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>
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index ea77512..9d200d5 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -106,6 +106,9 @@
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;
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 43e3179..adbf340 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -306,7 +306,8 @@
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 @@
* 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)