drm/i915/cnl: Introduce initial Cannonlake Workarounds.

Let's inherit workarounds from previous platforms that
according to wa_database and BSpec are still valid for
Cannonlake.

v2: Add missed workarounds.
v3: Rebase
v4: Remove bad chunk that was added to rc6 disable. (Ander)
    Also remove A0 W/a that are not needed anymore.
v5: Rebase on top of CFL.
v6: Remove empty gen9_init_perctx_bb and gen9_init_indirectctx_bb
    since they don't carry any gen10 related W/a. (by Oscar).
    Also Remove A0 exclusive workaround.
v7: Remove more A0 exclusive workarounds. As pointed out by Oscar
    many workarounds were changed to be A0 only so let's remove
    them.

Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Oscar Mateo <oscar.mateo@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170815231651.975-1-rodrigo.vivi@intel.com
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 9ab5969..58a2353 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1065,6 +1065,23 @@ static int bxt_init_workarounds(struct intel_engine_cs *engine)
 	return 0;
 }
 
+static int cnl_init_workarounds(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+	int ret;
+
+	/* WaInPlaceDecompressionHang:cnl */
+	WA_SET_BIT(GEN9_GAMT_ECO_REG_RW_IA,
+		   GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS);
+
+	/* WaEnablePreemptionGranularityControlByUMD:cnl */
+	ret= wa_ring_whitelist_reg(engine, GEN8_CS_CHICKEN1);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int kbl_init_workarounds(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *dev_priv = engine->i915;
@@ -1185,6 +1202,8 @@ int init_workarounds_ring(struct intel_engine_cs *engine)
 		err =  glk_init_workarounds(engine);
 	else if (IS_COFFEELAKE(dev_priv))
 		err = cfl_init_workarounds(engine);
+	else if (IS_CANNONLAKE(dev_priv))
+		err = cnl_init_workarounds(engine);
 	else
 		err = 0;
 	if (err)