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diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -1,7 +1,7 @@
/*-
* Copyright (c) 2015-2016 Mellanox Technologies, Ltd.
* All rights reserved.
- * Copyright (c) 2020-2025 The FreeBSD Foundation
+ * Copyright (c) 2020-2026 The FreeBSD Foundation
*
* Portions of this software were developed by Björn Zeeb
* under sponsorship from the FreeBSD Foundation.
@@ -28,6 +28,15 @@
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+/*
+ * We have two ways to create a pci_dev (pdev):
+ * (1) coming from the device_attach DEVMETHOD, and
+ * (2) the other from manual creation via lkpinew_pci_dev().
+ *
+ * Only devices from (1) end up on our LinuxKPI global pci_devices list.
+ * All others are "place fillers" -- XXX if only "place filler" was always true.
+ */
+
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
@@ -100,6 +109,7 @@
static int linux_backlight_update_status(device_t dev, struct backlight_props *props);
static int linux_backlight_get_info(device_t dev, struct backlight_info *info);
static void lkpi_pcim_iomap_table_release(struct device *, void *);
+static void lkpinew_pci_dev_release(struct device *);
static device_method_t pci_methods[] = {
DEVMETHOD(device_probe, linux_pci_probe),
@@ -335,9 +345,82 @@
static void
lkpi_pci_dev_release(struct device *dev)
{
+ struct pci_dev *pdev;
+ /*
+ * The very first we have to free all the dynamic
+ * resource which are on the devres list.
+ * Otherwise we risk that supporting infrastructure
+ * is gone and we panic 'randomly'.
+ */
lkpi_devres_release_free_list(dev);
+
+ /*
+ * Now undo linux_pci_attach_device() in reverse-ish
+ * order.
+ */
+ pdev = to_pci_dev(dev);
+
+ /*
+ * pdrv->remove happens before pci_put_dev() in
+ * linux_pci_detach_device(), which means the driver should have
+ * cleaned up before we get here; see irqents and mmio below.
+ */
+
+ /* Clear the hierarchy recursively to root. */
+ if (pdev->bus->self != pdev) {
+ pci_dev_put(pdev->bus->self);
+ pdev->bus->self = NULL;
+ }
+
+ if (pdev->root != NULL) {
+ lkpinew_pci_dev_release(&pdev->root->dev); /* pci_dev_put(pdev->root); ? */
+ pdev->root = NULL;
+ }
+
+ spin_lock(&pci_lock);
+ list_del(&pdev->links);
+ spin_unlock(&pci_lock);
+
+ linux_pdev_dma_uninit(pdev);
+
+ /* irq? */
+
+ /* Undo lkpifill_pci_dev(). */
+ /* devres is gone already; went at the very top. */
+ if (!list_empty_careful(&pdev->dev.irqents)) {
+ dev_warn(&pdev->dev, "%s: driver did not clean up; "
+ "leaking IRQs\n", __func__);
+ /*
+ * XXX add private function to interrupt.h/linux_interrupt.c
+ * to walk the list and call free_irq on each if we have to.
+ */
+ }
+
spin_lock_destroy(&dev->devres_lock);
+ spin_lock_destroy(&pdev->pcie_cap_lock);
+
+ if (!TAILQ_EMPTY(&pdev->mmio)) {
+ dev_warn(&pdev->dev, "%s: driver did not clean up; "
+ "leaking mmio resources\n", __func__);
+ /* XXX we have two functions to walk and release in here. */
+ }
+
+ if (pdev->msi_desc != NULL) {
+ for (int i = pci_msi_count(pdev->dev.bsddev) - 1; i >= 0; i--)
+ free(pdev->msi_desc[i], M_DEVBUF);
+ free(pdev->msi_desc, M_DEVBUF);
+ }
+
+ free(pdev->bus, M_DEVBUF);
+ kfree(pdev->path_name);
+
+ /*
+ * Very last do an internal hack in order to signal
+ * that this was run (device reference fully dropped).
+ * See comment in linux_pci_detach_device().
+ */
+ pdev->dev.release = NULL;
}
static int
@@ -664,14 +747,16 @@
linux_pci_detach(device_t dev)
{
struct pci_dev *pdev;
+ int error;
pdev = device_get_softc(dev);
-
MPASS(pdev != NULL);
- device_set_desc(dev, NULL);
+ error = linux_pci_detach_device(pdev);
+ if (error == 0)
+ device_set_desc(dev, NULL);
- return (linux_pci_detach_device(pdev));
+ return (error);
}
int
@@ -680,21 +765,51 @@
linux_set_current(curthread);
+ /*
+ * We cannot do much here as almost everything will have
+ * to happen as the last reference to the LinuxKPI device
+ * goes away. That will call the release function,
+ * which lkpifill_pci_dev() set. That is were most
+ * of the cleanup will happen. But before that give
+ * the driver a chance to cleanup.
+ * The big problem is that the Linux KPI does not
+ * report back if it was the last kref (well kref
+ * does report back but then kobj, dev, pdev do not).
+ * So we have little way of knowing if the release
+ * happened or not. We have to play tricks for that
+ * and we can given the softc (pdev) is still valid
+ * until we return from here.
+ */
+
if (pdev->pdrv != NULL)
pdev->pdrv->remove(pdev);
- if (pdev->root != NULL)
- pci_dev_put(pdev->root);
- free(pdev->bus, M_DEVBUF);
- linux_pdev_dma_uninit(pdev);
+ pci_dev_put(pdev);
- spin_lock(&pci_lock);
- list_del(&pdev->links);
- spin_unlock(&pci_lock);
- spin_lock_destroy(&pdev->pcie_cap_lock);
- put_device(&pdev->dev);
+ /*
+ * We (ab)use the release function as a guard to
+ * know if we made it there and the device is gone.
+ */
+ if (pdev->dev.release != lkpi_pci_dev_release)
+ return (0);
- return (0);
+ /*
+ * Detach failed.
+ * We need to re-acquire the ref and wait for
+ * the other refs to be gone... In theory this
+ * should never happen, so log it!
+ * XXX I wish there was a KPI to query the ref.
+ *
+ * If we do not error and wait, we will have a
+ * LinuxKPI device dangling active with pointers
+ * but the FreeBSD device_t will be 'gone'.
+ */
+ device_printf(pdev->dev.bsddev, "%s failed due to %u other pending "
+ "references on the LinuxKPI device.\n", __func__,
+ kref_read(&pdev->dev.kobj.kref));
+ pci_dev_get(pdev);
+
+ return (EBUSY);
}
static int

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