PCI hotplug: introduce functions for ACPI slot detection

Some ACPI related PCI hotplug code can be shared among PCI hotplug
drivers. This patch introduces the following functions in
drivers/pci/hotplug/acpi_pcihp.c to share the code, and changes
acpiphp and pciehp to use them.

- int acpi_pci_detect_ejectable(struct pci_bus *pbus)
  This checks if the specified PCI bus has ejectable slots.

- int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
  This checks if the specified handle is ejectable ACPI PCI slot. The
  'pbus' parameter is needed to check if 'handle' is PCI related ACPI
  object.

This patch also introduces the following inline function in
include/linux/pci-acpi.h, which is useful to get ACPI handle of the
PCI bridge from struct pci_bus of the bridge's secondary bus.

- static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
  This returns ACPI handle of the PCI bridge which generates PCI bus
  specified by 'pbus'.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 5 insertions, 50 deletions

diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
index 88a5c57..438d795 100644
--- a/drivers/pci/hotplug/pciehp_acpi.c
+++ b/drivers/pci/hotplug/pciehp_acpi.c
@@ -24,6 +24,8 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
 #include "pciehp.h"
 
 #define PCIEHP_DETECT_PCIE	(0)
@@ -41,59 +43,11 @@ MODULE_PARM_DESC(pciehp_detect_mode,
 	 "  auto(default) - Auto select mode. Use acpi option if duplicate\n"
 	 "                  slot ids are found. Otherwise, use pcie option\n");
 
-static int is_ejectable(acpi_handle handle)
-{
-	acpi_status status;
-	acpi_handle tmp;
-	unsigned long long removable;
-	status = acpi_get_handle(handle, "_ADR", &tmp);
-	if (ACPI_FAILURE(status))
-		return 0;
-	status = acpi_get_handle(handle, "_EJ0", &tmp);
-	if (ACPI_SUCCESS(status))
-		return 1;
-	status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
-	if (ACPI_SUCCESS(status) && removable)
-		return 1;
-	return 0;
-}
-
-static acpi_status
-check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
-{
-	int *found = (int *)context;
-	if (is_ejectable(handle)) {
-		*found = 1;
-		return AE_CTRL_TERMINATE;
-	}
-	return AE_OK;
-}
-
-static int pciehp_detect_acpi_slot(struct pci_bus *pbus)
-{
-	acpi_handle handle;
-	struct pci_dev *pdev = pbus->self;
-	int found = 0;
-
-	if (!pdev){
-		int seg = pci_domain_nr(pbus), busnr = pbus->number;
-		handle = acpi_get_pci_rootbridge_handle(seg, busnr);
-	} else
-		handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
-
-	if (!handle)
-		return 0;
-
-	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-			    check_hotplug, (void *)&found, NULL);
-	return found;
-}
-
 int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
 {
 	if (slot_detection_mode != PCIEHP_DETECT_ACPI)
 		return 0;
-	if (pciehp_detect_acpi_slot(dev->subordinate))
+	if (acpi_pci_detect_ejectable(dev->subordinate))
 		return 0;
 	return -ENODEV;
 }
@@ -135,6 +89,7 @@ static int __init dummy_probe(struct pcie_device *dev,
 	u32 slot_cap;
 	struct slot *slot, *tmp;
 	struct pci_dev *pdev = dev->port;
+	struct pci_bus *pbus = pdev->subordinate;
 	if (!(slot = kzalloc(sizeof(*slot), GFP_KERNEL)))
 		return -ENOMEM;
 	/* Note: pciehp_detect_mode != PCIEHP_DETECT_ACPI here */
@@ -149,7 +104,7 @@ static int __init dummy_probe(struct pcie_device *dev,
 			dup_slot_id++;
 	}
 	list_add_tail(&slot->slot_list, &dummy_slots);
-	if (!acpi_slot_detected && pciehp_detect_acpi_slot(pdev->subordinate))
+	if (!acpi_slot_detected && acpi_pci_detect_ejectable(pbus))
 		acpi_slot_detected = 1;
 	return -ENODEV;         /* dummy driver always returns error */
 }