drm/i915/error: Capture WA ctx batch in error state

execute during context save/restore, good to have them in error state.

v2: use wa_ctx->size and print only size values (Mika)
v3: simplify conditions when recording and freeing object (Chris)
v4: resolve checkpatch errors (Tvrtko)

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456831476-10782-1-git-send-email-arun.siluvery@linux.intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -561,6 +561,8 @@ struct drm_i915_error_state {
 			u32 *pages[0];
 		} *ringbuffer, *batchbuffer, *wa_batchbuffer, *ctx, *hws_page;
 
+		struct drm_i915_error_object *wa_ctx;
+
 		struct drm_i915_error_request {
 			long jiffies;
 			u32 seqno;

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -493,6 +493,28 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 			}
 		}
 
+		obj = error->ring[i].wa_ctx;
+		if (obj) {
+			u64 wa_ctx_offset = obj->gtt_offset;
+			u32 *wa_ctx_page = &obj->pages[0][0];
+			struct intel_engine_cs *ring = &dev_priv->ring[RCS];
+			u32 wa_ctx_size = (ring->wa_ctx.indirect_ctx.size +
+					   ring->wa_ctx.per_ctx.size);
+
+			err_printf(m, "%s --- WA ctx batch buffer = 0x%08llx\n",
+				   dev_priv->ring[i].name, wa_ctx_offset);
+			offset = 0;
+			for (elt = 0; elt < wa_ctx_size; elt += 4) {
+				err_printf(m, "[%04x] %08x %08x %08x %08x\n",
+					   offset,
+					   wa_ctx_page[elt + 0],
+					   wa_ctx_page[elt + 1],
+					   wa_ctx_page[elt + 2],
+					   wa_ctx_page[elt + 3]);
+				offset += 16;
+			}
+		}
+
 		if ((obj = error->ring[i].ctx)) {
 			err_printf(m, "%s --- HW Context = 0x%08x\n",
 				   dev_priv->ring[i].name,
@@ -585,6 +607,7 @@ static void i915_error_state_free(struct kref *error_ref)
 		i915_error_object_free(error->ring[i].hws_page);
 		i915_error_object_free(error->ring[i].ctx);
 		kfree(error->ring[i].requests);
+		i915_error_object_free(error->ring[i].wa_ctx);
 	}
 
 	i915_error_object_free(error->semaphore_obj);
@@ -1067,6 +1090,12 @@ static void i915_gem_record_rings(struct drm_device *dev,
 		error->ring[i].hws_page =
 			i915_error_ggtt_object_create(dev_priv, ring->status_page.obj);
 
+		if (ring->wa_ctx.obj) {
+			error->ring[i].wa_ctx =
+				i915_error_ggtt_object_create(dev_priv,
+							      ring->wa_ctx.obj);
+		}
+
 		i915_gem_record_active_context(ring, error, &error->ring[i]);
 
 		count = 0;