예제 #1
0
static ssize_t
store_mem_state(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct memory_block *mem = to_memory_block(dev);
	int ret, online_type;

	ret = lock_device_hotplug_sysfs();
	if (ret)
		return ret;

	if (sysfs_streq(buf, "online_kernel"))
		online_type = MMOP_ONLINE_KERNEL;
	else if (sysfs_streq(buf, "online_movable"))
		online_type = MMOP_ONLINE_MOVABLE;
	else if (sysfs_streq(buf, "online"))
		online_type = MMOP_ONLINE_KEEP;
	else if (sysfs_streq(buf, "offline"))
		online_type = MMOP_OFFLINE;
	else {
		ret = -EINVAL;
		goto err;
	}

	/*
	 * Memory hotplug needs to hold mem_hotplug_begin() for probe to find
	 * the correct memory block to online before doing device_online(dev),
	 * which will take dev->mutex.  Take the lock early to prevent an
	 * inversion, memory_subsys_online() callbacks will be implemented by
	 * assuming it's already protected.
	 */
	mem_hotplug_begin();

	switch (online_type) {
	case MMOP_ONLINE_KERNEL:
	case MMOP_ONLINE_MOVABLE:
	case MMOP_ONLINE_KEEP:
		mem->online_type = online_type;
		ret = device_online(&mem->dev);
		break;
	case MMOP_OFFLINE:
		ret = device_offline(&mem->dev);
		break;
	default:
		ret = -EINVAL; /* should never happen */
	}

	mem_hotplug_done();
err:
	unlock_device_hotplug();

	if (ret)
		return ret;
	return count;
}
예제 #2
0
파일: memory.c 프로젝트: 3null/linux
static ssize_t
store_mem_state(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct memory_block *mem = to_memory_block(dev);
	int ret, online_type;

	ret = lock_device_hotplug_sysfs();
	if (ret)
		return ret;

	if (sysfs_streq(buf, "online_kernel"))
		online_type = MMOP_ONLINE_KERNEL;
	else if (sysfs_streq(buf, "online_movable"))
		online_type = MMOP_ONLINE_MOVABLE;
	else if (sysfs_streq(buf, "online"))
		online_type = MMOP_ONLINE_KEEP;
	else if (sysfs_streq(buf, "offline"))
		online_type = MMOP_OFFLINE;
	else {
		ret = -EINVAL;
		goto err;
	}

	switch (online_type) {
	case MMOP_ONLINE_KERNEL:
	case MMOP_ONLINE_MOVABLE:
	case MMOP_ONLINE_KEEP:
		/*
		 * mem->online_type is not protected so there can be a
		 * race here.  However, when racing online, the first
		 * will succeed and the second will just return as the
		 * block will already be online.  The online type
		 * could be either one, but that is expected.
		 */
		mem->online_type = online_type;
		ret = device_online(&mem->dev);
		break;
	case MMOP_OFFLINE:
		ret = device_offline(&mem->dev);
		break;
	default:
		ret = -EINVAL; /* should never happen */
	}

err:
	unlock_device_hotplug();

	if (ret)
		return ret;
	return count;
}
예제 #3
0
파일: cpu.c 프로젝트: 1800alex/linux
static ssize_t cpu_probe_store(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf,
			       size_t count)
{
	ssize_t cnt;
	int ret;

	ret = lock_device_hotplug_sysfs();
	if (ret)
		return ret;

	cnt = arch_cpu_probe(buf, count);

	unlock_device_hotplug();
	return cnt;
}
예제 #4
0
파일: cpu.c 프로젝트: 545191228/linux
static ssize_t write_cpuhp_target(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
	struct cpuhp_step *sp;
	int target, ret;

	ret = kstrtoint(buf, 10, &target);
	if (ret)
		return ret;

#ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL
	if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE)
		return -EINVAL;
#else
	if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE)
		return -EINVAL;
#endif

	ret = lock_device_hotplug_sysfs();
	if (ret)
		return ret;

	mutex_lock(&cpuhp_state_mutex);
	sp = cpuhp_get_step(target);
	ret = !sp->name || sp->cant_stop ? -EINVAL : 0;
	mutex_unlock(&cpuhp_state_mutex);
	if (ret)
		return ret;

	if (st->state < target)
		ret = do_cpu_up(dev->id, target);
	else
		ret = do_cpu_down(dev->id, target);

	unlock_device_hotplug();
	return ret ? ret : count;
}