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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
This commit is contained in:
Rafael J. Wysocki 2013-11-28 23:58:08 +01:00
parent d9fef0c4d2
commit 5ce79d2013
2 changed files with 13 additions and 6 deletions

View File

@ -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;

View File

@ -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;
/*
@ -314,14 +315,17 @@ 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;
return 0;
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)