5 files changed, 626 insertions, 249 deletions

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index f244dcb4f..2b93ae8d5 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -20,7 +20,6 @@
 #include <linux/of.h>
 
 #include "of_helpers.h"
-#include "offline_states.h"
 #include "pseries.h"
 
 #include <asm/prom.h>
@@ -338,185 +337,6 @@ int dlpar_release_drc(u32 drc_index)
 	return 0;
 }
 
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
-
-static int dlpar_online_cpu(struct device_node *dn)
-{
-	int rc = 0;
-	unsigned int cpu;
-	int len, nthreads, i;
-	const __be32 *intserv;
-	u32 thread;
-
-	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
-	if (!intserv)
-		return -EINVAL;
-
-	nthreads = len / sizeof(u32);
-
-	cpu_maps_update_begin();
-	for (i = 0; i < nthreads; i++) {
-		thread = be32_to_cpu(intserv[i]);
-		for_each_present_cpu(cpu) {
-			if (get_hard_smp_processor_id(cpu) != thread)
-				continue;
-			BUG_ON(get_cpu_current_state(cpu)
-					!= CPU_STATE_OFFLINE);
-			cpu_maps_update_done();
-			rc = device_online(get_cpu_device(cpu));
-			if (rc)
-				goto out;
-			cpu_maps_update_begin();
-
-			break;
-		}
-		if (cpu == num_possible_cpus())
-			printk(KERN_WARNING "Could not find cpu to online "
-			       "with physical id 0x%x\n", thread);
-	}
-	cpu_maps_update_done();
-
-out:
-	return rc;
-
-}
-
-static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
-{
-	struct device_node *dn, *parent;
-	u32 drc_index;
-	int rc;
-
-	rc = kstrtou32(buf, 0, &drc_index);
-	if (rc)
-		return -EINVAL;
-
-	rc = dlpar_acquire_drc(drc_index);
-	if (rc)
-		return -EINVAL;
-
-	parent = of_find_node_by_path("/cpus");
-	if (!parent)
-		return -ENODEV;
-
-	dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
-	of_node_put(parent);
-	if (!dn) {
-		dlpar_release_drc(drc_index);
-		return -EINVAL;
-	}
-
-	rc = dlpar_attach_node(dn);
-	if (rc) {
-		dlpar_release_drc(drc_index);
-		dlpar_free_cc_nodes(dn);
-		return rc;
-	}
-
-	rc = dlpar_online_cpu(dn);
-	if (rc)
-		return rc;
-
-	return count;
-}
-
-static int dlpar_offline_cpu(struct device_node *dn)
-{
-	int rc = 0;
-	unsigned int cpu;
-	int len, nthreads, i;
-	const __be32 *intserv;
-	u32 thread;
-
-	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
-	if (!intserv)
-		return -EINVAL;
-
-	nthreads = len / sizeof(u32);
-
-	cpu_maps_update_begin();
-	for (i = 0; i < nthreads; i++) {
-		thread = be32_to_cpu(intserv[i]);
-		for_each_present_cpu(cpu) {
-			if (get_hard_smp_processor_id(cpu) != thread)
-				continue;
-
-			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
-				break;
-
-			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
-				set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
-				cpu_maps_update_done();
-				rc = device_offline(get_cpu_device(cpu));
-				if (rc)
-					goto out;
-				cpu_maps_update_begin();
-				break;
-
-			}
-
-			/*
-			 * 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, thread)
-								!= 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", thread);
-	}
-	cpu_maps_update_done();
-
-out:
-	return rc;
-
-}
-
-static ssize_t dlpar_cpu_release(const char *buf, size_t count)
-{
-	struct device_node *dn;
-	u32 drc_index;
-	int rc;
-
-	dn = of_find_node_by_path(buf);
-	if (!dn)
-		return -EINVAL;
-
-	rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index);
-	if (rc) {
-		of_node_put(dn);
-		return -EINVAL;
-	}
-
-	rc = dlpar_offline_cpu(dn);
-	if (rc) {
-		of_node_put(dn);
-		return -EINVAL;
-	}
-
-	rc = dlpar_release_drc(drc_index);
-	if (rc) {
-		of_node_put(dn);
-		return rc;
-	}
-
-	rc = dlpar_detach_node(dn);
-	if (rc) {
-		dlpar_acquire_drc(drc_index);
-		return rc;
-	}
-
-	of_node_put(dn);
-
-	return count;
-}
-
-#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
-
 static int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
 {
 	int rc;
@@ -536,6 +356,9 @@ static int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
 	case PSERIES_HP_ELOG_RESOURCE_MEM:
 		rc = dlpar_memory(hp_elog);
 		break;
+	case PSERIES_HP_ELOG_RESOURCE_CPU:
+		rc = dlpar_cpu(hp_elog);
+		break;
 	default:
 		pr_warn_ratelimited("Invalid resource (%d) specified\n",
 				    hp_elog->resource);
@@ -565,6 +388,9 @@ static ssize_t dlpar_store(struct class *class, struct class_attribute *attr,
 	if (!strncmp(arg, "memory", 6)) {
 		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_MEM;
 		arg += strlen("memory ");
+	} else if (!strncmp(arg, "cpu", 3)) {
+		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_CPU;
+		arg += strlen("cpu ");
 	} else {
 		pr_err("Invalid resource specified: \"%s\"\n", buf);
 		rc = -EINVAL;
@@ -624,16 +450,7 @@ static CLASS_ATTR(dlpar, S_IWUSR, NULL, dlpar_store);
 
 static int __init pseries_dlpar_init(void)
 {
-	int rc;
-
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
-	ppc_md.cpu_probe = dlpar_cpu_probe;
-	ppc_md.cpu_release = dlpar_cpu_release;
-#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
-
-	rc = sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);
-
-	return rc;
+	return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);
 }
 machine_device_initcall(pseries, pseries_dlpar_init);
 
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 62475440f..32274f72f 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -18,12 +18,15 @@
  *      2 of the License, or (at your option) any later version.
  */
 
+#define pr_fmt(fmt)     "pseries-hotplug-cpu: " fmt
+
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/sched.h>	/* for idle_task_exit */
 #include <linux/cpu.h>
 #include <linux/of.h>
+#include <linux/slab.h>
 #include <asm/prom.h>
 #include <asm/rtas.h>
 #include <asm/firmware.h>
@@ -32,6 +35,7 @@
 #include <asm/xics.h>
 #include <asm/plpar_wrappers.h>
 
+#include "pseries.h"
 #include "offline_states.h"
 
 /* This version can't take the spinlock, because it never returns */
@@ -88,13 +92,7 @@ void set_default_offline_state(int cpu)
 
 static void rtas_stop_self(void)
 {
-	static struct rtas_args args = {
-		.nargs = 0,
-		.nret = cpu_to_be32(1),
-		.rets = &args.args[0],
-	};
-
-	args.token = cpu_to_be32(rtas_stop_self_token);
+	static struct rtas_args args;
 
 	local_irq_disable();
 
@@ -102,7 +100,8 @@ static void rtas_stop_self(void)
 
 	printk("cpu %u (hwid %u) Ready to die...\n",
 	       smp_processor_id(), hard_smp_processor_id());
-	enter_rtas(__pa(&args));
+
+	rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL);
 
 	panic("Alas, I survived.\n");
 }
@@ -339,6 +338,536 @@ static void pseries_remove_processor(struct device_node *np)
 	cpu_maps_update_done();
 }
 
+static int dlpar_online_cpu(struct device_node *dn)
+{
+	int rc = 0;
+	unsigned int cpu;
+	int len, nthreads, i;
+	const __be32 *intserv;
+	u32 thread;
+
+	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
+	if (!intserv)
+		return -EINVAL;
+
+	nthreads = len / sizeof(u32);
+
+	cpu_maps_update_begin();
+	for (i = 0; i < nthreads; i++) {
+		thread = be32_to_cpu(intserv[i]);
+		for_each_present_cpu(cpu) {
+			if (get_hard_smp_processor_id(cpu) != thread)
+				continue;
+			BUG_ON(get_cpu_current_state(cpu)
+					!= CPU_STATE_OFFLINE);
+			cpu_maps_update_done();
+			rc = device_online(get_cpu_device(cpu));
+			if (rc)
+				goto out;
+			cpu_maps_update_begin();
+
+			break;
+		}
+		if (cpu == num_possible_cpus())
+			printk(KERN_WARNING "Could not find cpu to online "
+			       "with physical id 0x%x\n", thread);
+	}
+	cpu_maps_update_done();
+
+out:
+	return rc;
+
+}
+
+static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
+{
+	struct device_node *child = NULL;
+	u32 my_drc_index;
+	bool found;
+	int rc;
+
+	/* Assume cpu doesn't exist */
+	found = false;
+
+	for_each_child_of_node(parent, child) {
+		rc = of_property_read_u32(child, "ibm,my-drc-index",
+					  &my_drc_index);
+		if (rc)
+			continue;
+
+		if (my_drc_index == drc_index) {
+			of_node_put(child);
+			found = true;
+			break;
+		}
+	}
+
+	return found;
+}
+
+static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
+{
+	bool found = false;
+	int rc, index;
+
+	index = 0;
+	while (!found) {
+		u32 drc;
+
+		rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
+						index++, &drc);
+		if (rc)
+			break;
+
+		if (drc == drc_index)
+			found = true;
+	}
+
+	return found;
+}
+
+static ssize_t dlpar_cpu_add(u32 drc_index)
+{
+	struct device_node *dn, *parent;
+	int rc, saved_rc;
+
+	pr_debug("Attempting to add CPU, drc index: %x\n", drc_index);
+
+	parent = of_find_node_by_path("/cpus");
+	if (!parent) {
+		pr_warn("Failed to find CPU root node \"/cpus\"\n");
+		return -ENODEV;
+	}
+
+	if (dlpar_cpu_exists(parent, drc_index)) {
+		of_node_put(parent);
+		pr_warn("CPU with drc index %x already exists\n", drc_index);
+		return -EINVAL;
+	}
+
+	if (!valid_cpu_drc_index(parent, drc_index)) {
+		of_node_put(parent);
+		pr_warn("Cannot find CPU (drc index %x) to add.\n", drc_index);
+		return -EINVAL;
+	}
+
+	rc = dlpar_acquire_drc(drc_index);
+	if (rc) {
+		pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n",
+			rc, drc_index);
+		of_node_put(parent);
+		return -EINVAL;
+	}
+
+	dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
+	of_node_put(parent);
+	if (!dn) {
+		pr_warn("Failed call to configure-connector, drc index: %x\n",
+			drc_index);
+		dlpar_release_drc(drc_index);
+		return -EINVAL;
+	}
+
+	rc = dlpar_attach_node(dn);
+	if (rc) {
+		saved_rc = rc;
+		pr_warn("Failed to attach node %s, rc: %d, drc index: %x\n",
+			dn->name, rc, drc_index);
+
+		rc = dlpar_release_drc(drc_index);
+		if (!rc)
+			dlpar_free_cc_nodes(dn);
+
+		return saved_rc;
+	}
+
+	rc = dlpar_online_cpu(dn);
+	if (rc) {
+		saved_rc = rc;
+		pr_warn("Failed to online cpu %s, rc: %d, drc index: %x\n",
+			dn->name, rc, drc_index);
+
+		rc = dlpar_detach_node(dn);
+		if (!rc)
+			dlpar_release_drc(drc_index);
+
+		return saved_rc;
+	}
+
+	pr_debug("Successfully added CPU %s, drc index: %x\n", dn->name,
+		 drc_index);
+	return rc;
+}
+
+static int dlpar_offline_cpu(struct device_node *dn)
+{
+	int rc = 0;
+	unsigned int cpu;
+	int len, nthreads, i;
+	const __be32 *intserv;
+	u32 thread;
+
+	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
+	if (!intserv)
+		return -EINVAL;
+
+	nthreads = len / sizeof(u32);
+
+	cpu_maps_update_begin();
+	for (i = 0; i < nthreads; i++) {
+		thread = be32_to_cpu(intserv[i]);
+		for_each_present_cpu(cpu) {
+			if (get_hard_smp_processor_id(cpu) != thread)
+				continue;
+
+			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
+				break;
+
+			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
+				set_preferred_offline_state(cpu,
+							    CPU_STATE_OFFLINE);
+				cpu_maps_update_done();
+				rc = device_offline(get_cpu_device(cpu));
+				if (rc)
+					goto out;
+				cpu_maps_update_begin();
+				break;
+
+			}
+
+			/*
+			 * 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, thread)
+								!= 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", thread);
+	}
+	cpu_maps_update_done();
+
+out:
+	return rc;
+
+}
+
+static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
+{
+	int rc;
+
+	pr_debug("Attemping to remove CPU %s, drc index: %x\n",
+		 dn->name, drc_index);
+
+	rc = dlpar_offline_cpu(dn);
+	if (rc) {
+		pr_warn("Failed to offline CPU %s, rc: %d\n", dn->name, rc);
+		return -EINVAL;
+	}
+
+	rc = dlpar_release_drc(drc_index);
+	if (rc) {
+		pr_warn("Failed to release drc (%x) for CPU %s, rc: %d\n",
+			drc_index, dn->name, rc);
+		dlpar_online_cpu(dn);
+		return rc;
+	}
+
+	rc = dlpar_detach_node(dn);
+	if (rc) {
+		int saved_rc = rc;
+
+		pr_warn("Failed to detach CPU %s, rc: %d", dn->name, rc);
+
+		rc = dlpar_acquire_drc(drc_index);
+		if (!rc)
+			dlpar_online_cpu(dn);
+
+		return saved_rc;
+	}
+
+	pr_debug("Successfully removed CPU, drc index: %x\n", drc_index);
+	return 0;
+}
+
+static struct device_node *cpu_drc_index_to_dn(u32 drc_index)
+{
+	struct device_node *dn;
+	u32 my_index;
+	int rc;
+
+	for_each_node_by_type(dn, "cpu") {
+		rc = of_property_read_u32(dn, "ibm,my-drc-index", &my_index);
+		if (rc)
+			continue;
+
+		if (my_index == drc_index)
+			break;
+	}
+
+	return dn;
+}
+
+static int dlpar_cpu_remove_by_index(u32 drc_index)
+{
+	struct device_node *dn;
+	int rc;
+
+	dn = cpu_drc_index_to_dn(drc_index);
+	if (!dn) {
+		pr_warn("Cannot find CPU (drc index %x) to remove\n",
+			drc_index);
+		return -ENODEV;
+	}
+
+	rc = dlpar_cpu_remove(dn, drc_index);
+	of_node_put(dn);
+	return rc;
+}
+
+static int find_dlpar_cpus_to_remove(u32 *cpu_drcs, int cpus_to_remove)
+{
+	struct device_node *dn;
+	int cpus_found = 0;
+	int rc;
+
+	/* We want to find cpus_to_remove + 1 CPUs to ensure we do not
+	 * remove the last CPU.
+	 */
+	for_each_node_by_type(dn, "cpu") {
+		cpus_found++;
+
+		if (cpus_found > cpus_to_remove) {
+			of_node_put(dn);
+			break;
+		}
+
+		/* Note that cpus_found is always 1 ahead of the index
+		 * into the cpu_drcs array, so we use cpus_found - 1
+		 */
+		rc = of_property_read_u32(dn, "ibm,my-drc-index",
+					  &cpu_drcs[cpus_found - 1]);
+		if (rc) {
+			pr_warn("Error occurred getting drc-index for %s\n",
+				dn->name);
+			of_node_put(dn);
+			return -1;
+		}
+	}
+
+	if (cpus_found < cpus_to_remove) {
+		pr_warn("Failed to find enough CPUs (%d of %d) to remove\n",
+			cpus_found, cpus_to_remove);
+	} else if (cpus_found == cpus_to_remove) {
+		pr_warn("Cannot remove all CPUs\n");
+	}
+
+	return cpus_found;
+}
+
+static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
+{
+	u32 *cpu_drcs;
+	int cpus_found;
+	int cpus_removed = 0;
+	int i, rc;
+
+	pr_debug("Attempting to hot-remove %d CPUs\n", cpus_to_remove);
+
+	cpu_drcs = kcalloc(cpus_to_remove, sizeof(*cpu_drcs), GFP_KERNEL);
+	if (!cpu_drcs)
+		return -EINVAL;
+
+	cpus_found = find_dlpar_cpus_to_remove(cpu_drcs, cpus_to_remove);
+	if (cpus_found <= cpus_to_remove) {
+		kfree(cpu_drcs);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < cpus_to_remove; i++) {
+		rc = dlpar_cpu_remove_by_index(cpu_drcs[i]);
+		if (rc)
+			break;
+
+		cpus_removed++;
+	}
+
+	if (cpus_removed != cpus_to_remove) {
+		pr_warn("CPU hot-remove failed, adding back removed CPUs\n");
+
+		for (i = 0; i < cpus_removed; i++)
+			dlpar_cpu_add(cpu_drcs[i]);
+
+		rc = -EINVAL;
+	} else {
+		rc = 0;
+	}
+
+	kfree(cpu_drcs);
+	return rc;
+}
+
+static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
+{
+	struct device_node *parent;
+	int cpus_found = 0;
+	int index, rc;
+
+	parent = of_find_node_by_path("/cpus");
+	if (!parent) {
+		pr_warn("Could not find CPU root node in device tree\n");
+		kfree(cpu_drcs);
+		return -1;
+	}
+
+	/* Search the ibm,drc-indexes array for possible CPU drcs to
+	 * add. Note that the format of the ibm,drc-indexes array is
+	 * the number of entries in the array followed by the array
+	 * of drc values so we start looking at index = 1.
+	 */
+	index = 1;
+	while (cpus_found < cpus_to_add) {
+		u32 drc;
+
+		rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
+						index++, &drc);
+		if (rc)
+			break;
+
+		if (dlpar_cpu_exists(parent, drc))
+			continue;
+
+		cpu_drcs[cpus_found++] = drc;
+	}
+
+	of_node_put(parent);
+	return cpus_found;
+}
+
+static int dlpar_cpu_add_by_count(u32 cpus_to_add)
+{
+	u32 *cpu_drcs;
+	int cpus_added = 0;
+	int cpus_found;
+	int i, rc;
+
+	pr_debug("Attempting to hot-add %d CPUs\n", cpus_to_add);
+
+	cpu_drcs = kcalloc(cpus_to_add, sizeof(*cpu_drcs), GFP_KERNEL);
+	if (!cpu_drcs)
+		return -EINVAL;
+
+	cpus_found = find_dlpar_cpus_to_add(cpu_drcs, cpus_to_add);
+	if (cpus_found < cpus_to_add) {
+		pr_warn("Failed to find enough CPUs (%d of %d) to add\n",
+			cpus_found, cpus_to_add);
+		kfree(cpu_drcs);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < cpus_to_add; i++) {
+		rc = dlpar_cpu_add(cpu_drcs[i]);
+		if (rc)
+			break;
+
+		cpus_added++;
+	}
+
+	if (cpus_added < cpus_to_add) {
+		pr_warn("CPU hot-add failed, removing any added CPUs\n");
+
+		for (i = 0; i < cpus_added; i++)
+			dlpar_cpu_remove_by_index(cpu_drcs[i]);
+
+		rc = -EINVAL;
+	} else {
+		rc = 0;
+	}
+
+	kfree(cpu_drcs);
+	return rc;
+}
+
+int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
+{
+	u32 count, drc_index;
+	int rc;
+
+	count = hp_elog->_drc_u.drc_count;
+	drc_index = hp_elog->_drc_u.drc_index;
+
+	lock_device_hotplug();
+
+	switch (hp_elog->action) {
+	case PSERIES_HP_ELOG_ACTION_REMOVE:
+		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
+			rc = dlpar_cpu_remove_by_count(count);
+		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
+			rc = dlpar_cpu_remove_by_index(drc_index);
+		else
+			rc = -EINVAL;
+		break;
+	case PSERIES_HP_ELOG_ACTION_ADD:
+		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
+			rc = dlpar_cpu_add_by_count(count);
+		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
+			rc = dlpar_cpu_add(drc_index);
+		else
+			rc = -EINVAL;
+		break;
+	default:
+		pr_err("Invalid action (%d) specified\n", hp_elog->action);
+		rc = -EINVAL;
+		break;
+	}
+
+	unlock_device_hotplug();
+	return rc;
+}
+
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+
+static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+{
+	u32 drc_index;
+	int rc;
+
+	rc = kstrtou32(buf, 0, &drc_index);
+	if (rc)
+		return -EINVAL;
+
+	rc = dlpar_cpu_add(drc_index);
+
+	return rc ? rc : count;
+}
+
+static ssize_t dlpar_cpu_release(const char *buf, size_t count)
+{
+	struct device_node *dn;
+	u32 drc_index;
+	int rc;
+
+	dn = of_find_node_by_path(buf);
+	if (!dn)
+		return -EINVAL;
+
+	rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index);
+	if (rc) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	rc = dlpar_cpu_remove(dn, drc_index);
+	of_node_put(dn);
+
+	return rc ? rc : count;
+}
+
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
 static int pseries_smp_notifier(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
@@ -385,6 +914,11 @@ static int __init pseries_cpu_hotplug_init(void)
 	int cpu;
 	int qcss_tok;
 
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+	ppc_md.cpu_probe = dlpar_cpu_probe;
+	ppc_md.cpu_release = dlpar_cpu_release;
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
 	for_each_node_by_name(np, "interrupt-controller") {
 		typep = of_get_property(np, "compatible", NULL);
 		if (strstr(typep, "open-pic")) {
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index b7a67e3d2..477290ad8 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -315,48 +315,48 @@ static long pSeries_lpar_hpte_updatepp(unsigned long slot,
 	return 0;
 }
 
-static unsigned long pSeries_lpar_hpte_getword0(unsigned long slot)
+static long __pSeries_lpar_hpte_find(unsigned long want_v, unsigned long hpte_group)
 {
-	unsigned long dword0;
-	unsigned long lpar_rc;
-	unsigned long dummy_word1;
-	unsigned long flags;
+	long lpar_rc;
+	unsigned long i, j;
+	struct {
+		unsigned long pteh;
+		unsigned long ptel;
+	} ptes[4];
 
-	/* Read 1 pte at a time                        */
-	/* Do not need RPN to logical page translation */
-	/* No cross CEC PFT access                     */
-	flags = 0;
+	for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
 
-	lpar_rc = plpar_pte_read(flags, slot, &dword0, &dummy_word1);
+		lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
+		if (lpar_rc != H_SUCCESS)
+			continue;
 
-	BUG_ON(lpar_rc != H_SUCCESS);
+		for (j = 0; j < 4; j++) {
+			if (HPTE_V_COMPARE(ptes[j].pteh, want_v) &&
+			    (ptes[j].pteh & HPTE_V_VALID))
+				return i + j;
+		}
+	}
 
-	return dword0;
+	return -1;
 }
 
 static long pSeries_lpar_hpte_find(unsigned long vpn, int psize, int ssize)
 {
-	unsigned long hash;
-	unsigned long i;
 	long slot;
-	unsigned long want_v, hpte_v;
+	unsigned long hash;
+	unsigned long want_v;
+	unsigned long hpte_group;
 
 	hash = hpt_hash(vpn, mmu_psize_defs[psize].shift, ssize);
 	want_v = hpte_encode_avpn(vpn, psize, ssize);
 
 	/* Bolted entries are always in the primary group */
-	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
-	for (i = 0; i < HPTES_PER_GROUP; i++) {
-		hpte_v = pSeries_lpar_hpte_getword0(slot);
-
-		if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID))
-			/* HPTE matches */
-			return slot;
-		++slot;
-	}
-
-	return -1;
-} 
+	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+	slot = __pSeries_lpar_hpte_find(want_v, hpte_group);
+	if (slot < 0)
+		return -1;
+	return hpte_group + slot;
+}
 
 static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
 					     unsigned long ea,
@@ -396,6 +396,7 @@ static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
 	BUG_ON(lpar_rc != H_SUCCESS);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /*
  * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
  * to make sure that we avoid bouncing the hypervisor tlbie lock.
@@ -494,6 +495,15 @@ static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
 		__pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
 						   index, psize, ssize);
 }
+#else
+static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
+					     unsigned long addr,
+					     unsigned char *hpte_slot_array,
+					     int psize, int ssize, int local)
+{
+	WARN(1, "%s called without THP support\n", __func__);
+}
+#endif
 
 static void pSeries_lpar_hpte_removebolted(unsigned long ea,
 					   int psize, int ssize)
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 8411c2729..7aa83f00a 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -73,6 +73,15 @@ static inline int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 }
 #endif
 
+#ifdef CONFIG_HOTPLUG_CPU
+int dlpar_cpu(struct pseries_hp_errorlog *hp_elog);
+#else
+static inline int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 /* PCI root bridge prepare function override for pseries */
 struct pci_host_bridge;
 int pseries_root_bridge_prepare(struct pci_host_bridge *bridge);
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 3b6647e57..9a3e27b86 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -40,6 +40,9 @@ static int ras_check_exception_token;
 #define EPOW_SENSOR_TOKEN	9
 #define EPOW_SENSOR_INDEX	0
 
+/* EPOW events counter variable */
+static int num_epow_events;
+
 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
 static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
 
@@ -82,32 +85,30 @@ static void handle_system_shutdown(char event_modifier)
 {
 	switch (event_modifier) {
 	case EPOW_SHUTDOWN_NORMAL:
-		pr_emerg("Firmware initiated power off");
+		pr_emerg("Power off requested\n");
 		orderly_poweroff(true);
 		break;
 
 	case EPOW_SHUTDOWN_ON_UPS:
-		pr_emerg("Loss of power reported by firmware, system is "
-			"running on UPS/battery");
-		pr_emerg("Check RTAS error log for details");
+		pr_emerg("Loss of system power detected. System is running on"
+			 " UPS/battery. Check RTAS error log for details\n");
 		orderly_poweroff(true);
 		break;
 
 	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
-		pr_emerg("Loss of system critical functions reported by "
-			"firmware");
-		pr_emerg("Check RTAS error log for details");
+		pr_emerg("Loss of system critical functions detected. Check"
+			 " RTAS error log for details\n");
 		orderly_poweroff(true);
 		break;
 
 	case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
-		pr_emerg("Ambient temperature too high reported by firmware");
-		pr_emerg("Check RTAS error log for details");
+		pr_emerg("High ambient temperature detected. Check RTAS"
+			 " error log for details\n");
 		orderly_poweroff(true);
 		break;
 
 	default:
-		pr_err("Unknown power/cooling shutdown event (modifier %d)",
+		pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
 			event_modifier);
 	}
 }
@@ -145,17 +146,20 @@ static void rtas_parse_epow_errlog(struct rtas_error_log *log)
 
 	switch (action_code) {
 	case EPOW_RESET:
-		pr_err("Non critical power or cooling issue cleared");
+		if (num_epow_events) {
+			pr_info("Non critical power/cooling issue cleared\n");
+			num_epow_events--;
+		}
 		break;
 
 	case EPOW_WARN_COOLING:
-		pr_err("Non critical cooling issue reported by firmware");
-		pr_err("Check RTAS error log for details");
+		pr_info("Non-critical cooling issue detected. Check RTAS error"
+			" log for details\n");
 		break;
 
 	case EPOW_WARN_POWER:
-		pr_err("Non critical power issue reported by firmware");
-		pr_err("Check RTAS error log for details");
+		pr_info("Non-critical power issue detected. Check RTAS error"
+			" log for details\n");
 		break;
 
 	case EPOW_SYSTEM_SHUTDOWN:
@@ -163,23 +167,27 @@ static void rtas_parse_epow_errlog(struct rtas_error_log *log)
 		break;
 
 	case EPOW_SYSTEM_HALT:
-		pr_emerg("Firmware initiated power off");
+		pr_emerg("Critical power/cooling issue detected. Check RTAS"
+			 " error log for details. Powering off.\n");
 		orderly_poweroff(true);
 		break;
 
 	case EPOW_MAIN_ENCLOSURE:
 	case EPOW_POWER_OFF:
-		pr_emerg("Critical power/cooling issue reported by firmware");
-		pr_emerg("Check RTAS error log for details");
-		pr_emerg("Immediate power off");
+		pr_emerg("System about to lose power. Check RTAS error log "
+			 " for details. Powering off immediately.\n");
 		emergency_sync();
 		kernel_power_off();
 		break;
 
 	default:
-		pr_err("Unknown power/cooling event (action code %d)",
+		pr_err("Unknown power/cooling event (action code  = %d)\n",
 			action_code);
 	}
+
+	/* Increment epow events counter variable */
+	if (action_code != EPOW_RESET)
+		num_epow_events++;
 }
 
 /* Handle environmental and power warning (EPOW) interrupts. */
@@ -249,13 +257,12 @@ static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
 	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
 
 	if (fatal) {
-		pr_emerg("Fatal hardware error reported by firmware");
-		pr_emerg("Check RTAS error log for details");
-		pr_emerg("Immediate power off");
+		pr_emerg("Fatal hardware error detected. Check RTAS error"
+			 " log for details. Powering off immediately\n");
 		emergency_sync();
 		kernel_power_off();
 	} else {
-		pr_err("Recoverable hardware error reported by firmware");
+		pr_err("Recoverable hardware error detected\n");
 	}
 
 	spin_unlock(&ras_log_buf_lock);