1 files changed, 501 insertions, 217 deletions

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index a1a7b9a67ffd..979487da6522 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -1,35 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Support for dynamic reconfiguration for PCI, Memory, and CPU
  * Hotplug and Dynamic Logical Partitioning on RPA platforms.
  *
  * Copyright (C) 2009 Nathan Fontenot
  * Copyright (C) 2009 IBM Corporation
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
  */
 
+#define pr_fmt(fmt)	"dlpar: " fmt
+
 #include <linux/kernel.h>
-#include <linux/kref.h>
 #include <linux/notifier.h>
 #include <linux/spinlock.h>
 #include <linux/cpu.h>
 #include <linux/slab.h>
 #include <linux/of.h>
-#include "offline_states.h"
 
-#include <asm/prom.h>
+#include "of_helpers.h"
+#include "pseries.h"
+
 #include <asm/machdep.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 #include <asm/rtas.h>
+#include <asm/rtas-work-area.h>
+#include <asm/prom.h>
+
+static struct workqueue_struct *pseries_hp_wq;
+
+struct pseries_hp_work {
+	struct work_struct work;
+	struct pseries_hp_errorlog *errlog;
+};
 
 struct cc_workarea {
-	u32	drc_index;
-	u32	zero;
-	u32	name_offset;
-	u32	prop_length;
-	u32	prop_offset;
+	__be32	drc_index;
+	__be32	zero;
+	__be32	name_offset;
+	__be32	prop_length;
+	__be32	prop_offset;
 };
 
 void dlpar_free_cc_property(struct property *prop)
@@ -49,11 +57,15 @@ static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
 	if (!prop)
 		return NULL;
 
-	name = (char *)ccwa + ccwa->name_offset;
+	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
 	prop->name = kstrdup(name, GFP_KERNEL);
+	if (!prop->name) {
+		dlpar_free_cc_property(prop);
+		return NULL;
+	}
 
-	prop->length = ccwa->prop_length;
-	value = (char *)ccwa + ccwa->prop_offset;
+	prop->length = be32_to_cpu(ccwa->prop_length);
+	value = (char *)ccwa + be32_to_cpu(ccwa->prop_offset);
 	prop->value = kmemdup(value, prop->length, GFP_KERNEL);
 	if (!prop->value) {
 		dlpar_free_cc_property(prop);
@@ -66,23 +78,22 @@ static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
 static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa)
 {
 	struct device_node *dn;
-	char *name;
+	const char *name;
 
 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
 	if (!dn)
 		return NULL;
 
-	/* The configure connector reported name does not contain a
-	 * preceding '/', so we allocate a buffer large enough to
-	 * prepend this to the full_name.
-	 */
-	name = (char *)ccwa + ccwa->name_offset;
-	dn->full_name = kasprintf(GFP_KERNEL, "/%s", name);
+	name = (const char *)ccwa + be32_to_cpu(ccwa->name_offset);
+	dn->full_name = kstrdup(name, GFP_KERNEL);
 	if (!dn->full_name) {
 		kfree(dn);
 		return NULL;
 	}
 
+	of_node_set_flag(dn, OF_DYNAMIC);
+	of_node_init(dn);
+
 	return dn;
 }
 
@@ -117,10 +128,10 @@ void dlpar_free_cc_nodes(struct device_node *dn)
 #define NEXT_PROPERTY   3
 #define PREV_PARENT     4
 #define MORE_MEMORY     5
-#define CALL_AGAIN	-2
 #define ERR_CFG_USE     -9003
 
-struct device_node *dlpar_configure_connector(u32 drc_index)
+struct device_node *dlpar_configure_connector(__be32 drc_index,
+					      struct device_node *parent)
 {
 	struct device_node *dn;
 	struct device_node *first_dn = NULL;
@@ -128,34 +139,27 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 	struct property *property;
 	struct property *last_property = NULL;
 	struct cc_workarea *ccwa;
+	struct rtas_work_area *work_area;
 	char *data_buf;
 	int cc_token;
 	int rc = -1;
 
-	cc_token = rtas_token("ibm,configure-connector");
+	cc_token = rtas_function_token(RTAS_FN_IBM_CONFIGURE_CONNECTOR);
 	if (cc_token == RTAS_UNKNOWN_SERVICE)
 		return NULL;
 
-	data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
-	if (!data_buf)
-		return NULL;
+	work_area = rtas_work_area_alloc(SZ_4K);
+	data_buf = rtas_work_area_raw_buf(work_area);
 
 	ccwa = (struct cc_workarea *)&data_buf[0];
 	ccwa->drc_index = drc_index;
 	ccwa->zero = 0;
 
 	do {
-		/* Since we release the rtas_data_buf lock between configure
-		 * connector calls we want to re-populate the rtas_data_buffer
-		 * with the contents of the previous call.
-		 */
-		spin_lock(&rtas_data_buf_lock);
-
-		memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
-		rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
-		memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
-
-		spin_unlock(&rtas_data_buf_lock);
+		do {
+			rc = rtas_call(cc_token, 2, 1, NULL,
+				       rtas_work_area_phys(work_area), NULL);
+		} while (rtas_busy_delay(rc));
 
 		switch (rc) {
 		case COMPLETE:
@@ -176,9 +180,10 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 			if (!dn)
 				goto cc_error;
 
-			if (!first_dn)
+			if (!first_dn) {
+				dn->parent = parent;
 				first_dn = dn;
-			else {
+			} else {
 				dn->parent = last_dn;
 				if (last_dn)
 					last_dn->child = dn;
@@ -204,9 +209,6 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 			last_dn = last_dn->parent;
 			break;
 
-		case CALL_AGAIN:
-			break;
-
 		case MORE_MEMORY:
 		case ERR_CFG_USE:
 		default:
@@ -217,7 +219,7 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 	} while (rc);
 
 cc_error:
-	kfree(data_buf);
+	rtas_work_area_free(work_area);
 
 	if (rc) {
 		if (first_dn)
@@ -229,61 +231,51 @@ cc_error:
 	return first_dn;
 }
 
-static struct device_node *derive_parent(const char *path)
-{
-	struct device_node *parent;
-	char *last_slash;
-
-	last_slash = strrchr(path, '/');
-	if (last_slash == path) {
-		parent = of_find_node_by_path("/");
-	} else {
-		char *parent_path;
-		int parent_path_len = last_slash - path + 1;
-		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
-		if (!parent_path)
-			return NULL;
-
-		strlcpy(parent_path, path, parent_path_len);
-		parent = of_find_node_by_path(parent_path);
-		kfree(parent_path);
-	}
-
-	return parent;
-}
-
-int dlpar_attach_node(struct device_node *dn)
+int dlpar_attach_node(struct device_node *dn, struct device_node *parent)
 {
 	int rc;
 
-	of_node_set_flag(dn, OF_DYNAMIC);
-	kref_init(&dn->kref);
-	dn->parent = derive_parent(dn->full_name);
-	if (!dn->parent)
-		return -ENOMEM;
+	dn->parent = parent;
 
 	rc = of_attach_node(dn);
 	if (rc) {
-		printk(KERN_ERR "Failed to add device node %s\n",
-		       dn->full_name);
+		printk(KERN_ERR "Failed to add device node %pOF\n", dn);
 		return rc;
 	}
 
-	of_node_put(dn->parent);
 	return 0;
 }
 
 int dlpar_detach_node(struct device_node *dn)
 {
+	struct device_node *child;
 	int rc;
 
+	for_each_child_of_node(dn, child)
+		dlpar_detach_node(child);
+
 	rc = of_detach_node(dn);
 	if (rc)
 		return rc;
 
-	of_node_put(dn); /* Must decrement the refcount */
+	of_node_put(dn);
+
 	return 0;
 }
+static int dlpar_changeset_attach_cc_nodes(struct of_changeset *ocs,
+					struct device_node *dn)
+{
+	int rc;
+
+	rc = of_changeset_attach_node(ocs, dn);
+
+	if (!rc && dn->child)
+		rc = dlpar_changeset_attach_cc_nodes(ocs, dn->child);
+	if (!rc && dn->sibling)
+		rc = dlpar_changeset_attach_cc_nodes(ocs, dn->sibling);
+
+	return rc;
+}
 
 #define DR_ENTITY_SENSE		9003
 #define DR_ENTITY_PRESENT	1
@@ -299,8 +291,7 @@ int dlpar_acquire_drc(u32 drc_index)
 {
 	int dr_status, rc;
 
-	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
-		       DR_ENTITY_SENSE, drc_index);
+	rc = rtas_get_sensor(DR_ENTITY_SENSE, drc_index, &dr_status);
 	if (rc || dr_status != DR_ENTITY_UNUSABLE)
 		return -1;
 
@@ -321,8 +312,7 @@ int dlpar_release_drc(u32 drc_index)
 {
 	int dr_status, rc;
 
-	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
-		       DR_ENTITY_SENSE, drc_index);
+	rc = rtas_get_sensor(DR_ENTITY_SENSE, drc_index, &dr_status);
 	if (rc || dr_status != DR_ENTITY_PRESENT)
 		return -1;
 
@@ -339,205 +329,499 @@ int dlpar_release_drc(u32 drc_index)
 	return 0;
 }
 
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+int dlpar_unisolate_drc(u32 drc_index)
+{
+	int dr_status, rc;
+
+	rc = rtas_get_sensor(DR_ENTITY_SENSE, drc_index, &dr_status);
+	if (rc || dr_status != DR_ENTITY_PRESENT)
+		return -1;
+
+	rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
+
+	return 0;
+}
 
-static int dlpar_online_cpu(struct device_node *dn)
+static struct device_node *
+get_device_node_with_drc_index(u32 index)
 {
-	int rc = 0;
-	unsigned int cpu;
-	int len, nthreads, i;
-	const u32 *intserv;
+	struct device_node *np = NULL;
+	u32 node_index;
+	int rc;
 
-	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
-	if (!intserv)
-		return -EINVAL;
+	for_each_node_with_property(np, "ibm,my-drc-index") {
+		rc = of_property_read_u32(np, "ibm,my-drc-index",
+					     &node_index);
+		if (rc) {
+			pr_err("%s: %pOF: of_property_read_u32 %s: %d\n",
+			       __func__, np, "ibm,my-drc-index", rc);
+			of_node_put(np);
+			return NULL;
+		}
 
-	nthreads = len / sizeof(u32);
+		if (index == node_index)
+			break;
+	}
+
+	return np;
+}
 
-	cpu_maps_update_begin();
-	for (i = 0; i < nthreads; i++) {
-		for_each_present_cpu(cpu) {
-			if (get_hard_smp_processor_id(cpu) != intserv[i])
+static struct device_node *
+get_device_node_with_drc_info(u32 index)
+{
+	struct device_node *np = NULL;
+	struct of_drc_info drc;
+	struct property *info;
+	const __be32 *value;
+	u32 node_index;
+	int i, j, count;
+
+	for_each_node_with_property(np, "ibm,drc-info") {
+		info = of_find_property(np, "ibm,drc-info", NULL);
+		if (info == NULL) {
+			/* XXX can this happen? */
+			of_node_put(np);
+			return NULL;
+		}
+		value = of_prop_next_u32(info, NULL, &count);
+		if (value == NULL)
+			continue;
+		value++;
+		for (i = 0; i < count; i++) {
+			if (of_read_drc_info_cell(&info, &value, &drc))
+				break;
+			if (index > drc.last_drc_index)
 				continue;
-			BUG_ON(get_cpu_current_state(cpu)
-					!= CPU_STATE_OFFLINE);
-			cpu_maps_update_done();
-			rc = cpu_up(cpu);
+			node_index = drc.drc_index_start;
+			for (j = 0; j < drc.num_sequential_elems; j++) {
+				if (index == node_index)
+					return np;
+				node_index += drc.sequential_inc;
+			}
+		}
+	}
+
+	return NULL;
+}
+
+static struct device_node *
+get_device_node_with_drc_indexes(u32 drc_index)
+{
+	struct device_node *np = NULL;
+	u32 nr_indexes, index;
+	int i, rc;
+
+	for_each_node_with_property(np, "ibm,drc-indexes") {
+		/*
+		 * First element in the array is the total number of
+		 * DRC indexes returned.
+		 */
+		rc = of_property_read_u32_index(np, "ibm,drc-indexes",
+				0, &nr_indexes);
+		if (rc)
+			goto out_put_np;
+
+		/*
+		 * Retrieve DRC index from the list and return the
+		 * device node if matched with the specified index.
+		 */
+		for (i = 0; i < nr_indexes; i++) {
+			rc = of_property_read_u32_index(np, "ibm,drc-indexes",
+							i+1, &index);
 			if (rc)
-				goto out;
-			cpu_maps_update_begin();
+				goto out_put_np;
 
-			break;
+			if (drc_index == index)
+				return np;
 		}
-		if (cpu == num_possible_cpus())
-			printk(KERN_WARNING "Could not find cpu to online "
-			       "with physical id 0x%x\n", intserv[i]);
 	}
-	cpu_maps_update_done();
 
-out:
-	return rc;
+	return NULL;
 
+out_put_np:
+	of_node_put(np);
+	return NULL;
 }
 
-static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+static int dlpar_hp_dt_add(u32 index)
 {
-	struct device_node *dn;
-	unsigned long drc_index;
-	char *cpu_name;
+	struct device_node *np, *nodes;
+	struct of_changeset ocs;
 	int rc;
 
-	cpu_hotplug_driver_lock();
-	rc = strict_strtoul(buf, 0, &drc_index);
-	if (rc) {
+	/*
+	 * Do not add device node(s) if already exists in the
+	 * device tree.
+	 */
+	np = get_device_node_with_drc_index(index);
+	if (np) {
+		pr_err("%s: Adding device node for index (%d), but "
+				"already exists in the device tree\n",
+				__func__, index);
 		rc = -EINVAL;
 		goto out;
 	}
 
-	dn = dlpar_configure_connector(drc_index);
-	if (!dn) {
-		rc = -EINVAL;
-		goto out;
+	/*
+	 * Recent FW provides ibm,drc-info property. So search
+	 * for the user specified DRC index from ibm,drc-info
+	 * property. If this property is not available, search
+	 * in the indexes array from ibm,drc-indexes property.
+	 */
+	np = get_device_node_with_drc_info(index);
+
+	if (!np) {
+		np = get_device_node_with_drc_indexes(index);
+		if (!np)
+			return -EIO;
 	}
 
-	/* configure-connector reports cpus as living in the base
-	 * directory of the device tree.  CPUs actually live in the
-	 * cpus directory so we need to fixup the full_name.
-	 */
-	cpu_name = kasprintf(GFP_KERNEL, "/cpus%s", dn->full_name);
-	if (!cpu_name) {
-		dlpar_free_cc_nodes(dn);
-		rc = -ENOMEM;
+	/* Next, configure the connector. */
+	nodes = dlpar_configure_connector(cpu_to_be32(index), np);
+	if (!nodes) {
+		rc = -EIO;
 		goto out;
 	}
 
-	kfree(dn->full_name);
-	dn->full_name = cpu_name;
+	/*
+	 * Add the new nodes from dlpar_configure_connector() onto
+	 * the device-tree.
+	 */
+	of_changeset_init(&ocs);
+	rc = dlpar_changeset_attach_cc_nodes(&ocs, nodes);
 
-	rc = dlpar_acquire_drc(drc_index);
-	if (rc) {
-		dlpar_free_cc_nodes(dn);
-		rc = -EINVAL;
-		goto out;
-	}
+	if (!rc)
+		rc = of_changeset_apply(&ocs);
+	else
+		dlpar_free_cc_nodes(nodes);
 
-	rc = dlpar_attach_node(dn);
-	if (rc) {
-		dlpar_release_drc(drc_index);
-		dlpar_free_cc_nodes(dn);
-		goto out;
-	}
+	of_changeset_destroy(&ocs);
 
-	rc = dlpar_online_cpu(dn);
 out:
-	cpu_hotplug_driver_unlock();
+	of_node_put(np);
+	return rc;
+}
 
-	return rc ? rc : count;
+static int changeset_detach_node_recursive(struct of_changeset *ocs,
+					struct device_node *node)
+{
+	struct device_node *child;
+	int rc;
+
+	for_each_child_of_node(node, child) {
+		rc = changeset_detach_node_recursive(ocs, child);
+		if (rc) {
+			of_node_put(child);
+			return rc;
+		}
+	}
+
+	return of_changeset_detach_node(ocs, node);
 }
 
-static int dlpar_offline_cpu(struct device_node *dn)
+static int dlpar_hp_dt_remove(u32 drc_index)
 {
+	struct device_node *np;
+	struct of_changeset ocs;
+	u32 index;
 	int rc = 0;
-	unsigned int cpu;
-	int len, nthreads, i;
-	const u32 *intserv;
 
-	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
-	if (!intserv)
+	/*
+	 * Prune all nodes with a matching index.
+	 */
+	of_changeset_init(&ocs);
+
+	for_each_node_with_property(np, "ibm,my-drc-index") {
+		rc = of_property_read_u32(np, "ibm,my-drc-index", &index);
+		if (rc) {
+			pr_err("%s: %pOF: of_property_read_u32 %s: %d\n",
+				__func__, np, "ibm,my-drc-index", rc);
+			of_node_put(np);
+			goto out;
+		}
+
+		if (index == drc_index) {
+			rc = changeset_detach_node_recursive(&ocs, np);
+			if (rc) {
+				of_node_put(np);
+				goto out;
+			}
+		}
+	}
+
+	rc = of_changeset_apply(&ocs);
+
+out:
+	of_changeset_destroy(&ocs);
+	return rc;
+}
+
+static int dlpar_hp_dt(struct pseries_hp_errorlog *phpe)
+{
+	u32 drc_index;
+	int rc;
+
+	if (phpe->id_type != PSERIES_HP_ELOG_ID_DRC_INDEX)
 		return -EINVAL;
 
-	nthreads = len / sizeof(u32);
+	drc_index = be32_to_cpu(phpe->_drc_u.drc_index);
 
-	cpu_maps_update_begin();
-	for (i = 0; i < nthreads; i++) {
-		for_each_present_cpu(cpu) {
-			if (get_hard_smp_processor_id(cpu) != intserv[i])
-				continue;
+	lock_device_hotplug();
 
-			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
-				break;
+	switch (phpe->action) {
+	case PSERIES_HP_ELOG_ACTION_ADD:
+		rc = dlpar_hp_dt_add(drc_index);
+		break;
+	case PSERIES_HP_ELOG_ACTION_REMOVE:
+		rc = dlpar_hp_dt_remove(drc_index);
+		break;
+	default:
+		pr_err("Invalid action (%d) specified\n", phpe->action);
+		rc = -EINVAL;
+		break;
+	}
 
-			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
-				set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
-				cpu_maps_update_done();
-				rc = cpu_down(cpu);
-				if (rc)
-					goto out;
-				cpu_maps_update_begin();
-				break;
+	unlock_device_hotplug();
 
-			}
+	return rc;
+}
 
-			/*
-			 * The cpu is in CPU_STATE_INACTIVE.
-			 * Upgrade it's state to CPU_STATE_OFFLINE.
-			 */
-			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
-			BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
-								!= H_SUCCESS);
-			__cpu_die(cpu);
-			break;
-		}
-		if (cpu == num_possible_cpus())
-			printk(KERN_WARNING "Could not find cpu to offline "
-			       "with physical id 0x%x\n", intserv[i]);
+int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
+{
+	int rc;
+
+	switch (hp_elog->resource) {
+	case PSERIES_HP_ELOG_RESOURCE_MEM:
+		rc = dlpar_memory(hp_elog);
+		break;
+	case PSERIES_HP_ELOG_RESOURCE_CPU:
+		rc = dlpar_cpu(hp_elog);
+		break;
+	case PSERIES_HP_ELOG_RESOURCE_PMEM:
+		rc = dlpar_hp_pmem(hp_elog);
+		break;
+	case PSERIES_HP_ELOG_RESOURCE_DT:
+		rc = dlpar_hp_dt(hp_elog);
+		break;
+
+	default:
+		pr_warn_ratelimited("Invalid resource (%d) specified\n",
+				    hp_elog->resource);
+		rc = -EINVAL;
 	}
-	cpu_maps_update_done();
 
-out:
 	return rc;
+}
+
+static void pseries_hp_work_fn(struct work_struct *work)
+{
+	struct pseries_hp_work *hp_work =
+			container_of(work, struct pseries_hp_work, work);
 
+	handle_dlpar_errorlog(hp_work->errlog);
+
+	kfree(hp_work->errlog);
+	kfree(work);
 }
 
-static ssize_t dlpar_cpu_release(const char *buf, size_t count)
+void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog)
 {
-	struct device_node *dn;
-	const u32 *drc_index;
-	int rc;
+	struct pseries_hp_work *work;
+	struct pseries_hp_errorlog *hp_errlog_copy;
+
+	hp_errlog_copy = kmemdup(hp_errlog, sizeof(*hp_errlog), GFP_ATOMIC);
+	if (!hp_errlog_copy)
+		return;
+
+	work = kmalloc(sizeof(struct pseries_hp_work), GFP_ATOMIC);
+	if (work) {
+		INIT_WORK((struct work_struct *)work, pseries_hp_work_fn);
+		work->errlog = hp_errlog_copy;
+		queue_work(pseries_hp_wq, (struct work_struct *)work);
+	} else {
+		kfree(hp_errlog_copy);
+	}
+}
 
-	dn = of_find_node_by_path(buf);
-	if (!dn)
+static int dlpar_parse_resource(char **cmd, struct pseries_hp_errorlog *hp_elog)
+{
+	char *arg;
+
+	arg = strsep(cmd, " ");
+	if (!arg)
 		return -EINVAL;
 
-	drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
-	if (!drc_index) {
-		of_node_put(dn);
+	if (sysfs_streq(arg, "memory")) {
+		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_MEM;
+	} else if (sysfs_streq(arg, "cpu")) {
+		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_CPU;
+	} else if (sysfs_streq(arg, "dt")) {
+		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_DT;
+	} else {
+		pr_err("Invalid resource specified.\n");
 		return -EINVAL;
 	}
 
-	cpu_hotplug_driver_lock();
-	rc = dlpar_offline_cpu(dn);
-	if (rc) {
-		of_node_put(dn);
-		rc = -EINVAL;
-		goto out;
-	}
+	return 0;
+}
 
-	rc = dlpar_release_drc(*drc_index);
-	if (rc) {
-		of_node_put(dn);
-		goto out;
+static int dlpar_parse_action(char **cmd, struct pseries_hp_errorlog *hp_elog)
+{
+	char *arg;
+
+	arg = strsep(cmd, " ");
+	if (!arg)
+		return -EINVAL;
+
+	if (sysfs_streq(arg, "add")) {
+		hp_elog->action = PSERIES_HP_ELOG_ACTION_ADD;
+	} else if (sysfs_streq(arg, "remove")) {
+		hp_elog->action = PSERIES_HP_ELOG_ACTION_REMOVE;
+	} else {
+		pr_err("Invalid action specified.\n");
+		return -EINVAL;
 	}
 
-	rc = dlpar_detach_node(dn);
-	if (rc) {
-		dlpar_acquire_drc(*drc_index);
-		goto out;
+	return 0;
+}
+
+static int dlpar_parse_id_type(char **cmd, struct pseries_hp_errorlog *hp_elog)
+{
+	char *arg;
+	u32 count, index;
+
+	arg = strsep(cmd, " ");
+	if (!arg)
+		return -EINVAL;
+
+	if (sysfs_streq(arg, "indexed-count")) {
+		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_IC;
+		arg = strsep(cmd, " ");
+		if (!arg) {
+			pr_err("No DRC count specified.\n");
+			return -EINVAL;
+		}
+
+		if (kstrtou32(arg, 0, &count)) {
+			pr_err("Invalid DRC count specified.\n");
+			return -EINVAL;
+		}
+
+		arg = strsep(cmd, " ");
+		if (!arg) {
+			pr_err("No DRC Index specified.\n");
+			return -EINVAL;
+		}
+
+		if (kstrtou32(arg, 0, &index)) {
+			pr_err("Invalid DRC Index specified.\n");
+			return -EINVAL;
+		}
+
+		hp_elog->_drc_u.ic.count = cpu_to_be32(count);
+		hp_elog->_drc_u.ic.index = cpu_to_be32(index);
+	} else if (sysfs_streq(arg, "index")) {
+		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
+		arg = strsep(cmd, " ");
+		if (!arg) {
+			pr_err("No DRC Index specified.\n");
+			return -EINVAL;
+		}
+
+		if (kstrtou32(arg, 0, &index)) {
+			pr_err("Invalid DRC Index specified.\n");
+			return -EINVAL;
+		}
+
+		hp_elog->_drc_u.drc_index = cpu_to_be32(index);
+	} else if (sysfs_streq(arg, "count")) {
+		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_COUNT;
+		arg = strsep(cmd, " ");
+		if (!arg) {
+			pr_err("No DRC count specified.\n");
+			return -EINVAL;
+		}
+
+		if (kstrtou32(arg, 0, &count)) {
+			pr_err("Invalid DRC count specified.\n");
+			return -EINVAL;
+		}
+
+		hp_elog->_drc_u.drc_count = cpu_to_be32(count);
+	} else {
+		pr_err("Invalid id_type specified.\n");
+		return -EINVAL;
 	}
 
-	of_node_put(dn);
-out:
-	cpu_hotplug_driver_unlock();
+	return 0;
+}
+
+static ssize_t dlpar_store(const struct class *class, const struct class_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct pseries_hp_errorlog hp_elog;
+	char *argbuf;
+	char *args;
+	int rc;
+
+	args = argbuf = kstrdup(buf, GFP_KERNEL);
+	if (!argbuf)
+		return -ENOMEM;
+
+	/*
+	 * Parse out the request from the user, this will be in the form:
+	 * <resource> <action> <id_type> <id>
+	 */
+	rc = dlpar_parse_resource(&args, &hp_elog);
+	if (rc)
+		goto dlpar_store_out;
+
+	rc = dlpar_parse_action(&args, &hp_elog);
+	if (rc)
+		goto dlpar_store_out;
+
+	rc = dlpar_parse_id_type(&args, &hp_elog);
+	if (rc)
+		goto dlpar_store_out;
+
+	rc = handle_dlpar_errorlog(&hp_elog);
+
+dlpar_store_out:
+	kfree(argbuf);
+
+	if (rc)
+		pr_err("Could not handle DLPAR request \"%s\"\n", buf);
+
 	return rc ? rc : count;
 }
 
-static int __init pseries_dlpar_init(void)
+static ssize_t dlpar_show(const struct class *class, const struct class_attribute *attr,
+			  char *buf)
 {
-	ppc_md.cpu_probe = dlpar_cpu_probe;
-	ppc_md.cpu_release = dlpar_cpu_release;
+	return sprintf(buf, "%s\n", "memory,cpu,dt");
+}
 
-	return 0;
+static CLASS_ATTR_RW(dlpar);
+
+int __init dlpar_workqueue_init(void)
+{
+	if (pseries_hp_wq)
+		return 0;
+
+	pseries_hp_wq = alloc_ordered_workqueue("pseries hotplug workqueue", 0);
+
+	return pseries_hp_wq ? 0 : -ENOMEM;
+}
+
+static int __init dlpar_sysfs_init(void)
+{
+	int rc;
+
+	rc = dlpar_workqueue_init();
+	if (rc)
+		return rc;
+
+	return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);
 }
-machine_device_initcall(pseries, pseries_dlpar_init);
+machine_device_initcall(pseries, dlpar_sysfs_init);
 
-#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */