drm/i915: abolish separate per-ring default_context pointers
Now that we've eliminated a lot of uses of ring->default_context,
we can eliminate the pointer itself.
All the engines share the same default intel_context, so we can just
keep a single reference to it in the dev_priv structure rather than one
in each of the engine[] elements. This make refcounting more sensible
too, as we now have a refcount of one for the one pointer, rather than
a refcount of one but multiple pointers.
From an idea by Chris Wilson.
v2: transform an extra instance of ring->default_context introduced by
42f1cae8c drm/i915: Restore inhibiting the load of the default context
That patch's commentary includes:
v2: Mark the global default context as uninitialized on GPU reset so
that the context-local workarounds are reloaded upon re-enabling
The code implementing that now also benefits from the replacement of
the multiple (per-ring) pointers to the default context with a single
pointer to the unique kernel context.
v4: Rebased, remove underused local (Nick Hoath)
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Nick Hoath <nicholas.hoath@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1453230175-19330-3-git-send-email-david.s.gordon@intel.com
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 c25083c..6a4f64b 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -347,22 +347,20 @@
i915_gem_context_unreference(lctx);
ring->last_context = NULL;
}
-
- /* Force the GPU state to be reinitialised on enabling */
- if (ring->default_context)
- ring->default_context->legacy_hw_ctx.initialized = false;
}
+
+ /* Force the GPU state to be reinitialised on enabling */
+ dev_priv->kernel_context->legacy_hw_ctx.initialized = false;
}
int i915_gem_context_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_context *ctx;
- int i;
/* Init should only be called once per module load. Eventually the
* restriction on the context_disabled check can be loosened. */
- if (WARN_ON(dev_priv->ring[RCS].default_context))
+ if (WARN_ON(dev_priv->kernel_context))
return 0;
if (intel_vgpu_active(dev) && HAS_LOGICAL_RING_CONTEXTS(dev)) {
@@ -392,12 +390,7 @@
return PTR_ERR(ctx);
}
- for (i = 0; i < I915_NUM_RINGS; i++) {
- struct intel_engine_cs *ring = &dev_priv->ring[i];
-
- /* NB: RCS will hold a ref for all rings */
- ring->default_context = ctx;
- }
+ dev_priv->kernel_context = ctx;
DRM_DEBUG_DRIVER("%s context support initialized\n",
i915.enable_execlists ? "LR" :
@@ -408,7 +401,7 @@
void i915_gem_context_fini(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- struct intel_context *dctx = dev_priv->ring[RCS].default_context;
+ struct intel_context *dctx = dev_priv->kernel_context;
int i;
if (dctx->legacy_hw_ctx.rcs_state) {
@@ -435,17 +428,17 @@
i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
}
- for (i = 0; i < I915_NUM_RINGS; i++) {
+ for (i = I915_NUM_RINGS; --i >= 0;) {
struct intel_engine_cs *ring = &dev_priv->ring[i];
- if (ring->last_context)
+ if (ring->last_context) {
i915_gem_context_unreference(ring->last_context);
-
- ring->default_context = NULL;
- ring->last_context = NULL;
+ ring->last_context = NULL;
+ }
}
i915_gem_context_unreference(dctx);
+ dev_priv->kernel_context = NULL;
}
int i915_gem_context_enable(struct drm_i915_gem_request *req)