From 4960e05e22604ee270a023f968e0e4f9bd0c6fef Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 8 May 2013 14:18:37 +0200 Subject: 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 Tested-by: Vasilis Liaskovitis Acked-by: Greg Kroah-Hartman Reviewed-by: Toshi Kani --- drivers/base/memory.c | 112 +++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 87 insertions(+), 25 deletions(-) (limited to 'drivers/base') 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; -- cgit v1.2.2