[POWERPC] Hotplug memory remove notifications for powerpc

obj-$(CONFIG_PCI_MSI)	+= msi.o

obj-$(CONFIG_HOTPLUG_CPU)	+= hotplug-cpu.o

obj-$(CONFIG_MEMORY_HOTPLUG)	+= hotplug-memory.o

obj-$(CONFIG_HVC_CONSOLE)	+= hvconsole.o

obj-$(CONFIG_HVCS)		+= hvcserver.o

/*

 * 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 <asm/firmware.h>

#include <asm/machdep.h>

#include <asm/pSeries_reconfig.h>

static int pseries_remove_memory(struct device_node *np)

{

	const char *type;

	const unsigned int *my_index;

	const unsigned int *regs;

	u64 start_pfn, start;

	struct zone *zone;

	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 memory index and size of the removing section

	 */

	my_index = of_get_property(np, "ibm,my-drc-index", NULL);

	if (!my_index)

		return ret;

	regs = of_get_property(np, "reg", NULL);

	if (!regs)

		return ret;

	start_pfn = section_nr_to_pfn(*my_index & 0xffff);

	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, regs[3] >> PAGE_SHIFT);

	if (ret)

		return ret;

	/*

	 * Remove htab bolted mappings for this section of memory

	 */

	start = (unsigned long)__va(start_pfn << PAGE_SHIFT);

	ret = remove_section_mapping(start, start + regs[3]);

	return ret;

}

static int pseries_memory_notifier(struct notifier_block *nb,

				unsigned long action, void *node)

{

	int err = NOTIFY_OK;

	switch (action) {

	case PSERIES_RECONFIG_ADD:

		break;

	case PSERIES_RECONFIG_REMOVE:

		if (pseries_remove_memory(node))

			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);