drm/i915/gt: Do not generate the command streamer for all the CCS

From Andi Shyti
726ff623869ddc3de887d99296cac3c849061b21 in linux-6.6.y/6.6.26
ea315f98e5d6d3191b74beb0c3e5fc16081d517c in mainline linux

diff --git a/sys/dev/pci/drm/i915/gt/intel_engine_cs.c b/sys/dev/pci/drm/i915/gt/intel_engine_cs.c
index 8dab7b7..32506b6 100644 (file)
--- a/sys/dev/pci/drm/i915/gt/intel_engine_cs.c
+++ b/sys/dev/pci/drm/i915/gt/intel_engine_cs.c
@@ -916,6 +916,23 @@ static intel_engine_mask_t init_engine_mask(struct intel_gt *gt)
                info->engine_mask &= ~BIT(GSC0);
        }
 
+       /*
+        * Do not create the command streamer for CCS slices beyond the first.
+        * All the workload submitted to the first engine will be shared among
+        * all the slices.
+        *
+        * Once the user will be allowed to customize the CCS mode, then this
+        * check needs to be removed.
+        */
+       if (IS_DG2(gt->i915)) {
+               u8 first_ccs = __ffs(CCS_MASK(gt));
+
+               /* Mask off all the CCS engine */
+               info->engine_mask &= ~GENMASK(CCS3, CCS0);
+               /* Put back in the first CCS engine */
+               info->engine_mask |= BIT(_CCS(first_ccs));
+       }
+
        return info->engine_mask;
 }