Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 923 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
new file mode 100644
index 0000000000..4adca5b61d
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -0,0 +1,923 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pseries Memory Hotplug infrastructure.
+ *
+ * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
+ */
+
+#define pr_fmt(fmt)	"pseries-hotplug-mem: " fmt
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/memblock.h>
+#include <linux/memory.h>
+#include <linux/memory_hotplug.h>
+#include <linux/slab.h>
+
+#include <asm/firmware.h>
+#include <asm/machdep.h>
+#include <asm/sparsemem.h>
+#include <asm/fadump.h>
+#include <asm/drmem.h>
+#include "pseries.h"
+
+static void dlpar_free_property(struct property *prop)
+{
+	kfree(prop->name);
+	kfree(prop->value);
+	kfree(prop);
+}
+
+static struct property *dlpar_clone_property(struct property *prop,
+					     u32 prop_size)
+{
+	struct property *new_prop;
+
+	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
+	if (!new_prop)
+		return NULL;
+
+	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
+	new_prop->value = kzalloc(prop_size, GFP_KERNEL);
+	if (!new_prop->name || !new_prop->value) {
+		dlpar_free_property(new_prop);
+		return NULL;
+	}
+
+	memcpy(new_prop->value, prop->value, prop->length);
+	new_prop->length = prop_size;
+
+	of_property_set_flag(new_prop, OF_DYNAMIC);
+	return new_prop;
+}
+
+static bool find_aa_index(struct device_node *dr_node,
+			 struct property *ala_prop,
+			 const u32 *lmb_assoc, u32 *aa_index)
+{
+	u32 *assoc_arrays, new_prop_size;
+	struct property *new_prop;
+	int aa_arrays, aa_array_entries, aa_array_sz;
+	int i, index;
+
+	/*
+	 * The ibm,associativity-lookup-arrays property is defined to be
+	 * a 32-bit value specifying the number of associativity arrays
+	 * followed by a 32-bitvalue specifying the number of entries per
+	 * array, followed by the associativity arrays.
+	 */
+	assoc_arrays = ala_prop->value;
+
+	aa_arrays = be32_to_cpu(assoc_arrays[0]);
+	aa_array_entries = be32_to_cpu(assoc_arrays[1]);
+	aa_array_sz = aa_array_entries * sizeof(u32);
+
+	for (i = 0; i < aa_arrays; i++) {
+		index = (i * aa_array_entries) + 2;
+
+		if (memcmp(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz))
+			continue;
+
+		*aa_index = i;
+		return true;
+	}
+
+	new_prop_size = ala_prop->length + aa_array_sz;
+	new_prop = dlpar_clone_property(ala_prop, new_prop_size);
+	if (!new_prop)
+		return false;
+
+	assoc_arrays = new_prop->value;
+
+	/* increment the number of entries in the lookup array */
+	assoc_arrays[0] = cpu_to_be32(aa_arrays + 1);
+
+	/* copy the new associativity into the lookup array */
+	index = aa_arrays * aa_array_entries + 2;
+	memcpy(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz);
+
+	of_update_property(dr_node, new_prop);
+
+	/*
+	 * The associativity lookup array index for this lmb is
+	 * number of entries - 1 since we added its associativity
+	 * to the end of the lookup array.
+	 */
+	*aa_index = be32_to_cpu(assoc_arrays[0]) - 1;
+	return true;
+}
+
+static int update_lmb_associativity_index(struct drmem_lmb *lmb)
+{
+	struct device_node *parent, *lmb_node, *dr_node;
+	struct property *ala_prop;
+	const u32 *lmb_assoc;
+	u32 aa_index;
+	bool found;
+
+	parent = of_find_node_by_path("/");
+	if (!parent)
+		return -ENODEV;
+
+	lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
+					     parent);
+	of_node_put(parent);
+	if (!lmb_node)
+		return -EINVAL;
+
+	lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
+	if (!lmb_assoc) {
+		dlpar_free_cc_nodes(lmb_node);
+		return -ENODEV;
+	}
+
+	update_numa_distance(lmb_node);
+
+	dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dr_node) {
+		dlpar_free_cc_nodes(lmb_node);
+		return -ENODEV;
+	}
+
+	ala_prop = of_find_property(dr_node, "ibm,associativity-lookup-arrays",
+				    NULL);
+	if (!ala_prop) {
+		of_node_put(dr_node);
+		dlpar_free_cc_nodes(lmb_node);
+		return -ENODEV;
+	}
+
+	found = find_aa_index(dr_node, ala_prop, lmb_assoc, &aa_index);
+
+	of_node_put(dr_node);
+	dlpar_free_cc_nodes(lmb_node);
+
+	if (!found) {
+		pr_err("Could not find LMB associativity\n");
+		return -1;
+	}
+
+	lmb->aa_index = aa_index;
+	return 0;
+}
+
+static struct memory_block *lmb_to_memblock(struct drmem_lmb *lmb)
+{
+	unsigned long section_nr;
+	struct memory_block *mem_block;
+
+	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
+
+	mem_block = find_memory_block(section_nr);
+	return mem_block;
+}
+
+static int get_lmb_range(u32 drc_index, int n_lmbs,
+			 struct drmem_lmb **start_lmb,
+			 struct drmem_lmb **end_lmb)
+{
+	struct drmem_lmb *lmb, *start, *end;
+	struct drmem_lmb *limit;
+
+	start = NULL;
+	for_each_drmem_lmb(lmb) {
+		if (lmb->drc_index == drc_index) {
+			start = lmb;
+			break;
+		}
+	}
+
+	if (!start)
+		return -EINVAL;
+
+	end = &start[n_lmbs];
+
+	limit = &drmem_info->lmbs[drmem_info->n_lmbs];
+	if (end > limit)
+		return -EINVAL;
+
+	*start_lmb = start;
+	*end_lmb = end;
+	return 0;
+}
+
+static int dlpar_change_lmb_state(struct drmem_lmb *lmb, bool online)
+{
+	struct memory_block *mem_block;
+	int rc;
+
+	mem_block = lmb_to_memblock(lmb);
+	if (!mem_block)
+		return -EINVAL;
+
+	if (online && mem_block->dev.offline)
+		rc = device_online(&mem_block->dev);
+	else if (!online && !mem_block->dev.offline)
+		rc = device_offline(&mem_block->dev);
+	else
+		rc = 0;
+
+	put_device(&mem_block->dev);
+
+	return rc;
+}
+
+static int dlpar_online_lmb(struct drmem_lmb *lmb)
+{
+	return dlpar_change_lmb_state(lmb, true);
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static int dlpar_offline_lmb(struct drmem_lmb *lmb)
+{
+	return dlpar_change_lmb_state(lmb, false);
+}
+
+static int pseries_remove_memblock(unsigned long base, unsigned long memblock_size)
+{
+	unsigned long start_pfn;
+	int sections_per_block;
+	int i;
+
+	start_pfn = base >> PAGE_SHIFT;
+
+	lock_device_hotplug();
+
+	if (!pfn_valid(start_pfn))
+		goto out;
+
+	sections_per_block = memory_block_size / MIN_MEMORY_BLOCK_SIZE;
+
+	for (i = 0; i < sections_per_block; i++) {
+		__remove_memory(base, MIN_MEMORY_BLOCK_SIZE);
+		base += MIN_MEMORY_BLOCK_SIZE;
+	}
+
+out:
+	/* Update memory regions for memory remove */
+	memblock_remove(base, memblock_size);
+	unlock_device_hotplug();
+	return 0;
+}
+
+static int pseries_remove_mem_node(struct device_node *np)
+{
+	int ret;
+	struct resource res;
+
+	/*
+	 * Check to see if we are actually removing memory
+	 */
+	if (!of_node_is_type(np, "memory"))
+		return 0;
+
+	/*
+	 * Find the base address and size of the memblock
+	 */
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret)
+		return ret;
+
+	pseries_remove_memblock(res.start, resource_size(&res));
+	return 0;
+}
+
+static bool lmb_is_removable(struct drmem_lmb *lmb)
+{
+	if ((lmb->flags & DRCONF_MEM_RESERVED) ||
+		!(lmb->flags & DRCONF_MEM_ASSIGNED))
+		return false;
+
+#ifdef CONFIG_FA_DUMP
+	/*
+	 * Don't hot-remove memory that falls in fadump boot memory area
+	 * and memory that is reserved for capturing old kernel memory.
+	 */
+	if (is_fadump_memory_area(lmb->base_addr, memory_block_size_bytes()))
+		return false;
+#endif
+	/* device_offline() will determine if we can actually remove this lmb */
+	return true;
+}
+
+static int dlpar_add_lmb(struct drmem_lmb *);
+
+static int dlpar_remove_lmb(struct drmem_lmb *lmb)
+{
+	struct memory_block *mem_block;
+	int rc;
+
+	if (!lmb_is_removable(lmb))
+		return -EINVAL;
+
+	mem_block = lmb_to_memblock(lmb);
+	if (mem_block == NULL)
+		return -EINVAL;
+
+	rc = dlpar_offline_lmb(lmb);
+	if (rc) {
+		put_device(&mem_block->dev);
+		return rc;
+	}
+
+	__remove_memory(lmb->base_addr, memory_block_size);
+	put_device(&mem_block->dev);
+
+	/* Update memory regions for memory remove */
+	memblock_remove(lmb->base_addr, memory_block_size);
+
+	invalidate_lmb_associativity_index(lmb);
+	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
+
+	return 0;
+}
+
+static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
+{
+	struct drmem_lmb *lmb;
+	int lmbs_reserved = 0;
+	int lmbs_available = 0;
+	int rc;
+
+	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
+
+	if (lmbs_to_remove == 0)
+		return -EINVAL;
+
+	/* Validate that there are enough LMBs to satisfy the request */
+	for_each_drmem_lmb(lmb) {
+		if (lmb_is_removable(lmb))
+			lmbs_available++;
+
+		if (lmbs_available == lmbs_to_remove)
+			break;
+	}
+
+	if (lmbs_available < lmbs_to_remove) {
+		pr_info("Not enough LMBs available (%d of %d) to satisfy request\n",
+			lmbs_available, lmbs_to_remove);
+		return -EINVAL;
+	}
+
+	for_each_drmem_lmb(lmb) {
+		rc = dlpar_remove_lmb(lmb);
+		if (rc)
+			continue;
+
+		/* Mark this lmb so we can add it later if all of the
+		 * requested LMBs cannot be removed.
+		 */
+		drmem_mark_lmb_reserved(lmb);
+
+		lmbs_reserved++;
+		if (lmbs_reserved == lmbs_to_remove)
+			break;
+	}
+
+	if (lmbs_reserved != lmbs_to_remove) {
+		pr_err("Memory hot-remove failed, adding LMB's back\n");
+
+		for_each_drmem_lmb(lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			rc = dlpar_add_lmb(lmb);
+			if (rc)
+				pr_err("Failed to add LMB back, drc index %x\n",
+				       lmb->drc_index);
+
+			drmem_remove_lmb_reservation(lmb);
+
+			lmbs_reserved--;
+			if (lmbs_reserved == 0)
+				break;
+		}
+
+		rc = -EINVAL;
+	} else {
+		for_each_drmem_lmb(lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			dlpar_release_drc(lmb->drc_index);
+			pr_info("Memory at %llx was hot-removed\n",
+				lmb->base_addr);
+
+			drmem_remove_lmb_reservation(lmb);
+
+			lmbs_reserved--;
+			if (lmbs_reserved == 0)
+				break;
+		}
+		rc = 0;
+	}
+
+	return rc;
+}
+
+static int dlpar_memory_remove_by_index(u32 drc_index)
+{
+	struct drmem_lmb *lmb;
+	int lmb_found;
+	int rc;
+
+	pr_debug("Attempting to hot-remove LMB, drc index %x\n", drc_index);
+
+	lmb_found = 0;
+	for_each_drmem_lmb(lmb) {
+		if (lmb->drc_index == drc_index) {
+			lmb_found = 1;
+			rc = dlpar_remove_lmb(lmb);
+			if (!rc)
+				dlpar_release_drc(lmb->drc_index);
+
+			break;
+		}
+	}
+
+	if (!lmb_found) {
+		pr_debug("Failed to look up LMB for drc index %x\n", drc_index);
+		rc = -EINVAL;
+	} else if (rc) {
+		pr_debug("Failed to hot-remove memory at %llx\n",
+			 lmb->base_addr);
+	} else {
+		pr_debug("Memory at %llx was hot-removed\n", lmb->base_addr);
+	}
+
+	return rc;
+}
+
+static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
+{
+	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
+	int rc;
+
+	pr_info("Attempting to hot-remove %u LMB(s) at %x\n",
+		lmbs_to_remove, drc_index);
+
+	if (lmbs_to_remove == 0)
+		return -EINVAL;
+
+	rc = get_lmb_range(drc_index, lmbs_to_remove, &start_lmb, &end_lmb);
+	if (rc)
+		return -EINVAL;
+
+	/*
+	 * Validate that all LMBs in range are not reserved. Note that it
+	 * is ok if they are !ASSIGNED since our goal here is to remove the
+	 * LMB range, regardless of whether some LMBs were already removed
+	 * by any other reason.
+	 *
+	 * This is a contrast to what is done in remove_by_count() where we
+	 * check for both RESERVED and !ASSIGNED (via lmb_is_removable()),
+	 * because we want to remove a fixed amount of LMBs in that function.
+	 */
+	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+		if (lmb->flags & DRCONF_MEM_RESERVED) {
+			pr_err("Memory at %llx (drc index %x) is reserved\n",
+				lmb->base_addr, lmb->drc_index);
+			return -EINVAL;
+		}
+	}
+
+	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+		/*
+		 * dlpar_remove_lmb() will error out if the LMB is already
+		 * !ASSIGNED, but this case is a no-op for us.
+		 */
+		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
+			continue;
+
+		rc = dlpar_remove_lmb(lmb);
+		if (rc)
+			break;
+
+		drmem_mark_lmb_reserved(lmb);
+	}
+
+	if (rc) {
+		pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n");
+
+
+		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			/*
+			 * Setting the isolation state of an UNISOLATED/CONFIGURED
+			 * device to UNISOLATE is a no-op, but the hypervisor can
+			 * use it as a hint that the LMB removal failed.
+			 */
+			dlpar_unisolate_drc(lmb->drc_index);
+
+			rc = dlpar_add_lmb(lmb);
+			if (rc)
+				pr_err("Failed to add LMB, drc index %x\n",
+				       lmb->drc_index);
+
+			drmem_remove_lmb_reservation(lmb);
+		}
+		rc = -EINVAL;
+	} else {
+		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			dlpar_release_drc(lmb->drc_index);
+			pr_info("Memory at %llx (drc index %x) was hot-removed\n",
+				lmb->base_addr, lmb->drc_index);
+
+			drmem_remove_lmb_reservation(lmb);
+		}
+	}
+
+	return rc;
+}
+
+#else
+static inline int pseries_remove_memblock(unsigned long base,
+					  unsigned long memblock_size)
+{
+	return -EOPNOTSUPP;
+}
+static inline int pseries_remove_mem_node(struct device_node *np)
+{
+	return 0;
+}
+static int dlpar_remove_lmb(struct drmem_lmb *lmb)
+{
+	return -EOPNOTSUPP;
+}
+static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
+{
+	return -EOPNOTSUPP;
+}
+static int dlpar_memory_remove_by_index(u32 drc_index)
+{
+	return -EOPNOTSUPP;
+}
+
+static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
+{
+	return -EOPNOTSUPP;
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+static int dlpar_add_lmb(struct drmem_lmb *lmb)
+{
+	unsigned long block_sz;
+	int nid, rc;
+
+	if (lmb->flags & DRCONF_MEM_ASSIGNED)
+		return -EINVAL;
+
+	rc = update_lmb_associativity_index(lmb);
+	if (rc) {
+		dlpar_release_drc(lmb->drc_index);
+		return rc;
+	}
+
+	block_sz = memory_block_size_bytes();
+
+	/* Find the node id for this LMB.  Fake one if necessary. */
+	nid = of_drconf_to_nid_single(lmb);
+	if (nid < 0 || !node_possible(nid))
+		nid = first_online_node;
+
+	/* Add the memory */
+	rc = __add_memory(nid, lmb->base_addr, block_sz, MHP_MEMMAP_ON_MEMORY);
+	if (rc) {
+		invalidate_lmb_associativity_index(lmb);
+		return rc;
+	}
+
+	rc = dlpar_online_lmb(lmb);
+	if (rc) {
+		__remove_memory(lmb->base_addr, block_sz);
+		invalidate_lmb_associativity_index(lmb);
+	} else {
+		lmb->flags |= DRCONF_MEM_ASSIGNED;
+	}
+
+	return rc;
+}
+
+static int dlpar_memory_add_by_count(u32 lmbs_to_add)
+{
+	struct drmem_lmb *lmb;
+	int lmbs_available = 0;
+	int lmbs_reserved = 0;
+	int rc;
+
+	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
+
+	if (lmbs_to_add == 0)
+		return -EINVAL;
+
+	/* Validate that there are enough LMBs to satisfy the request */
+	for_each_drmem_lmb(lmb) {
+		if (lmb->flags & DRCONF_MEM_RESERVED)
+			continue;
+
+		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
+			lmbs_available++;
+
+		if (lmbs_available == lmbs_to_add)
+			break;
+	}
+
+	if (lmbs_available < lmbs_to_add)
+		return -EINVAL;
+
+	for_each_drmem_lmb(lmb) {
+		if (lmb->flags & DRCONF_MEM_ASSIGNED)
+			continue;
+
+		rc = dlpar_acquire_drc(lmb->drc_index);
+		if (rc)
+			continue;
+
+		rc = dlpar_add_lmb(lmb);
+		if (rc) {
+			dlpar_release_drc(lmb->drc_index);
+			continue;
+		}
+
+		/* Mark this lmb so we can remove it later if all of the
+		 * requested LMBs cannot be added.
+		 */
+		drmem_mark_lmb_reserved(lmb);
+		lmbs_reserved++;
+		if (lmbs_reserved == lmbs_to_add)
+			break;
+	}
+
+	if (lmbs_reserved != lmbs_to_add) {
+		pr_err("Memory hot-add failed, removing any added LMBs\n");
+
+		for_each_drmem_lmb(lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			rc = dlpar_remove_lmb(lmb);
+			if (rc)
+				pr_err("Failed to remove LMB, drc index %x\n",
+				       lmb->drc_index);
+			else
+				dlpar_release_drc(lmb->drc_index);
+
+			drmem_remove_lmb_reservation(lmb);
+			lmbs_reserved--;
+
+			if (lmbs_reserved == 0)
+				break;
+		}
+		rc = -EINVAL;
+	} else {
+		for_each_drmem_lmb(lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			pr_debug("Memory at %llx (drc index %x) was hot-added\n",
+				 lmb->base_addr, lmb->drc_index);
+			drmem_remove_lmb_reservation(lmb);
+			lmbs_reserved--;
+
+			if (lmbs_reserved == 0)
+				break;
+		}
+		rc = 0;
+	}
+
+	return rc;
+}
+
+static int dlpar_memory_add_by_index(u32 drc_index)
+{
+	struct drmem_lmb *lmb;
+	int rc, lmb_found;
+
+	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
+
+	lmb_found = 0;
+	for_each_drmem_lmb(lmb) {
+		if (lmb->drc_index == drc_index) {
+			lmb_found = 1;
+			rc = dlpar_acquire_drc(lmb->drc_index);
+			if (!rc) {
+				rc = dlpar_add_lmb(lmb);
+				if (rc)
+					dlpar_release_drc(lmb->drc_index);
+			}
+
+			break;
+		}
+	}
+
+	if (!lmb_found)
+		rc = -EINVAL;
+
+	if (rc)
+		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
+	else
+		pr_info("Memory at %llx (drc index %x) was hot-added\n",
+			lmb->base_addr, drc_index);
+
+	return rc;
+}
+
+static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index)
+{
+	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
+	int rc;
+
+	pr_info("Attempting to hot-add %u LMB(s) at index %x\n",
+		lmbs_to_add, drc_index);
+
+	if (lmbs_to_add == 0)
+		return -EINVAL;
+
+	rc = get_lmb_range(drc_index, lmbs_to_add, &start_lmb, &end_lmb);
+	if (rc)
+		return -EINVAL;
+
+	/* Validate that the LMBs in this range are not reserved */
+	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+		/* Fail immediately if the whole range can't be hot-added */
+		if (lmb->flags & DRCONF_MEM_RESERVED) {
+			pr_err("Memory at %llx (drc index %x) is reserved\n",
+					lmb->base_addr, lmb->drc_index);
+			return -EINVAL;
+		}
+	}
+
+	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+		if (lmb->flags & DRCONF_MEM_ASSIGNED)
+			continue;
+
+		rc = dlpar_acquire_drc(lmb->drc_index);
+		if (rc)
+			break;
+
+		rc = dlpar_add_lmb(lmb);
+		if (rc) {
+			dlpar_release_drc(lmb->drc_index);
+			break;
+		}
+
+		drmem_mark_lmb_reserved(lmb);
+	}
+
+	if (rc) {
+		pr_err("Memory indexed-count-add failed, removing any added LMBs\n");
+
+		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			rc = dlpar_remove_lmb(lmb);
+			if (rc)
+				pr_err("Failed to remove LMB, drc index %x\n",
+				       lmb->drc_index);
+			else
+				dlpar_release_drc(lmb->drc_index);
+
+			drmem_remove_lmb_reservation(lmb);
+		}
+		rc = -EINVAL;
+	} else {
+		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
+			if (!drmem_lmb_reserved(lmb))
+				continue;
+
+			pr_info("Memory at %llx (drc index %x) was hot-added\n",
+				lmb->base_addr, lmb->drc_index);
+			drmem_remove_lmb_reservation(lmb);
+		}
+	}
+
+	return rc;
+}
+
+int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
+{
+	u32 count, drc_index;
+	int rc;
+
+	lock_device_hotplug();
+
+	switch (hp_elog->action) {
+	case PSERIES_HP_ELOG_ACTION_ADD:
+		switch (hp_elog->id_type) {
+		case PSERIES_HP_ELOG_ID_DRC_COUNT:
+			count = hp_elog->_drc_u.drc_count;
+			rc = dlpar_memory_add_by_count(count);
+			break;
+		case PSERIES_HP_ELOG_ID_DRC_INDEX:
+			drc_index = hp_elog->_drc_u.drc_index;
+			rc = dlpar_memory_add_by_index(drc_index);
+			break;
+		case PSERIES_HP_ELOG_ID_DRC_IC:
+			count = hp_elog->_drc_u.ic.count;
+			drc_index = hp_elog->_drc_u.ic.index;
+			rc = dlpar_memory_add_by_ic(count, drc_index);
+			break;
+		default:
+			rc = -EINVAL;
+			break;
+		}
+
+		break;
+	case PSERIES_HP_ELOG_ACTION_REMOVE:
+		switch (hp_elog->id_type) {
+		case PSERIES_HP_ELOG_ID_DRC_COUNT:
+			count = hp_elog->_drc_u.drc_count;
+			rc = dlpar_memory_remove_by_count(count);
+			break;
+		case PSERIES_HP_ELOG_ID_DRC_INDEX:
+			drc_index = hp_elog->_drc_u.drc_index;
+			rc = dlpar_memory_remove_by_index(drc_index);
+			break;
+		case PSERIES_HP_ELOG_ID_DRC_IC:
+			count = hp_elog->_drc_u.ic.count;
+			drc_index = hp_elog->_drc_u.ic.index;
+			rc = dlpar_memory_remove_by_ic(count, drc_index);
+			break;
+		default:
+			rc = -EINVAL;
+			break;
+		}
+
+		break;
+	default:
+		pr_err("Invalid action (%d) specified\n", hp_elog->action);
+		rc = -EINVAL;
+		break;
+	}
+
+	if (!rc)
+		rc = drmem_update_dt();
+
+	unlock_device_hotplug();
+	return rc;
+}
+
+static int pseries_add_mem_node(struct device_node *np)
+{
+	int ret;
+	struct resource res;
+
+	/*
+	 * Check to see if we are actually adding memory
+	 */
+	if (!of_node_is_type(np, "memory"))
+		return 0;
+
+	/*
+	 * Find the base and size of the memblock
+	 */
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret)
+		return ret;
+
+	/*
+	 * Update memory region to represent the memory add
+	 */
+	ret = memblock_add(res.start, resource_size(&res));
+	return (ret < 0) ? -EINVAL : 0;
+}
+
+static int pseries_memory_notifier(struct notifier_block *nb,
+				   unsigned long action, void *data)
+{
+	struct of_reconfig_data *rd = data;
+	int err = 0;
+
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		err = pseries_add_mem_node(rd->dn);
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		err = pseries_remove_mem_node(rd->dn);
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		if (!strcmp(rd->dn->name,
+			    "ibm,dynamic-reconfiguration-memory"))
+			drmem_update_lmbs(rd->prop);
+	}
+	return notifier_from_errno(err);
+}
+
+static struct notifier_block pseries_mem_nb = {
+	.notifier_call = pseries_memory_notifier,
+};
+
+static int __init pseries_memory_hotplug_init(void)
+{
+	if (firmware_has_feature(FW_FEATURE_LPAR))
+		of_reconfig_notifier_register(&pseries_mem_nb);
+
+	return 0;
+}
+machine_device_initcall(pseries, pseries_memory_hotplug_init);