Merge remote-tracking branch 'asoc/topic/core' into asoc-next
[linux-2.6-block.git] / arch / powerpc / platforms / powernv / opal-elog.c
1 /*
2  * Error log support on PowerNV.
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 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/of.h>
15 #include <linux/slab.h>
16 #include <linux/sysfs.h>
17 #include <linux/fs.h>
18 #include <linux/vmalloc.h>
19 #include <linux/fcntl.h>
20 #include <linux/kobject.h>
21 #include <asm/uaccess.h>
22 #include <asm/opal.h>
23
24 struct elog_obj {
25         struct kobject kobj;
26         struct bin_attribute raw_attr;
27         uint64_t id;
28         uint64_t type;
29         size_t size;
30         char *buffer;
31 };
32 #define to_elog_obj(x) container_of(x, struct elog_obj, kobj)
33
34 struct elog_attribute {
35         struct attribute attr;
36         ssize_t (*show)(struct elog_obj *elog, struct elog_attribute *attr,
37                         char *buf);
38         ssize_t (*store)(struct elog_obj *elog, struct elog_attribute *attr,
39                          const char *buf, size_t count);
40 };
41 #define to_elog_attr(x) container_of(x, struct elog_attribute, attr)
42
43 static ssize_t elog_id_show(struct elog_obj *elog_obj,
44                             struct elog_attribute *attr,
45                             char *buf)
46 {
47         return sprintf(buf, "0x%llx\n", elog_obj->id);
48 }
49
50 static const char *elog_type_to_string(uint64_t type)
51 {
52         switch (type) {
53         case 0: return "PEL";
54         default: return "unknown";
55         }
56 }
57
58 static ssize_t elog_type_show(struct elog_obj *elog_obj,
59                               struct elog_attribute *attr,
60                               char *buf)
61 {
62         return sprintf(buf, "0x%llx %s\n",
63                        elog_obj->type,
64                        elog_type_to_string(elog_obj->type));
65 }
66
67 static ssize_t elog_ack_show(struct elog_obj *elog_obj,
68                              struct elog_attribute *attr,
69                              char *buf)
70 {
71         return sprintf(buf, "ack - acknowledge log message\n");
72 }
73
74 static ssize_t elog_ack_store(struct elog_obj *elog_obj,
75                               struct elog_attribute *attr,
76                               const char *buf,
77                               size_t count)
78 {
79         opal_send_ack_elog(elog_obj->id);
80         sysfs_remove_file_self(&elog_obj->kobj, &attr->attr);
81         kobject_put(&elog_obj->kobj);
82         return count;
83 }
84
85 static struct elog_attribute id_attribute =
86         __ATTR(id, S_IRUGO, elog_id_show, NULL);
87 static struct elog_attribute type_attribute =
88         __ATTR(type, S_IRUGO, elog_type_show, NULL);
89 static struct elog_attribute ack_attribute =
90         __ATTR(acknowledge, 0660, elog_ack_show, elog_ack_store);
91
92 static struct kset *elog_kset;
93
94 static ssize_t elog_attr_show(struct kobject *kobj,
95                               struct attribute *attr,
96                               char *buf)
97 {
98         struct elog_attribute *attribute;
99         struct elog_obj *elog;
100
101         attribute = to_elog_attr(attr);
102         elog = to_elog_obj(kobj);
103
104         if (!attribute->show)
105                 return -EIO;
106
107         return attribute->show(elog, attribute, buf);
108 }
109
110 static ssize_t elog_attr_store(struct kobject *kobj,
111                                struct attribute *attr,
112                                const char *buf, size_t len)
113 {
114         struct elog_attribute *attribute;
115         struct elog_obj *elog;
116
117         attribute = to_elog_attr(attr);
118         elog = to_elog_obj(kobj);
119
120         if (!attribute->store)
121                 return -EIO;
122
123         return attribute->store(elog, attribute, buf, len);
124 }
125
126 static const struct sysfs_ops elog_sysfs_ops = {
127         .show = elog_attr_show,
128         .store = elog_attr_store,
129 };
130
131 static void elog_release(struct kobject *kobj)
132 {
133         struct elog_obj *elog;
134
135         elog = to_elog_obj(kobj);
136         kfree(elog->buffer);
137         kfree(elog);
138 }
139
140 static struct attribute *elog_default_attrs[] = {
141         &id_attribute.attr,
142         &type_attribute.attr,
143         &ack_attribute.attr,
144         NULL,
145 };
146
147 static struct kobj_type elog_ktype = {
148         .sysfs_ops = &elog_sysfs_ops,
149         .release = &elog_release,
150         .default_attrs = elog_default_attrs,
151 };
152
153 /* Maximum size of a single log on FSP is 16KB */
154 #define OPAL_MAX_ERRLOG_SIZE    16384
155
156 static ssize_t raw_attr_read(struct file *filep, struct kobject *kobj,
157                              struct bin_attribute *bin_attr,
158                              char *buffer, loff_t pos, size_t count)
159 {
160         int opal_rc;
161
162         struct elog_obj *elog = to_elog_obj(kobj);
163
164         /* We may have had an error reading before, so let's retry */
165         if (!elog->buffer) {
166                 elog->buffer = kzalloc(elog->size, GFP_KERNEL);
167                 if (!elog->buffer)
168                         return -EIO;
169
170                 opal_rc = opal_read_elog(__pa(elog->buffer),
171                                          elog->size, elog->id);
172                 if (opal_rc != OPAL_SUCCESS) {
173                         pr_err("ELOG: log read failed for log-id=%llx\n",
174                                elog->id);
175                         kfree(elog->buffer);
176                         elog->buffer = NULL;
177                         return -EIO;
178                 }
179         }
180
181         memcpy(buffer, elog->buffer + pos, count);
182
183         return count;
184 }
185
186 static struct elog_obj *create_elog_obj(uint64_t id, size_t size, uint64_t type)
187 {
188         struct elog_obj *elog;
189         int rc;
190
191         elog = kzalloc(sizeof(*elog), GFP_KERNEL);
192         if (!elog)
193                 return NULL;
194
195         elog->kobj.kset = elog_kset;
196
197         kobject_init(&elog->kobj, &elog_ktype);
198
199         sysfs_bin_attr_init(&elog->raw_attr);
200
201         elog->raw_attr.attr.name = "raw";
202         elog->raw_attr.attr.mode = 0400;
203         elog->raw_attr.size = size;
204         elog->raw_attr.read = raw_attr_read;
205
206         elog->id = id;
207         elog->size = size;
208         elog->type = type;
209
210         elog->buffer = kzalloc(elog->size, GFP_KERNEL);
211
212         if (elog->buffer) {
213                 rc = opal_read_elog(__pa(elog->buffer),
214                                          elog->size, elog->id);
215                 if (rc != OPAL_SUCCESS) {
216                         pr_err("ELOG: log read failed for log-id=%llx\n",
217                                elog->id);
218                         kfree(elog->buffer);
219                         elog->buffer = NULL;
220                 }
221         }
222
223         rc = kobject_add(&elog->kobj, NULL, "0x%llx", id);
224         if (rc) {
225                 kobject_put(&elog->kobj);
226                 return NULL;
227         }
228
229         rc = sysfs_create_bin_file(&elog->kobj, &elog->raw_attr);
230         if (rc) {
231                 kobject_put(&elog->kobj);
232                 return NULL;
233         }
234
235         kobject_uevent(&elog->kobj, KOBJ_ADD);
236
237         return elog;
238 }
239
240 static irqreturn_t elog_event(int irq, void *data)
241 {
242         __be64 size;
243         __be64 id;
244         __be64 type;
245         uint64_t elog_size;
246         uint64_t log_id;
247         uint64_t elog_type;
248         int rc;
249         char name[2+16+1];
250
251         rc = opal_get_elog_size(&id, &size, &type);
252         if (rc != OPAL_SUCCESS) {
253                 pr_err("ELOG: OPAL log info read failed\n");
254                 return IRQ_HANDLED;
255         }
256
257         elog_size = be64_to_cpu(size);
258         log_id = be64_to_cpu(id);
259         elog_type = be64_to_cpu(type);
260
261         WARN_ON(elog_size > OPAL_MAX_ERRLOG_SIZE);
262
263         if (elog_size >= OPAL_MAX_ERRLOG_SIZE)
264                 elog_size  =  OPAL_MAX_ERRLOG_SIZE;
265
266         sprintf(name, "0x%llx", log_id);
267
268         /* we may get notified twice, let's handle
269          * that gracefully and not create two conflicting
270          * entries.
271          */
272         if (kset_find_obj(elog_kset, name))
273                 return IRQ_HANDLED;
274
275         create_elog_obj(log_id, elog_size, elog_type);
276
277         return IRQ_HANDLED;
278 }
279
280 int __init opal_elog_init(void)
281 {
282         int rc = 0, irq;
283
284         /* ELOG not supported by firmware */
285         if (!opal_check_token(OPAL_ELOG_READ))
286                 return -1;
287
288         elog_kset = kset_create_and_add("elog", NULL, opal_kobj);
289         if (!elog_kset) {
290                 pr_warn("%s: failed to create elog kset\n", __func__);
291                 return -1;
292         }
293
294         irq = opal_event_request(ilog2(OPAL_EVENT_ERROR_LOG_AVAIL));
295         if (!irq) {
296                 pr_err("%s: Can't register OPAL event irq (%d)\n",
297                        __func__, irq);
298                 return irq;
299         }
300
301         rc = request_threaded_irq(irq, NULL, elog_event,
302                         IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "opal-elog", NULL);
303         if (rc) {
304                 pr_err("%s: Can't request OPAL event irq (%d)\n",
305                        __func__, rc);
306                 return rc;
307         }
308
309         /* We are now ready to pull error logs from opal. */
310         if (opal_check_token(OPAL_ELOG_RESEND))
311                 opal_resend_pending_logs();
312
313         return 0;
314 }