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