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Commit d96ae530 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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memory-hotplug: create /sys/firmware/memmap entry for new memory 



A memmap is a directory in sysfs which includes 3 text files: start, end
and type.  For example:

start: 	0x100000
end:	0x7e7b1cff
type:	System RAM

Interface firmware_map_add was not called explicitly.  Remove it and add
function firmware_map_add_hotplug as hotplug interface of memmap.

Each memory entry has a memmap in sysfs, When we hot-add new memory, sysfs
does not export memmap entry for it.  We add a call in function add_memory
to function firmware_map_add_hotplug.

Add a new function add_sysfs_fw_map_entry() to create memmap entry, it
will be called when initialize memmap and hot-add memory.

[akpm@linux-foundation.org: un-kernedoc a no longer kerneldoc comment]
Signed-off-by: default avatarShaohui Zheng <shaohui.zheng@intel.com>
Acked-by: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarYasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9d8cebd4

drivers/firmware/memmap.c

+36 −21
Original line number Diff line number Diff line
@@ -122,29 +122,53 @@ static int firmware_map_add_entry(u64 start, u64 end, 
	return 0;

}



/*

 * Add memmap entry on sysfs

 */

static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)

{

	static int map_entries_nr;

	static struct kset *mmap_kset;



	if (!mmap_kset) {

		mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);

		if (!mmap_kset)

			return -ENOMEM;

	}



	entry->kobj.kset = mmap_kset;

	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))

		kobject_put(&entry->kobj);



	return 0;

}



/**

 * firmware_map_add() - Adds a firmware mapping entry.

 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do

 * memory hotplug.

 * @start: Start of the memory range.

 * @end:   End of the memory range (inclusive).

 * @type:  Type of the memory range.

 *

 * This function uses kmalloc() for memory

 * allocation. Use firmware_map_add_early() if you want to use the bootmem

 * allocator.

 *

 * That function must be called before late_initcall.

 * Adds a firmware mapping entry. This function is for memory hotplug, it is

 * similar to function firmware_map_add_early(). The only difference is that

 * it will create the syfs entry dynamically.

 *

 * Returns 0 on success, or -ENOMEM if no memory could be allocated.

 **/

int firmware_map_add(u64 start, u64 end, const char *type)

int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)

{

	struct firmware_map_entry *entry;



	entry = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);

	entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);

	if (!entry)

		return -ENOMEM;



	return firmware_map_add_entry(start, end, type, entry);

	firmware_map_add_entry(start, end, type, entry);

	/* create the memmap entry */

	add_sysfs_fw_map_entry(entry);



	return 0;

}



/**
@@ -154,7 +178,7 @@ int firmware_map_add(u64 start, u64 end, const char *type) 
 * @type:  Type of the memory range.

 *

 * Adds a firmware mapping entry. This function uses the bootmem allocator

 * for memory allocation. Use firmware_map_add() if you want to use kmalloc().

 * for memory allocation.

 *

 * That function must be called before late_initcall.

 *
@@ -214,19 +238,10 @@ static ssize_t memmap_attr_show(struct kobject *kobj, 
 */

static int __init memmap_init(void)

{

	int i = 0;

	struct firmware_map_entry *entry;

	struct kset *memmap_kset;



	memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);

	if (WARN_ON(!memmap_kset))

		return -ENOMEM;



	list_for_each_entry(entry, &map_entries, list) {

		entry->kobj.kset = memmap_kset;

		if (kobject_add(&entry->kobj, NULL, "%d", i++))

			kobject_put(&entry->kobj);

	}

	list_for_each_entry(entry, &map_entries, list)

		add_sysfs_fw_map_entry(entry);



	return 0;

}

include/linux/firmware-map.h

+3 −3
Original line number Diff line number Diff line
@@ -24,17 +24,17 @@ 
 */

#ifdef CONFIG_FIRMWARE_MEMMAP



int firmware_map_add(u64 start, u64 end, const char *type);

int firmware_map_add_early(u64 start, u64 end, const char *type);

int firmware_map_add_hotplug(u64 start, u64 end, const char *type);



#else /* CONFIG_FIRMWARE_MEMMAP */



static inline int firmware_map_add(u64 start, u64 end, const char *type)

static inline int firmware_map_add_early(u64 start, u64 end, const char *type)

{

	return 0;

}



static inline int firmware_map_add_early(u64 start, u64 end, const char *type)

static inline int firmware_map_add_hotplug(u64 start, u64 end, const char *type)

{

	return 0;

}

mm/memory_hotplug.c

+4 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/pfn.h>

#include <linux/suspend.h>

#include <linux/mm_inline.h>

#include <linux/firmware-map.h>



#include <asm/tlbflush.h>
@@ -523,6 +524,9 @@ int __ref add_memory(int nid, u64 start, u64 size) 
		BUG_ON(ret);

	}



	/* create new memmap entry */

	firmware_map_add_hotplug(start, start + size, "System RAM");



	goto out;



error: