Commit bc32df00 authored by Heiko Carstens's avatar Heiko Carstens Committed by Linus Torvalds
Browse files

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 <>
Cc: Dave Hansen <>
Cc: Gerald Schaefer <>
Cc: KAMEZAWA Hiroyuki <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent e5d61511
......@@ -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;
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))
err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE,
0, BOOT);
if (!ret)
ret = err;
......@@ -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 */
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