drm/xe/guc: Fix resource leak in xe_guc_ct_init_noalloc()

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>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patch.msgid.link/20251110184522.1581001-2-shuicheng.lin@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit 2e4ad5b0667244f496783c58de0995b9562d3344)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 283d846c35129dfe65ac9c36c8629e8d2e82ea47..7b008afb2a8f40e8f49ebd6f1733a072be67eeeb 100644 (file)
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -226,6 +226,12 @@ 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;
@@ -241,12 +247,6 @@ 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;