drm/i915: put context upon switching
In order to be notified of when the context and all of its associated
objects is idle (for if the context maps to a ppgtt) we need a callback
from the retire handler. We can arrange this by using the kref_get/put
of the context for request tracking and by inserting a request to
demarque the switch away from the old context.
[Ben: fixed minor error to patch compile, AND s/last_context/from/]
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 280617e..efa0ede 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -361,13 +361,13 @@
static int do_switch(struct i915_hw_context *to)
{
struct intel_ring_buffer *ring = to->ring;
- struct drm_i915_gem_object *from_obj = ring->last_context_obj;
+ struct i915_hw_context *from = ring->last_context;
u32 hw_flags = 0;
int ret;
- BUG_ON(from_obj != NULL && from_obj->pin_count == 0);
+ BUG_ON(from != NULL && from->obj != NULL && from->obj->pin_count == 0);
- if (from_obj == to->obj)
+ if (from == to)
return 0;
ret = i915_gem_object_pin(to->obj, CONTEXT_ALIGN, false, false);
@@ -390,7 +390,7 @@
if (!to->is_initialized || is_default_context(to))
hw_flags |= MI_RESTORE_INHIBIT;
- else if (WARN_ON_ONCE(from_obj == to->obj)) /* not yet expected */
+ else if (WARN_ON_ONCE(from == to)) /* not yet expected */
hw_flags |= MI_FORCE_RESTORE;
ret = mi_set_context(ring, to, hw_flags);
@@ -405,9 +405,9 @@
* is a bit suboptimal because the retiring can occur simply after the
* MI_SET_CONTEXT instead of when the next seqno has completed.
*/
- if (from_obj != NULL) {
- from_obj->base.read_domains = I915_GEM_DOMAIN_INSTRUCTION;
- i915_gem_object_move_to_active(from_obj, ring);
+ if (from != NULL) {
+ from->obj->base.read_domains = I915_GEM_DOMAIN_INSTRUCTION;
+ i915_gem_object_move_to_active(from->obj, ring);
/* As long as MI_SET_CONTEXT is serializing, ie. it flushes the
* whole damn pipeline, we don't need to explicitly mark the
* object dirty. The only exception is that the context must be
@@ -415,15 +415,26 @@
* able to defer doing this until we know the object would be
* swapped, but there is no way to do that yet.
*/
- from_obj->dirty = 1;
- BUG_ON(from_obj->ring != ring);
- i915_gem_object_unpin(from_obj);
+ from->obj->dirty = 1;
+ BUG_ON(from->obj->ring != ring);
- drm_gem_object_unreference(&from_obj->base);
+ ret = i915_add_request(ring, NULL, NULL);
+ if (ret) {
+ /* Too late, we've already scheduled a context switch.
+ * Try to undo the change so that the hw state is
+ * consistent with out tracking. In case of emergency,
+ * scream.
+ */
+ WARN_ON(mi_set_context(ring, from, MI_RESTORE_INHIBIT));
+ return ret;
+ }
+
+ i915_gem_object_unpin(from->obj);
+ i915_gem_context_unreference(from);
}
- drm_gem_object_reference(&to->obj->base);
- ring->last_context_obj = to->obj;
+ i915_gem_context_reference(to);
+ ring->last_context = to;
to->is_initialized = true;
return 0;