Commit 2f7bbceb authored by Alexander Chiang's avatar Alexander Chiang Committed by Len Brown
Browse files

ACPI: Introduce acpi_get_pci_dev() 



Convert an ACPI CA handle to a struct pci_dev.

Performing this lookup dynamically allows us to get rid of the
ACPI-PCI binding code, which:

	- eliminates struct acpi_device vs struct pci_dev lifetime issues
	- lays more groundwork for eliminating .start from acpi_device_ops
	  and thus simplifying ACPI drivers
	- whacks out a lot of code

This change lays the groundwork for eliminating much of pci_bind.c.

Although pci_root.c may not be the most logical place for this
change, putting it here saves us from having to export acpi_pci_find_root.

Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Acked-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 27558203

drivers/acpi/pci_root.c

+81 −0
Original line number Diff line number Diff line
@@ -329,6 +329,87 @@ 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

include/acpi/acpi_drivers.h

+1 −0
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ void acpi_pci_irq_del_prt(int segment, int bus); 


struct pci_bus;



struct pci_dev *acpi_get_pci_dev(acpi_handle);

acpi_status acpi_get_pci_id(acpi_handle handle, struct acpi_pci_id *id);

int acpi_pci_bind_root(struct acpi_device *device, struct acpi_pci_id *id,

		       struct pci_bus *bus);

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