drm/i915: Dump the whole context object.

As we've learned over time, the HW context is just a series of GPU
commands that we're able to decode without any changes in
intel_error_decode. Since many bugs recently have been implicated in
the HW context state, it makes sense to dump the whole context object
in a form which can be parsed.

Sample:
render ring --- HW Context = 0x042db000
ringbuffer (render ring) at 0x0160c000; HEAD points to: 0x0160c000
0x0160c000:      0x00000000: MI_NOOP
0x0160c004:      0x00000000: MI_NOOP
0x0160c008:      0x00000000: MI_NOOP
0x0160c00c:      0x00000000: MI_NOOP
0x0160c010:      0x00000000: MI_NOOP
0x0160c014:      0x00000000: MI_NOOP
0x0160c018:      0x00000000: MI_NOOP
0x0160c01c:      0x00000000: MI_NOOP

Unfortunately, our decoder isn't quite smart enough to deal with the
variable length LRIs - but that is a tools problem.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Clarify commit message a bit, seems to have lost a few
crucial words.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -453,16 +453,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 			err_printf(m, "%s --- HW Context = 0x%08x\n",
 				   dev_priv->ring[i].name,
 				   obj->gtt_offset);
-			offset = 0;
-			for (elt = 0; elt < PAGE_SIZE/16; elt += 4) {
-				err_printf(m, "[%04x] %08x %08x %08x %08x\n",
-					   offset,
-					   obj->pages[0][elt],
-					   obj->pages[0][elt+1],
-					   obj->pages[0][elt+2],
-					   obj->pages[0][elt+3]);
-					offset += 16;
-			}
+			print_error_obj(m, obj);
 		}
 	}
 
@@ -878,10 +869,7 @@ static void i915_gem_record_active_context(struct intel_ring_buffer *ring,
 
 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
 		if ((error->ccid & PAGE_MASK) == i915_gem_obj_ggtt_offset(obj)) {
-			ering->ctx = i915_error_object_create_sized(dev_priv,
-								    obj,
-								    &dev_priv->gtt.base,
-								    1);
+			ering->ctx = i915_error_ggtt_object_create(dev_priv, obj);
 			break;
 		}
 	}