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().
CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
CC: Rafael J. Wysocki <rjw@xxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
drivers/acpi/acpi_memhotplug.c | 87 +++++-------------------------------------
1 file changed, 9 insertions(+), 78 deletions(-)
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 2918be1..6e12042 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -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, ¤t_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) {
@@ -394,31 +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;
}
- /*
- * TBD: Invoke acpi_bus_remove to cleanup data structures
- */
+ 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));
--
1.8.0
--
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