[PATCH part4 07/11] PCI, ACPI: Add pci_root_hp hot removal notification support.

Yinghai Lu
2012-09-02T21:54:17Z

Add missing hot_remove support for root device.

How to use it?
Find out root bus number to acpi root name mapping from dmesg or /sys

echo "\_SB.PCIB 3" > /proc/acpi/sci/notify
to remove root bus

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
---
drivers/acpi/pci_root_hp.c | 61 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 61 insertions(+), 0 deletions(-)

diff --git a/drivers/acpi/pci_root_hp.c b/drivers/acpi/pci_root_hp.c
index e07c31b..214adcb 100644
--- a/drivers/acpi/pci_root_hp.c
+++ b/drivers/acpi/pci_root_hp.c
@@ -73,6 +73,12 @@ static void add_acpi_root_bridge(acpi_handle handle)
list_add(&bridge->list, &acpi_root_bridge_list);
}

+static void remove_acpi_root_bridge(struct acpi_root_bridge *bridge)
+{
+ list_del(&bridge->list);
+ kfree(bridge);
+}
+
struct acpi_root_hp_work {
struct work_struct work;
acpi_handle handle;
@@ -143,6 +149,55 @@ static void handle_root_bridge_insertion(acpi_handle handle)
printk(KERN_ERR "cannot start bridge\n");
}

+static int acpi_root_evaluate_object(acpi_handle handle, char *cmd, int val)
+{
+ acpi_status status;
+ struct acpi_object_list arg_list;
+ union acpi_object arg;
+
+ arg_list.count = 1;
+ arg_list.pointer = &arg;
+ arg.type = ACPI_TYPE_INTEGER;
+ arg.integer.value = val;
+
+ status = acpi_evaluate_object(handle, cmd, &arg_list, NULL);
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_WARNING "%s: %s to %d failed\n",
+ __func__, cmd, val);
+ return -1;
+ }
+
+ return 0;
+}
+
+static void handle_root_bridge_removal(acpi_handle handle,
+ struct acpi_root_bridge *bridge)
+{
+ u32 flags = 0;
+ struct acpi_device *device;
+
+ if (bridge) {
+ flags = bridge->flags;
+ remove_acpi_root_bridge(bridge);
+ }
+
+ if (!acpi_bus_get_device(handle, &device)) {
+ int ret_val = acpi_bus_trim(device, 1);
+
+ printk(KERN_DEBUG "acpi_bus_trim return %x\n", ret_val);
+ }
+
+ if (flags & ROOT_BRIDGE_HAS_PS3) {
+ acpi_status status;
+
+ status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
+ if (ACPI_FAILURE(status))
+ printk(KERN_WARNING "%s: _PS3 failed\n", __func__);
+ }
+ if (flags & ROOT_BRIDGE_HAS_EJ0)
+ acpi_root_evaluate_object(handle, "_EJ0", 1);
+}
+
static void _handle_hotplug_event_root(struct work_struct *work)
{
struct acpi_root_bridge *bridge;
@@ -183,6 +238,12 @@ static void _handle_hotplug_event_root(struct work_struct *work)
}
break;

+ case ACPI_NOTIFY_EJECT_REQUEST:
+ /* request device eject */
+ printk(KERN_DEBUG "%s: Device eject notify on %s\n", __func__,
+ objname);
+ handle_root_bridge_removal(handle, bridge);
+ break;
default:
printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
type, objname);
--
1.7.7