Merge tag 'for-v3.8' of git://git.infradead.org/users/cbou/linux-pstore
[~shefty/rdma-dev.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/time.h>
31 #include <linux/io.h>
32 #include <linux/ioport.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/compiler.h>
36 #include <linux/pstore_ram.h>
37
38 #define RAMOOPS_KERNMSG_HDR "===="
39 #define MIN_MEM_SIZE 4096UL
40
41 static ulong record_size = MIN_MEM_SIZE;
42 module_param(record_size, ulong, 0400);
43 MODULE_PARM_DESC(record_size,
44                 "size of each dump done on oops/panic");
45
46 static ulong ramoops_console_size = MIN_MEM_SIZE;
47 module_param_named(console_size, ramoops_console_size, ulong, 0400);
48 MODULE_PARM_DESC(console_size, "size of kernel console log");
49
50 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
51 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
52 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
53
54 static ulong mem_address;
55 module_param(mem_address, ulong, 0400);
56 MODULE_PARM_DESC(mem_address,
57                 "start of reserved RAM used to store oops/panic logs");
58
59 static ulong mem_size;
60 module_param(mem_size, ulong, 0400);
61 MODULE_PARM_DESC(mem_size,
62                 "size of reserved RAM used to store oops/panic logs");
63
64 static int dump_oops = 1;
65 module_param(dump_oops, int, 0600);
66 MODULE_PARM_DESC(dump_oops,
67                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
68
69 static int ramoops_ecc;
70 module_param_named(ecc, ramoops_ecc, int, 0600);
71 MODULE_PARM_DESC(ramoops_ecc,
72                 "if non-zero, the option enables ECC support and specifies "
73                 "ECC buffer size in bytes (1 is a special value, means 16 "
74                 "bytes ECC)");
75
76 struct ramoops_context {
77         struct persistent_ram_zone **przs;
78         struct persistent_ram_zone *cprz;
79         struct persistent_ram_zone *fprz;
80         phys_addr_t phys_addr;
81         unsigned long size;
82         size_t record_size;
83         size_t console_size;
84         size_t ftrace_size;
85         int dump_oops;
86         int ecc_size;
87         unsigned int max_dump_cnt;
88         unsigned int dump_write_cnt;
89         unsigned int dump_read_cnt;
90         unsigned int console_read_cnt;
91         unsigned int ftrace_read_cnt;
92         struct pstore_info pstore;
93 };
94
95 static struct platform_device *dummy;
96 static struct ramoops_platform_data *dummy_data;
97
98 static int ramoops_pstore_open(struct pstore_info *psi)
99 {
100         struct ramoops_context *cxt = psi->data;
101
102         cxt->dump_read_cnt = 0;
103         cxt->console_read_cnt = 0;
104         return 0;
105 }
106
107 static struct persistent_ram_zone *
108 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
109                      u64 *id,
110                      enum pstore_type_id *typep, enum pstore_type_id type,
111                      bool update)
112 {
113         struct persistent_ram_zone *prz;
114         int i = (*c)++;
115
116         if (i >= max)
117                 return NULL;
118
119         prz = przs[i];
120
121         if (update) {
122                 /* Update old/shadowed buffer. */
123                 persistent_ram_save_old(prz);
124                 if (!persistent_ram_old_size(prz))
125                         return NULL;
126         }
127
128         *typep = type;
129         *id = i;
130
131         return prz;
132 }
133
134 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
135                                    int *count, struct timespec *time,
136                                    char **buf, struct pstore_info *psi)
137 {
138         ssize_t size;
139         struct ramoops_context *cxt = psi->data;
140         struct persistent_ram_zone *prz;
141
142         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
143                                    cxt->max_dump_cnt, id, type,
144                                    PSTORE_TYPE_DMESG, 1);
145         if (!prz)
146                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
147                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
148         if (!prz)
149                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
150                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
151         if (!prz)
152                 return 0;
153
154         /* TODO(kees): Bogus time for the moment. */
155         time->tv_sec = 0;
156         time->tv_nsec = 0;
157
158         size = persistent_ram_old_size(prz);
159         *buf = kmalloc(size, GFP_KERNEL);
160         if (*buf == NULL)
161                 return -ENOMEM;
162         memcpy(*buf, persistent_ram_old(prz), size);
163
164         return size;
165 }
166
167 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
168 {
169         char *hdr;
170         struct timeval timestamp;
171         size_t len;
172
173         do_gettimeofday(&timestamp);
174         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
175                 (long)timestamp.tv_sec, (long)timestamp.tv_usec);
176         WARN_ON_ONCE(!hdr);
177         len = hdr ? strlen(hdr) : 0;
178         persistent_ram_write(prz, hdr, len);
179         kfree(hdr);
180
181         return len;
182 }
183
184 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
185                                             enum kmsg_dump_reason reason,
186                                             u64 *id, unsigned int part,
187                                             const char *buf, size_t size,
188                                             struct pstore_info *psi)
189 {
190         struct ramoops_context *cxt = psi->data;
191         struct persistent_ram_zone *prz;
192         size_t hlen;
193
194         if (type == PSTORE_TYPE_CONSOLE) {
195                 if (!cxt->cprz)
196                         return -ENOMEM;
197                 persistent_ram_write(cxt->cprz, buf, size);
198                 return 0;
199         } else if (type == PSTORE_TYPE_FTRACE) {
200                 if (!cxt->fprz)
201                         return -ENOMEM;
202                 persistent_ram_write(cxt->fprz, buf, size);
203                 return 0;
204         }
205
206         if (type != PSTORE_TYPE_DMESG)
207                 return -EINVAL;
208
209         /* Out of the various dmesg dump types, ramoops is currently designed
210          * to only store crash logs, rather than storing general kernel logs.
211          */
212         if (reason != KMSG_DUMP_OOPS &&
213             reason != KMSG_DUMP_PANIC)
214                 return -EINVAL;
215
216         /* Skip Oopes when configured to do so. */
217         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
218                 return -EINVAL;
219
220         /* Explicitly only take the first part of any new crash.
221          * If our buffer is larger than kmsg_bytes, this can never happen,
222          * and if our buffer is smaller than kmsg_bytes, we don't want the
223          * report split across multiple records.
224          */
225         if (part != 1)
226                 return -ENOSPC;
227
228         if (!cxt->przs)
229                 return -ENOSPC;
230
231         prz = cxt->przs[cxt->dump_write_cnt];
232
233         hlen = ramoops_write_kmsg_hdr(prz);
234         if (size + hlen > prz->buffer_size)
235                 size = prz->buffer_size - hlen;
236         persistent_ram_write(prz, buf, size);
237
238         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
239
240         return 0;
241 }
242
243 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
244                                 struct timespec time, struct pstore_info *psi)
245 {
246         struct ramoops_context *cxt = psi->data;
247         struct persistent_ram_zone *prz;
248
249         switch (type) {
250         case PSTORE_TYPE_DMESG:
251                 if (id >= cxt->max_dump_cnt)
252                         return -EINVAL;
253                 prz = cxt->przs[id];
254                 break;
255         case PSTORE_TYPE_CONSOLE:
256                 prz = cxt->cprz;
257                 break;
258         case PSTORE_TYPE_FTRACE:
259                 prz = cxt->fprz;
260                 break;
261         default:
262                 return -EINVAL;
263         }
264
265         persistent_ram_free_old(prz);
266         persistent_ram_zap(prz);
267
268         return 0;
269 }
270
271 static struct ramoops_context oops_cxt = {
272         .pstore = {
273                 .owner  = THIS_MODULE,
274                 .name   = "ramoops",
275                 .open   = ramoops_pstore_open,
276                 .read   = ramoops_pstore_read,
277                 .write_buf      = ramoops_pstore_write_buf,
278                 .erase  = ramoops_pstore_erase,
279         },
280 };
281
282 static void ramoops_free_przs(struct ramoops_context *cxt)
283 {
284         int i;
285
286         if (!cxt->przs)
287                 return;
288
289         for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
290                 persistent_ram_free(cxt->przs[i]);
291         kfree(cxt->przs);
292 }
293
294 static int __devinit ramoops_init_przs(struct device *dev,
295                                        struct ramoops_context *cxt,
296                                        phys_addr_t *paddr, size_t dump_mem_sz)
297 {
298         int err = -ENOMEM;
299         int i;
300
301         if (!cxt->record_size)
302                 return 0;
303
304         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
305                 dev_err(dev, "no room for dumps\n");
306                 return -ENOMEM;
307         }
308
309         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
310         if (!cxt->max_dump_cnt)
311                 return -ENOMEM;
312
313         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
314                              GFP_KERNEL);
315         if (!cxt->przs) {
316                 dev_err(dev, "failed to initialize a prz array for dumps\n");
317                 return -ENOMEM;
318         }
319
320         for (i = 0; i < cxt->max_dump_cnt; i++) {
321                 size_t sz = cxt->record_size;
322
323                 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, cxt->ecc_size);
324                 if (IS_ERR(cxt->przs[i])) {
325                         err = PTR_ERR(cxt->przs[i]);
326                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
327                                 sz, (unsigned long long)*paddr, err);
328                         goto fail_prz;
329                 }
330                 *paddr += sz;
331         }
332
333         return 0;
334 fail_prz:
335         ramoops_free_przs(cxt);
336         return err;
337 }
338
339 static int __devinit ramoops_init_prz(struct device *dev,
340                                       struct ramoops_context *cxt,
341                                       struct persistent_ram_zone **prz,
342                                       phys_addr_t *paddr, size_t sz, u32 sig)
343 {
344         if (!sz)
345                 return 0;
346
347         if (*paddr + sz - cxt->phys_addr > cxt->size) {
348                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
349                         sz, (unsigned long long)*paddr,
350                         cxt->size, (unsigned long long)cxt->phys_addr);
351                 return -ENOMEM;
352         }
353
354         *prz = persistent_ram_new(*paddr, sz, sig, cxt->ecc_size);
355         if (IS_ERR(*prz)) {
356                 int err = PTR_ERR(*prz);
357
358                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
359                         sz, (unsigned long long)*paddr, err);
360                 return err;
361         }
362
363         persistent_ram_zap(*prz);
364
365         *paddr += sz;
366
367         return 0;
368 }
369
370 static int __devinit ramoops_probe(struct platform_device *pdev)
371 {
372         struct device *dev = &pdev->dev;
373         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
374         struct ramoops_context *cxt = &oops_cxt;
375         size_t dump_mem_sz;
376         phys_addr_t paddr;
377         int err = -EINVAL;
378
379         /* Only a single ramoops area allowed at a time, so fail extra
380          * probes.
381          */
382         if (cxt->max_dump_cnt)
383                 goto fail_out;
384
385         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
386                         !pdata->ftrace_size)) {
387                 pr_err("The memory size and the record/console size must be "
388                         "non-zero\n");
389                 goto fail_out;
390         }
391
392         if (!is_power_of_2(pdata->mem_size))
393                 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
394         if (!is_power_of_2(pdata->record_size))
395                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
396         if (!is_power_of_2(pdata->console_size))
397                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
398         if (!is_power_of_2(pdata->ftrace_size))
399                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
400
401         cxt->dump_read_cnt = 0;
402         cxt->size = pdata->mem_size;
403         cxt->phys_addr = pdata->mem_address;
404         cxt->record_size = pdata->record_size;
405         cxt->console_size = pdata->console_size;
406         cxt->ftrace_size = pdata->ftrace_size;
407         cxt->dump_oops = pdata->dump_oops;
408         cxt->ecc_size = pdata->ecc_size;
409
410         paddr = cxt->phys_addr;
411
412         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
413         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
414         if (err)
415                 goto fail_out;
416
417         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
418                                cxt->console_size, 0);
419         if (err)
420                 goto fail_init_cprz;
421
422         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
423                                LINUX_VERSION_CODE);
424         if (err)
425                 goto fail_init_fprz;
426
427         if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
428                 pr_err("memory size too small, minimum is %zu\n",
429                         cxt->console_size + cxt->record_size +
430                         cxt->ftrace_size);
431                 goto fail_cnt;
432         }
433
434         cxt->pstore.data = cxt;
435         /*
436          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
437          * have to handle dumps, we must have at least record_size buffer. And
438          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
439          * ZERO_SIZE_PTR).
440          */
441         if (cxt->console_size)
442                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
443         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
444         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
445         spin_lock_init(&cxt->pstore.buf_lock);
446         if (!cxt->pstore.buf) {
447                 pr_err("cannot allocate pstore buffer\n");
448                 goto fail_clear;
449         }
450
451         err = pstore_register(&cxt->pstore);
452         if (err) {
453                 pr_err("registering with pstore failed\n");
454                 goto fail_buf;
455         }
456
457         /*
458          * Update the module parameter variables as well so they are visible
459          * through /sys/module/ramoops/parameters/
460          */
461         mem_size = pdata->mem_size;
462         mem_address = pdata->mem_address;
463         record_size = pdata->record_size;
464         dump_oops = pdata->dump_oops;
465
466         pr_info("attached 0x%lx@0x%llx, ecc: %d\n",
467                 cxt->size, (unsigned long long)cxt->phys_addr,
468                 cxt->ecc_size);
469
470         return 0;
471
472 fail_buf:
473         kfree(cxt->pstore.buf);
474 fail_clear:
475         cxt->pstore.bufsize = 0;
476         cxt->max_dump_cnt = 0;
477 fail_cnt:
478         kfree(cxt->fprz);
479 fail_init_fprz:
480         kfree(cxt->cprz);
481 fail_init_cprz:
482         ramoops_free_przs(cxt);
483 fail_out:
484         return err;
485 }
486
487 static int __exit ramoops_remove(struct platform_device *pdev)
488 {
489 #if 0
490         /* TODO(kees): We cannot unload ramoops since pstore doesn't support
491          * unregistering yet.
492          */
493         struct ramoops_context *cxt = &oops_cxt;
494
495         iounmap(cxt->virt_addr);
496         release_mem_region(cxt->phys_addr, cxt->size);
497         cxt->max_dump_cnt = 0;
498
499         /* TODO(kees): When pstore supports unregistering, call it here. */
500         kfree(cxt->pstore.buf);
501         cxt->pstore.bufsize = 0;
502
503         return 0;
504 #endif
505         return -EBUSY;
506 }
507
508 static struct platform_driver ramoops_driver = {
509         .probe          = ramoops_probe,
510         .remove         = __exit_p(ramoops_remove),
511         .driver         = {
512                 .name   = "ramoops",
513                 .owner  = THIS_MODULE,
514         },
515 };
516
517 static void ramoops_register_dummy(void)
518 {
519         if (!mem_size)
520                 return;
521
522         pr_info("using module parameters\n");
523
524         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
525         if (!dummy_data) {
526                 pr_info("could not allocate pdata\n");
527                 return;
528         }
529
530         dummy_data->mem_size = mem_size;
531         dummy_data->mem_address = mem_address;
532         dummy_data->record_size = record_size;
533         dummy_data->console_size = ramoops_console_size;
534         dummy_data->ftrace_size = ramoops_ftrace_size;
535         dummy_data->dump_oops = dump_oops;
536         /*
537          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
538          * (using 1 byte for ECC isn't much of use anyway).
539          */
540         dummy_data->ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
541
542         dummy = platform_device_register_data(NULL, "ramoops", -1,
543                         dummy_data, sizeof(struct ramoops_platform_data));
544         if (IS_ERR(dummy)) {
545                 pr_info("could not create platform device: %ld\n",
546                         PTR_ERR(dummy));
547         }
548 }
549
550 static int __init ramoops_init(void)
551 {
552         ramoops_register_dummy();
553         return platform_driver_register(&ramoops_driver);
554 }
555 postcore_initcall(ramoops_init);
556
557 static void __exit ramoops_exit(void)
558 {
559         platform_driver_unregister(&ramoops_driver);
560         platform_device_unregister(dummy);
561         kfree(dummy_data);
562 }
563 module_exit(ramoops_exit);
564
565 MODULE_LICENSE("GPL");
566 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
567 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");