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: Wen Congyang <wency@cn.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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: Wen Congyang <wency@cn.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Wen Congyang · Rafael J. Wysocki
1 parent 19387b27e4
Showing 1 changed file with 9 additions and 79 deletions Side-by-side Diff
drivers/acpi/acpi_memhotplug.c
@@ -272,40 +272,6 @@
 	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 @@
 	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 @@
 			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));
...	...	@@ -272,40 +272,6 @@
272	272	return 0;
273	273	}
274	274
275		-static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
276		-{
277		- acpi_status status;
278		- struct acpi_object_list arg_list;
279		- union acpi_object arg;
280		- unsigned long long current_status;
281		-
282		-
283		- /* Issue the _EJ0 command */
284		- arg_list.count = 1;
285		- arg_list.pointer = &arg;
286		- arg.type = ACPI_TYPE_INTEGER;
287		- arg.integer.value = 1;
288		- status = acpi_evaluate_object(mem_device->device->handle,
289		- "_EJ0", &arg_list, NULL);
290		- /* Return on _EJ0 failure */
291		- if (ACPI_FAILURE(status)) {
292		- ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
293		- return -ENODEV;
294		- }
295		-
296		- /* Evalute _STA to check if the device is disabled */
297		- status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
298		- NULL, &current_status);
299		- if (ACPI_FAILURE(status))
300		- return -ENODEV;
301		-
302		- /* Check for device status. Device should be disabled */
303		- if (current_status & ACPI_STA_DEVICE_ENABLED)
304		- return -EINVAL;
305		-
306		- return 0;
307		-}
308		-
309	275	static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
310	276	{
311	277	int result;
312	278
...	...	@@ -325,34 +291,11 @@
325	291	return 0;
326	292	}
327	293
328		-static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
329		-{
330		- int result;
331		-
332		- /*
333		- * Ask the VM to offline this memory range.
334		- * Note: Assume that this function returns zero on success
335		- */
336		- result = acpi_memory_remove_memory(mem_device);
337		- if (result)
338		- return result;
339		-
340		- /* Power-off and eject the device */
341		- result = acpi_memory_powerdown_device(mem_device);
342		- if (result) {
343		- /* Set the status of the device to invalid */
344		- mem_device->state = MEMORY_INVALID_STATE;
345		- return result;
346		- }
347		-
348		- mem_device->state = MEMORY_POWER_OFF_STATE;
349		- return result;
350		-}
351		-
352	294	static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
353	295	{
354	296	struct acpi_memory_device *mem_device;
355	297	struct acpi_device *device;
	298	+ struct acpi_eject_event *ej_event = NULL;
356	299	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
357	300
358	301	switch (event) {
359	302
360	303
361	304
...	...	@@ -394,32 +337,19 @@
394	337	break;
395	338	}
396	339
397		- /*
398		- * Currently disabling memory device from kernel mode
399		- * TBD: Can also be disabled from user mode scripts
400		- * TBD: Can also be disabled by Callback registration
401		- * with generic sysfs driver
402		- */
403		- if (acpi_memory_disable_device(mem_device)) {
404		- printk(KERN_ERR PREFIX "Disable memory device\n");
405		- /*
406		- * If _EJ0 was called but failed, _OST is not
407		- * necessary.
408		- */
409		- if (mem_device->state == MEMORY_INVALID_STATE)
410		- return;
411		-
	340	+ ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
	341	+ if (!ej_event) {
	342	+ pr_err(PREFIX "No memory, dropping EJECT\n");
412	343	break;
413	344	}
414	345
415		- /*
416		- * Invoke acpi_bus_trim() to remove memory device
417		- */
418		- acpi_bus_trim(device, 1);
	346	+ ej_event->handle = handle;
	347	+ ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
	348	+ acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
	349	+ (void *)ej_event);
419	350
420		- /* _EJ0 succeeded; _OST is not necessary */
	351	+ /* eject is performed asynchronously */
421	352	return;
422		-
423	353	default:
424	354	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
425	355	"Unsupported event [0x%x]\n", event));