dmaengine: idxd: Fix refcount underflow on module unload

JIRA: https://issues.redhat.com/browse/RHEL-114133
Upstream-Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

commit b7cb9a0
Author: Yi Sun <yi.sun@intel.com>
Date: Tue Jul 29 23:03:13 2025 +0800

    dmaengine: idxd: Fix refcount underflow on module unload

    A recent refactor introduced a misplaced put_device() call, resulting in a
    reference count underflow during module unload.

    There is no need to add additional put_device() calls for idxd groups,
    engines, or workqueues. Although the commit claims: "Note, this also
    fixes the missing put_device() for idxd groups, engines, and wqs."

    It appears no such omission actually existed. The required cleanup is
    already handled by the call chain:
    idxd_unregister_devices() -> device_unregister() -> put_device()

    Extend idxd_cleanup() to handle the remaining necessary cleanup and
    remove idxd_cleanup_internals(), which duplicates deallocation logic
    for idxd, engines, groups, and workqueues. Memory management is also
    properly handled through the Linux device model.

    Fixes: a409e91 ("dmaengine: idxd: Refactor remove call with idxd_cleanup() helper")
    Signed-off-by: Yi Sun <yi.sun@intel.com>
    Tested-by: Shuai Xue <xueshuai@linux.alibaba.com>
    Reviewed-by: Dave Jiang <dave.jiang@intel.com>
    Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>

    Link: https://lore.kernel.org/r/20250729150313.1934101-3-yi.sun@intel.com
    Signed-off-by: Vinod Koul <vkoul@kernel.org>

(cherry picked from commit b7cb9a0)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>

Author: snits

drivers/dma/idxd/init.c

@@ -1320,7 +1320,10 @@ static void idxd_remove(struct pci_dev *pdev)
 	device_unregister(idxd_confdev(idxd));
 	idxd_shutdown(pdev);
 	idxd_device_remove_debugfs(idxd);
-	idxd_cleanup(idxd);
+	perfmon_pmu_remove(idxd);
+	idxd_cleanup_interrupts(idxd);
+	if (device_pasid_enabled(idxd))
+		idxd_disable_system_pasid(idxd);
 	pci_iounmap(pdev, idxd->reg_base);
 	put_device(idxd_confdev(idxd));
 	pci_disable_device(pdev);