[PATCH v3] drm/xe/guc: Fix resource leak in xe_guc_ct_init_noalloc()

[Shuicheng Lin <shuicheng.lin@intel.com>]

xe_guc_ct_init_noalloc() allocates the CT workqueue and other helpers
before it tries to initialize ct->lock. If drmm_mutex_init() fails
we currently bail out without releasing those resources because the
guc_ct_fini() hasn’t been registered yet.

Since destroy_workqueue() in guc_ct_fini() may flush the workqueue, which
in turn can take the ct lock, the initialization sequence is restructured
to first initialize the ct->lock, then set up all CT state, and finally
register guc_ct_fini().

v2: guc_ct_fini() does take ct lock. (Matt)
v3: move primelockdep() together with drmm_mutex_init(). (Lucas)

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_ct.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 671d69958ce7..c29807ace363 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -225,6 +225,12 @@ int xe_guc_ct_init_noalloc(struct xe_guc_ct *ct)
 
 	xe_gt_assert(gt, !(guc_ct_size() % PAGE_SIZE));
 
+	err = drmm_mutex_init(&xe->drm, &ct->lock);
+	if (err)
+		return err;
+
+	primelockdep(ct);
+
 	ct->g2h_wq = alloc_ordered_workqueue("xe-g2h-wq", WQ_MEM_RECLAIM);
 	if (!ct->g2h_wq)
 		return -ENOMEM;
@@ -240,12 +246,6 @@ int xe_guc_ct_init_noalloc(struct xe_guc_ct *ct)
 	init_waitqueue_head(&ct->wq);
 	init_waitqueue_head(&ct->g2h_fence_wq);
 
-	err = drmm_mutex_init(&xe->drm, &ct->lock);
-	if (err)
-		return err;
-
-	primelockdep(ct);
-
 	err = drmm_add_action_or_reset(&xe->drm, guc_ct_fini, ct);
 	if (err)
 		return err;
-- 
2.49.0