e6d9560ea4557e7c36b8ab62b4a7a85acf97790d
[sfrench/cifs-2.6.git] / fs / pstore / ram.c
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 static struct ramoops_platform_data *dummy_data;
114
115 static int ramoops_pstore_open(struct pstore_info *psi)
116 {
117         struct ramoops_context *cxt = psi->data;
118
119         cxt->dump_read_cnt = 0;
120         cxt->console_read_cnt = 0;
121         cxt->ftrace_read_cnt = 0;
122         cxt->pmsg_read_cnt = 0;
123         return 0;
124 }
125
126 static struct persistent_ram_zone *
127 ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
128                      struct pstore_record *record)
129 {
130         struct persistent_ram_zone *prz;
131         bool update = (record->type == PSTORE_TYPE_DMESG);
132
133         /* Give up if we never existed or have hit the end. */
134         if (!przs)
135                 return NULL;
136
137         prz = przs[id];
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         record->type = prz->type;
149         record->id = id;
150
151         return prz;
152 }
153
154 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
155                                   bool *compressed)
156 {
157         char data_type;
158         int header_length = 0;
159
160         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
161                    (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
162                    &header_length) == 3) {
163                 if (data_type == 'C')
164                         *compressed = true;
165                 else
166                         *compressed = false;
167         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
168                           (time64_t *)&time->tv_sec, &time->tv_nsec,
169                           &header_length) == 2) {
170                 *compressed = false;
171         } else {
172                 time->tv_sec = 0;
173                 time->tv_nsec = 0;
174                 *compressed = false;
175         }
176         return header_length;
177 }
178
179 static bool prz_ok(struct persistent_ram_zone *prz)
180 {
181         return !!prz && !!(persistent_ram_old_size(prz) +
182                            persistent_ram_ecc_string(prz, NULL, 0));
183 }
184
185 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
186                                   struct persistent_ram_zone *src)
187 {
188         size_t dest_size, src_size, total, dest_off, src_off;
189         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
190         void *merged_buf;
191         struct pstore_ftrace_record *drec, *srec, *mrec;
192         size_t record_size = sizeof(struct pstore_ftrace_record);
193
194         dest_off = dest->old_log_size % record_size;
195         dest_size = dest->old_log_size - dest_off;
196
197         src_off = src->old_log_size % record_size;
198         src_size = src->old_log_size - src_off;
199
200         total = dest_size + src_size;
201         merged_buf = kmalloc(total, GFP_KERNEL);
202         if (!merged_buf)
203                 return -ENOMEM;
204
205         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
206         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
207         mrec = (struct pstore_ftrace_record *)(merged_buf);
208
209         while (dest_size > 0 && src_size > 0) {
210                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
211                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
212                         mrec[merged_idx++] = drec[dest_idx++];
213                         dest_size -= record_size;
214                 } else {
215                         mrec[merged_idx++] = srec[src_idx++];
216                         src_size -= record_size;
217                 }
218         }
219
220         while (dest_size > 0) {
221                 mrec[merged_idx++] = drec[dest_idx++];
222                 dest_size -= record_size;
223         }
224
225         while (src_size > 0) {
226                 mrec[merged_idx++] = srec[src_idx++];
227                 src_size -= record_size;
228         }
229
230         kfree(dest->old_log);
231         dest->old_log = merged_buf;
232         dest->old_log_size = total;
233
234         return 0;
235 }
236
237 static ssize_t ramoops_pstore_read(struct pstore_record *record)
238 {
239         ssize_t size = 0;
240         struct ramoops_context *cxt = record->psi->data;
241         struct persistent_ram_zone *prz = NULL;
242         int header_length = 0;
243         bool free_prz = false;
244
245         /*
246          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
247          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
248          * valid time stamps, so it is initialized to zero.
249          */
250         record->time.tv_sec = 0;
251         record->time.tv_nsec = 0;
252         record->compressed = false;
253
254         /* Find the next valid persistent_ram_zone for DMESG */
255         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
256                 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
257                                            record);
258                 if (!prz_ok(prz))
259                         continue;
260                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
261                                                       &record->time,
262                                                       &record->compressed);
263                 /* Clear and skip this DMESG record if it has no valid header */
264                 if (!header_length) {
265                         persistent_ram_free_old(prz);
266                         persistent_ram_zap(prz);
267                         prz = NULL;
268                 }
269         }
270
271         if (!prz_ok(prz) && !cxt->console_read_cnt++)
272                 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
273
274         if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
275                 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
276
277         /* ftrace is last since it may want to dynamically allocate memory. */
278         if (!prz_ok(prz)) {
279                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
280                     !cxt->ftrace_read_cnt++) {
281                         prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
282                                                    record);
283                 } else {
284                         /*
285                          * Build a new dummy record which combines all the
286                          * per-cpu records including metadata and ecc info.
287                          */
288                         struct persistent_ram_zone *tmp_prz, *prz_next;
289
290                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
291                                           GFP_KERNEL);
292                         if (!tmp_prz)
293                                 return -ENOMEM;
294                         free_prz = true;
295
296                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
297                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
298                                                 cxt->ftrace_read_cnt++, record);
299
300                                 if (!prz_ok(prz_next))
301                                         continue;
302
303                                 tmp_prz->ecc_info = prz_next->ecc_info;
304                                 tmp_prz->corrected_bytes +=
305                                                 prz_next->corrected_bytes;
306                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
307                                 size = ftrace_log_combine(tmp_prz, prz_next);
308                                 if (size)
309                                         goto out;
310                         }
311                         record->id = 0;
312                         prz = tmp_prz;
313                 }
314         }
315
316         if (!prz_ok(prz)) {
317                 size = 0;
318                 goto out;
319         }
320
321         size = persistent_ram_old_size(prz) - header_length;
322
323         /* ECC correction notice */
324         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
325
326         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
327         if (record->buf == NULL) {
328                 size = -ENOMEM;
329                 goto out;
330         }
331
332         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
333                size);
334
335         persistent_ram_ecc_string(prz, record->buf + size,
336                                   record->ecc_notice_size + 1);
337
338 out:
339         if (free_prz) {
340                 kfree(prz->old_log);
341                 kfree(prz);
342         }
343
344         return size;
345 }
346
347 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
348                                      struct pstore_record *record)
349 {
350         char *hdr;
351         size_t len;
352
353         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
354                 (time64_t)record->time.tv_sec,
355                 record->time.tv_nsec / 1000,
356                 record->compressed ? 'C' : 'D');
357         WARN_ON_ONCE(!hdr);
358         len = hdr ? strlen(hdr) : 0;
359         persistent_ram_write(prz, hdr, len);
360         kfree(hdr);
361
362         return len;
363 }
364
365 static int notrace ramoops_pstore_write(struct pstore_record *record)
366 {
367         struct ramoops_context *cxt = record->psi->data;
368         struct persistent_ram_zone *prz;
369         size_t size, hlen;
370
371         if (record->type == PSTORE_TYPE_CONSOLE) {
372                 if (!cxt->cprz)
373                         return -ENOMEM;
374                 persistent_ram_write(cxt->cprz, record->buf, record->size);
375                 return 0;
376         } else if (record->type == PSTORE_TYPE_FTRACE) {
377                 int zonenum;
378
379                 if (!cxt->fprzs)
380                         return -ENOMEM;
381                 /*
382                  * Choose zone by if we're using per-cpu buffers.
383                  */
384                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
385                         zonenum = smp_processor_id();
386                 else
387                         zonenum = 0;
388
389                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
390                                      record->size);
391                 return 0;
392         } else if (record->type == PSTORE_TYPE_PMSG) {
393                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
394                 return -EINVAL;
395         }
396
397         if (record->type != PSTORE_TYPE_DMESG)
398                 return -EINVAL;
399
400         /*
401          * Out of the various dmesg dump types, ramoops is currently designed
402          * to only store crash logs, rather than storing general kernel logs.
403          */
404         if (record->reason != KMSG_DUMP_OOPS &&
405             record->reason != KMSG_DUMP_PANIC)
406                 return -EINVAL;
407
408         /* Skip Oopes when configured to do so. */
409         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
410                 return -EINVAL;
411
412         /*
413          * Explicitly only take the first part of any new crash.
414          * If our buffer is larger than kmsg_bytes, this can never happen,
415          * and if our buffer is smaller than kmsg_bytes, we don't want the
416          * report split across multiple records.
417          */
418         if (record->part != 1)
419                 return -ENOSPC;
420
421         if (!cxt->dprzs)
422                 return -ENOSPC;
423
424         prz = cxt->dprzs[cxt->dump_write_cnt];
425
426         /* Build header and append record contents. */
427         hlen = ramoops_write_kmsg_hdr(prz, record);
428         size = record->size;
429         if (size + hlen > prz->buffer_size)
430                 size = prz->buffer_size - hlen;
431         persistent_ram_write(prz, record->buf, size);
432
433         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
434
435         return 0;
436 }
437
438 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
439                                              const char __user *buf)
440 {
441         if (record->type == PSTORE_TYPE_PMSG) {
442                 struct ramoops_context *cxt = record->psi->data;
443
444                 if (!cxt->mprz)
445                         return -ENOMEM;
446                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
447         }
448
449         return -EINVAL;
450 }
451
452 static int ramoops_pstore_erase(struct pstore_record *record)
453 {
454         struct ramoops_context *cxt = record->psi->data;
455         struct persistent_ram_zone *prz;
456
457         switch (record->type) {
458         case PSTORE_TYPE_DMESG:
459                 if (record->id >= cxt->max_dump_cnt)
460                         return -EINVAL;
461                 prz = cxt->dprzs[record->id];
462                 break;
463         case PSTORE_TYPE_CONSOLE:
464                 prz = cxt->cprz;
465                 break;
466         case PSTORE_TYPE_FTRACE:
467                 if (record->id >= cxt->max_ftrace_cnt)
468                         return -EINVAL;
469                 prz = cxt->fprzs[record->id];
470                 break;
471         case PSTORE_TYPE_PMSG:
472                 prz = cxt->mprz;
473                 break;
474         default:
475                 return -EINVAL;
476         }
477
478         persistent_ram_free_old(prz);
479         persistent_ram_zap(prz);
480
481         return 0;
482 }
483
484 static struct ramoops_context oops_cxt = {
485         .pstore = {
486                 .owner  = THIS_MODULE,
487                 .name   = "ramoops",
488                 .open   = ramoops_pstore_open,
489                 .read   = ramoops_pstore_read,
490                 .write  = ramoops_pstore_write,
491                 .write_user     = ramoops_pstore_write_user,
492                 .erase  = ramoops_pstore_erase,
493         },
494 };
495
496 static void ramoops_free_przs(struct ramoops_context *cxt)
497 {
498         int i;
499
500         /* Free dump PRZs */
501         if (cxt->dprzs) {
502                 for (i = 0; i < cxt->max_dump_cnt; i++)
503                         persistent_ram_free(cxt->dprzs[i]);
504
505                 kfree(cxt->dprzs);
506                 cxt->max_dump_cnt = 0;
507         }
508
509         /* Free ftrace PRZs */
510         if (cxt->fprzs) {
511                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
512                         persistent_ram_free(cxt->fprzs[i]);
513                 kfree(cxt->fprzs);
514                 cxt->max_ftrace_cnt = 0;
515         }
516 }
517
518 static int ramoops_init_przs(const char *name,
519                              struct device *dev, struct ramoops_context *cxt,
520                              struct persistent_ram_zone ***przs,
521                              phys_addr_t *paddr, size_t mem_sz,
522                              ssize_t record_size,
523                              unsigned int *cnt, u32 sig, u32 flags)
524 {
525         int err = -ENOMEM;
526         int i;
527         size_t zone_sz;
528         struct persistent_ram_zone **prz_ar;
529
530         /* Allocate nothing for 0 mem_sz or 0 record_size. */
531         if (mem_sz == 0 || record_size == 0) {
532                 *cnt = 0;
533                 return 0;
534         }
535
536         /*
537          * If we have a negative record size, calculate it based on
538          * mem_sz / *cnt. If we have a positive record size, calculate
539          * cnt from mem_sz / record_size.
540          */
541         if (record_size < 0) {
542                 if (*cnt == 0)
543                         return 0;
544                 record_size = mem_sz / *cnt;
545                 if (record_size == 0) {
546                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
547                                 name, mem_sz, *cnt);
548                         goto fail;
549                 }
550         } else {
551                 *cnt = mem_sz / record_size;
552                 if (*cnt == 0) {
553                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
554                                 name, mem_sz, record_size);
555                         goto fail;
556                 }
557         }
558
559         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
560                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
561                         name,
562                         mem_sz, (unsigned long long)*paddr,
563                         cxt->size, (unsigned long long)cxt->phys_addr);
564                 goto fail;
565         }
566
567         zone_sz = mem_sz / *cnt;
568         if (!zone_sz) {
569                 dev_err(dev, "%s zone size == 0\n", name);
570                 goto fail;
571         }
572
573         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
574         if (!prz_ar)
575                 goto fail;
576
577         for (i = 0; i < *cnt; i++) {
578                 char *label;
579
580                 if (*cnt == 1)
581                         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
582                 else
583                         label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
584                                           name, i, *cnt - 1);
585                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
586                                                &cxt->ecc_info,
587                                                cxt->memtype, flags, label);
588                 if (IS_ERR(prz_ar[i])) {
589                         err = PTR_ERR(prz_ar[i]);
590                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
591                                 name, record_size,
592                                 (unsigned long long)*paddr, err);
593
594                         while (i > 0) {
595                                 i--;
596                                 persistent_ram_free(prz_ar[i]);
597                         }
598                         kfree(prz_ar);
599                         goto fail;
600                 }
601                 *paddr += zone_sz;
602                 prz_ar[i]->type = pstore_name_to_type(name);
603         }
604
605         *przs = prz_ar;
606         return 0;
607
608 fail:
609         *cnt = 0;
610         return err;
611 }
612
613 static int ramoops_init_prz(const char *name,
614                             struct device *dev, struct ramoops_context *cxt,
615                             struct persistent_ram_zone **prz,
616                             phys_addr_t *paddr, size_t sz, u32 sig)
617 {
618         char *label;
619
620         if (!sz)
621                 return 0;
622
623         if (*paddr + sz - cxt->phys_addr > cxt->size) {
624                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
625                         name, sz, (unsigned long long)*paddr,
626                         cxt->size, (unsigned long long)cxt->phys_addr);
627                 return -ENOMEM;
628         }
629
630         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
631         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
632                                   cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
633         if (IS_ERR(*prz)) {
634                 int err = PTR_ERR(*prz);
635
636                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
637                         name, sz, (unsigned long long)*paddr, err);
638                 return err;
639         }
640
641         *paddr += sz;
642         (*prz)->type = pstore_name_to_type(name);
643
644         return 0;
645 }
646
647 static int ramoops_parse_dt_size(struct platform_device *pdev,
648                                  const char *propname, u32 *value)
649 {
650         u32 val32 = 0;
651         int ret;
652
653         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
654         if (ret < 0 && ret != -EINVAL) {
655                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
656                         propname, ret);
657                 return ret;
658         }
659
660         if (val32 > INT_MAX) {
661                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
662                 return -EOVERFLOW;
663         }
664
665         *value = val32;
666         return 0;
667 }
668
669 static int ramoops_parse_dt(struct platform_device *pdev,
670                             struct ramoops_platform_data *pdata)
671 {
672         struct device_node *of_node = pdev->dev.of_node;
673         struct resource *res;
674         u32 value;
675         int ret;
676
677         dev_dbg(&pdev->dev, "using Device Tree\n");
678
679         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
680         if (!res) {
681                 dev_err(&pdev->dev,
682                         "failed to locate DT /reserved-memory resource\n");
683                 return -EINVAL;
684         }
685
686         pdata->mem_size = resource_size(res);
687         pdata->mem_address = res->start;
688         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
689         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
690
691 #define parse_size(name, field) {                                       \
692                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
693                 if (ret < 0)                                            \
694                         return ret;                                     \
695                 field = value;                                          \
696         }
697
698         parse_size("record-size", pdata->record_size);
699         parse_size("console-size", pdata->console_size);
700         parse_size("ftrace-size", pdata->ftrace_size);
701         parse_size("pmsg-size", pdata->pmsg_size);
702         parse_size("ecc-size", pdata->ecc_info.ecc_size);
703         parse_size("flags", pdata->flags);
704
705 #undef parse_size
706
707         return 0;
708 }
709
710 static int ramoops_probe(struct platform_device *pdev)
711 {
712         struct device *dev = &pdev->dev;
713         struct ramoops_platform_data *pdata = dev->platform_data;
714         struct ramoops_context *cxt = &oops_cxt;
715         size_t dump_mem_sz;
716         phys_addr_t paddr;
717         int err = -EINVAL;
718
719         if (dev_of_node(dev) && !pdata) {
720                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
721                 if (!pdata) {
722                         pr_err("cannot allocate platform data buffer\n");
723                         err = -ENOMEM;
724                         goto fail_out;
725                 }
726
727                 err = ramoops_parse_dt(pdev, pdata);
728                 if (err < 0)
729                         goto fail_out;
730         }
731
732         /*
733          * Only a single ramoops area allowed at a time, so fail extra
734          * probes.
735          */
736         if (cxt->max_dump_cnt) {
737                 pr_err("already initialized\n");
738                 goto fail_out;
739         }
740
741         /* Make sure we didn't get bogus platform data pointer. */
742         if (!pdata) {
743                 pr_err("NULL platform data\n");
744                 goto fail_out;
745         }
746
747         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
748                         !pdata->ftrace_size && !pdata->pmsg_size)) {
749                 pr_err("The memory size and the record/console size must be "
750                         "non-zero\n");
751                 goto fail_out;
752         }
753
754         if (pdata->record_size && !is_power_of_2(pdata->record_size))
755                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
756         if (pdata->console_size && !is_power_of_2(pdata->console_size))
757                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
758         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
759                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
760         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
761                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
762
763         cxt->size = pdata->mem_size;
764         cxt->phys_addr = pdata->mem_address;
765         cxt->memtype = pdata->mem_type;
766         cxt->record_size = pdata->record_size;
767         cxt->console_size = pdata->console_size;
768         cxt->ftrace_size = pdata->ftrace_size;
769         cxt->pmsg_size = pdata->pmsg_size;
770         cxt->dump_oops = pdata->dump_oops;
771         cxt->flags = pdata->flags;
772         cxt->ecc_info = pdata->ecc_info;
773
774         paddr = cxt->phys_addr;
775
776         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
777                         - cxt->pmsg_size;
778         err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
779                                 dump_mem_sz, cxt->record_size,
780                                 &cxt->max_dump_cnt, 0, 0);
781         if (err)
782                 goto fail_out;
783
784         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
785                                cxt->console_size, 0);
786         if (err)
787                 goto fail_init_cprz;
788
789         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
790                                 ? nr_cpu_ids
791                                 : 1;
792         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
793                                 cxt->ftrace_size, -1,
794                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
795                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
796                                         ? PRZ_FLAG_NO_LOCK : 0);
797         if (err)
798                 goto fail_init_fprz;
799
800         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
801                                 cxt->pmsg_size, 0);
802         if (err)
803                 goto fail_init_mprz;
804
805         cxt->pstore.data = cxt;
806         /*
807          * Since bufsize is only used for dmesg crash dumps, it
808          * must match the size of the dprz record (after PRZ header
809          * and ECC bytes have been accounted for).
810          */
811         cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
812         cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
813         if (!cxt->pstore.buf) {
814                 pr_err("cannot allocate pstore crash dump buffer\n");
815                 err = -ENOMEM;
816                 goto fail_clear;
817         }
818
819         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
820         if (cxt->console_size)
821                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
822         if (cxt->ftrace_size)
823                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
824         if (cxt->pmsg_size)
825                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
826
827         err = pstore_register(&cxt->pstore);
828         if (err) {
829                 pr_err("registering with pstore failed\n");
830                 goto fail_buf;
831         }
832
833         /*
834          * Update the module parameter variables as well so they are visible
835          * through /sys/module/ramoops/parameters/
836          */
837         mem_size = pdata->mem_size;
838         mem_address = pdata->mem_address;
839         record_size = pdata->record_size;
840         dump_oops = pdata->dump_oops;
841         ramoops_console_size = pdata->console_size;
842         ramoops_pmsg_size = pdata->pmsg_size;
843         ramoops_ftrace_size = pdata->ftrace_size;
844
845         pr_info("using 0x%lx@0x%llx, ecc: %d\n",
846                 cxt->size, (unsigned long long)cxt->phys_addr,
847                 cxt->ecc_info.ecc_size);
848
849         return 0;
850
851 fail_buf:
852         kfree(cxt->pstore.buf);
853 fail_clear:
854         cxt->pstore.bufsize = 0;
855         persistent_ram_free(cxt->mprz);
856 fail_init_mprz:
857 fail_init_fprz:
858         persistent_ram_free(cxt->cprz);
859 fail_init_cprz:
860         ramoops_free_przs(cxt);
861 fail_out:
862         return err;
863 }
864
865 static int ramoops_remove(struct platform_device *pdev)
866 {
867         struct ramoops_context *cxt = &oops_cxt;
868
869         pstore_unregister(&cxt->pstore);
870
871         kfree(cxt->pstore.buf);
872         cxt->pstore.bufsize = 0;
873
874         persistent_ram_free(cxt->mprz);
875         persistent_ram_free(cxt->cprz);
876         ramoops_free_przs(cxt);
877
878         return 0;
879 }
880
881 static const struct of_device_id dt_match[] = {
882         { .compatible = "ramoops" },
883         {}
884 };
885
886 static struct platform_driver ramoops_driver = {
887         .probe          = ramoops_probe,
888         .remove         = ramoops_remove,
889         .driver         = {
890                 .name           = "ramoops",
891                 .of_match_table = dt_match,
892         },
893 };
894
895 static inline void ramoops_unregister_dummy(void)
896 {
897         platform_device_unregister(dummy);
898         dummy = NULL;
899
900         kfree(dummy_data);
901         dummy_data = NULL;
902 }
903
904 static void __init ramoops_register_dummy(void)
905 {
906         /*
907          * Prepare a dummy platform data structure to carry the module
908          * parameters. If mem_size isn't set, then there are no module
909          * parameters, and we can skip this.
910          */
911         if (!mem_size)
912                 return;
913
914         pr_info("using module parameters\n");
915
916         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
917         if (!dummy_data) {
918                 pr_info("could not allocate pdata\n");
919                 return;
920         }
921
922         dummy_data->mem_size = mem_size;
923         dummy_data->mem_address = mem_address;
924         dummy_data->mem_type = mem_type;
925         dummy_data->record_size = record_size;
926         dummy_data->console_size = ramoops_console_size;
927         dummy_data->ftrace_size = ramoops_ftrace_size;
928         dummy_data->pmsg_size = ramoops_pmsg_size;
929         dummy_data->dump_oops = dump_oops;
930         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
931
932         /*
933          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
934          * (using 1 byte for ECC isn't much of use anyway).
935          */
936         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
937
938         dummy = platform_device_register_data(NULL, "ramoops", -1,
939                         dummy_data, sizeof(struct ramoops_platform_data));
940         if (IS_ERR(dummy)) {
941                 pr_info("could not create platform device: %ld\n",
942                         PTR_ERR(dummy));
943                 dummy = NULL;
944                 ramoops_unregister_dummy();
945         }
946 }
947
948 static int __init ramoops_init(void)
949 {
950         int ret;
951
952         ramoops_register_dummy();
953         ret = platform_driver_register(&ramoops_driver);
954         if (ret != 0)
955                 ramoops_unregister_dummy();
956
957         return ret;
958 }
959 postcore_initcall(ramoops_init);
960
961 static void __exit ramoops_exit(void)
962 {
963         platform_driver_unregister(&ramoops_driver);
964         ramoops_unregister_dummy();
965 }
966 module_exit(ramoops_exit);
967
968 MODULE_LICENSE("GPL");
969 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
970 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");