Commit 315bbae9 authored by Wen Congyang's avatar Wen Congyang Committed by Rafael J. Wysocki

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 <>
Reviewed-by: default avatarYasuaki Ishimatsu <>
Reviewed-by: default avatarToshi Kani <>
Signed-off-by: default avatarRafael J. Wysocki <>
parent 19387b27
......@@ -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.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)
* 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)
ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
if (!ej_event) {
pr_err(PREFIX "No memory, dropping EJECT\n");
* Invoke acpi_bus_trim() to remove memory device
acpi_bus_trim(device, 1);
ej_event->handle = handle;
ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
(void *)ej_event);
/* _EJ0 succeeded; _OST is not necessary */
/* eject is performed asynchronously */
"Unsupported event [0x%x]\n", event));
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