The branch main has been updated by bz:
URL:
https://cgit.FreeBSD.org/src/commit/?id=bbeeb585315645db20118ef349a4e3dc83b148cc
commit bbeeb585315645db20118ef349a4e3dc83b148cc
Author: Bjoern A. Zeeb <b...@freebsd.org>
AuthorDate: 2025-09-04 20:22:00 +0000
Commit: Bjoern A. Zeeb <b...@freebsd.org>
CommitDate: 2025-09-05 23:24:14 +0000
LinuxKPI: pci: allocate entire pci_dev hiereachy up to root port on attach
In linux_pci_attach_device() allocate a LinuxKPI pci_dev for each device in
the hierarchy up to the root port[1] as we cannot do that later on demand
as we may be in a context where we may not sleep.
Take special care of DRM as there is a non-PCI device in the chain which
needs to be skipped.
iwlwifi(4) can hit this case called from a callout.
While here leave a comment sa the cleanup order of
linux_pci_attach_device() needs correction seperately.
Sponsored by: The FreeBSD Foundation (initially)
PR: 283027
Suggested by: jhb [1]
MFC after: 3 days
Reviewed by: dumbbell
Differential Revision: https://reviews.freebsd.org/D52069
---
sys/compat/linuxkpi/common/src/linux_pci.c | 47 +++++++++++++++++++++++++-----
1 file changed, 40 insertions(+), 7 deletions(-)
diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c
b/sys/compat/linuxkpi/common/src/linux_pci.c
index 7db8af8e88f9..863f44a384e5 100644
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -339,6 +339,7 @@ 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,
@@ -359,15 +360,24 @@ 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;
@@ -392,7 +402,7 @@ 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)
+ if (pdev->bus->self != pdev && pdev->bus->self != NULL)
pci_dev_put(pdev->bus->self);
free(pdev->bus, M_DEVBUF);
if (pdev->msi_desc != NULL) {
@@ -548,6 +558,7 @@ 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;
@@ -591,6 +602,27 @@ 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)
@@ -598,6 +630,7 @@ 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);
