summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/powernv/opal-elog.c
blob: ba6e437abb4bb96fa8f78f18517208bb570a08c6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 * Error log support on PowerNV.
 *
 * Copyright 2013,2014 IBM Corp.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/fcntl.h>
#include <linux/kobject.h>
#include <linux/uaccess.h>
#include <asm/opal.h>

struct elog_obj {
	struct kobject kobj;
	struct bin_attribute raw_attr;
	uint64_t id;
	uint64_t type;
	size_t size;
	char *buffer;
};
#define to_elog_obj(x) container_of(x, struct elog_obj, kobj)

struct elog_attribute {
	struct attribute attr;
	ssize_t (*show)(struct elog_obj *elog, struct elog_attribute *attr,
			char *buf);
	ssize_t (*store)(struct elog_obj *elog, struct elog_attribute *attr,
			 const char *buf, size_t count);
};
#define to_elog_attr(x) container_of(x, struct elog_attribute, attr)

static ssize_t elog_id_show(struct elog_obj *elog_obj,
			    struct elog_attribute *attr,
			    char *buf)
{
	return sprintf(buf, "0x%llx\n", elog_obj->id);
}

static const char *elog_type_to_string(uint64_t type)
{
	switch (type) {
	case 0: return "PEL";
	default: return "unknown";
	}
}

static ssize_t elog_type_show(struct elog_obj *elog_obj,
			      struct elog_attribute *attr,
			      char *buf)
{
	return sprintf(buf, "0x%llx %s\n",
		       elog_obj->type,
		       elog_type_to_string(elog_obj->type));
}

static ssize_t elog_ack_show(struct elog_obj *elog_obj,
			     struct elog_attribute *attr,
			     char *buf)
{
	return sprintf(buf, "ack - acknowledge log message\n");
}

static ssize_t elog_ack_store(struct elog_obj *elog_obj,
			      struct elog_attribute *attr,
			      const char *buf,
			      size_t count)
{
	opal_send_ack_elog(elog_obj->id);
	sysfs_remove_file_self(&elog_obj->kobj, &attr->attr);
	kobject_put(&elog_obj->kobj);
	return count;
}

static struct elog_attribute id_attribute =
	__ATTR(id, 0444, elog_id_show, NULL);
static struct elog_attribute type_attribute =
	__ATTR(type, 0444, elog_type_show, NULL);
static struct elog_attribute ack_attribute =
	__ATTR(acknowledge, 0660, elog_ack_show, elog_ack_store);

static struct kset *elog_kset;

static ssize_t elog_attr_show(struct kobject *kobj,
			      struct attribute *attr,
			      char *buf)
{
	struct elog_attribute *attribute;
	struct elog_obj *elog;

	attribute = to_elog_attr(attr);
	elog = to_elog_obj(kobj);

	if (!attribute->show)
		return -EIO;

	return attribute->show(elog, attribute, buf);
}

static ssize_t elog_attr_store(struct kobject *kobj,
			       struct attribute *attr,
			       const char *buf, size_t len)
{
	struct elog_attribute *attribute;
	struct elog_obj *elog;

	attribute = to_elog_attr(attr);
	elog = to_elog_obj(kobj);

	if (!attribute->store)
		return -EIO;

	return attribute->store(elog, attribute, buf, len);
}

static const struct sysfs_ops elog_sysfs_ops = {
	.show = elog_attr_show,
	.store = elog_attr_store,
};

static void elog_release(struct kobject *kobj)
{
	struct elog_obj *elog;

	elog = to_elog_obj(kobj);
	kfree(elog->buffer);
	kfree(elog);
}

static struct attribute *elog_default_attrs[] = {
	&id_attribute.attr,
	&type_attribute.attr,
	&ack_attribute.attr,
	NULL,
};

static struct kobj_type elog_ktype = {
	.sysfs_ops = &elog_sysfs_ops,
	.release = &elog_release,
	.default_attrs = elog_default_attrs,
};

/* Maximum size of a single log on FSP is 16KB */
#define OPAL_MAX_ERRLOG_SIZE	16384

static ssize_t raw_attr_read(struct file *filep, struct kobject *kobj,
			     struct bin_attribute *bin_attr,
			     char *buffer, loff_t pos, size_t count)
{
	int opal_rc;

	struct elog_obj *elog = to_elog_obj(kobj);

	/* We may have had an error reading before, so let's retry */
	if (!elog->buffer) {
		elog->buffer = kzalloc(elog->size, GFP_KERNEL);
		if (!elog->buffer)
			return -EIO;

		opal_rc = opal_read_elog(__pa(elog->buffer),
					 elog->size, elog->id);
		if (opal_rc != OPAL_SUCCESS) {
			pr_err("ELOG: log read failed for log-id=%llx\n",
			       elog->id);
			kfree(elog->buffer);
			elog->buffer = NULL;
			return -EIO;
		}
	}

	memcpy(buffer, elog->buffer + pos, count);

	return count;
}

static struct elog_obj *create_elog_obj(uint64_t id, size_t size, uint64_t type)
{
	struct elog_obj *elog;
	int rc;

	elog = kzalloc(sizeof(*elog), GFP_KERNEL);
	if (!elog)
		return NULL;

	elog->kobj.kset = elog_kset;

	kobject_init(&elog->kobj, &elog_ktype);

	sysfs_bin_attr_init(&elog->raw_attr);

	elog->raw_attr.attr.name = "raw";
	elog->raw_attr.attr.mode = 0400;
	elog->raw_attr.size = size;
	elog->raw_attr.read = raw_attr_read;

	elog->id = id;
	elog->size = size;
	elog->type = type;

	elog->buffer = kzalloc(elog->size, GFP_KERNEL);

	if (elog->buffer) {
		rc = opal_read_elog(__pa(elog->buffer),
					 elog->size, elog->id);
		if (rc != OPAL_SUCCESS) {
			pr_err("ELOG: log read failed for log-id=%llx\n",
			       elog->id);
			kfree(elog->buffer);
			elog->buffer = NULL;
		}
	}

	rc = kobject_add(&elog->kobj, NULL, "0x%llx", id);
	if (rc) {
		kobject_put(&elog->kobj);
		return NULL;
	}

	rc = sysfs_create_bin_file(&elog->kobj, &elog->raw_attr);
	if (rc) {
		kobject_put(&elog->kobj);
		return NULL;
	}

	kobject_uevent(&elog->kobj, KOBJ_ADD);

	return elog;
}

static irqreturn_t elog_event(int irq, void *data)
{
	__be64 size;
	__be64 id;
	__be64 type;
	uint64_t elog_size;
	uint64_t log_id;
	uint64_t elog_type;
	int rc;
	char name[2+16+1];
	struct kobject *kobj;

	rc = opal_get_elog_size(&id, &size, &type);
	if (rc != OPAL_SUCCESS) {
		pr_err("ELOG: OPAL log info read failed\n");
		return IRQ_HANDLED;
	}

	elog_size = be64_to_cpu(size);
	log_id = be64_to_cpu(id);
	elog_type = be64_to_cpu(type);

	WARN_ON(elog_size > OPAL_MAX_ERRLOG_SIZE);

	if (elog_size >= OPAL_MAX_ERRLOG_SIZE)
		elog_size  =  OPAL_MAX_ERRLOG_SIZE;

	sprintf(name, "0x%llx", log_id);

	/* we may get notified twice, let's handle
	 * that gracefully and not create two conflicting
	 * entries.
	 */
	kobj = kset_find_obj(elog_kset, name);
	if (kobj) {
		/* Drop reference added by kset_find_obj() */
		kobject_put(kobj);
		return IRQ_HANDLED;
	}

	create_elog_obj(log_id, elog_size, elog_type);

	return IRQ_HANDLED;
}

int __init opal_elog_init(void)
{
	int rc = 0, irq;

	/* ELOG not supported by firmware */
	if (!opal_check_token(OPAL_ELOG_READ))
		return -1;

	elog_kset = kset_create_and_add("elog", NULL, opal_kobj);
	if (!elog_kset) {
		pr_warn("%s: failed to create elog kset\n", __func__);
		return -1;
	}

	irq = opal_event_request(ilog2(OPAL_EVENT_ERROR_LOG_AVAIL));
	if (!irq) {
		pr_err("%s: Can't register OPAL event irq (%d)\n",
		       __func__, irq);
		return irq;
	}

	rc = request_threaded_irq(irq, NULL, elog_event,
			IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "opal-elog", NULL);
	if (rc) {
		pr_err("%s: Can't request OPAL event irq (%d)\n",
		       __func__, rc);
		return rc;
	}

	/* We are now ready to pull error logs from opal. */
	if (opal_check_token(OPAL_ELOG_RESEND))
		opal_resend_pending_logs();

	return 0;
}