Change in coreboot[master]: device/device_const.c: Write loop with topology

[Arthur Heymans (Code Review)]

Attention is currently required from: Arthur Heymans.
Hello Arthur Heymans,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/62896

to review the following change.

Change subject: device/device_const.c: Write loop with topology
......................................................................

device/device_const.c: Write loop with topology

A side benefit is that more than one domain gets probed.

Change-Id: I6f35ab1efc7c293f129ec16d45b155275c2a8b52
Signed-off-by: Arthur Heymans 
---
M src/device/device_const.c
1 file changed, 18 insertions(+), 13 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/96/62896/1

diff --git a/src/device/device_const.c b/src/device/device_const.c
index c629f05..dc97ab7 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -218,21 +218,26 @@
    return find_dev_path(parent, &path);
 }

+static const struct bus *find_pci_bus(const struct device *dev, unsigned int bus)
+{
+	const struct device *d;
+	for (d = dev; d != NULL; d = d->sibling) {
+		if (d->path.type == DEVICE_PATH_PCI && d->bus->secondary == bus)
+			return d->bus;
+		if (d->link_list && d->link_list->children) {
+			const struct bus *child_bus = find_pci_bus(d->link_list->children, bus);
+			if (child_bus)
+				return child_bus;
+		}
+	}
+	return NULL;
+}
+
 DEVTREE_CONST struct device *pcidev_path_on_bus(unsigned int bus, pci_devfn_t devfn)
 {
-	DEVTREE_CONST struct bus *parent = pci_root_bus();
-	DEVTREE_CONST struct device *dev = parent->children;
-
-	/* FIXME: Write the loop with topology links. */
-	while (dev) {
-		if (dev->path.type != DEVICE_PATH_PCI) {
-			dev = dev->next;
-			continue;
-		}
-		if (dev->bus->secondary == bus)
-			return pcidev_path_behind(dev->bus, devfn);
-		dev = dev->next;
-	}
+	const struct bus *pci_bus = find_pci_bus(dev_find_path(NULL, DEVICE_PATH_DOMAIN), bus);
+	if (pci_bus)
+		return pcidev_path_behind(pci_bus, devfn);
    return NULL;
 }