Merge tag 'drm-xe-next-fixes-2024-11-21' of https://gitlab.freedesktop.org/drm/xe/kernel into drm-next

Driver Changes:
- Wake up waiters after wait condition set to true (Nirmoy Das)
- Mark the preempt fence workqueue as reclaim. (Matthew Brost)

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Zz-MiVLFjOZQLrlc@fedora

Author: airlied

drivers/gpu/drm/xe/xe_device.c

@@ -360,7 +360,8 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
 	INIT_LIST_HEAD(&xe->pinned.external_vram);
 	INIT_LIST_HEAD(&xe->pinned.evicted);
 
-	xe->preempt_fence_wq = alloc_ordered_workqueue("xe-preempt-fence-wq", 0);
+	xe->preempt_fence_wq = alloc_ordered_workqueue("xe-preempt-fence-wq",
+						       WQ_MEM_RECLAIM);
 	xe->ordered_wq = alloc_ordered_workqueue("xe-ordered-wq", 0);
 	xe->unordered_wq = alloc_workqueue("xe-unordered-wq", 0, 0);
 	xe->destroy_wq = alloc_workqueue("xe-destroy-wq", 0, 0);

drivers/gpu/drm/xe/xe_sync.c

@@ -87,8 +87,12 @@ static void user_fence_worker(struct work_struct *w)
 		drm_dbg(&ufence->xe->drm, "mmget_not_zero() failed, ufence wasn't signaled\n");
 	}
 
-	wake_up_all(&ufence->xe->ufence_wq);
+	/*
+	 * Wake up waiters only after updating the ufence state, allowing the UMD
+	 * to safely reuse the same ufence without encountering -EBUSY errors.
+	 */
 	WRITE_ONCE(ufence->signalled, 1);
+	wake_up_all(&ufence->xe->ufence_wq);
 	user_fence_put(ufence);
 }