device: Add a helper to find device behind a PCI-to-PCI bridge device
This change adds a helper function to find PCI device with dev# and
function# behind a PCI-to-PCI bridge device.
BUG=b:153858769
BRANCH=None
TEST=None
Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: Ie5672b35cda66431a0f1977f217bdf61d3012ace
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40474
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/device/device_const.c b/src/device/device_const.c
index 2e0ccc4..de404dc 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -232,6 +232,19 @@
return pcidev_path_on_root(PCI_DEVFN(dev, fn));
}
+DEVTREE_CONST struct device *pcidev_path_behind_pci2pci_bridge(
+ const struct device *bridge,
+ pci_devfn_t devfn)
+{
+ if (!bridge || (bridge->path.type != DEVICE_PATH_PCI)) {
+ assert(0);
+ /* Return NULL in case asserts are non-fatal. */
+ return NULL;
+ }
+
+ return pcidev_path_behind(bridge->link_list, devfn);
+}
+
DEVTREE_CONST struct device *pcidev_path_on_root_debug(pci_devfn_t devfn, const char *func)
{
DEVTREE_CONST struct device *dev = pcidev_path_on_root(devfn);
diff --git a/src/include/device/device.h b/src/include/device/device.h
index 4e9c594..a33702a 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -293,6 +293,10 @@
DEVTREE_CONST struct device *pcidev_path_on_bus(unsigned int bus, pci_devfn_t devfn);
DEVTREE_CONST struct device *pcidev_on_root(uint8_t dev, uint8_t fn);
DEVTREE_CONST struct bus *pci_root_bus(void);
+/* Find PCI device with given D#:F# sitting behind the given PCI-to-PCI bridge device. */
+DEVTREE_CONST struct device *pcidev_path_behind_pci2pci_bridge(
+ const struct device *bridge,
+ pci_devfn_t devfn);
/* To be deprecated, avoid using.
*