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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-05-08 14:18:37 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-05-12 14:14:45 +0200
commit4960e05e22604ee270a023f968e0e4f9bd0c6fef (patch)
treeabdc39a81c6ab9868bc75f0f50ddedb7fcb10f9b /drivers/base/memory.c
parente2ff39400d81233374e780b133496a2296643d7d (diff)
Driver core: Introduce offline/online callbacks for memory blocks
Introduce .offline() and .online() callbacks for memory_subsys that will allow the generic device_offline() and device_online() to be used with device objects representing memory blocks. That, in turn, allows the ACPI subsystem to use device_offline() to put removable memory blocks offline, if possible, before removing memory modules holding them. The 'online' sysfs attribute of memory block devices will attempt to put them offline if 0 is written to it and will attempt to apply the previously used online type when onlining them (i.e. when 1 is written to it). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Diffstat (limited to 'drivers/base/memory.c')
-rw-r--r--drivers/base/memory.c112
1 files changed, 87 insertions, 25 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 14f8a6954da0..c8f3b63fcacd 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -37,9 +37,14 @@ static inline int base_memory_block_id(int section_nr)
return section_nr / sections_per_block;
}
+static int memory_subsys_online(struct device *dev);
+static int memory_subsys_offline(struct device *dev);
+
static struct bus_type memory_subsys = {
.name = MEMORY_CLASS_NAME,
.dev_name = MEMORY_CLASS_NAME,
+ .online = memory_subsys_online,
+ .offline = memory_subsys_offline,
};
static BLOCKING_NOTIFIER_HEAD(memory_chain);
@@ -88,6 +93,7 @@ int register_memory(struct memory_block *memory)
memory->dev.bus = &memory_subsys;
memory->dev.id = memory->start_section_nr / sections_per_block;
memory->dev.release = memory_block_release;
+ memory->dev.offline = memory->state == MEM_OFFLINE;
error = device_register(&memory->dev);
return error;
@@ -278,33 +284,70 @@ static int __memory_block_change_state(struct memory_block *mem,
{
int ret = 0;
- if (mem->state != from_state_req) {
- ret = -EINVAL;
- goto out;
- }
+ if (mem->state != from_state_req)
+ return -EINVAL;
if (to_state == MEM_OFFLINE)
mem->state = MEM_GOING_OFFLINE;
ret = memory_block_action(mem->start_section_nr, to_state, online_type);
-
if (ret) {
mem->state = from_state_req;
- goto out;
+ } else {
+ mem->state = to_state;
+ if (to_state == MEM_ONLINE)
+ mem->last_online = online_type;
}
+ return ret;
+}
- mem->state = to_state;
- switch (mem->state) {
- case MEM_OFFLINE:
- kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE);
- break;
- case MEM_ONLINE:
- kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE);
- break;
- default:
- break;
+static int memory_subsys_online(struct device *dev)
+{
+ struct memory_block *mem = container_of(dev, struct memory_block, dev);
+ int ret;
+
+ mutex_lock(&mem->state_mutex);
+
+ ret = mem->state == MEM_ONLINE ? 0 :
+ __memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE,
+ mem->last_online);
+
+ mutex_unlock(&mem->state_mutex);
+ return ret;
+}
+
+static int memory_subsys_offline(struct device *dev)
+{
+ struct memory_block *mem = container_of(dev, struct memory_block, dev);
+ int ret;
+
+ mutex_lock(&mem->state_mutex);
+
+ ret = mem->state == MEM_OFFLINE ? 0 :
+ __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE, -1);
+
+ mutex_unlock(&mem->state_mutex);
+ return ret;
+}
+
+static int __memory_block_change_state_uevent(struct memory_block *mem,
+ unsigned long to_state, unsigned long from_state_req,
+ int online_type)
+{
+ int ret = __memory_block_change_state(mem, to_state, from_state_req,
+ online_type);
+ if (!ret) {
+ switch (mem->state) {
+ case MEM_OFFLINE:
+ kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE);
+ break;
+ case MEM_ONLINE:
+ kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE);
+ break;
+ default:
+ break;
+ }
}
-out:
return ret;
}
@@ -315,8 +358,8 @@ static int memory_block_change_state(struct memory_block *mem,
int ret;
mutex_lock(&mem->state_mutex);
- ret = __memory_block_change_state(mem, to_state, from_state_req,
- online_type);
+ ret = __memory_block_change_state_uevent(mem, to_state, from_state_req,
+ online_type);
mutex_unlock(&mem->state_mutex);
return ret;
@@ -326,22 +369,34 @@ store_mem_state(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct memory_block *mem;
+ bool offline;
int ret = -EINVAL;
mem = container_of(dev, struct memory_block, dev);
- if (!strncmp(buf, "online_kernel", min_t(int, count, 13)))
+ lock_device_hotplug();
+
+ if (!strncmp(buf, "online_kernel", min_t(int, count, 13))) {
+ offline = false;
ret = memory_block_change_state(mem, MEM_ONLINE,
MEM_OFFLINE, ONLINE_KERNEL);
- else if (!strncmp(buf, "online_movable", min_t(int, count, 14)))
+ } else if (!strncmp(buf, "online_movable", min_t(int, count, 14))) {
+ offline = false;
ret = memory_block_change_state(mem, MEM_ONLINE,
MEM_OFFLINE, ONLINE_MOVABLE);
- else if (!strncmp(buf, "online", min_t(int, count, 6)))
+ } else if (!strncmp(buf, "online", min_t(int, count, 6))) {
+ offline = false;
ret = memory_block_change_state(mem, MEM_ONLINE,
MEM_OFFLINE, ONLINE_KEEP);
- else if(!strncmp(buf, "offline", min_t(int, count, 7)))
+ } else if(!strncmp(buf, "offline", min_t(int, count, 7))) {
+ offline = true;
ret = memory_block_change_state(mem, MEM_OFFLINE,
MEM_ONLINE, -1);
+ }
+ if (!ret)
+ dev->offline = offline;
+
+ unlock_device_hotplug();
if (ret)
return ret;
@@ -563,6 +618,7 @@ static int init_memory_block(struct memory_block **memory,
base_memory_block_id(scn_nr) * sections_per_block;
mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
mem->state = state;
+ mem->last_online = ONLINE_KEEP;
mem->section_count++;
mutex_init(&mem->state_mutex);
start_pfn = section_nr_to_pfn(mem->start_section_nr);
@@ -681,14 +737,20 @@ int unregister_memory_section(struct mem_section *section)
/*
* offline one memory block. If the memory block has been offlined, do nothing.
+ *
+ * Call under device_hotplug_lock.
*/
int offline_memory_block(struct memory_block *mem)
{
int ret = 0;
mutex_lock(&mem->state_mutex);
- if (mem->state != MEM_OFFLINE)
- ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE, -1);
+ if (mem->state != MEM_OFFLINE) {
+ ret = __memory_block_change_state_uevent(mem, MEM_OFFLINE,
+ MEM_ONLINE, -1);
+ if (!ret)
+ mem->dev.offline = true;
+ }
mutex_unlock(&mem->state_mutex);
return ret;