drm/i915/gen9: Set value of Indirect Context Offset based on gen version

The cache line offset for the Indirect CS context (0x21C8) varies from gen
to gen.

v2: Move it into a function (Arun), use MISSING_CASE (Chris)
v3: Rebased (catched by ci bat)

Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456223509-6454-1-git-send-email-michel.thierry@intel.com

drivers/gpu/drm/i915/intel_lrc.c

@@ -223,7 +223,8 @@ enum {
 	FAULT_AND_CONTINUE /* Unsupported */
 };
 #define GEN8_CTX_ID_SHIFT 32
-#define CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT  0x17
+#define GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT	0x17
+#define GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT	0x26
 
 static int intel_lr_context_pin(struct intel_context *ctx,
 				struct intel_engine_cs *engine);
@@ -2317,6 +2318,27 @@ make_rpcs(struct drm_device *dev)
 	return rpcs;
 }
 
+static u32 intel_lr_indirect_ctx_offset(struct intel_engine_cs *ring)
+{
+	u32 indirect_ctx_offset;
+
+	switch (INTEL_INFO(ring->dev)->gen) {
+	default:
+		MISSING_CASE(INTEL_INFO(ring->dev)->gen);
+		/* fall through */
+	case 9:
+		indirect_ctx_offset =
+			GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
+		break;
+	case 8:
+		indirect_ctx_offset =
+			GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
+		break;
+	}
+
+	return indirect_ctx_offset;
+}
+
 static int
 populate_lr_context(struct intel_context *ctx, struct drm_i915_gem_object *ctx_obj,
 		    struct intel_engine_cs *ring, struct intel_ringbuffer *ringbuf)
@@ -2389,7 +2411,7 @@ populate_lr_context(struct intel_context *ctx, struct drm_i915_gem_object *ctx_o
 				(wa_ctx->indirect_ctx.size / CACHELINE_DWORDS);
 
 			reg_state[CTX_RCS_INDIRECT_CTX_OFFSET+1] =
-				CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT << 6;
+				intel_lr_indirect_ctx_offset(ring) << 6;
 
 			reg_state[CTX_BB_PER_CTX_PTR+1] =
 				(ggtt_offset + wa_ctx->per_ctx.offset * sizeof(uint32_t)) |