--- /dev/null
+What: /sys/firmware/opal/elog
+Date: Feb 2014
+Contact: Stewart Smith <stewart@linux.vnet.ibm.com>
+Description:
+ This directory exposes error log entries retrieved
+ through the OPAL firmware interface.
+
+ Each error log is identified by a unique ID and will
+ exist until explicitly acknowledged to firmware.
+
+ Each log entry has a directory in /sys/firmware/opal/elog.
+
+ Log entries may be purged by the service processor
+ before retrieved by firmware or retrieved/acknowledged by
+ Linux if there is no room for more log entries.
+
+ In the event that Linux has retrieved the log entries
+ but not explicitly acknowledged them to firmware and
+ the service processor needs more room for log entries,
+ the only remaining copy of a log message may be in
+ Linux.
+
+ Typically, a user space daemon will monitor for new
+ entries, read them out and acknowledge them.
+
+ The service processor may be able to store more log
+ entries than firmware can, so after you acknowledge
+ an event from Linux you may instantly get another one
+ from the queue that was generated some time in the past.
+
+ The raw log format is a binary format. We currently
+ do not parse this at all in kernel, leaving it up to
+ user space to solve the problem. In future, we may
+ do more parsing in kernel and add more files to make
+ it easier for simple user space processes to extract
+ more information.
+
+ For each log entry (directory), there are the following
+ files:
+
+ id: An ASCII representation of the ID of the
+ error log, in hex - e.g. "0x01".
+
+ type: An ASCII representation of the type id and
+ description of the type of error log.
+ Currently just "0x00 PEL" - platform error log.
+ In the future there may be additional types.
+
+ raw: A read-only binary file that can be read
+ to get the raw log entry. These are
+ <16kb, often just hundreds of bytes and
+ "average" 2kb.
+
+ acknowledge: Writing 'ack' to this file will acknowledge
+ the error log to firmware (and in turn
+ the service processor, if applicable).
+ Shortly after acknowledging it, the log
+ entry will be removed from sysfs.
+ Reading this file will list the supported
+ operations (curently just acknowledge).
\ No newline at end of file
#define OPAL_LPC_READ 67
#define OPAL_LPC_WRITE 68
#define OPAL_RETURN_CPU 69
+#define OPAL_ELOG_READ 71
+#define OPAL_ELOG_WRITE 72
+#define OPAL_ELOG_ACK 73
+#define OPAL_ELOG_RESEND 74
+#define OPAL_ELOG_SIZE 75
#define OPAL_FLASH_VALIDATE 76
#define OPAL_FLASH_MANAGE 77
#define OPAL_FLASH_UPDATE 78
uint32_t addr, uint32_t data, uint32_t sz);
int64_t opal_lpc_read(uint32_t chip_id, enum OpalLPCAddressType addr_type,
uint32_t addr, __be32 *data, uint32_t sz);
+
+int64_t opal_read_elog(uint64_t buffer, size_t size, uint64_t log_id);
+int64_t opal_get_elog_size(uint64_t *log_id, size_t *size, uint64_t *elog_type);
+int64_t opal_write_elog(uint64_t buffer, uint64_t size, uint64_t offset);
+int64_t opal_send_ack_elog(uint64_t log_id);
+void opal_resend_pending_logs(void);
+
int64_t opal_validate_flash(uint64_t buffer, uint32_t *size, uint32_t *result);
int64_t opal_manage_flash(uint8_t op);
int64_t opal_update_flash(uint64_t blk_list);
extern unsigned long opal_get_boot_time(void);
extern void opal_nvram_init(void);
extern void opal_flash_init(void);
+extern int opal_elog_init(void);
extern int opal_machine_check(struct pt_regs *regs);
extern bool opal_mce_check_early_recovery(struct pt_regs *regs);
--- /dev/null
+/*
+ * 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 void delay_release_kobj(void *kobj)
+{
+ kobject_put((struct kobject *)kobj);
+}
+
+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_schedule_callback(&elog_obj->kobj, delay_release_kobj,
+ &elog_obj->kobj, THIS_MODULE);
+ 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;
+}
projects / platform / kernel / linux-exynos.git / commitdiff