Merge tag 'dmaengine-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw...
[cascardo/linux.git] / arch / powerpc / platforms / powernv / opal-dump.c
1 /*
2  * PowerNV OPAL Dump Interface
3  *
4  * Copyright 2013,2014 IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11
12 #include <linux/kobject.h>
13 #include <linux/mm.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
16 #include <linux/pagemap.h>
17 #include <linux/delay.h>
18
19 #include <asm/opal.h>
20
21 #define DUMP_TYPE_FSP   0x01
22
23 struct dump_obj {
24         struct kobject  kobj;
25         struct bin_attribute dump_attr;
26         uint32_t        id;  /* becomes object name */
27         uint32_t        type;
28         uint32_t        size;
29         char            *buffer;
30 };
31 #define to_dump_obj(x) container_of(x, struct dump_obj, kobj)
32
33 struct dump_attribute {
34         struct attribute attr;
35         ssize_t (*show)(struct dump_obj *dump, struct dump_attribute *attr,
36                         char *buf);
37         ssize_t (*store)(struct dump_obj *dump, struct dump_attribute *attr,
38                          const char *buf, size_t count);
39 };
40 #define to_dump_attr(x) container_of(x, struct dump_attribute, attr)
41
42 static ssize_t dump_id_show(struct dump_obj *dump_obj,
43                             struct dump_attribute *attr,
44                             char *buf)
45 {
46         return sprintf(buf, "0x%x\n", dump_obj->id);
47 }
48
49 static const char* dump_type_to_string(uint32_t type)
50 {
51         switch (type) {
52         case 0x01: return "SP Dump";
53         case 0x02: return "System/Platform Dump";
54         case 0x03: return "SMA Dump";
55         default: return "unknown";
56         }
57 }
58
59 static ssize_t dump_type_show(struct dump_obj *dump_obj,
60                               struct dump_attribute *attr,
61                               char *buf)
62 {
63         
64         return sprintf(buf, "0x%x %s\n", dump_obj->type,
65                        dump_type_to_string(dump_obj->type));
66 }
67
68 static ssize_t dump_ack_show(struct dump_obj *dump_obj,
69                              struct dump_attribute *attr,
70                              char *buf)
71 {
72         return sprintf(buf, "ack - acknowledge dump\n");
73 }
74
75 /*
76  * Send acknowledgement to OPAL
77  */
78 static int64_t dump_send_ack(uint32_t dump_id)
79 {
80         int rc;
81
82         rc = opal_dump_ack(dump_id);
83         if (rc)
84                 pr_warn("%s: Failed to send ack to Dump ID 0x%x (%d)\n",
85                         __func__, dump_id, rc);
86         return rc;
87 }
88
89 static ssize_t dump_ack_store(struct dump_obj *dump_obj,
90                               struct dump_attribute *attr,
91                               const char *buf,
92                               size_t count)
93 {
94         dump_send_ack(dump_obj->id);
95         sysfs_remove_file_self(&dump_obj->kobj, &attr->attr);
96         kobject_put(&dump_obj->kobj);
97         return count;
98 }
99
100 /* Attributes of a dump
101  * The binary attribute of the dump itself is dynamic
102  * due to the dynamic size of the dump
103  */
104 static struct dump_attribute id_attribute =
105         __ATTR(id, S_IRUGO, dump_id_show, NULL);
106 static struct dump_attribute type_attribute =
107         __ATTR(type, S_IRUGO, dump_type_show, NULL);
108 static struct dump_attribute ack_attribute =
109         __ATTR(acknowledge, 0660, dump_ack_show, dump_ack_store);
110
111 static ssize_t init_dump_show(struct dump_obj *dump_obj,
112                               struct dump_attribute *attr,
113                               char *buf)
114 {
115         return sprintf(buf, "1 - initiate dump\n");
116 }
117
118 static int64_t dump_fips_init(uint8_t type)
119 {
120         int rc;
121
122         rc = opal_dump_init(type);
123         if (rc)
124                 pr_warn("%s: Failed to initiate FipS dump (%d)\n",
125                         __func__, rc);
126         return rc;
127 }
128
129 static ssize_t init_dump_store(struct dump_obj *dump_obj,
130                                struct dump_attribute *attr,
131                                const char *buf,
132                                size_t count)
133 {
134         dump_fips_init(DUMP_TYPE_FSP);
135         pr_info("%s: Initiated FSP dump\n", __func__);
136         return count;
137 }
138
139 static struct dump_attribute initiate_attribute =
140         __ATTR(initiate_dump, 0600, init_dump_show, init_dump_store);
141
142 static struct attribute *initiate_attrs[] = {
143         &initiate_attribute.attr,
144         NULL,
145 };
146
147 static struct attribute_group initiate_attr_group = {
148         .attrs = initiate_attrs,
149 };
150
151 static struct kset *dump_kset;
152
153 static ssize_t dump_attr_show(struct kobject *kobj,
154                               struct attribute *attr,
155                               char *buf)
156 {
157         struct dump_attribute *attribute;
158         struct dump_obj *dump;
159
160         attribute = to_dump_attr(attr);
161         dump = to_dump_obj(kobj);
162
163         if (!attribute->show)
164                 return -EIO;
165
166         return attribute->show(dump, attribute, buf);
167 }
168
169 static ssize_t dump_attr_store(struct kobject *kobj,
170                                struct attribute *attr,
171                                const char *buf, size_t len)
172 {
173         struct dump_attribute *attribute;
174         struct dump_obj *dump;
175
176         attribute = to_dump_attr(attr);
177         dump = to_dump_obj(kobj);
178
179         if (!attribute->store)
180                 return -EIO;
181
182         return attribute->store(dump, attribute, buf, len);
183 }
184
185 static const struct sysfs_ops dump_sysfs_ops = {
186         .show = dump_attr_show,
187         .store = dump_attr_store,
188 };
189
190 static void dump_release(struct kobject *kobj)
191 {
192         struct dump_obj *dump;
193
194         dump = to_dump_obj(kobj);
195         vfree(dump->buffer);
196         kfree(dump);
197 }
198
199 static struct attribute *dump_default_attrs[] = {
200         &id_attribute.attr,
201         &type_attribute.attr,
202         &ack_attribute.attr,
203         NULL,
204 };
205
206 static struct kobj_type dump_ktype = {
207         .sysfs_ops = &dump_sysfs_ops,
208         .release = &dump_release,
209         .default_attrs = dump_default_attrs,
210 };
211
212 static int64_t dump_read_info(uint32_t *dump_id, uint32_t *dump_size, uint32_t *dump_type)
213 {
214         __be32 id, size, type;
215         int rc;
216
217         type = cpu_to_be32(0xffffffff);
218
219         rc = opal_dump_info2(&id, &size, &type);
220         if (rc == OPAL_PARAMETER)
221                 rc = opal_dump_info(&id, &size);
222
223         *dump_id = be32_to_cpu(id);
224         *dump_size = be32_to_cpu(size);
225         *dump_type = be32_to_cpu(type);
226
227         if (rc)
228                 pr_warn("%s: Failed to get dump info (%d)\n",
229                         __func__, rc);
230         return rc;
231 }
232
233 static int64_t dump_read_data(struct dump_obj *dump)
234 {
235         struct opal_sg_list *list;
236         uint64_t addr;
237         int64_t rc;
238
239         /* Allocate memory */
240         dump->buffer = vzalloc(PAGE_ALIGN(dump->size));
241         if (!dump->buffer) {
242                 pr_err("%s : Failed to allocate memory\n", __func__);
243                 rc = -ENOMEM;
244                 goto out;
245         }
246
247         /* Generate SG list */
248         list = opal_vmalloc_to_sg_list(dump->buffer, dump->size);
249         if (!list) {
250                 rc = -ENOMEM;
251                 goto out;
252         }
253
254         /* First entry address */
255         addr = __pa(list);
256
257         /* Fetch data */
258         rc = OPAL_BUSY_EVENT;
259         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
260                 rc = opal_dump_read(dump->id, addr);
261                 if (rc == OPAL_BUSY_EVENT) {
262                         opal_poll_events(NULL);
263                         msleep(20);
264                 }
265         }
266
267         if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL)
268                 pr_warn("%s: Extract dump failed for ID 0x%x\n",
269                         __func__, dump->id);
270
271         /* Free SG list */
272         opal_free_sg_list(list);
273
274 out:
275         return rc;
276 }
277
278 static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj,
279                               struct bin_attribute *bin_attr,
280                               char *buffer, loff_t pos, size_t count)
281 {
282         ssize_t rc;
283
284         struct dump_obj *dump = to_dump_obj(kobj);
285
286         if (!dump->buffer) {
287                 rc = dump_read_data(dump);
288
289                 if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
290                         vfree(dump->buffer);
291                         dump->buffer = NULL;
292
293                         return -EIO;
294                 }
295                 if (rc == OPAL_PARTIAL) {
296                         /* On a partial read, we just return EIO
297                          * and rely on userspace to ask us to try
298                          * again.
299                          */
300                         pr_info("%s: Platform dump partially read.ID = 0x%x\n",
301                                 __func__, dump->id);
302                         return -EIO;
303                 }
304         }
305
306         memcpy(buffer, dump->buffer + pos, count);
307
308         /* You may think we could free the dump buffer now and retrieve
309          * it again later if needed, but due to current firmware limitation,
310          * that's not the case. So, once read into userspace once,
311          * we keep the dump around until it's acknowledged by userspace.
312          */
313
314         return count;
315 }
316
317 static struct dump_obj *create_dump_obj(uint32_t id, size_t size,
318                                         uint32_t type)
319 {
320         struct dump_obj *dump;
321         int rc;
322
323         dump = kzalloc(sizeof(*dump), GFP_KERNEL);
324         if (!dump)
325                 return NULL;
326
327         dump->kobj.kset = dump_kset;
328
329         kobject_init(&dump->kobj, &dump_ktype);
330
331         sysfs_bin_attr_init(&dump->dump_attr);
332
333         dump->dump_attr.attr.name = "dump";
334         dump->dump_attr.attr.mode = 0400;
335         dump->dump_attr.size = size;
336         dump->dump_attr.read = dump_attr_read;
337
338         dump->id = id;
339         dump->size = size;
340         dump->type = type;
341
342         rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id);
343         if (rc) {
344                 kobject_put(&dump->kobj);
345                 return NULL;
346         }
347
348         rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr);
349         if (rc) {
350                 kobject_put(&dump->kobj);
351                 return NULL;
352         }
353
354         pr_info("%s: New platform dump. ID = 0x%x Size %u\n",
355                 __func__, dump->id, dump->size);
356
357         kobject_uevent(&dump->kobj, KOBJ_ADD);
358
359         return dump;
360 }
361
362 static int process_dump(void)
363 {
364         int rc;
365         uint32_t dump_id, dump_size, dump_type;
366         struct dump_obj *dump;
367         char name[22];
368
369         rc = dump_read_info(&dump_id, &dump_size, &dump_type);
370         if (rc != OPAL_SUCCESS)
371                 return rc;
372
373         sprintf(name, "0x%x-0x%x", dump_type, dump_id);
374
375         /* we may get notified twice, let's handle
376          * that gracefully and not create two conflicting
377          * entries.
378          */
379         if (kset_find_obj(dump_kset, name))
380                 return 0;
381
382         dump = create_dump_obj(dump_id, dump_size, dump_type);
383         if (!dump)
384                 return -1;
385
386         return 0;
387 }
388
389 static void dump_work_fn(struct work_struct *work)
390 {
391         process_dump();
392 }
393
394 static DECLARE_WORK(dump_work, dump_work_fn);
395
396 static void schedule_process_dump(void)
397 {
398         schedule_work(&dump_work);
399 }
400
401 /*
402  * New dump available notification
403  *
404  * Once we get notification, we add sysfs entries for it.
405  * We only fetch the dump on demand, and create sysfs asynchronously.
406  */
407 static int dump_event(struct notifier_block *nb,
408                       unsigned long events, void *change)
409 {
410         if (events & OPAL_EVENT_DUMP_AVAIL)
411                 schedule_process_dump();
412
413         return 0;
414 }
415
416 static struct notifier_block dump_nb = {
417         .notifier_call  = dump_event,
418         .next           = NULL,
419         .priority       = 0
420 };
421
422 void __init opal_platform_dump_init(void)
423 {
424         int rc;
425
426         dump_kset = kset_create_and_add("dump", NULL, opal_kobj);
427         if (!dump_kset) {
428                 pr_warn("%s: Failed to create dump kset\n", __func__);
429                 return;
430         }
431
432         rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group);
433         if (rc) {
434                 pr_warn("%s: Failed to create initiate dump attr group\n",
435                         __func__);
436                 kobject_put(&dump_kset->kobj);
437                 return;
438         }
439
440         rc = opal_notifier_register(&dump_nb);
441         if (rc) {
442                 pr_warn("%s: Can't register OPAL event notifier (%d)\n",
443                         __func__, rc);
444                 return;
445         }
446
447         opal_dump_resend_notification();
448 }