blob: ef7bc2a978627422d659d783ea21f0869975df53 [file] [log] [blame]
/*
* 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)
{
size_t elog_size;
uint64_t log_id;
uint64_t elog_type;
int rc;
char name[2+16+1];
rc = opal_get_elog_size(&log_id, &elog_size, &elog_type);
if (rc != OPAL_SUCCESS) {
pr_err("ELOG: Opal log read failed\n");
return;
}
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;
}