Commit 5ce79d20 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PCI / ACPI: Use acpi_find_child_device() for child devices lookup 



It is much more efficient to use acpi_find_child_device()
for child devices lookup in acpi_pci_find_device() and pass
ACPI_COMPANION(dev->parent) to it directly instead of obtaining
ACPI_HANDLE() of ACPI_COMPANION(dev->parent) and passing it to
acpi_find_child() which has to run acpi_bus_get_device() to
obtain ACPI_COMPANION(dev->parent) from that again.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarAaron Lu <aaron.lu@intel.com>
parent d9fef0c4

drivers/acpi/glue.c

+3 −0
Original line number Diff line number Diff line
@@ -106,6 +106,9 @@ struct acpi_device *acpi_find_child_device(struct acpi_device *parent, 
	struct acpi_device *adev, *ret = NULL;

	int ret_score = 0;



	if (!parent)

		return NULL;



	list_for_each_entry(adev, &parent->children, node) {

		unsigned long long addr;

		acpi_status status;

drivers/pci/pci-acpi.c

+10 −6
Original line number Diff line number Diff line
@@ -306,7 +306,8 @@ void acpi_pci_remove_bus(struct pci_bus *bus) 
static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)

{

	struct pci_dev *pci_dev = to_pci_dev(dev);

	bool is_bridge;

	struct acpi_device *adev;

	bool check_children;

	u64 addr;



	/*
@@ -314,15 +315,18 @@ static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 
	 * is set only after acpi_pci_find_device() has been called for the

	 * given device.

	 */

	is_bridge = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE

	check_children = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE

			|| pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;

	/* Please ref to ACPI spec for the syntax of _ADR */

	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);

	*handle = acpi_find_child(ACPI_HANDLE(dev->parent), addr, is_bridge);

	if (!*handle)

		return -ENODEV;

	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,

				      check_children);

	if (adev) {

		*handle = adev->handle;

		return 0;

	}

	return -ENODEV;

}



static void pci_acpi_setup(struct device *dev)

{

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