git: 3860afe99ec3 - main - Revert "LinuxKPI: pci: allocate entire pci_dev hiereachy up to root port on attach"

The branch main has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=3860afe99ec39b9942967941181f28f27f3fc548

commit 3860afe99ec39b9942967941181f28f27f3fc548
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2025-09-08 14:32:24 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2025-09-08 14:32:24 +0000

    Revert "LinuxKPI: pci: allocate entire pci_dev hiereachy up to root port on attach"
    
    It turns out this breaks the nvidia-drm drviers.
    We'll try to rework things and put it back later.
    
    This reverts commit bbeeb585315645db20118ef349a4e3dc83b148cc.
---
 sys/compat/linuxkpi/common/src/linux_pci.c | 47 +++++-------------------------
 1 file changed, 7 insertions(+), 40 deletions(-)

diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
index d0f1d5e3f9c5..43fd6ad28ac4 100644
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -342,7 +342,6 @@ lkpi_pci_dev_release(struct device *dev)
 static int
 lkpifill_pci_dev(device_t dev, struct pci_dev *pdev)
 {
-	struct pci_devinfo *dinfo;
 	int error;
 
 	error = kobject_init_and_add(&pdev->dev.kobj, &linux_dev_ktype,
@@ -363,24 +362,15 @@ lkpifill_pci_dev(device_t dev, struct pci_dev *pdev)
 	pdev->path_name = kasprintf(GFP_KERNEL, "%04d:%02d:%02d.%d",
 	    pci_get_domain(dev), pci_get_bus(dev), pci_get_slot(dev),
 	    pci_get_function(dev));
-
 	pdev->bus = malloc(sizeof(*pdev->bus), M_DEVBUF, M_WAITOK | M_ZERO);
+	/*
+	 * This should be the upstream bridge; pci_upstream_bridge()
+	 * handles that case on demand as otherwise we'll shadow the
+	 * entire PCI hierarchy.
+	 */
+	pdev->bus->self = pdev;
 	pdev->bus->number = pci_get_bus(dev);
 	pdev->bus->domain = pci_get_domain(dev);
-
-	/* Check if we have reached the root to satisfy pci_is_root_bus() */
-	dinfo = device_get_ivars(dev);
-	if (dinfo->cfg.pcie.pcie_location != 0 &&
-	    dinfo->cfg.pcie.pcie_type == PCIEM_TYPE_ROOT_PORT) {
-		pdev->bus->self = NULL;
-	} else {
-		/*
-		 * This should be the upstream bridge; pci_upstream_bridge()
-		 * handles that case on demand as otherwise we'll shadow the
-		 * entire PCI hierarchy.
-		 */
-		pdev->bus->self = pdev;
-	}
 	pdev->dev.bsddev = dev;
 	pdev->dev.parent = &linux_root_device;
 	pdev->dev.release = lkpi_pci_dev_release;
@@ -405,7 +395,7 @@ lkpinew_pci_dev_release(struct device *dev)
 	pdev = to_pci_dev(dev);
 	if (pdev->root != NULL)
 		pci_dev_put(pdev->root);
-	if (pdev->bus->self != pdev && pdev->bus->self != NULL)
+	if (pdev->bus->self != pdev)
 		pci_dev_put(pdev->bus->self);
 	free(pdev->bus, M_DEVBUF);
 	if (pdev->msi_desc != NULL) {
@@ -561,7 +551,6 @@ linux_pci_attach_device(device_t dev, struct pci_driver *pdrv,
 {
 	struct resource_list_entry *rle;
 	device_t parent;
-	struct pci_dev *pbus, *ppbus;
 	uintptr_t rid;
 	int error;
 	bool isdrm;
@@ -605,27 +594,6 @@ linux_pci_attach_device(device_t dev, struct pci_driver *pdrv,
 	list_add(&pdev->links, &pci_devices);
 	spin_unlock(&pci_lock);
 
-	/*
-	 * Create the hierarchy now as we cannot on demand later.
-	 * Take special care of DRM as there is a non-PCI device in the chain.
-	 */
-	pbus = pdev;
-	if (isdrm) {
-		pbus = lkpinew_pci_dev(parent);
-		if (pbus == NULL) {
-			error = ENXIO;
-			goto out_dma_init;
-		}
-	}
-	pcie_find_root_port(pbus);
-	if (isdrm)
-		pdev->root = pbus->root;
-	ppbus = pci_upstream_bridge(pbus);
-	while (ppbus != NULL && ppbus != pbus) {
-		pbus = ppbus;
-		ppbus = pci_upstream_bridge(pbus);
-	}
-
 	if (pdrv != NULL) {
 		error = pdrv->probe(pdev, id);
 		if (error)
@@ -633,7 +601,6 @@ linux_pci_attach_device(device_t dev, struct pci_driver *pdrv,
 	}
 	return (0);
 
-/* XXX the cleanup does not match the allocation up there. */
 out_probe:
 	free(pdev->bus, M_DEVBUF);
 	spin_lock_destroy(&pdev->pcie_cap_lock);