drm/i915: gen 9 h/w w/a (WaEnableForceRestoreInCtxtDescForVCS)

Add:
WaEnableForceRestoreInCtxtDescForVCS

v2: Add stepping check.

v3: Fixed stepping check direction. Cleaned up indentation.

Signed-off-by: Nick Hoath <nicholas.hoath@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index a94346fee160..091555f34731 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -254,8 +254,10 @@ u32 intel_execlists_ctx_id(struct drm_i915_gem_object *ctx_obj)
         return lrca >> 12;
 }
 
-static uint64_t execlists_ctx_descriptor(struct drm_i915_gem_object *ctx_obj)
+static uint64_t execlists_ctx_descriptor(struct intel_engine_cs *ring,
+                                         struct drm_i915_gem_object *ctx_obj)
 {
+        struct drm_device *dev = ring->dev;
         uint64_t desc;
         uint64_t lrca = i915_gem_obj_ggtt_offset(ctx_obj);
 
@@ -272,6 +274,13 @@ static uint64_t execlists_ctx_descriptor(struct drm_i915_gem_object *ctx_obj)
          * signalling between Command Streamers */
         /* desc |= GEN8_CTX_FORCE_RESTORE; */
 
+        /* WaEnableForceRestoreInCtxtDescForVCS:skl */
+        if (IS_GEN9(dev) &&
+            INTEL_REVID(dev) <= SKL_REVID_B0 &&
+            (ring->id == BCS || ring->id == VCS ||
+            ring->id == VECS || ring->id == VCS2))
+                desc |= GEN8_CTX_FORCE_RESTORE;
+
         return desc;
 }
 
@@ -286,13 +295,13 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
 
         /* XXX: You must always write both descriptors in the order below. */
         if (ctx_obj1)
-                temp = execlists_ctx_descriptor(ctx_obj1);
+                temp = execlists_ctx_descriptor(ring, ctx_obj1);
         else
                 temp = 0;
         desc[1] = (u32)(temp >> 32);
         desc[0] = (u32)temp;
 
-        temp = execlists_ctx_descriptor(ctx_obj0);
+        temp = execlists_ctx_descriptor(ring, ctx_obj0);
         desc[3] = (u32)(temp >> 32);
         desc[2] = (u32)temp;