drm/i915: Track which ring a context ran on
Previously we dropped the association of a context to a ring. It is
however very important to know which ring a context ran on (we could
have reused the other member, but I was nitpicky).
This is very important when we switch address spaces, which unlike
context objects, do change per ring.
As an example, if we have:
RCS BCS
ctx A
ctx A
ctx B
ctx B
Without tracking the last ring B ran on, we wouldn't know to switch the
address space on BCS in the last row.
As a result, we no longer need to track which ring a context "belongs"
to, as it never really made much sense anyway.
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 7a5311c..5f8bc06e 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -176,11 +176,6 @@
goto err_out;
}
- /* The ring associated with the context object is handled by the normal
- * object tracking code. We give an initial ring value simple to pass an
- * assertion in the context switch code.
- */
- ctx->ring = &dev_priv->ring[RCS];
list_add_tail(&ctx->link, &dev_priv->context_list);
/* Default context will never have a file_priv */
@@ -208,7 +203,8 @@
static inline bool is_default_context(struct i915_hw_context *ctx)
{
- return (ctx == ctx->ring->default_context);
+ /* Cheap trick to determine default contexts */
+ return ctx->file_priv ? false : true;
}
/**
@@ -338,6 +334,7 @@
i915_gem_context_unreference(ring->last_context);
ring->default_context = NULL;
+ ring->last_context = NULL;
}
i915_gem_object_ggtt_unpin(dctx->obj);
@@ -467,7 +464,7 @@
BUG_ON(!i915_gem_obj_is_pinned(from->obj));
}
- if (from == to && !to->remap_slice)
+ if (from == to && from->last_ring == ring && !to->remap_slice)
return 0;
if (ring != &dev_priv->ring[RCS]) {
@@ -547,6 +544,7 @@
i915_gem_context_reference(to);
ring->last_context = to;
to->is_initialized = true;
+ to->last_ring = ring;
return 0;
}