[PATCH 28/40] PCI, ACPI: Add pci_root_hp hot removal notification support.

[Yinghai Lu <yinghai@kernel.org>]

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" > /sys/kernel/debug/acpi/sci_notify
to remove root bus

-v2: separate stop and remove, so could use acpi_pci_bind_notify()...

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 |   67 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 67 insertions(+), 0 deletions(-)

diff --git a/drivers/acpi/pci_root_hp.c b/drivers/acpi/pci_root_hp.c
index eb4344c..434ee35 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 +149,61 @@ 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;
+
+		/* remove pci devices at first */
+		ret_val = acpi_bus_trim(device, 0);
+		printk(KERN_DEBUG "acpi_bus_trim stop return %x\n", ret_val);
+
+		/* remove acpi devices */
+		ret_val = acpi_bus_trim(device, 1);
+		printk(KERN_DEBUG "acpi_bus_trim remove 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 +244,12 @@ 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