blob: 3fe3ddb30c04b45f10b5ed0a4fefaac621297e73 [file] [log] [blame]
// 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)
{
__be32 *assoc_arrays;
u32 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) {
pr_err("Failed memory block lookup for LMB 0x%x\n", lmb->drc_index);
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);
pr_err("Failed to configure LMB 0x%x\n", 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) {
pr_err("Failed to add LMB 0x%x to node %u", lmb->drc_index, nid);
invalidate_lmb_associativity_index(lmb);
return rc;
}
rc = dlpar_online_lmb(lmb);
if (rc) {
pr_err("Failed to online LMB 0x%x on node %u\n", lmb->drc_index, nid);
__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);