Revert "drm/i915: Clean up associated VMAs on context destruction"

This reverts commit e9f24d5.

The patch was only a stop-gap measure that fixed half the problem - the
leak of the fbcon when restarting X. A complete solution required
releasing the VMA when the object itself was closed rather than rely on
file/process exit. The previous patches add the VMA tracking necessary
to do close them along with the object, context or file, and so the time
has come to remove the partial fix.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-28-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -3044,11 +3044,6 @@ int i915_vma_bind(struct i915_vma *vma, enum i915_cache_level cache_level,
 		  u32 flags);
 void __i915_vma_set_map_and_fenceable(struct i915_vma *vma);
 int __must_check i915_vma_unbind(struct i915_vma *vma);
-/*
- * BEWARE: Do not use the function below unless you can _absolutely_
- * _guarantee_ VMA in question is _not in use_ anywhere.
- */
-int __must_check __i915_vma_unbind_no_wait(struct i915_vma *vma);
 void i915_vma_close(struct i915_vma *vma);
 void i915_vma_destroy(struct i915_vma *vma);
 

drivers/gpu/drm/i915/i915_gem.c

@@ -2803,7 +2803,7 @@ static void __i915_vma_iounmap(struct i915_vma *vma)
 	vma->iomap = NULL;
 }
 
-static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
+int i915_vma_unbind(struct i915_vma *vma)
 {
 	struct drm_i915_gem_object *obj = vma->obj;
 	unsigned long active;
@@ -2813,7 +2813,7 @@ static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
 	 * have side-effects such as unpinning or even unbinding this vma.
 	 */
 	active = i915_vma_get_active(vma);
-	if (active && wait) {
+	if (active) {
 		int idx;
 
 		/* When a closed VMA is retired, it is unbound - eek.
@@ -2895,16 +2895,6 @@ static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
 	return 0;
 }
 
-int i915_vma_unbind(struct i915_vma *vma)
-{
-	return __i915_vma_unbind(vma, true);
-}
-
-int __i915_vma_unbind_no_wait(struct i915_vma *vma)
-{
-	return __i915_vma_unbind(vma, false);
-}
-
 int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv)
 {
 	struct intel_engine_cs *engine;

drivers/gpu/drm/i915/i915_gem_context.c

@@ -134,21 +134,6 @@ static int get_context_size(struct drm_i915_private *dev_priv)
 	return ret;
 }
 
-static void i915_gem_context_clean(struct i915_gem_context *ctx)
-{
-	struct i915_hw_ppgtt *ppgtt = ctx->ppgtt;
-	struct i915_vma *vma, *next;
-
-	if (!ppgtt)
-		return;
-
-	list_for_each_entry_safe(vma, next, &ppgtt->base.inactive_list,
-				 vm_link) {
-		if (WARN_ON(__i915_vma_unbind_no_wait(vma)))
-			break;
-	}
-}
-
 void i915_gem_context_free(struct kref *ctx_ref)
 {
 	struct i915_gem_context *ctx = container_of(ctx_ref, typeof(*ctx), ref);
@@ -158,13 +143,6 @@ void i915_gem_context_free(struct kref *ctx_ref)
 	trace_i915_context_free(ctx);
 	GEM_BUG_ON(!ctx->closed);
 
-	/*
-	 * This context is going away and we need to remove all VMAs still
-	 * around. This is to handle imported shared objects for which
-	 * destructor did not run when their handles were closed.
-	 */
-	i915_gem_context_clean(ctx);
-
 	i915_ppgtt_put(ctx->ppgtt);
 
 	for (i = 0; i < I915_NUM_ENGINES; i++) {

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -3368,7 +3368,7 @@ void i915_vma_close(struct i915_vma *vma)
 
 	list_del_init(&vma->obj_link);
 	if (!i915_vma_is_active(vma) && !vma->pin_count)
-		WARN_ON(__i915_vma_unbind_no_wait(vma));
+		WARN_ON(i915_vma_unbind(vma));
 }
 
 static struct i915_vma *