM_SIZE 4096UL
42 
43 static ulong record_size = MIN_MEM_SIZE;
44 module_param(record_size, ulong, 0400);
45 MODULE_PARM_DESC(record_size,
46 		"size of each dump done on oops/panic");
47 
48 static ulong ramoops_console_size = MIN_MEM_SIZE;
49 module_param_named(console_size, ramoops_console_size, ulong, 0400);
50 MODULE_PARM_DESC(console_size, "size of kernel console log");
51 
52 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
53 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
54 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
55 
56 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
57 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
58 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
59 
60 static unsigned long long mem_address;
61 module_param(mem_address, ullong, 0400);
62 MODULE_PARM_DESC(mem_address,
63 		"start of reserved RAM used to store oops/panic logs");
64 
65 static ulong mem_size;
66 module_param(mem_size, ulong, 0400);
67 MODULE_PARM_DESC(mem_size,
68 		"size of reserved RAM used to store oops/panic logs");
69 
70 static unsigned int mem_type;
71 module_param(mem_type, uint, 0600);
72 MODULE_PARM_DESC(mem_type,
73 		"set to 1 to try to use unbuffered memory (default 0)");
74 
75 static int dump_oops = 1;
76 module_param(dump_oops, int, 0600);
77 MODULE_PARM_DESC(dump_oops,
78 		"set to 1 to dump oopses, 0 to only dump panics (default 1)");
79 
80 static int ramoops_ecc;
81 module_param_named(ecc, ramoops_ecc, int, 0600);
82 MODULE_PARM_DESC(ramoops_ecc,
83 		"if non-zero, the option enables ECC support and specifies "
84 		"ECC buffer size in bytes (1 is a special value, means 16 "
85 		"bytes ECC)");
86 
87 struct ramoops_context {
88 	struct persistent_ram_zone **przs;
89 	struct persistent_ram_zone *cprz;
90 	struct persistent_ram_zone *fprz;
91 	struct persistent_ram_zone *mprz;
92 	phys_addr_t phys_addr;
93 	unsigned long size;
94 	unsigned int memtype;
95 	size_t record_size;
96 	size_t console_size;
97 	size_t ftrace_size;
98 	size_t pmsg_size;
99 	int dump_oops;
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 ftrace_read_cnt;
107 	unsigned int pmsg_read_cnt;
108 	struct pstore_info pstore;
109 };
110 
111 static struct platform_device *dummy;
112 static struct ramoops_platform_data *dummy_data;
113 
ramoops_pstore_open(struct pstore_info * psi)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 *
ramoops_get_next_prz(struct persistent_ram_zone * przs[],uint * c,uint max,u64 * id,enum pstore_type_id * typep,enum pstore_type_id type,bool update)126 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
127 		     u64 *id,
128 		     enum pstore_type_id *typep, enum pstore_type_id type,
129 		     bool update)
130 {
131 	struct persistent_ram_zone *prz;
132 	int i = (*c)++;
133 
134 	if (i >= max)
135 		return NULL;
136 
137 	prz = przs[i];
138 	if (!prz)
139 		return NULL;
140 
141 	/* Update old/shadowed buffer. */
142 	if (update)
143 		persistent_ram_save_old(prz);
144 
145 	if (!persistent_ram_old_size(prz))
146 		return NULL;
147 
148 	*typep = type;
149 	*id = i;
150 
151 	return prz;
152 }
153 
ramoops_read_kmsg_hdr(char * buffer,struct timespec * time,bool * compressed)154 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
155 				  bool *compressed)
156 {
157 	char data_type;
158 	int header_length = 0;
159 
160 	if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
161 			&time->tv_nsec, &data_type, &header_length) == 3) {
162 		if (data_type == 'C')
163 			*compressed = true;
164 		else
165 			*compressed = false;
166 	} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
167 			&time->tv_sec, &time->tv_nsec, &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 
prz_ok(struct persistent_ram_zone * prz)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 
ramoops_pstore_read(u64 * id,enum pstore_type_id * type,int * count,struct timespec * time,char ** buf,bool * compressed,ssize_t * ecc_notice_size,struct pstore_info * psi)183 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
184 				   int *count, struct timespec *time,
185 				   char **buf, bool *compressed,
186 				   ssize_t *ecc_notice_size,
187 				   struct pstore_info *psi)
188 {
189 	ssize_t size;
190 	struct ramoops_context *cxt = psi->data;
191 	struct persistent_ram_zone *prz = NULL;
192 	int header_length = 0;
193 
194 	/* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
195 	 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
196 	 * valid time stamps, so it is initialized to zero.
197 	 */
198 	time->tv_sec = 0;
199 	time->tv_nsec = 0;
200 	*compressed = false;
201 
202 	/* Find the next valid persistent_ram_zone for DMESG */
203 	while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
204 		prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
205 					   cxt->max_dump_cnt, id, type,
206 					   PSTORE_TYPE_DMESG, 1);
207 		if (!prz_ok(prz))
208 			continue;
209 		header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
210 						      time, compressed);
211 		/* Clear and skip this DMESG record if it has no valid header */
212 		if (!header_length) {
213 			persistent_ram_free_old(prz);
214 			persistent_ram_zap(prz);
215 			prz = NULL;
216 		}
217 	}
218 
219 	if (!prz_ok(prz))
220 		prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
221 					   1, id, type, PSTORE_TYPE_CONSOLE, 0);
222 	if (!prz_ok(prz))
223 		prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
224 					   1, id, type, PSTORE_TYPE_FTRACE, 0);
225 	if (!prz_ok(prz))
226 		prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
227 					   1, id, type, PSTORE_TYPE_PMSG, 0);
228 	if (!prz_ok(prz))
229 		return 0;
230 
231 	size = persistent_ram_old_size(prz) - header_length;
232 
233 	/* ECC correction notice */
234 	*ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
235 
236 	*buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
237 	if (*buf == NULL)
238 		return -ENOMEM;
239 
240 	memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
241 	persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
242 
243 	return size;
244 }
245 
ramoops_write_kmsg_hdr(struct persistent_ram_zone * prz,bool compressed)246 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
247 				     bool compressed)
248 {
249 	char *hdr;
250 	struct timespec timestamp;
251 	size_t len;
252 
253 	/* Report zeroed timestamp if called before timekeeping has resumed. */
254 	if (__getnstimeofday(&timestamp)) {
255 		timestamp.tv_sec = 0;
256 		timestamp.tv_nsec = 0;
257 	}
258 	hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
259 		(long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
260 		compressed ? 'C' : 'D');
261 	WARN_ON_ONCE(!hdr);
262 	len = hdr ? strlen(hdr) : 0;
263 	persistent_ram_write(prz, hdr, len);
264 	kfree(hdr);
265 
266 	return len;
267 }
268 
ramoops_pstore_write_buf(enum pstore_type_id type,enum kmsg_dump_reason reason,u64 * id,unsigned int part,const char * buf,bool compressed,size_t size,struct pstore_info * psi)269 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
270 					    enum kmsg_dump_reason reason,
271 					    u64 *id, unsigned int part,
272 					    const char *buf,
273 					    bool compressed, size_t size,
274 					    struct pstore_info *psi)
275 {
276 	struct ramoops_context *cxt = psi->data;
277 	struct persistent_ram_zone *prz;
278 	size_t hlen;
279 
280 	if (type == PSTORE_TYPE_CONSOLE) {
281 		if (!cxt->cprz)
282 			return -ENOMEM;
283 		persistent_ram_write(cxt->cprz, buf, size);
284 		return 0;
285 	} else if (type == PSTORE_TYPE_FTRACE) {
286 		if (!cxt->fprz)
287 			return -ENOMEM;
288 		persistent_ram_write(cxt->fprz, buf, size);
289 		return 0;
290 	} else if (type == PSTORE_TYPE_PMSG) {
291 		if (!cxt->mprz)
292 			return -ENOMEM;
293 		persistent_ram_write(cxt->mprz, buf, size);
294 		return 0;
295 	}
296 
297 	if (type != PSTORE_TYPE_DMESG)
298 		return -EINVAL;
299 
300 	/* Out of the various dmesg dump types, ramoops is currently designed
301 	 * to only store crash logs, rather than storing general kernel logs.
302 	 */
303 	if (reason != KMSG_DUMP_OOPS &&
304 	    reason != KMSG_DUMP_PANIC)
305 		return -EINVAL;
306 
307 	/* Skip Oopes when configured to do so. */
308 	if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
309 		return -EINVAL;
310 
311 	/* Explicitly only take the first part of any new crash.
312 	 * If our buffer is larger than kmsg_bytes, this can never happen,
313 	 * and if our buffer is smaller than kmsg_bytes, we don't want the
314 	 * report split across multiple records.
315 	 */
316 	if (part != 1)
317 		return -ENOSPC;
318 
319 	if (!cxt->przs)
320 		return -ENOSPC;
321 
322 	prz = cxt->przs[cxt->dump_write_cnt];
323 
324 	hlen = ramoops_write_kmsg_hdr(prz, compressed);
325 	if (size + hlen > prz->buffer_size)
326 		size = prz->buffer_size - hlen;
327 	persistent_ram_write(prz, buf, size);
328 
329 	cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
330 
331 	return 0;
332 }
333 
ramoops_pstore_write_buf_user(enum pstore_type_id type,enum kmsg_dump_reason reason,u64 * id,unsigned int part,const char __user * buf,bool compressed,size_t size,struct pstore_info * psi)334 static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
335 						 enum kmsg_dump_reason reason,
336 						 u64 *id, unsigned int part,
337 						 const char __user *buf,
338 						 bool compressed, size_t size,
339 						 struct pstore_info *psi)
340 {
341 	if (type == PSTORE_TYPE_PMSG) {
342 		struct ramoops_context *cxt = psi->data;
343 
344 		if (!cxt->mprz)
345 			return -ENOMEM;
346 		return persistent_ram_write_user(cxt->mprz, buf, size);
347 	}
348 
349 	return -EINVAL;
350 }
351 
ramoops_pstore_erase(enum pstore_type_id type,u64 id,int count,struct timespec time,struct pstore_info * psi)352 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
353 				struct timespec time, struct pstore_info *psi)
354 {
355 	struct ramoops_context *cxt = psi->data;
356 	struct persistent_ram_zone *prz;
357 
358 	switch (type) {
359 	case PSTORE_TYPE_DMESG:
360 		if (id >= cxt->max_dump_cnt)
361 			return -EINVAL;
362 		prz = cxt->przs[id];
363 		break;
364 	case PSTORE_TYPE_CONSOLE:
365 		prz = cxt->cprz;
366 		break;
367 	case PSTORE_TYPE_FTRACE:
368 		prz = cxt->fprz;
369 		break;
370 	case PSTORE_TYPE_PMSG:
371 		prz = cxt->mprz;
372 		break;
373 	default:
374 		return -EINVAL;
375 	}
376 
377 	persistent_ram_free_old(prz);
378 	persistent_ram_zap(prz);
379 
380 	return 0;
381 }
382 
383 static struct ramoops_context oops_cxt = {
384 	.pstore = {
385 		.owner	= THIS_MODULE,
386 		.name	= "ramoops",
387 		.open	= ramoops_pstore_open,
388 		.read	= ramoops_pstore_read,
389 		.write_buf	= ramoops_pstore_write_buf,
390 		.write_buf_user	= ramoops_pstore_write_buf_user,
391 		.erase	= ramoops_pstore_erase,
392 	},
393 };
394 
ramoops_free_przs(struct ramoops_context * cxt)395 static void ramoops_free_przs(struct ramoops_context *cxt)
396 {
397 	int i;
398 
399 	if (!cxt->przs)
400 		return;
401 
402 	for (i = 0; i < cxt->max_dump_cnt; i++)
403 		persistent_ram_free(cxt->przs[i]);
404 
405 	kfree(cxt->przs);
406 	cxt->max_dump_cnt = 0;
407 }
408 
ramoops_init_przs(struct device * dev,struct ramoops_context * cxt,phys_addr_t * paddr,size_t dump_mem_sz)409 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
410 			     phys_addr_t *paddr, size_t dump_mem_sz)
411 {
412 	int err = -ENOMEM;
413 	int i;
414 
415 	if (!cxt->record_size)
416 		return 0;
417 
418 	if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
419 		dev_err(dev, "no room for dumps\n");
420 		return -ENOMEM;
421 	}
422 
423 	cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
424 	if (!cxt->max_dump_cnt)
425 		return -ENOMEM;
426 
427 	cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
428 			     GFP_KERNEL);
429 	if (!cxt->przs) {
430 		dev_err(dev, "failed to initialize a prz array for dumps\n");
431 		goto fail_mem;
432 	}
433 
434 	for (i = 0; i < cxt->max_dump_cnt; i++) {
435 		cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
436 						  &cxt->ecc_info,
437 						  cxt->memtype, 0);
438 		if (IS_ERR(cxt->przs[i])) {
439 			err = PTR_ERR(cxt->przs[i]);
440 			dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
441 				cxt->record_size, (unsigned long long)*paddr, err);
442 
443 			while (i > 0) {
444 				i--;
445 				persistent_ram_free(cxt->przs[i]);
446 			}
447 			goto fail_prz;
448 		}
449 		*paddr += cxt->record_size;
450 	}
451 
452 	return 0;
453 fail_prz:
454 	kfree(cxt->przs);
455 fail_mem:
456 	cxt->max_dump_cnt = 0;
457 	return err;
458 }
459 
ramoops_init_prz(struct device * dev,struct ramoops_context * cxt,struct persistent_ram_zone ** prz,phys_addr_t * paddr,size_t sz,u32 sig)460 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
461 			    struct persistent_ram_zone **prz,
462 			    phys_addr_t *paddr, size_t sz, u32 sig)
463 {
464 	if (!sz)
465 		return 0;
466 
467 	if (*paddr + sz - cxt->phys_addr > cxt->size) {
468 		dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
469 			sz, (unsigned long long)*paddr,
470 			cxt->size, (unsigned long long)cxt->phys_addr);
471 		return -ENOMEM;
472 	}
473 
474 	*prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
475 				  cxt->memtype, 0);
476 	if (IS_ERR(*prz)) {
477 		int err = PTR_ERR(*prz);
478 
479 		dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
480 			sz, (unsigned long long)*paddr, err);
481 		return err;
482 	}
483 
484 	persistent_ram_zap(*prz);
485 
486 	*paddr += sz;
487 
488 	return 0;
489 }
490 
ramoops_parse_dt_size(struct platform_device * pdev,const char * propname,u32 * value)491 static int ramoops_parse_dt_size(struct platform_device *pdev,
492 				 const char *propname, u32 *value)
493 {
494 	u32 val32 = 0;
495 	int ret;
496 
497 	ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
498 	if (ret < 0 && ret != -EINVAL) {
499 		dev_err(&pdev->dev, "failed to parse property %s: %d\n",
500 			propname, ret);
501 		return ret;
502 	}
503 
504 	if (val32 > INT_MAX) {
505 		dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
506 		return -EOVERFLOW;
507 	}
508 
509 	*value = val32;
510 	return 0;
511 }
512 
ramoops_parse_dt(struct platform_device * pdev,struct ramoops_platform_data * pdata)513 static int ramoops_parse_dt(struct platform_device *pdev,
514 			    struct ramoops_platform_data *pdata)
515 {
516 	struct device_node *of_node = pdev->dev.of_node;
517 	struct resource *res;
518 	u32 value;
519 	int ret;
520 
521 	dev_dbg(&pdev->dev, "using Device Tree\n");
522 
523 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
524 	if (!res) {
525 		dev_err(&pdev->dev,
526 			"failed to locate DT /reserved-memory resource\n");
527 		return -EINVAL;
528 	}
529 
530 	pdata->mem_size = resource_size(res);
531 	pdata->mem_address = res->start;
532 	pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
533 	pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
534 
535 #define parse_size(name, field) {					\
536 		ret = ramoops_parse_dt_size(pdev, name, &value);	\
537 		if (ret < 0)						\
538 			return ret;					\
539 		field = value;						\
540 	}
541 
542 	parse_size("record-size", pdata->record_size);
543 	parse_size("console-size", pdata->console_size);
544 	parse_size("ftrace-size", pdata->ftrace_size);
545 	parse_size("pmsg-size", pdata->pmsg_size);
546 	parse_size("ecc-size", pdata->ecc_info.ecc_size);
547 
548 #undef parse_size
549 
550 	return 0;
551 }
552 
ramoops_console_write_buf(const char * buf,size_t size)553 void notrace ramoops_console_write_buf(const char *buf, size_t size)
554 {
555 	struct ramoops_context *cxt = &oops_cxt;
556 	persistent_ram_write(cxt->cprz, buf, size);
557 }
558 
ramoops_probe(struct platform_device * pdev)559 static int ramoops_probe(struct platform_device *pdev)
560 {
561 	struct device *dev = &pdev->dev;
562 	struct ramoops_platform_data *pdata = dev->platform_data;
563 	struct ramoops_context *cxt = &oops_cxt;
564 	size_t dump_mem_sz;
565 	phys_addr_t paddr;
566 	int err = -EINVAL;
567 
568 	if (dev_of_node(dev) && !pdata) {
569 		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
570 		if (!pdata) {
571 			err = -ENOMEM;
572 			goto fail_out;
573 		}
574 
575 		err = ramoops_parse_dt(pdev, pdata);
576 		if (err < 0)
577 			goto fail_out;
578 	}
579 
580 	/* Only a single ramoops area allowed at a time, so fail extra
581 	 * probes.
582 	 */
583 	if (cxt->max_dump_cnt)
584 		goto fail_out;
585 
586 	if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
587 			!pdata->ftrace_size && !pdata->pmsg_size)) {
588 		pr_err("The memory size and the record/console size must be "
589 			"non-zero\n");
590 		goto fail_out;
591 	}
592 
593 	if (pdata->record_size && !is_power_of_2(pdata->record_size))
594 		pdata->record_size = rounddown_pow_of_two(pdata->record_size);
595 	if (pdata->console_size && !is_power_of_2(pdata->console_size))
596 		pdata->console_size = rounddown_pow_of_two(pdata->console_size);
597 	if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
598 		pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
599 	if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
600 		pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
601 
602 	cxt->size = pdata->mem_size;
603 	cxt->phys_addr = pdata->mem_address;
604 	cxt->memtype = pdata->mem_type;
605 	cxt->record_size = pdata->record_size;
606 	cxt->console_size = pdata->console_size;
607 	cxt->ftrace_size = pdata->ftrace_size;
608 	cxt->pmsg_size = pdata->pmsg_size;
609 	cxt->dump_oops = pdata->dump_oops;
610 	cxt->ecc_info = pdata->ecc_info;
611 
612 	paddr = cxt->phys_addr;
613 
614 	dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
615 			- cxt->pmsg_size;
616 	err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
617 	if (err)
618 		goto fail_out;
619 
620 	err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
621 			       cxt->console_size, 0);
622 	if (err)
623 		goto fail_init_cprz;
624 
625 	err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
626 			       LINUX_VERSION_CODE);
627 	if (err)
628 		goto fail_init_fprz;
629 
630 	err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
631 	if (err)
632 		goto fail_init_mprz;
633 
634 	cxt->pstore.data = cxt;
635 	/*
636 	 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
637 	 * have to handle dumps, we must have at least record_size buffer. And
638 	 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
639 	 * ZERO_SIZE_PTR).
640 	 */
641 	if (cxt->console_size)
642 		cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
643 	cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
644 	cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
645 	if (!cxt->pstore.buf) {
646 		pr_err("cannot allocate pstore buffer\n");
647 		err = -ENOMEM;
648 		goto fail_clear;
649 	}
650 	spin_lock_init(&cxt->pstore.buf_lock);
651 
652 	cxt->pstore.flags = PSTORE_FLAGS_DMESG;
653 	if (cxt->console_size)
654 		cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
655 	if (cxt->ftrace_size)
656 		cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
657 	if (cxt->pmsg_size)
658 		cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
659 
660 	err = pstore_register(&cxt->pstore);
661 	if (err) {
662 		pr_err("registering with pstore failed\n");
663 		goto fail_buf;
664 	}
665 
666 	/*
667 	 * Update the module parameter variables as well so they are visible
668 	 * through /sys/module/ramoops/parameters/
669 	 */
670 	mem_size = pdata->mem_size;
671 	mem_address = pdata->mem_address;
672 	record_size = pdata->record_size;
673 	dump_oops = pdata->dump_oops;
674 	ramoops_console_size = pdata->console_size;
675 	ramoops_pmsg_size = pdata->pmsg_size;
676 	ramoops_ftrace_size = pdata->ftrace_size;
677 
678 	pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
679 		cxt->size, (unsigned long long)cxt->phys_addr,
680 		cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
681 
682 	return 0;
683 
684 fail_buf:
685 	kfree(cxt->pstore.buf);
686 fail_clear:
687 	cxt->pstore.bufsize = 0;
688 	persistent_ram_free(cxt->mprz);
689 fail_init_mprz:
690 	persistent_ram_free(cxt->fprz);
691 fail_init_fprz:
692 	persistent_ram_free(cxt->cprz);
693 fail_init_cprz:
694 	ramoops_free_przs(cxt);
695 fail_out:
696 	return err;
697 }
698 
ramoops_remove(struct platform_device * pdev)699 static int ramoops_remove(struct platform_device *pdev)
700 {
701 	struct ramoops_context *cxt = &oops_cxt;
702 
703 	pstore_unregister(&cxt->pstore);
704 
705 	kfree(cxt->pstore.buf);
706 	cxt->pstore.bufsize = 0;
707 
708 	persistent_ram_free(cxt->mprz);
709 	persistent_ram_free(cxt->fprz);
710 	persistent_ram_free(cxt->cprz);
711 	ramoops_free_przs(cxt);
712 
713 	return 0;
714 }
715 
716 static const struct of_device_id dt_match[] = {
717 	{ .compatible = "ramoops" },
718 	{}
719 };
720 
721 static struct platform_driver ramoops_driver = {
722 	.probe		= ramoops_probe,
723 	.remove		= ramoops_remove,
724 	.driver		= {
725 		.name		= "ramoops",
726 		.of_match_table	= dt_match,
727 	},
728 };
729 
ramoops_register_dummy(void)730 static void ramoops_register_dummy(void)
731 {
732 	if (!mem_size)
733 		return;
734 
735 	pr_info("using module parameters\n");
736 
737 	dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
738 	if (!dummy_data) {
739 		pr_info("could not allocate pdata\n");
740 		return;
741 	}
742 
743 	dummy_data->mem_size = mem_size;
744 	dummy_data->mem_address = mem_address;
745 	dummy_data->mem_type = mem_type;
746 	dummy_data->record_size = record_size;
747 	dummy_data->console_size = ramoops_console_size;
748 	dummy_data->ftrace_size = ramoops_ftrace_size;
749 	dummy_data->pmsg_size = ramoops_pmsg_size;
750 	dummy_data->dump_oops = dump_oops;
751 	/*
752 	 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
753 	 * (using 1 byte for ECC isn't much of use anyway).
754 	 */
755 	dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
756 
757 	dummy = platform_device_register_data(NULL, "ramoops", -1,
758 			dummy_data, sizeof(struct ramoops_platform_data));
759 	if (IS_ERR(dummy)) {
760 		pr_info("could not create platform device: %ld\n",
761 			PTR_ERR(dummy));
762 	}
763 }
764 
ramoops_init(void)765 static int __init ramoops_init(void)
766 {
767 	ramoops_register_dummy();
768 	return platform_driver_register(&ramoops_driver);
769 }
770 postcore_initcall(ramoops_init);
771 
ramoops_exit(void)772 static void __exit ramoops_exit(void)
773 {
774 	platform_driver_unregister(&ramoops_driver);
775 	platform_device_unregister(dummy);
776 	kfree(dummy_data);
777 }
778 module_exit(ramoops_exit);
779 
780 MODULE_LICENSE("GPL");
781 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
782 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
783