Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[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/time.h>
31 #include <linux/io.h>
32 #include <linux/ioport.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/compiler.h>
36 #include <linux/pstore_ram.h>
37 #include <linux/of.h>
38 #include <linux/of_address.h>
39
40 #define RAMOOPS_KERNMSG_HDR "===="
41 #define MIN_MEM_SIZE 4096UL
42
43 static ulong record_size = MIN_MEM_SIZE;
44 module_param(record_size, ulong, 0400);
45 MODULE_PARM_DESC(record_size,
46                 "size of each dump done on oops/panic");
47
48 static ulong ramoops_console_size = MIN_MEM_SIZE;
49 module_param_named(console_size, ramoops_console_size, ulong, 0400);
50 MODULE_PARM_DESC(console_size, "size of kernel console log");
51
52 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
53 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
54 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
55
56 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
57 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
58 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
59
60 static unsigned long long mem_address;
61 module_param(mem_address, ullong, 0400);
62 MODULE_PARM_DESC(mem_address,
63                 "start of reserved RAM used to store oops/panic logs");
64
65 static ulong mem_size;
66 module_param(mem_size, ulong, 0400);
67 MODULE_PARM_DESC(mem_size,
68                 "size of reserved RAM used to store oops/panic logs");
69
70 static unsigned int mem_type;
71 module_param(mem_type, uint, 0600);
72 MODULE_PARM_DESC(mem_type,
73                 "set to 1 to try to use unbuffered memory (default 0)");
74
75 static int dump_oops = 1;
76 module_param(dump_oops, int, 0600);
77 MODULE_PARM_DESC(dump_oops,
78                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
79
80 static int ramoops_ecc;
81 module_param_named(ecc, ramoops_ecc, int, 0600);
82 MODULE_PARM_DESC(ramoops_ecc,
83                 "if non-zero, the option enables ECC support and specifies "
84                 "ECC buffer size in bytes (1 is a special value, means 16 "
85                 "bytes ECC)");
86
87 struct ramoops_context {
88         struct persistent_ram_zone **przs;
89         struct persistent_ram_zone *cprz;
90         struct persistent_ram_zone *fprz;
91         struct persistent_ram_zone *mprz;
92         phys_addr_t phys_addr;
93         unsigned long size;
94         unsigned int memtype;
95         size_t record_size;
96         size_t console_size;
97         size_t ftrace_size;
98         size_t pmsg_size;
99         int dump_oops;
100         struct persistent_ram_ecc_info ecc_info;
101         unsigned int max_dump_cnt;
102         unsigned int dump_write_cnt;
103         /* _read_cnt need clear on ramoops_pstore_open */
104         unsigned int dump_read_cnt;
105         unsigned int console_read_cnt;
106         unsigned int ftrace_read_cnt;
107         unsigned int pmsg_read_cnt;
108         struct pstore_info pstore;
109 };
110
111 static struct platform_device *dummy;
112 static struct ramoops_platform_data *dummy_data;
113
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[], uint *c, uint max,
127                      u64 *id,
128                      enum pstore_type_id *typep, enum pstore_type_id type,
129                      bool update)
130 {
131         struct persistent_ram_zone *prz;
132         int i = (*c)++;
133
134         if (i >= max)
135                 return NULL;
136
137         prz = przs[i];
138         if (!prz)
139                 return NULL;
140
141         /* Update old/shadowed buffer. */
142         if (update)
143                 persistent_ram_save_old(prz);
144
145         if (!persistent_ram_old_size(prz))
146                 return NULL;
147
148         *typep = type;
149         *id = i;
150
151         return prz;
152 }
153
154 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
155                                   bool *compressed)
156 {
157         char data_type;
158         int header_length = 0;
159
160         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
161                         &time->tv_nsec, &data_type, &header_length) == 3) {
162                 if (data_type == 'C')
163                         *compressed = true;
164                 else
165                         *compressed = false;
166         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
167                         &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
168                         *compressed = false;
169         } else {
170                 time->tv_sec = 0;
171                 time->tv_nsec = 0;
172                 *compressed = false;
173         }
174         return header_length;
175 }
176
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 ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
184                                    int *count, struct timespec *time,
185                                    char **buf, bool *compressed,
186                                    ssize_t *ecc_notice_size,
187                                    struct pstore_info *psi)
188 {
189         ssize_t size;
190         struct ramoops_context *cxt = psi->data;
191         struct persistent_ram_zone *prz = NULL;
192         int header_length = 0;
193
194         /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
195          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
196          * valid time stamps, so it is initialized to zero.
197          */
198         time->tv_sec = 0;
199         time->tv_nsec = 0;
200         *compressed = false;
201
202         /* Find the next valid persistent_ram_zone for DMESG */
203         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
204                 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
205                                            cxt->max_dump_cnt, id, type,
206                                            PSTORE_TYPE_DMESG, 1);
207                 if (!prz_ok(prz))
208                         continue;
209                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
210                                                       time, compressed);
211                 /* Clear and skip this DMESG record if it has no valid header */
212                 if (!header_length) {
213                         persistent_ram_free_old(prz);
214                         persistent_ram_zap(prz);
215                         prz = NULL;
216                 }
217         }
218
219         if (!prz_ok(prz))
220                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
221                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
222         if (!prz_ok(prz))
223                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
224                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
225         if (!prz_ok(prz))
226                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
227                                            1, id, type, PSTORE_TYPE_PMSG, 0);
228         if (!prz_ok(prz))
229                 return 0;
230
231         size = persistent_ram_old_size(prz) - header_length;
232
233         /* ECC correction notice */
234         *ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
235
236         *buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
237         if (*buf == NULL)
238                 return -ENOMEM;
239
240         memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
241         persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
242
243         return size;
244 }
245
246 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
247                                      bool compressed)
248 {
249         char *hdr;
250         struct timespec timestamp;
251         size_t len;
252
253         /* Report zeroed timestamp if called before timekeeping has resumed. */
254         if (__getnstimeofday(&timestamp)) {
255                 timestamp.tv_sec = 0;
256                 timestamp.tv_nsec = 0;
257         }
258         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
259                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
260                 compressed ? 'C' : 'D');
261         WARN_ON_ONCE(!hdr);
262         len = hdr ? strlen(hdr) : 0;
263         persistent_ram_write(prz, hdr, len);
264         kfree(hdr);
265
266         return len;
267 }
268
269 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
270                                             enum kmsg_dump_reason reason,
271                                             u64 *id, unsigned int part,
272                                             const char *buf,
273                                             bool compressed, size_t size,
274                                             struct pstore_info *psi)
275 {
276         struct ramoops_context *cxt = psi->data;
277         struct persistent_ram_zone *prz;
278         size_t hlen;
279
280         if (type == PSTORE_TYPE_CONSOLE) {
281                 if (!cxt->cprz)
282                         return -ENOMEM;
283                 persistent_ram_write(cxt->cprz, buf, size);
284                 return 0;
285         } else if (type == PSTORE_TYPE_FTRACE) {
286                 if (!cxt->fprz)
287                         return -ENOMEM;
288                 persistent_ram_write(cxt->fprz, buf, size);
289                 return 0;
290         } else if (type == PSTORE_TYPE_PMSG) {
291                 if (!cxt->mprz)
292                         return -ENOMEM;
293                 persistent_ram_write(cxt->mprz, buf, size);
294                 return 0;
295         }
296
297         if (type != PSTORE_TYPE_DMESG)
298                 return -EINVAL;
299
300         /* Out of the various dmesg dump types, ramoops is currently designed
301          * to only store crash logs, rather than storing general kernel logs.
302          */
303         if (reason != KMSG_DUMP_OOPS &&
304             reason != KMSG_DUMP_PANIC)
305                 return -EINVAL;
306
307         /* Skip Oopes when configured to do so. */
308         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
309                 return -EINVAL;
310
311         /* Explicitly only take the first part of any new crash.
312          * If our buffer is larger than kmsg_bytes, this can never happen,
313          * and if our buffer is smaller than kmsg_bytes, we don't want the
314          * report split across multiple records.
315          */
316         if (part != 1)
317                 return -ENOSPC;
318
319         if (!cxt->przs)
320                 return -ENOSPC;
321
322         prz = cxt->przs[cxt->dump_write_cnt];
323
324         hlen = ramoops_write_kmsg_hdr(prz, compressed);
325         if (size + hlen > prz->buffer_size)
326                 size = prz->buffer_size - hlen;
327         persistent_ram_write(prz, buf, size);
328
329         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
330
331         return 0;
332 }
333
334 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
335                                 struct timespec time, struct pstore_info *psi)
336 {
337         struct ramoops_context *cxt = psi->data;
338         struct persistent_ram_zone *prz;
339
340         switch (type) {
341         case PSTORE_TYPE_DMESG:
342                 if (id >= cxt->max_dump_cnt)
343                         return -EINVAL;
344                 prz = cxt->przs[id];
345                 break;
346         case PSTORE_TYPE_CONSOLE:
347                 prz = cxt->cprz;
348                 break;
349         case PSTORE_TYPE_FTRACE:
350                 prz = cxt->fprz;
351                 break;
352         case PSTORE_TYPE_PMSG:
353                 prz = cxt->mprz;
354                 break;
355         default:
356                 return -EINVAL;
357         }
358
359         persistent_ram_free_old(prz);
360         persistent_ram_zap(prz);
361
362         return 0;
363 }
364
365 static struct ramoops_context oops_cxt = {
366         .pstore = {
367                 .owner  = THIS_MODULE,
368                 .name   = "ramoops",
369                 .open   = ramoops_pstore_open,
370                 .read   = ramoops_pstore_read,
371                 .write_buf      = ramoops_pstore_write_buf,
372                 .erase  = ramoops_pstore_erase,
373         },
374 };
375
376 static void ramoops_free_przs(struct ramoops_context *cxt)
377 {
378         int i;
379
380         cxt->max_dump_cnt = 0;
381         if (!cxt->przs)
382                 return;
383
384         for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
385                 persistent_ram_free(cxt->przs[i]);
386         kfree(cxt->przs);
387 }
388
389 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
390                              phys_addr_t *paddr, size_t dump_mem_sz)
391 {
392         int err = -ENOMEM;
393         int i;
394
395         if (!cxt->record_size)
396                 return 0;
397
398         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
399                 dev_err(dev, "no room for dumps\n");
400                 return -ENOMEM;
401         }
402
403         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
404         if (!cxt->max_dump_cnt)
405                 return -ENOMEM;
406
407         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
408                              GFP_KERNEL);
409         if (!cxt->przs) {
410                 dev_err(dev, "failed to initialize a prz array for dumps\n");
411                 goto fail_prz;
412         }
413
414         for (i = 0; i < cxt->max_dump_cnt; i++) {
415                 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
416                                                   &cxt->ecc_info,
417                                                   cxt->memtype);
418                 if (IS_ERR(cxt->przs[i])) {
419                         err = PTR_ERR(cxt->przs[i]);
420                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
421                                 cxt->record_size, (unsigned long long)*paddr, err);
422                         goto fail_prz;
423                 }
424                 *paddr += cxt->record_size;
425         }
426
427         return 0;
428 fail_prz:
429         ramoops_free_przs(cxt);
430         return err;
431 }
432
433 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
434                             struct persistent_ram_zone **prz,
435                             phys_addr_t *paddr, size_t sz, u32 sig)
436 {
437         if (!sz)
438                 return 0;
439
440         if (*paddr + sz - cxt->phys_addr > cxt->size) {
441                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
442                         sz, (unsigned long long)*paddr,
443                         cxt->size, (unsigned long long)cxt->phys_addr);
444                 return -ENOMEM;
445         }
446
447         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
448         if (IS_ERR(*prz)) {
449                 int err = PTR_ERR(*prz);
450
451                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
452                         sz, (unsigned long long)*paddr, err);
453                 return err;
454         }
455
456         persistent_ram_zap(*prz);
457
458         *paddr += sz;
459
460         return 0;
461 }
462
463 static int ramoops_parse_dt_size(struct platform_device *pdev,
464                                  const char *propname, u32 *value)
465 {
466         u32 val32 = 0;
467         int ret;
468
469         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
470         if (ret < 0 && ret != -EINVAL) {
471                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
472                         propname, ret);
473                 return ret;
474         }
475
476         if (val32 > INT_MAX) {
477                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
478                 return -EOVERFLOW;
479         }
480
481         *value = val32;
482         return 0;
483 }
484
485 static int ramoops_parse_dt(struct platform_device *pdev,
486                             struct ramoops_platform_data *pdata)
487 {
488         struct device_node *of_node = pdev->dev.of_node;
489         struct device_node *mem_region;
490         struct resource res;
491         u32 value;
492         int ret;
493
494         dev_dbg(&pdev->dev, "using Device Tree\n");
495
496         mem_region = of_parse_phandle(of_node, "memory-region", 0);
497         if (!mem_region) {
498                 dev_err(&pdev->dev, "no memory-region phandle\n");
499                 return -ENODEV;
500         }
501
502         ret = of_address_to_resource(mem_region, 0, &res);
503         of_node_put(mem_region);
504         if (ret) {
505                 dev_err(&pdev->dev,
506                         "failed to translate memory-region to resource: %d\n",
507                         ret);
508                 return ret;
509         }
510
511         pdata->mem_size = resource_size(&res);
512         pdata->mem_address = res.start;
513         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
514         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
515
516 #define parse_size(name, field) {                                       \
517                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
518                 if (ret < 0)                                            \
519                         return ret;                                     \
520                 field = value;                                          \
521         }
522
523         parse_size("record-size", pdata->record_size);
524         parse_size("console-size", pdata->console_size);
525         parse_size("ftrace-size", pdata->ftrace_size);
526         parse_size("pmsg-size", pdata->pmsg_size);
527         parse_size("ecc-size", pdata->ecc_info.ecc_size);
528
529 #undef parse_size
530
531         return 0;
532 }
533
534 static int ramoops_probe(struct platform_device *pdev)
535 {
536         struct device *dev = &pdev->dev;
537         struct ramoops_platform_data *pdata = dev->platform_data;
538         struct ramoops_context *cxt = &oops_cxt;
539         size_t dump_mem_sz;
540         phys_addr_t paddr;
541         int err = -EINVAL;
542
543         if (dev_of_node(dev) && !pdata) {
544                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
545                 if (!pdata) {
546                         err = -ENOMEM;
547                         goto fail_out;
548                 }
549
550                 err = ramoops_parse_dt(pdev, pdata);
551                 if (err < 0)
552                         goto fail_out;
553         }
554
555         /* Only a single ramoops area allowed at a time, so fail extra
556          * probes.
557          */
558         if (cxt->max_dump_cnt)
559                 goto fail_out;
560
561         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
562                         !pdata->ftrace_size && !pdata->pmsg_size)) {
563                 pr_err("The memory size and the record/console size must be "
564                         "non-zero\n");
565                 goto fail_out;
566         }
567
568         if (pdata->record_size && !is_power_of_2(pdata->record_size))
569                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
570         if (pdata->console_size && !is_power_of_2(pdata->console_size))
571                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
572         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
573                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
574         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
575                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
576
577         cxt->size = pdata->mem_size;
578         cxt->phys_addr = pdata->mem_address;
579         cxt->memtype = pdata->mem_type;
580         cxt->record_size = pdata->record_size;
581         cxt->console_size = pdata->console_size;
582         cxt->ftrace_size = pdata->ftrace_size;
583         cxt->pmsg_size = pdata->pmsg_size;
584         cxt->dump_oops = pdata->dump_oops;
585         cxt->ecc_info = pdata->ecc_info;
586
587         paddr = cxt->phys_addr;
588
589         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
590                         - cxt->pmsg_size;
591         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
592         if (err)
593                 goto fail_out;
594
595         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
596                                cxt->console_size, 0);
597         if (err)
598                 goto fail_init_cprz;
599
600         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
601                                LINUX_VERSION_CODE);
602         if (err)
603                 goto fail_init_fprz;
604
605         err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
606         if (err)
607                 goto fail_init_mprz;
608
609         cxt->pstore.data = cxt;
610         /*
611          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
612          * have to handle dumps, we must have at least record_size buffer. And
613          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
614          * ZERO_SIZE_PTR).
615          */
616         if (cxt->console_size)
617                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
618         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
619         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
620         spin_lock_init(&cxt->pstore.buf_lock);
621         if (!cxt->pstore.buf) {
622                 pr_err("cannot allocate pstore buffer\n");
623                 err = -ENOMEM;
624                 goto fail_clear;
625         }
626
627         err = pstore_register(&cxt->pstore);
628         if (err) {
629                 pr_err("registering with pstore failed\n");
630                 goto fail_buf;
631         }
632
633         /*
634          * Update the module parameter variables as well so they are visible
635          * through /sys/module/ramoops/parameters/
636          */
637         mem_size = pdata->mem_size;
638         mem_address = pdata->mem_address;
639         record_size = pdata->record_size;
640         dump_oops = pdata->dump_oops;
641         ramoops_console_size = pdata->console_size;
642         ramoops_pmsg_size = pdata->pmsg_size;
643         ramoops_ftrace_size = pdata->ftrace_size;
644
645         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
646                 cxt->size, (unsigned long long)cxt->phys_addr,
647                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
648
649         return 0;
650
651 fail_buf:
652         kfree(cxt->pstore.buf);
653 fail_clear:
654         cxt->pstore.bufsize = 0;
655         kfree(cxt->mprz);
656 fail_init_mprz:
657         kfree(cxt->fprz);
658 fail_init_fprz:
659         kfree(cxt->cprz);
660 fail_init_cprz:
661         ramoops_free_przs(cxt);
662 fail_out:
663         return err;
664 }
665
666 static int ramoops_remove(struct platform_device *pdev)
667 {
668         struct ramoops_context *cxt = &oops_cxt;
669
670         pstore_unregister(&cxt->pstore);
671         cxt->max_dump_cnt = 0;
672
673         kfree(cxt->pstore.buf);
674         cxt->pstore.bufsize = 0;
675
676         persistent_ram_free(cxt->mprz);
677         persistent_ram_free(cxt->fprz);
678         persistent_ram_free(cxt->cprz);
679         ramoops_free_przs(cxt);
680
681         return 0;
682 }
683
684 static const struct of_device_id dt_match[] = {
685         { .compatible = "ramoops" },
686         {}
687 };
688
689 static struct platform_driver ramoops_driver = {
690         .probe          = ramoops_probe,
691         .remove         = ramoops_remove,
692         .driver         = {
693                 .name           = "ramoops",
694                 .of_match_table = dt_match,
695         },
696 };
697
698 static void ramoops_register_dummy(void)
699 {
700         if (!mem_size)
701                 return;
702
703         pr_info("using module parameters\n");
704
705         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
706         if (!dummy_data) {
707                 pr_info("could not allocate pdata\n");
708                 return;
709         }
710
711         dummy_data->mem_size = mem_size;
712         dummy_data->mem_address = mem_address;
713         dummy_data->mem_type = mem_type;
714         dummy_data->record_size = record_size;
715         dummy_data->console_size = ramoops_console_size;
716         dummy_data->ftrace_size = ramoops_ftrace_size;
717         dummy_data->pmsg_size = ramoops_pmsg_size;
718         dummy_data->dump_oops = dump_oops;
719         /*
720          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
721          * (using 1 byte for ECC isn't much of use anyway).
722          */
723         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
724
725         dummy = platform_device_register_data(NULL, "ramoops", -1,
726                         dummy_data, sizeof(struct ramoops_platform_data));
727         if (IS_ERR(dummy)) {
728                 pr_info("could not create platform device: %ld\n",
729                         PTR_ERR(dummy));
730         }
731 }
732
733 static int __init ramoops_init(void)
734 {
735         ramoops_register_dummy();
736         return platform_driver_register(&ramoops_driver);
737 }
738 postcore_initcall(ramoops_init);
739
740 static void __exit ramoops_exit(void)
741 {
742         platform_driver_unregister(&ramoops_driver);
743         platform_device_unregister(dummy);
744         kfree(dummy_data);
745 }
746 module_exit(ramoops_exit);
747
748 MODULE_LICENSE("GPL");
749 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
750 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");