[PATCH] drm/xe/ufence: Flush xe ordered_wq in case of ufence timeout

[Nirmoy Das <nirmoy.das@xxxxxxxxx>]

Flush xe ordered_wq in case of ufence timeout which is observed
on LNL and that points to recent scheduling issue with E-cores.

This is similar to the recent fix:
commit e51527233804 ("drm/xe/guc/ct: Flush g2h worker in case of g2h
response timeout") and should be removed once there is a E-core
scheduling fix for LNL.

v2: Add platform check(Himal)
    s/__flush_workqueue/flush_workqueue(Jani)
v3: Remove gfx platform check as the issue related to cpu
    platform(John)
v4: Use the Common macro(John) and print when the flush resolves
    timeout(Matt B)

Cc: Badal Nilawar <badal.nilawar@xxxxxxxxx>
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: John Harrison <John.C.Harrison@xxxxxxxxx>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@xxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v6.11+
Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2754
Suggested-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20241029120117.449694-2-nirmoy.das@xxxxxxxxx
Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
(cherry picked from commit 38c4c8722bd74452280951edc44c23de47612001)
Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>

diff --git a/drivers/gpu/drm/xe/xe_wait_user_fence.c b/drivers/gpu/drm/xe/xe_wait_user_fence.c
index f5deb81eba01..5b4264ea38bd 100644
--- a/drivers/gpu/drm/xe/xe_wait_user_fence.c
+++ b/drivers/gpu/drm/xe/xe_wait_user_fence.c
@@ -155,6 +155,13 @@ int xe_wait_user_fence_ioctl(struct drm_device *dev, void *data,
 		}
 
 		if (!timeout) {
+			LNL_FLUSH_WORKQUEUE(xe->ordered_wq);
+			err = do_compare(addr, args->value, args->mask,
+					 args->op);
+			if (err <= 0) {
+				drm_dbg(&xe->drm, "LNL_FLUSH_WORKQUEUE resolved ufence timeout\n");
+				break;
+			}
 			err = -ETIME;
 			break;
 		}