drm/i915/context: switch contexts with execbuf2

Use the rsvd1 field in execbuf2 to specify the context ID associated
with the workload. This will allow the driver to do the proper context
switch when/if needed.

v2: Add checks for context switches on rings not supporting contexts.
Before the code would silently ignore such requests.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 974a9f1068a3..f32d02464bce 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1044,6 +1044,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
         struct drm_i915_gem_object *batch_obj;
         struct drm_clip_rect *cliprects = NULL;
         struct intel_ring_buffer *ring;
+        u32 ctx_id = i915_execbuffer2_get_context_id(*args);
         u32 exec_start, exec_len;
         u32 seqno;
         u32 mask;
@@ -1065,9 +1066,19 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
                 break;
         case I915_EXEC_BSD:
                 ring = &dev_priv->ring[VCS];
+                if (ctx_id != 0) {
+                        DRM_DEBUG("Ring %s doesn't support contexts\n",
+                                  ring->name);
+                        return -EPERM;
+                }
                 break;
         case I915_EXEC_BLT:
                 ring = &dev_priv->ring[BCS];
+                if (ctx_id != 0) {
+                        DRM_DEBUG("Ring %s doesn't support contexts\n",
+                                  ring->name);
+                        return -EPERM;
+                }
                 break;
         default:
                 DRM_DEBUG("execbuf with unknown ring: %d\n",
@@ -1261,6 +1272,10 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
                         goto err;
         }
 
+        ret = i915_switch_context(ring, file, ctx_id);
+        if (ret)
+                goto err;
+
         trace_i915_gem_ring_dispatch(ring, seqno);
 
         exec_start = batch_obj->gtt_offset + args->batch_start_offset;
@@ -1367,6 +1382,7 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
         exec2.num_cliprects = args->num_cliprects;
         exec2.cliprects_ptr = args->cliprects_ptr;
         exec2.flags = I915_EXEC_RENDER;
+        i915_execbuffer2_set_context_id(exec2, 0);
 
         ret = i915_gem_do_execbuffer(dev, data, file, &exec2, exec2_list);
         if (!ret) {