drm/i915/bdw: Write the tail pointer, LRC style

Each logical ring context has the tail pointer in the context object,
so update it before submission.

v2: New namespace.

Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index aa81fd41b9c1ed60b4c69dd5db0d465b26cc9933..26bc063f137b6b9c1fab3c3d61f16f23d60d2830 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -178,6 +178,21 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
        gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
 }
 
+static int execlists_ctx_write_tail(struct drm_i915_gem_object *ctx_obj, u32 tail)
+{
+       struct page *page;
+       uint32_t *reg_state;
+
+       page = i915_gem_object_get_page(ctx_obj, 1);
+       reg_state = kmap_atomic(page);
+
+       reg_state[CTX_RING_TAIL+1] = tail;
+
+       kunmap_atomic(reg_state);
+
+       return 0;
+}
+
 static int execlists_submit_context(struct intel_engine_cs *ring,
                                    struct intel_context *to0, u32 tail0,
                                    struct intel_context *to1, u32 tail1)
@@ -189,10 +204,14 @@ static int execlists_submit_context(struct intel_engine_cs *ring,
        BUG_ON(!ctx_obj0);
        BUG_ON(!i915_gem_obj_is_pinned(ctx_obj0));
 
+       execlists_ctx_write_tail(ctx_obj0, tail0);
+
        if (to1) {
                ctx_obj1 = to1->engine[ring->id].state;
                BUG_ON(!ctx_obj1);
                BUG_ON(!i915_gem_obj_is_pinned(ctx_obj1));
+
+               execlists_ctx_write_tail(ctx_obj1, tail1);
        }
 
        execlists_elsp_write(ring, ctx_obj0, ctx_obj1);