1 files changed, 107 insertions, 5 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index e95b5ac2e60..8a5bf3b356f 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -137,6 +137,30 @@ acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 
 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
 
+/**
+ * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
+ * @handle - the ACPI CA node in question.
+ *
+ * Note: we could make this API take a struct acpi_device * instead, but
+ * for now, it's more convenient to operate on an acpi_handle.
+ */
+int acpi_is_root_bridge(acpi_handle handle)
+{
+	int ret;
+	struct acpi_device *device;
+
+	ret = acpi_bus_get_device(handle, &device);
+	if (ret)
+		return 0;
+
+	ret = acpi_match_device_ids(device, root_device_ids);
+	if (ret)
+		return 0;
+	else
+		return 1;
+}
+EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
+
 static acpi_status
 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 {
@@ -304,6 +328,87 @@ static struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 	return NULL;
 }
 
+struct acpi_handle_node {
+	struct list_head node;
+	acpi_handle handle;
+};
+
+/**
+ * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
+ * @handle: the handle in question
+ *
+ * Given an ACPI CA handle, the desired PCI device is located in the
+ * list of PCI devices.
+ *
+ * If the device is found, its reference count is increased and this
+ * function returns a pointer to its data structure.  The caller must
+ * decrement the reference count by calling pci_dev_put().
+ * If no device is found, %NULL is returned.
+ */
+struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
+{
+	int dev, fn;
+	unsigned long long adr;
+	acpi_status status;
+	acpi_handle phandle;
+	struct pci_bus *pbus;
+	struct pci_dev *pdev = NULL;
+	struct acpi_handle_node *node, *tmp;
+	struct acpi_pci_root *root;
+	LIST_HEAD(device_list);
+
+	/*
+	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
+	 */
+	phandle = handle;
+	while (!acpi_is_root_bridge(phandle)) {
+		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
+		if (!node)
+			goto out;
+
+		INIT_LIST_HEAD(&node->node);
+		node->handle = phandle;
+		list_add(&node->node, &device_list);
+
+		status = acpi_get_parent(phandle, &phandle);
+		if (ACPI_FAILURE(status))
+			goto out;
+	}
+
+	root = acpi_pci_find_root(phandle);
+	if (!root)
+		goto out;
+
+	pbus = root->bus;
+
+	/*
+	 * Now, walk back down the PCI device tree until we return to our
+	 * original handle. Assumes that everything between the PCI root
+	 * bridge and the device we're looking for must be a P2P bridge.
+	 */
+	list_for_each_entry(node, &device_list, node) {
+		acpi_handle hnd = node->handle;
+		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
+		if (ACPI_FAILURE(status))
+			goto out;
+		dev = (adr >> 16) & 0xffff;
+		fn  = adr & 0xffff;
+
+		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
+		if (hnd == handle)
+			break;
+
+		pbus = pdev->subordinate;
+		pci_dev_put(pdev);
+	}
+out:
+	list_for_each_entry_safe(node, tmp, &device_list, node)
+		kfree(node);
+
+	return pdev;
+}
+EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
+
 /**
  * acpi_pci_osc_control_set - commit requested control to Firmware
  * @handle: acpi_handle for the target ACPI object
@@ -402,8 +507,6 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 	device->driver_data = root;
 
-	device->ops.bind = acpi_pci_bind;
-
 	/*
 	 * All supported architectures that use ACPI have support for
 	 * PCI domains, so we indicate this in _OSC support capabilities.
@@ -443,7 +546,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 * -----------------------
 	 * Thus binding the ACPI and PCI devices.
 	 */
-	result = acpi_pci_bind_root(device, &root->id, root->bus);
+	result = acpi_pci_bind_root(device);
 	if (result)
 		goto end;
 
@@ -454,8 +557,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 */
 	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
 	if (ACPI_SUCCESS(status))
-		result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
-					      root->id.bus);
+		result = acpi_pci_irq_add_prt(device->handle, root->bus);
 
 	/*
 	 * Scan and bind all _ADR-Based Devices