satip-axe/kernel/arch/powerpc/platforms/pseries/hotplug-memory.c

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/*
* pseries Memory Hotplug infrastructure.
*
* Copyright (C) 2008 Badari Pulavarty, IBM Corporation
*
* 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/of.h>
#include <linux/lmb.h>
#include <asm/firmware.h>
#include <asm/machdep.h>
#include <asm/pSeries_reconfig.h>
#include <asm/sparsemem.h>
static int pseries_remove_lmb(unsigned long base, unsigned int lmb_size)
{
unsigned long start, start_pfn;
struct zone *zone;
int ret;
start_pfn = base >> PAGE_SHIFT;
if (!pfn_valid(start_pfn)) {
lmb_remove(base, lmb_size);
return 0;
}
zone = page_zone(pfn_to_page(start_pfn));
/*
* Remove section mappings and sysfs entries for the
* section of the memory we are removing.
*
* NOTE: Ideally, this should be done in generic code like
* remove_memory(). But remove_memory() gets called by writing
* to sysfs "state" file and we can't remove sysfs entries
* while writing to it. So we have to defer it to here.
*/
ret = __remove_pages(zone, start_pfn, lmb_size >> PAGE_SHIFT);
if (ret)
return ret;
/*
* Update memory regions for memory remove
*/
lmb_remove(base, lmb_size);
/*
* Remove htab bolted mappings for this section of memory
*/
start = (unsigned long)__va(base);
ret = remove_section_mapping(start, start + lmb_size);
return ret;
}
static int pseries_remove_memory(struct device_node *np)
{
const char *type;
const unsigned int *regs;
unsigned long base;
unsigned int lmb_size;
int ret = -EINVAL;
/*
* Check to see if we are actually removing memory
*/
type = of_get_property(np, "device_type", NULL);
if (type == NULL || strcmp(type, "memory") != 0)
return 0;
/*
* Find the bae address and size of the lmb
*/
regs = of_get_property(np, "reg", NULL);
if (!regs)
return ret;
base = *(unsigned long *)regs;
lmb_size = regs[3];
ret = pseries_remove_lmb(base, lmb_size);
return ret;
}
static int pseries_add_memory(struct device_node *np)
{
const char *type;
const unsigned int *regs;
unsigned long base;
unsigned int lmb_size;
int ret = -EINVAL;
/*
* Check to see if we are actually adding memory
*/
type = of_get_property(np, "device_type", NULL);
if (type == NULL || strcmp(type, "memory") != 0)
return 0;
/*
* Find the base and size of the lmb
*/
regs = of_get_property(np, "reg", NULL);
if (!regs)
return ret;
base = *(unsigned long *)regs;
lmb_size = regs[3];
/*
* Update memory region to represent the memory add
*/
ret = lmb_add(base, lmb_size);
return (ret < 0) ? -EINVAL : 0;
}
static int pseries_drconf_memory(unsigned long *base, unsigned int action)
{
struct device_node *np;
const unsigned long *lmb_size;
int rc;
np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (!np)
return -EINVAL;
lmb_size = of_get_property(np, "ibm,lmb-size", NULL);
if (!lmb_size) {
of_node_put(np);
return -EINVAL;
}
if (action == PSERIES_DRCONF_MEM_ADD) {
rc = lmb_add(*base, *lmb_size);
rc = (rc < 0) ? -EINVAL : 0;
} else if (action == PSERIES_DRCONF_MEM_REMOVE) {
rc = pseries_remove_lmb(*base, *lmb_size);
} else {
rc = -EINVAL;
}
of_node_put(np);
return rc;
}
static int pseries_memory_notifier(struct notifier_block *nb,
unsigned long action, void *node)
{
int err = NOTIFY_OK;
switch (action) {
case PSERIES_RECONFIG_ADD:
if (pseries_add_memory(node))
err = NOTIFY_BAD;
break;
case PSERIES_RECONFIG_REMOVE:
if (pseries_remove_memory(node))
err = NOTIFY_BAD;
break;
case PSERIES_DRCONF_MEM_ADD:
case PSERIES_DRCONF_MEM_REMOVE:
if (pseries_drconf_memory(node, action))
err = NOTIFY_BAD;
break;
default:
err = NOTIFY_DONE;
break;
}
return 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))
pSeries_reconfig_notifier_register(&pseries_mem_nb);
return 0;
}
machine_device_initcall(pseries, pseries_memory_hotplug_init);