--- /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 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, S_IRUGO, elog_id_show, NULL);
+static struct elog_attribute type_attribute =
+ __ATTR(type, S_IRUGO, 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 info read failed\n");
+ return;
+ }
+
+ 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.
+ */
+ 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 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;
+ }
+
+ 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. */
+ if (opal_check_token(OPAL_ELOG_RESEND))
+ opal_resend_pending_logs();
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff