[Intel-gfx] [PATCH] drm/i915: Defer adding preallocated stolen objects to the VM list

[Chris Wilson]

When preallocating a stolen object during early initialisation, we may
be running before we have setup the the global GTT VM state, in
particular before we have initialised the range manager and associated
lists. As this is the case, we defer binding the stolen object until we
call i915_gem_setup_global_gtt(). Not only should we defer the binding,
but we should also defer the VM list manipulation.

Fixes regression from commit a2cad9dff4dd44d0244b966d980de9d602d87593
Author: Michał Winiarski <michal.winiarski at intel.com>
Date:   Wed Sep 16 11:49:00 2015 +0200

    drm/i915/gtt: Do not initialize drm_mm twice.

Whilst I am here remove the duplicate work leaving dangling pointers
from the error path...

Reported-by: Jesse Barnes <jesse at virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92099
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jesse Barnes <jesse at virtuousgeek.org>
Cc: Michel Thierry <michel.thierry at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c    |  2 +-
 drivers/gpu/drm/i915/i915_gem_stolen.c | 16 ++++++----------
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 01f3521e77d3..9cc68624410e 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2533,7 +2533,6 @@ static int ggtt_bind_vma(struct i915_vma *vma,
 		 * the bound flag ourselves.
 		 */
 		vma->bound |= GLOBAL_BIND;
-
 	}
 
 	if (dev_priv->mm.aliasing_ppgtt && flags & LOCAL_BIND) {
@@ -2657,6 +2656,7 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 			return ret;
 		}
 		vma->bound |= GLOBAL_BIND;
+		list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 	}
 
 	/* Clear any non-preallocated blocks */
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 55df6ce34751..15207796e1b3 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -584,7 +584,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
-		goto err_out;
+		goto err;
 	}
 
 	/* To simplify the initialisation sequence between KMS and GTT,
@@ -598,23 +598,19 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
 		if (ret) {
 			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
-			goto err_vma;
+			goto err;
 		}
-	}
 
-	vma->bound |= GLOBAL_BIND;
+		vma->bound |= GLOBAL_BIND;
+		list_add_tail(&vma->mm_list, &ggtt->inactive_list);
+	}
 
 	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
-	list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 	i915_gem_object_pin_pages(obj);
 
 	return obj;
 
-err_vma:
-	i915_gem_vma_destroy(vma);
-err_out:
-	i915_gem_stolen_remove_node(dev_priv, stolen);
-	kfree(stolen);
+err:
 	drm_gem_object_unreference(&obj->base);
 	return NULL;
 }
-- 
2.5.3