1 files changed, 313 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-elog.c b/arch/powerpc/platforms/powernv/opal-elog.c
new file mode 100644
index 000000000000..1d7355bc9db0
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-elog.c
@@ -0,0 +1,313 @@
+/*
+ * 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;
+}