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Date: Sat, 04 May 2013 13:21:16 +0200
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Toshi Kani <toshi.kani@...com>,
ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>,
isimatu.yasuaki@...fujitsu.com,
vasilis.liaskovitis@...fitbricks.com, Len Brown <lenb@...nel.org>,
linux-mm@...ck.org
Subject: [PATCH 2/2 v2, RFC] Driver core: Introduce offline/online callbacks for memory blocks
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
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@...el.com>
---
drivers/base/memory.c | 105 +++++++++++++++++++++++++++++++++++++------------
include/linux/memory.h | 1
2 files changed, 81 insertions(+), 25 deletions(-)
Index: linux-pm/drivers/base/memory.c
===================================================================
--- linux-pm.orig/drivers/base/memory.c
+++ linux-pm/drivers/base/memory.c
@@ -37,9 +37,14 @@ static inline int base_memory_block_id(i
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);
@@ -278,33 +283,64 @@ static int __memory_block_change_state(s
{
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 = __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 = __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 +351,8 @@ static int memory_block_change_state(str
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 +362,34 @@ 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 +611,7 @@ static int init_memory_block(struct memo
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);
@@ -686,10 +735,16 @@ int offline_memory_block(struct memory_b
{
int ret = 0;
+ lock_device_hotplug();
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);
+ unlock_device_hotplug();
return ret;
}
Index: linux-pm/include/linux/memory.h
===================================================================
--- linux-pm.orig/include/linux/memory.h
+++ linux-pm/include/linux/memory.h
@@ -26,6 +26,7 @@ struct memory_block {
unsigned long start_section_nr;
unsigned long end_section_nr;
unsigned long state;
+ int last_online;
int section_count;
/*
--
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