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Commit bc32df00 authored by Heiko Carstens's avatar Heiko Carstens Committed by Linus Torvalds
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memory hotplug: allow setting of phys_device 



/sys/devices/system/memory/memoryX/phys_device is supposed to contain the
number of the physical device that the corresponding piece of memory
belongs to.

In case a physical device should be replaced or taken offline for whatever
reason it is necessary to set all corresponding memory pieces offline.
The current implementation always sets phys_device to '0' and there is no
way or hook to change that.  Seems like there was a plan to implement that
but it wasn't finished for whatever reason.

So add a weak function which architectures can override to actually set
the phys_device from within add_memory_block().

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e5d61511

drivers/base/memory.c

+10 −5
Original line number Diff line number Diff line
@@ -429,12 +429,16 @@ static inline int memory_fail_init(void) 
 * differentiation between which *physical* devices each

 * section belongs to...

 */

int __weak arch_get_memory_phys_device(unsigned long start_pfn)

{

	return 0;

}



static int add_memory_block(int nid, struct mem_section *section,

			unsigned long state, int phys_device,

			enum mem_add_context context)

			unsigned long state, enum mem_add_context context)

{

	struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);

	unsigned long start_pfn;

	int ret = 0;



	if (!mem)
@@ -443,7 +447,8 @@ static int add_memory_block(int nid, struct mem_section *section, 
	mem->phys_index = __section_nr(section);

	mem->state = state;

	mutex_init(&mem->state_mutex);

	mem->phys_device = phys_device;

	start_pfn = section_nr_to_pfn(mem->phys_index);

	mem->phys_device = arch_get_memory_phys_device(start_pfn);



	ret = register_memory(mem, section);

	if (!ret)
@@ -515,7 +520,7 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section, 
 */

int register_new_memory(int nid, struct mem_section *section)

{

	return add_memory_block(nid, section, MEM_OFFLINE, 0, HOTPLUG);

	return add_memory_block(nid, section, MEM_OFFLINE, HOTPLUG);

}



int unregister_memory_section(struct mem_section *section)
@@ -548,7 +553,7 @@ int __init memory_dev_init(void) 
		if (!present_section_nr(i))

			continue;

		err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE,

					0, BOOT);

				       BOOT);

		if (!ret)

			ret = err;

	}

include/linux/memory.h

+2 −0
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ struct memory_block { 
	struct sys_device sysdev;

};



int arch_get_memory_phys_device(unsigned long start_pfn);



/* These states are exposed to userspace as text strings in sysfs */

#define	MEM_ONLINE		(1<<0) /* exposed to userspace */

#define	MEM_GOING_OFFLINE	(1<<1) /* exposed to userspace */