Merge tag 'pstore-v4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees...
[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[], uint *c, uint max,
128                      u64 *id,
129                      enum pstore_type_id *typep, enum pstore_type_id type,
130                      bool update)
131 {
132         struct persistent_ram_zone *prz;
133         int i = (*c)++;
134
135         /* Give up if we never existed or have hit the end. */
136         if (!przs || i >= max)
137                 return NULL;
138
139         prz = przs[i];
140         if (!prz)
141                 return NULL;
142
143         /* Update old/shadowed buffer. */
144         if (update)
145                 persistent_ram_save_old(prz);
146
147         if (!persistent_ram_old_size(prz))
148                 return NULL;
149
150         *typep = type;
151         *id = i;
152
153         return prz;
154 }
155
156 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
157                                   bool *compressed)
158 {
159         char data_type;
160         int header_length = 0;
161
162         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
163                    (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
164                    &header_length) == 3) {
165                 if (data_type == 'C')
166                         *compressed = true;
167                 else
168                         *compressed = false;
169         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
170                           (time64_t *)&time->tv_sec, &time->tv_nsec,
171                           &header_length) == 2) {
172                 *compressed = false;
173         } else {
174                 time->tv_sec = 0;
175                 time->tv_nsec = 0;
176                 *compressed = false;
177         }
178         return header_length;
179 }
180
181 static bool prz_ok(struct persistent_ram_zone *prz)
182 {
183         return !!prz && !!(persistent_ram_old_size(prz) +
184                            persistent_ram_ecc_string(prz, NULL, 0));
185 }
186
187 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
188                                   struct persistent_ram_zone *src)
189 {
190         size_t dest_size, src_size, total, dest_off, src_off;
191         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
192         void *merged_buf;
193         struct pstore_ftrace_record *drec, *srec, *mrec;
194         size_t record_size = sizeof(struct pstore_ftrace_record);
195
196         dest_off = dest->old_log_size % record_size;
197         dest_size = dest->old_log_size - dest_off;
198
199         src_off = src->old_log_size % record_size;
200         src_size = src->old_log_size - src_off;
201
202         total = dest_size + src_size;
203         merged_buf = kmalloc(total, GFP_KERNEL);
204         if (!merged_buf)
205                 return -ENOMEM;
206
207         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
208         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
209         mrec = (struct pstore_ftrace_record *)(merged_buf);
210
211         while (dest_size > 0 && src_size > 0) {
212                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
213                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
214                         mrec[merged_idx++] = drec[dest_idx++];
215                         dest_size -= record_size;
216                 } else {
217                         mrec[merged_idx++] = srec[src_idx++];
218                         src_size -= record_size;
219                 }
220         }
221
222         while (dest_size > 0) {
223                 mrec[merged_idx++] = drec[dest_idx++];
224                 dest_size -= record_size;
225         }
226
227         while (src_size > 0) {
228                 mrec[merged_idx++] = srec[src_idx++];
229                 src_size -= record_size;
230         }
231
232         kfree(dest->old_log);
233         dest->old_log = merged_buf;
234         dest->old_log_size = total;
235
236         return 0;
237 }
238
239 static ssize_t ramoops_pstore_read(struct pstore_record *record)
240 {
241         ssize_t size = 0;
242         struct ramoops_context *cxt = record->psi->data;
243         struct persistent_ram_zone *prz = NULL;
244         int header_length = 0;
245         bool free_prz = false;
246
247         /*
248          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
249          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
250          * valid time stamps, so it is initialized to zero.
251          */
252         record->time.tv_sec = 0;
253         record->time.tv_nsec = 0;
254         record->compressed = false;
255
256         /* Find the next valid persistent_ram_zone for DMESG */
257         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
258                 prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
259                                            cxt->max_dump_cnt, &record->id,
260                                            &record->type,
261                                            PSTORE_TYPE_DMESG, 1);
262                 if (!prz_ok(prz))
263                         continue;
264                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
265                                                       &record->time,
266                                                       &record->compressed);
267                 /* Clear and skip this DMESG record if it has no valid header */
268                 if (!header_length) {
269                         persistent_ram_free_old(prz);
270                         persistent_ram_zap(prz);
271                         prz = NULL;
272                 }
273         }
274
275         if (!prz_ok(prz))
276                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
277                                            1, &record->id, &record->type,
278                                            PSTORE_TYPE_CONSOLE, 0);
279
280         if (!prz_ok(prz))
281                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
282                                            1, &record->id, &record->type,
283                                            PSTORE_TYPE_PMSG, 0);
284
285         /* ftrace is last since it may want to dynamically allocate memory. */
286         if (!prz_ok(prz)) {
287                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
288                         prz = ramoops_get_next_prz(cxt->fprzs,
289                                         &cxt->ftrace_read_cnt, 1, &record->id,
290                                         &record->type, PSTORE_TYPE_FTRACE, 0);
291                 } else {
292                         /*
293                          * Build a new dummy record which combines all the
294                          * per-cpu records including metadata and ecc info.
295                          */
296                         struct persistent_ram_zone *tmp_prz, *prz_next;
297
298                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
299                                           GFP_KERNEL);
300                         if (!tmp_prz)
301                                 return -ENOMEM;
302                         free_prz = true;
303
304                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
305                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
306                                                 &cxt->ftrace_read_cnt,
307                                                 cxt->max_ftrace_cnt,
308                                                 &record->id,
309                                                 &record->type,
310                                                 PSTORE_TYPE_FTRACE, 0);
311
312                                 if (!prz_ok(prz_next))
313                                         continue;
314
315                                 tmp_prz->ecc_info = prz_next->ecc_info;
316                                 tmp_prz->corrected_bytes +=
317                                                 prz_next->corrected_bytes;
318                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
319                                 size = ftrace_log_combine(tmp_prz, prz_next);
320                                 if (size)
321                                         goto out;
322                         }
323                         record->id = 0;
324                         prz = tmp_prz;
325                 }
326         }
327
328         if (!prz_ok(prz)) {
329                 size = 0;
330                 goto out;
331         }
332
333         size = persistent_ram_old_size(prz) - header_length;
334
335         /* ECC correction notice */
336         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
337
338         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
339         if (record->buf == NULL) {
340                 size = -ENOMEM;
341                 goto out;
342         }
343
344         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
345                size);
346
347         persistent_ram_ecc_string(prz, record->buf + size,
348                                   record->ecc_notice_size + 1);
349
350 out:
351         if (free_prz) {
352                 kfree(prz->old_log);
353                 kfree(prz);
354         }
355
356         return size;
357 }
358
359 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
360                                      struct pstore_record *record)
361 {
362         char *hdr;
363         size_t len;
364
365         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
366                 (time64_t)record->time.tv_sec,
367                 record->time.tv_nsec / 1000,
368                 record->compressed ? 'C' : 'D');
369         WARN_ON_ONCE(!hdr);
370         len = hdr ? strlen(hdr) : 0;
371         persistent_ram_write(prz, hdr, len);
372         kfree(hdr);
373
374         return len;
375 }
376
377 static int notrace ramoops_pstore_write(struct pstore_record *record)
378 {
379         struct ramoops_context *cxt = record->psi->data;
380         struct persistent_ram_zone *prz;
381         size_t size, hlen;
382
383         if (record->type == PSTORE_TYPE_CONSOLE) {
384                 if (!cxt->cprz)
385                         return -ENOMEM;
386                 persistent_ram_write(cxt->cprz, record->buf, record->size);
387                 return 0;
388         } else if (record->type == PSTORE_TYPE_FTRACE) {
389                 int zonenum;
390
391                 if (!cxt->fprzs)
392                         return -ENOMEM;
393                 /*
394                  * Choose zone by if we're using per-cpu buffers.
395                  */
396                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
397                         zonenum = smp_processor_id();
398                 else
399                         zonenum = 0;
400
401                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
402                                      record->size);
403                 return 0;
404         } else if (record->type == PSTORE_TYPE_PMSG) {
405                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
406                 return -EINVAL;
407         }
408
409         if (record->type != PSTORE_TYPE_DMESG)
410                 return -EINVAL;
411
412         /*
413          * Out of the various dmesg dump types, ramoops is currently designed
414          * to only store crash logs, rather than storing general kernel logs.
415          */
416         if (record->reason != KMSG_DUMP_OOPS &&
417             record->reason != KMSG_DUMP_PANIC)
418                 return -EINVAL;
419
420         /* Skip Oopes when configured to do so. */
421         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
422                 return -EINVAL;
423
424         /*
425          * Explicitly only take the first part of any new crash.
426          * If our buffer is larger than kmsg_bytes, this can never happen,
427          * and if our buffer is smaller than kmsg_bytes, we don't want the
428          * report split across multiple records.
429          */
430         if (record->part != 1)
431                 return -ENOSPC;
432
433         if (!cxt->dprzs)
434                 return -ENOSPC;
435
436         prz = cxt->dprzs[cxt->dump_write_cnt];
437
438         /* Build header and append record contents. */
439         hlen = ramoops_write_kmsg_hdr(prz, record);
440         size = record->size;
441         if (size + hlen > prz->buffer_size)
442                 size = prz->buffer_size - hlen;
443         persistent_ram_write(prz, record->buf, size);
444
445         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
446
447         return 0;
448 }
449
450 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
451                                              const char __user *buf)
452 {
453         if (record->type == PSTORE_TYPE_PMSG) {
454                 struct ramoops_context *cxt = record->psi->data;
455
456                 if (!cxt->mprz)
457                         return -ENOMEM;
458                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
459         }
460
461         return -EINVAL;
462 }
463
464 static int ramoops_pstore_erase(struct pstore_record *record)
465 {
466         struct ramoops_context *cxt = record->psi->data;
467         struct persistent_ram_zone *prz;
468
469         switch (record->type) {
470         case PSTORE_TYPE_DMESG:
471                 if (record->id >= cxt->max_dump_cnt)
472                         return -EINVAL;
473                 prz = cxt->dprzs[record->id];
474                 break;
475         case PSTORE_TYPE_CONSOLE:
476                 prz = cxt->cprz;
477                 break;
478         case PSTORE_TYPE_FTRACE:
479                 if (record->id >= cxt->max_ftrace_cnt)
480                         return -EINVAL;
481                 prz = cxt->fprzs[record->id];
482                 break;
483         case PSTORE_TYPE_PMSG:
484                 prz = cxt->mprz;
485                 break;
486         default:
487                 return -EINVAL;
488         }
489
490         persistent_ram_free_old(prz);
491         persistent_ram_zap(prz);
492
493         return 0;
494 }
495
496 static struct ramoops_context oops_cxt = {
497         .pstore = {
498                 .owner  = THIS_MODULE,
499                 .name   = "ramoops",
500                 .open   = ramoops_pstore_open,
501                 .read   = ramoops_pstore_read,
502                 .write  = ramoops_pstore_write,
503                 .write_user     = ramoops_pstore_write_user,
504                 .erase  = ramoops_pstore_erase,
505         },
506 };
507
508 static void ramoops_free_przs(struct ramoops_context *cxt)
509 {
510         int i;
511
512         /* Free dump PRZs */
513         if (cxt->dprzs) {
514                 for (i = 0; i < cxt->max_dump_cnt; i++)
515                         persistent_ram_free(cxt->dprzs[i]);
516
517                 kfree(cxt->dprzs);
518                 cxt->max_dump_cnt = 0;
519         }
520
521         /* Free ftrace PRZs */
522         if (cxt->fprzs) {
523                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
524                         persistent_ram_free(cxt->fprzs[i]);
525                 kfree(cxt->fprzs);
526                 cxt->max_ftrace_cnt = 0;
527         }
528 }
529
530 static int ramoops_init_przs(const char *name,
531                              struct device *dev, struct ramoops_context *cxt,
532                              struct persistent_ram_zone ***przs,
533                              phys_addr_t *paddr, size_t mem_sz,
534                              ssize_t record_size,
535                              unsigned int *cnt, u32 sig, u32 flags)
536 {
537         int err = -ENOMEM;
538         int i;
539         size_t zone_sz;
540         struct persistent_ram_zone **prz_ar;
541
542         /* Allocate nothing for 0 mem_sz or 0 record_size. */
543         if (mem_sz == 0 || record_size == 0) {
544                 *cnt = 0;
545                 return 0;
546         }
547
548         /*
549          * If we have a negative record size, calculate it based on
550          * mem_sz / *cnt. If we have a positive record size, calculate
551          * cnt from mem_sz / record_size.
552          */
553         if (record_size < 0) {
554                 if (*cnt == 0)
555                         return 0;
556                 record_size = mem_sz / *cnt;
557                 if (record_size == 0) {
558                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
559                                 name, mem_sz, *cnt);
560                         goto fail;
561                 }
562         } else {
563                 *cnt = mem_sz / record_size;
564                 if (*cnt == 0) {
565                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
566                                 name, mem_sz, record_size);
567                         goto fail;
568                 }
569         }
570
571         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
572                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
573                         name,
574                         mem_sz, (unsigned long long)*paddr,
575                         cxt->size, (unsigned long long)cxt->phys_addr);
576                 goto fail;
577         }
578
579         zone_sz = mem_sz / *cnt;
580         if (!zone_sz) {
581                 dev_err(dev, "%s zone size == 0\n", name);
582                 goto fail;
583         }
584
585         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
586         if (!prz_ar)
587                 goto fail;
588
589         for (i = 0; i < *cnt; i++) {
590                 char *label;
591
592                 if (*cnt == 1)
593                         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
594                 else
595                         label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
596                                           name, i, *cnt - 1);
597                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
598                                                &cxt->ecc_info,
599                                                cxt->memtype, flags, label);
600                 if (IS_ERR(prz_ar[i])) {
601                         err = PTR_ERR(prz_ar[i]);
602                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
603                                 name, record_size,
604                                 (unsigned long long)*paddr, err);
605
606                         while (i > 0) {
607                                 i--;
608                                 persistent_ram_free(prz_ar[i]);
609                         }
610                         kfree(prz_ar);
611                         goto fail;
612                 }
613                 *paddr += zone_sz;
614         }
615
616         *przs = prz_ar;
617         return 0;
618
619 fail:
620         *cnt = 0;
621         return err;
622 }
623
624 static int ramoops_init_prz(const char *name,
625                             struct device *dev, struct ramoops_context *cxt,
626                             struct persistent_ram_zone **prz,
627                             phys_addr_t *paddr, size_t sz, u32 sig)
628 {
629         char *label;
630
631         if (!sz)
632                 return 0;
633
634         if (*paddr + sz - cxt->phys_addr > cxt->size) {
635                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
636                         name, sz, (unsigned long long)*paddr,
637                         cxt->size, (unsigned long long)cxt->phys_addr);
638                 return -ENOMEM;
639         }
640
641         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
642         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
643                                   cxt->memtype, 0, label);
644         if (IS_ERR(*prz)) {
645                 int err = PTR_ERR(*prz);
646
647                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
648                         name, sz, (unsigned long long)*paddr, err);
649                 return err;
650         }
651
652         persistent_ram_zap(*prz);
653
654         *paddr += sz;
655
656         return 0;
657 }
658
659 static int ramoops_parse_dt_size(struct platform_device *pdev,
660                                  const char *propname, u32 *value)
661 {
662         u32 val32 = 0;
663         int ret;
664
665         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
666         if (ret < 0 && ret != -EINVAL) {
667                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
668                         propname, ret);
669                 return ret;
670         }
671
672         if (val32 > INT_MAX) {
673                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
674                 return -EOVERFLOW;
675         }
676
677         *value = val32;
678         return 0;
679 }
680
681 static int ramoops_parse_dt(struct platform_device *pdev,
682                             struct ramoops_platform_data *pdata)
683 {
684         struct device_node *of_node = pdev->dev.of_node;
685         struct resource *res;
686         u32 value;
687         int ret;
688
689         dev_dbg(&pdev->dev, "using Device Tree\n");
690
691         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
692         if (!res) {
693                 dev_err(&pdev->dev,
694                         "failed to locate DT /reserved-memory resource\n");
695                 return -EINVAL;
696         }
697
698         pdata->mem_size = resource_size(res);
699         pdata->mem_address = res->start;
700         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
701         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
702
703 #define parse_size(name, field) {                                       \
704                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
705                 if (ret < 0)                                            \
706                         return ret;                                     \
707                 field = value;                                          \
708         }
709
710         parse_size("record-size", pdata->record_size);
711         parse_size("console-size", pdata->console_size);
712         parse_size("ftrace-size", pdata->ftrace_size);
713         parse_size("pmsg-size", pdata->pmsg_size);
714         parse_size("ecc-size", pdata->ecc_info.ecc_size);
715         parse_size("flags", pdata->flags);
716
717 #undef parse_size
718
719         return 0;
720 }
721
722 static int ramoops_probe(struct platform_device *pdev)
723 {
724         struct device *dev = &pdev->dev;
725         struct ramoops_platform_data *pdata = dev->platform_data;
726         struct ramoops_context *cxt = &oops_cxt;
727         size_t dump_mem_sz;
728         phys_addr_t paddr;
729         int err = -EINVAL;
730
731         if (dev_of_node(dev) && !pdata) {
732                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
733                 if (!pdata) {
734                         pr_err("cannot allocate platform data buffer\n");
735                         err = -ENOMEM;
736                         goto fail_out;
737                 }
738
739                 err = ramoops_parse_dt(pdev, pdata);
740                 if (err < 0)
741                         goto fail_out;
742         }
743
744         /*
745          * Only a single ramoops area allowed at a time, so fail extra
746          * probes.
747          */
748         if (cxt->max_dump_cnt) {
749                 pr_err("already initialized\n");
750                 goto fail_out;
751         }
752
753         /* Make sure we didn't get bogus platform data pointer. */
754         if (!pdata) {
755                 pr_err("NULL platform data\n");
756                 goto fail_out;
757         }
758
759         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
760                         !pdata->ftrace_size && !pdata->pmsg_size)) {
761                 pr_err("The memory size and the record/console size must be "
762                         "non-zero\n");
763                 goto fail_out;
764         }
765
766         if (pdata->record_size && !is_power_of_2(pdata->record_size))
767                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
768         if (pdata->console_size && !is_power_of_2(pdata->console_size))
769                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
770         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
771                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
772         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
773                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
774
775         cxt->size = pdata->mem_size;
776         cxt->phys_addr = pdata->mem_address;
777         cxt->memtype = pdata->mem_type;
778         cxt->record_size = pdata->record_size;
779         cxt->console_size = pdata->console_size;
780         cxt->ftrace_size = pdata->ftrace_size;
781         cxt->pmsg_size = pdata->pmsg_size;
782         cxt->dump_oops = pdata->dump_oops;
783         cxt->flags = pdata->flags;
784         cxt->ecc_info = pdata->ecc_info;
785
786         paddr = cxt->phys_addr;
787
788         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
789                         - cxt->pmsg_size;
790         err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
791                                 dump_mem_sz, cxt->record_size,
792                                 &cxt->max_dump_cnt, 0, 0);
793         if (err)
794                 goto fail_out;
795
796         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
797                                cxt->console_size, 0);
798         if (err)
799                 goto fail_init_cprz;
800
801         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
802                                 ? nr_cpu_ids
803                                 : 1;
804         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
805                                 cxt->ftrace_size, -1,
806                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
807                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
808                                         ? PRZ_FLAG_NO_LOCK : 0);
809         if (err)
810                 goto fail_init_fprz;
811
812         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
813                                 cxt->pmsg_size, 0);
814         if (err)
815                 goto fail_init_mprz;
816
817         cxt->pstore.data = cxt;
818         /*
819          * Since bufsize is only used for dmesg crash dumps, it
820          * must match the size of the dprz record (after PRZ header
821          * and ECC bytes have been accounted for).
822          */
823         cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
824         cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
825         if (!cxt->pstore.buf) {
826                 pr_err("cannot allocate pstore crash dump buffer\n");
827                 err = -ENOMEM;
828                 goto fail_clear;
829         }
830         spin_lock_init(&cxt->pstore.buf_lock);
831
832         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
833         if (cxt->console_size)
834                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
835         if (cxt->ftrace_size)
836                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
837         if (cxt->pmsg_size)
838                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
839
840         err = pstore_register(&cxt->pstore);
841         if (err) {
842                 pr_err("registering with pstore failed\n");
843                 goto fail_buf;
844         }
845
846         /*
847          * Update the module parameter variables as well so they are visible
848          * through /sys/module/ramoops/parameters/
849          */
850         mem_size = pdata->mem_size;
851         mem_address = pdata->mem_address;
852         record_size = pdata->record_size;
853         dump_oops = pdata->dump_oops;
854         ramoops_console_size = pdata->console_size;
855         ramoops_pmsg_size = pdata->pmsg_size;
856         ramoops_ftrace_size = pdata->ftrace_size;
857
858         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
859                 cxt->size, (unsigned long long)cxt->phys_addr,
860                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
861
862         return 0;
863
864 fail_buf:
865         kfree(cxt->pstore.buf);
866 fail_clear:
867         cxt->pstore.bufsize = 0;
868         persistent_ram_free(cxt->mprz);
869 fail_init_mprz:
870 fail_init_fprz:
871         persistent_ram_free(cxt->cprz);
872 fail_init_cprz:
873         ramoops_free_przs(cxt);
874 fail_out:
875         return err;
876 }
877
878 static int ramoops_remove(struct platform_device *pdev)
879 {
880         struct ramoops_context *cxt = &oops_cxt;
881
882         pstore_unregister(&cxt->pstore);
883
884         kfree(cxt->pstore.buf);
885         cxt->pstore.bufsize = 0;
886
887         persistent_ram_free(cxt->mprz);
888         persistent_ram_free(cxt->cprz);
889         ramoops_free_przs(cxt);
890
891         return 0;
892 }
893
894 static const struct of_device_id dt_match[] = {
895         { .compatible = "ramoops" },
896         {}
897 };
898
899 static struct platform_driver ramoops_driver = {
900         .probe          = ramoops_probe,
901         .remove         = ramoops_remove,
902         .driver         = {
903                 .name           = "ramoops",
904                 .of_match_table = dt_match,
905         },
906 };
907
908 static inline void ramoops_unregister_dummy(void)
909 {
910         platform_device_unregister(dummy);
911         dummy = NULL;
912
913         kfree(dummy_data);
914         dummy_data = NULL;
915 }
916
917 static void __init ramoops_register_dummy(void)
918 {
919         /*
920          * Prepare a dummy platform data structure to carry the module
921          * parameters. If mem_size isn't set, then there are no module
922          * parameters, and we can skip this.
923          */
924         if (!mem_size)
925                 return;
926
927         pr_info("using module parameters\n");
928
929         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
930         if (!dummy_data) {
931                 pr_info("could not allocate pdata\n");
932                 return;
933         }
934
935         dummy_data->mem_size = mem_size;
936         dummy_data->mem_address = mem_address;
937         dummy_data->mem_type = mem_type;
938         dummy_data->record_size = record_size;
939         dummy_data->console_size = ramoops_console_size;
940         dummy_data->ftrace_size = ramoops_ftrace_size;
941         dummy_data->pmsg_size = ramoops_pmsg_size;
942         dummy_data->dump_oops = dump_oops;
943         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
944
945         /*
946          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
947          * (using 1 byte for ECC isn't much of use anyway).
948          */
949         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
950
951         dummy = platform_device_register_data(NULL, "ramoops", -1,
952                         dummy_data, sizeof(struct ramoops_platform_data));
953         if (IS_ERR(dummy)) {
954                 pr_info("could not create platform device: %ld\n",
955                         PTR_ERR(dummy));
956                 dummy = NULL;
957                 ramoops_unregister_dummy();
958         }
959 }
960
961 static int __init ramoops_init(void)
962 {
963         int ret;
964
965         ramoops_register_dummy();
966         ret = platform_driver_register(&ramoops_driver);
967         if (ret != 0)
968                 ramoops_unregister_dummy();
969
970         return ret;
971 }
972 postcore_initcall(ramoops_init);
973
974 static void __exit ramoops_exit(void)
975 {
976         platform_driver_unregister(&ramoops_driver);
977         ramoops_unregister_dummy();
978 }
979 module_exit(ramoops_exit);
980
981 MODULE_LICENSE("GPL");
982 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
983 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");