[PATCH 2/2] Improve container_notify_cb() to support container hot-remove.

From: Tang Chen
Date: Tue Oct 23 2012 - 09:11:53 EST


This patch introduces a new function container_device_remove() to do
the container hot-remove job. It works like the following:

1. call acpi_bus_trim(device, 0) to stop the container device.
2. generate the KOBJ_OFFLINE uevent. (Did I do this correct ?)
3. call acpi_bus_hot_remove_device(), which will call acpi_bus_trim(device, 1)
to remove the container.

This patch is based on Lu Yinghai's work.
git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci-split-pci-root-hp-2

Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
---
drivers/acpi/container.c | 58 ++++++++++++++++++++++++++++++++++++++-------
1 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c
index 643657a..1de4672 100644
--- a/drivers/acpi/container.c
+++ b/drivers/acpi/container.c
@@ -180,6 +180,35 @@ static int container_device_add(struct acpi_device **device, acpi_handle handle)
return result;
}

+static int container_device_remove(struct acpi_device *device)
+{
+ int ret;
+ struct acpi_eject_event *ej_event;
+
+ ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
+ if (!ej_event)
+ return -ENOMEM;
+
+ ej_event->device = device;
+ ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
+
+ /* stop container device at first */
+ ret = acpi_bus_trim(device, 0);
+ printk(KERN_WARNING "acpi_bus_trim stop return %x\n", ret);
+ if (ret)
+ return ret;
+
+ /* event originated from ACPI eject notification */
+ device->flags.eject_pending = 1;
+
+ /* send the uevent before remove the device */
+ kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
+
+ acpi_bus_hot_remove_device(ej_event);
+
+ return 0;
+}
+
static void __container_notify_cb(struct work_struct *work)
{
struct acpi_device *device = NULL;
@@ -195,6 +224,9 @@ static void __container_notify_cb(struct work_struct *work)
handle = hp_work->handle;
type = hp_work->type;

+ present = is_device_present(handle);
+ status = acpi_bus_get_device(handle, &device);
+
switch (type) {
case ACPI_NOTIFY_BUS_CHECK:
/* Fall through */
@@ -203,13 +235,14 @@ static void __container_notify_cb(struct work_struct *work)
(type == ACPI_NOTIFY_BUS_CHECK) ?
"ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");

- present = is_device_present(handle);
- status = acpi_bus_get_device(handle, &device);
if (!present) {
if (ACPI_SUCCESS(status)) {
/* device exist and this is a remove request */
- device->flags.eject_pending = 1;
- kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
+ result = container_device_remove(device);
+ if (result) {
+ printk(KERN_WARNING "Failed to remove container\n");
+ break;
+ }
return;
}
break;
@@ -229,12 +262,19 @@ static void __container_notify_cb(struct work_struct *work)
break;

case ACPI_NOTIFY_EJECT_REQUEST:
- if (!acpi_bus_get_device(handle, &device) && device) {
- device->flags.eject_pending = 1;
- kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
- return;
+ printk(KERN_WARNING "Container driver received %s event\n",
+ "ACPI_NOTIFY_EJECT_REQUEST");
+
+ if (!present || ACPI_FAILURE(status) || !device)
+ break;
+
+ result = container_device_remove(device);
+ if (result) {
+ printk(KERN_WARNING "Failed to remove container\n");
+ break;
}
- break;
+
+ return;

default:
/* non-hotplug event; possibly handled by other handler */
--
1.7.1

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