drm/i915/perf: fix gen11 engine class shift

Use the correct engine class shift value while storing the ctx hw id.
Fixes the copy+paste error from commit 61d5676b55 ("drm/i915/perf: fix
ctx_id read with GuC & ICL").

Apologies for not spotting this in the original review, the
specific_ctx_id_mask is correct, only the specific_ctx_id had this
problem.

v2: Just use the upper 32 bits of lrc_desc (Chris)
v3: If we use the lrc_desc, we must apply the ctx_id_mask too (Lionel)

Fixes: 61d5676b55 ("drm/i915/perf: fix ctx_id read with GuC & ICL")
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180604233250.609-2-michel.thierry@intel.com

drivers/gpu/drm/i915/i915_perf.c

@@ -1289,16 +1289,13 @@ static int oa_get_render_ctx_id(struct i915_perf_stream *stream)
 		break;
 
 	case 11: {
-		struct intel_engine_cs *engine = i915->engine[RCS];
-
-		i915->perf.oa.specific_ctx_id =
-			stream->ctx->hw_id << (GEN11_SW_CTX_ID_SHIFT - 32) |
-			engine->instance << (GEN11_ENGINE_INSTANCE_SHIFT - 32) |
-			engine->class << (GEN11_ENGINE_INSTANCE_SHIFT - 32);
 		i915->perf.oa.specific_ctx_id_mask =
 			((1U << GEN11_SW_CTX_ID_WIDTH) - 1) << (GEN11_SW_CTX_ID_SHIFT - 32) |
 			((1U << GEN11_ENGINE_INSTANCE_WIDTH) - 1) << (GEN11_ENGINE_INSTANCE_SHIFT - 32) |
 			((1 << GEN11_ENGINE_CLASS_WIDTH) - 1) << (GEN11_ENGINE_CLASS_SHIFT - 32);
+		i915->perf.oa.specific_ctx_id = upper_32_bits(ce->lrc_desc);
+		i915->perf.oa.specific_ctx_id &=
+			i915->perf.oa.specific_ctx_id_mask;
 		break;
 	}