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Commit 315bbae9 authored by Wen Congyang's avatar Wen Congyang Committed by Rafael J. Wysocki
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ACPI / memhotplug: deal with eject request in hotplug queue 



The memory device can be removed by 2 ways:
 1. send eject request by SCI
 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject

We handle the 1st case in the module acpi_memhotplug, and handle
the 2nd case in ACPI eject notification. This 2 events may happen
at the same time, so we may touch acpi_memory_device.res_list at
the same time. This patch reimplements memory-hotremove support
through an ACPI eject notification. Now the memory device is
offlined and hotremoved only in the function acpi_memory_device_remove()
which is protected by device_lock().

Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Reviewed-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: default avatarToshi Kani <toshi.kani@hp.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 19387b27

drivers/acpi/acpi_memhotplug.c

+9 −79
Original line number Diff line number Diff line
@@ -272,40 +272,6 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) 
	return 0;

}



static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)

{

	acpi_status status;

	struct acpi_object_list arg_list;

	union acpi_object arg;

	unsigned long long current_status;





	/* Issue the _EJ0 command */

	arg_list.count = 1;

	arg_list.pointer = &arg;

	arg.type = ACPI_TYPE_INTEGER;

	arg.integer.value = 1;

	status = acpi_evaluate_object(mem_device->device->handle,

				      "_EJ0", &arg_list, NULL);

	/* Return on _EJ0 failure */

	if (ACPI_FAILURE(status)) {

		ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));

		return -ENODEV;

	}



	/* Evalute _STA to check if the device is disabled */

	status = acpi_evaluate_integer(mem_device->device->handle, "_STA",

				       NULL, &current_status);

	if (ACPI_FAILURE(status))

		return -ENODEV;



	/* Check for device status.  Device should be disabled */

	if (current_status & ACPI_STA_DEVICE_ENABLED)

		return -EINVAL;



	return 0;

}



static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)

{

	int result;
@@ -325,34 +291,11 @@ static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) 
	return 0;

}



static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)

{

	int result;



	/*

	 * Ask the VM to offline this memory range.

	 * Note: Assume that this function returns zero on success

	 */

	result = acpi_memory_remove_memory(mem_device);

	if (result)

		return result;



	/* Power-off and eject the device */

	result = acpi_memory_powerdown_device(mem_device);

	if (result) {

		/* Set the status of the device to invalid */

		mem_device->state = MEMORY_INVALID_STATE;

		return result;

	}



	mem_device->state = MEMORY_POWER_OFF_STATE;

	return result;

}



static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)

{

	struct acpi_memory_device *mem_device;

	struct acpi_device *device;

	struct acpi_eject_event *ej_event = NULL;

	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */



	switch (event) {
@@ -394,32 +337,19 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) 
			break;

		}



		/*

		 * Currently disabling memory device from kernel mode

		 * TBD: Can also be disabled from user mode scripts

		 * TBD: Can also be disabled by Callback registration

		 *      with generic sysfs driver

		 */

		if (acpi_memory_disable_device(mem_device)) {

			printk(KERN_ERR PREFIX "Disable memory device\n");

			/*

			 * If _EJ0 was called but failed, _OST is not

			 * necessary.

			 */

			if (mem_device->state == MEMORY_INVALID_STATE)

				return;



		ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);

		if (!ej_event) {

			pr_err(PREFIX "No memory, dropping EJECT\n");

			break;

		}



		/*

		 * Invoke acpi_bus_trim() to remove memory device

		 */

		acpi_bus_trim(device, 1);

		ej_event->handle = handle;

		ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;

		acpi_os_hotplug_execute(acpi_bus_hot_remove_device,

					(void *)ej_event);



		/* _EJ0 succeeded; _OST is not necessary */

		/* eject is performed asynchronously */

		return;



	default:

		ACPI_DEBUG_PRINT((ACPI_DB_INFO,

				  "Unsupported event [0x%x]\n", event));