[deliverable/linux.git] / arch / powerpc / platforms / powernv / opal-elog.c

/*
 * 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/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 <asm/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, 0666, elog_id_show, NULL);
static struct elog_attribute type_attribute =
	__ATTR(type, 0666, 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 void elog_work_fn(struct work_struct *work)
{
	__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];

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

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

	BUG_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.
	 */
	if (kset_find_obj(elog_kset, name))
		return;

	create_elog_obj(log_id, elog_size, elog_type);
}

static DECLARE_WORK(elog_work, elog_work_fn);

static int elog_event(struct notifier_block *nb,
				unsigned long events, void *change)
{
	/* check for error log event */
	if (events & OPAL_EVENT_ERROR_LOG_AVAIL)
		schedule_work(&elog_work);
	return 0;
}

static struct notifier_block elog_nb = {
	.notifier_call  = elog_event,
	.next           = NULL,
	.priority       = 0
};

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

	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;
	}

	rc = opal_notifier_register(&elog_nb);
	if (rc) {
		pr_err("%s: Can't register OPAL event notifier (%d)\n",
		__func__, rc);
		return rc;
	}

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

	return 0;
}
Commit	Line	Data
774fea1a SS	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/of.h>
	14	#include <linux/slab.h>
	15	#include <linux/sysfs.h>
	16	#include <linux/fs.h>
	17	#include <linux/vmalloc.h>
	18	#include <linux/fcntl.h>
	19	#include <linux/kobject.h>
	20	#include <asm/uaccess.h>
	21	#include <asm/opal.h>
	22
	23	struct elog_obj {
	24	struct kobject kobj;
	25	struct bin_attribute raw_attr;
	26	uint64_t id;
	27	uint64_t type;
	28	size_t size;
	29	char *buffer;
	30	};
	31	#define to_elog_obj(x) container_of(x, struct elog_obj, kobj)
	32
	33	struct elog_attribute {
	34	struct attribute attr;
	35	ssize_t (show)(struct elog_obj elog, struct elog_attribute *attr,
	36	char *buf);
	37	ssize_t (store)(struct elog_obj elog, struct elog_attribute *attr,
	38	const char *buf, size_t count);
	39	};
	40	#define to_elog_attr(x) container_of(x, struct elog_attribute, attr)
	41
	42	static ssize_t elog_id_show(struct elog_obj *elog_obj,
	43	struct elog_attribute *attr,
	44	char *buf)
	45	{
	46	return sprintf(buf, "0x%llx\n", elog_obj->id);
	47	}
	48
	49	static const char *elog_type_to_string(uint64_t type)
	50	{
	51	switch (type) {
	52	case 0: return "PEL";
	53	default: return "unknown";
	54	}
	55	}
	56
	57	static ssize_t elog_type_show(struct elog_obj *elog_obj,
	58	struct elog_attribute *attr,
	59	char *buf)
	60	{
	61	return sprintf(buf, "0x%llx %s\n",
	62	elog_obj->type,
	63	elog_type_to_string(elog_obj->type));
	64	}
65
66	static ssize_t elog_ack_show(struct elog_obj *elog_obj,
67	struct elog_attribute *attr,
68	char *buf)
69	{
70	return sprintf(buf, "ack - acknowledge log message\n");
71	}
72
774fea1a SS	73	static ssize_t elog_ack_store(struct elog_obj *elog_obj,
	74	struct elog_attribute *attr,
	75	const char *buf,
	76	size_t count)
	77	{
	78	opal_send_ack_elog(elog_obj->id);
cc4f265a SS	79	sysfs_remove_file_self(&elog_obj->kobj, &attr->attr);
cc4f265a SS	80	kobject_put(&elog_obj->kobj);
774fea1a SS	81	return count;
	82	}
	83
	84	static struct elog_attribute id_attribute =
	85	__ATTR(id, 0666, elog_id_show, NULL);
	86	static struct elog_attribute type_attribute =
	87	__ATTR(type, 0666, elog_type_show, NULL);
	88	static struct elog_attribute ack_attribute =
	89	__ATTR(acknowledge, 0660, elog_ack_show, elog_ack_store);
	90
	91	static struct kset *elog_kset;
	92
	93	static ssize_t elog_attr_show(struct kobject *kobj,
	94	struct attribute *attr,
	95	char *buf)
	96	{
	97	struct elog_attribute *attribute;
	98	struct elog_obj *elog;
	99
	100	attribute = to_elog_attr(attr);
	101	elog = to_elog_obj(kobj);
	102
	103	if (!attribute->show)
	104	return -EIO;
	105
	106	return attribute->show(elog, attribute, buf);
	107	}
	108
	109	static ssize_t elog_attr_store(struct kobject *kobj,
	110	struct attribute *attr,
	111	const char *buf, size_t len)
	112	{
	113	struct elog_attribute *attribute;
	114	struct elog_obj *elog;
	115
	116	attribute = to_elog_attr(attr);
	117	elog = to_elog_obj(kobj);
	118
	119	if (!attribute->store)
	120	return -EIO;
	121
	122	return attribute->store(elog, attribute, buf, len);
	123	}
	124
	125	static const struct sysfs_ops elog_sysfs_ops = {
	126	.show = elog_attr_show,
	127	.store = elog_attr_store,
	128	};
	129
	130	static void elog_release(struct kobject *kobj)
	131	{
	132	struct elog_obj *elog;
	133
	134	elog = to_elog_obj(kobj);
	135	kfree(elog->buffer);
	136	kfree(elog);
	137	}
	138
	139	static struct attribute *elog_default_attrs[] = {
	140	&id_attribute.attr,
	141	&type_attribute.attr,
	142	&ack_attribute.attr,
	143	NULL,
	144	};
145
146	static struct kobj_type elog_ktype = {
147	.sysfs_ops = &elog_sysfs_ops,
148	.release = &elog_release,
149	.default_attrs = elog_default_attrs,
150	};
151
152	/* Maximum size of a single log on FSP is 16KB */
153	#define OPAL_MAX_ERRLOG_SIZE 16384
154
155	static ssize_t raw_attr_read(struct file filep, struct kobject kobj,
156	struct bin_attribute *bin_attr,
157	char *buffer, loff_t pos, size_t count)
158	{
159	int opal_rc;
160
161	struct elog_obj *elog = to_elog_obj(kobj);
162
163	/* We may have had an error reading before, so let's retry */
164	if (!elog->buffer) {
165	elog->buffer = kzalloc(elog->size, GFP_KERNEL);
166	if (!elog->buffer)
167	return -EIO;
168
169	opal_rc = opal_read_elog(__pa(elog->buffer),
170	elog->size, elog->id);
171	if (opal_rc != OPAL_SUCCESS) {
172	pr_err("ELOG: log read failed for log-id=%llx\n",
173	elog->id);
174	kfree(elog->buffer);
175	elog->buffer = NULL;
176	return -EIO;
177	}
178	}
179
180	memcpy(buffer, elog->buffer + pos, count);
181
182	return count;
183	}
184
185	static struct elog_obj *create_elog_obj(uint64_t id, size_t size, uint64_t type)
186	{
187	struct elog_obj *elog;
188	int rc;
189
190	elog = kzalloc(sizeof(*elog), GFP_KERNEL);
191	if (!elog)
192	return NULL;
193
194	elog->kobj.kset = elog_kset;
195
196	kobject_init(&elog->kobj, &elog_ktype);
197
198	sysfs_bin_attr_init(&elog->raw_attr);
199
200	elog->raw_attr.attr.name = "raw";
201	elog->raw_attr.attr.mode = 0400;
202	elog->raw_attr.size = size;
203	elog->raw_attr.read = raw_attr_read;
204
205	elog->id = id;
206	elog->size = size;
207	elog->type = type;
208
209	elog->buffer = kzalloc(elog->size, GFP_KERNEL);
210
211	if (elog->buffer) {
212	rc = opal_read_elog(__pa(elog->buffer),
213	elog->size, elog->id);
214	if (rc != OPAL_SUCCESS) {
215	pr_err("ELOG: log read failed for log-id=%llx\n",
216	elog->id);
217	kfree(elog->buffer);
218	elog->buffer = NULL;
219	}
220	}
221
222	rc = kobject_add(&elog->kobj, NULL, "0x%llx", id);
223	if (rc) {
224	kobject_put(&elog->kobj);
225	return NULL;
226	}
227
228	rc = sysfs_create_bin_file(&elog->kobj, &elog->raw_attr);
229	if (rc) {
230	kobject_put(&elog->kobj);
231	return NULL;
232	}
233
234	kobject_uevent(&elog->kobj, KOBJ_ADD);
235
236	return elog;
237	}
238
239	static void elog_work_fn(struct work_struct *work)
240	{
14ad0c58 AB	241	__be64 size;
	242	__be64 id;
	243	__be64 type;
2bad7423	244	uint64_t elog_size;
774fea1a SS	245	uint64_t log_id;
	246	uint64_t elog_type;
	247	int rc;
	248	char name[2+16+1];
	249
14ad0c58	250	rc = opal_get_elog_size(&id, &size, &type);
774fea1a SS	251	if (rc != OPAL_SUCCESS) {
	252	pr_err("ELOG: Opal log read failed\n");
	253	return;
	254	}
	255
14ad0c58 AB	256	elog_size = be64_to_cpu(size);
	257	log_id = be64_to_cpu(id);
	258	elog_type = be64_to_cpu(type);
	259
774fea1a SS	260	BUG_ON(elog_size > OPAL_MAX_ERRLOG_SIZE);
	261
	262	if (elog_size >= OPAL_MAX_ERRLOG_SIZE)
	263	elog_size = OPAL_MAX_ERRLOG_SIZE;
	264
	265	sprintf(name, "0x%llx", log_id);
	266
	267	/* we may get notified twice, let's handle
	268	* that gracefully and not create two conflicting
	269	* entries.
	270	*/
	271	if (kset_find_obj(elog_kset, name))
	272	return;
	273
	274	create_elog_obj(log_id, elog_size, elog_type);
	275	}
	276
	277	static DECLARE_WORK(elog_work, elog_work_fn);
	278
	279	static int elog_event(struct notifier_block *nb,
	280	unsigned long events, void *change)
	281	{
	282	/* check for error log event */
	283	if (events & OPAL_EVENT_ERROR_LOG_AVAIL)
	284	schedule_work(&elog_work);
	285	return 0;
	286	}
	287
	288	static struct notifier_block elog_nb = {
	289	.notifier_call = elog_event,
	290	.next = NULL,
	291	.priority = 0
	292	};
	293
	294	int __init opal_elog_init(void)
	295	{
	296	int rc = 0;
	297
	298	elog_kset = kset_create_and_add("elog", NULL, opal_kobj);
	299	if (!elog_kset) {
	300	pr_warn("%s: failed to create elog kset\n", __func__);
	301	return -1;
	302	}
	303
	304	rc = opal_notifier_register(&elog_nb);
	305	if (rc) {
	306	pr_err("%s: Can't register OPAL event notifier (%d)\n",
	307	__func__, rc);
	308	return rc;
	309	}
	310
	311	/* We are now ready to pull error logs from opal. */
	312	opal_resend_pending_logs();
	313
	314	return 0;
	315	}