[PATCH v3 3/3] Improve container_notify_cb() to support container hot-remove.

From: Tang Chen
Date: Wed Oct 31 2012 - 03:29:48 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,
which means to unbind ACPI drivers first before remove devices.
(This feature is introduced by Lu Yinghai:
http://www.spinics.net/lists/linux-pci/msg17667.html)
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 | 63 ++++++++++++++++++++++++++++++++++++++-------
1 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c
index a10eee6..4abec98 100644
--- a/drivers/acpi/container.c
+++ b/drivers/acpi/container.c
@@ -166,6 +166,32 @@ 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;
+
+ /* stop container device at first */
+ ret = acpi_bus_trim(device, 0);
+ pr_debug("acpi_bus_trim stop return %x\n", ret);
+ if (ret)
+ return ret;
+
+ /* send the uevent before remove the device */
+ kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
+
+ ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
+ if (!ej_event)
+ return -ENOMEM;
+
+ ej_event->device = device;
+ ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
+
+ acpi_bus_hot_remove_device(ej_event);
+
+ return 0;
+}
+
/* This function is of type acpi_osd_exec_callback */
static void _container_notify_cb(void *context)
{
@@ -182,6 +208,9 @@ static void _container_notify_cb(void *context)
handle = cb_data->handle;
type = cb_data->type;

+ present = is_device_present(handle);
+ status = acpi_bus_get_device(handle, &device);
+
switch (type) {
case ACPI_NOTIFY_BUS_CHECK:
/* Fall through */
@@ -190,13 +219,16 @@ static void _container_notify_cb(void *context)
(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) {
+ dev_warn(&device->dev, "%s: Failed to "
+ "remove container\n",
+ __func__);
+ break;
+ }
goto out;
}
break;
@@ -207,7 +239,9 @@ static void _container_notify_cb(void *context)

result = container_device_add(&device, handle);
if (result) {
- printk(KERN_WARNING "Failed to add container\n");
+ dev_warn(&device->dev,
+ "%s: Failed to add container\n",
+ __func__);
break;
}

@@ -216,12 +250,21 @@ static void _container_notify_cb(void *context)
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);
- goto out;
+ 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) {
+ dev_warn(&device->dev,
+ "%s: Failed to remove container\n",
+ __func__);
+ break;
}
- break;
+
+ goto out;

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

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