drm/nv10: Fix crash when allocating a BO larger than half the available VRAM.

Reported-by: Alex Buell <alex.buell@munted.org.uk>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index a7fae26f465..98dd970cea2 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -128,6 +128,7 @@ nouveau_bo_new(struct drm_device *dev, struct nouveau_channel *chan,
                 }
         }
 
+        nvbo->bo.mem.num_pages = size >> PAGE_SHIFT;
         nouveau_bo_placement_set(nvbo, flags, 0);
 
         nvbo->channel = chan;
@@ -166,17 +167,17 @@ static void
 set_placement_range(struct nouveau_bo *nvbo, uint32_t type)
 {
         struct drm_nouveau_private *dev_priv = nouveau_bdev(nvbo->bo.bdev);
+        int vram_pages = dev_priv->vram_size >> PAGE_SHIFT;
 
         if (dev_priv->card_type == NV_10 &&
-            nvbo->tile_mode && (type & TTM_PL_FLAG_VRAM)) {
+            nvbo->tile_mode && (type & TTM_PL_FLAG_VRAM) &&
+            nvbo->bo.mem.num_pages < vram_pages / 2) {
                 /*
                  * Make sure that the color and depth buffers are handled
                  * by independent memory controller units. Up to a 9x
                  * speed up when alpha-blending and depth-test are enabled
                  * at the same time.
                  */
-                int vram_pages = dev_priv->vram_size >> PAGE_SHIFT;
-
                 if (nvbo->tile_flags & NOUVEAU_GEM_TILE_ZETA) {
                         nvbo->placement.fpfn = vram_pages / 2;
                         nvbo->placement.lpfn = ~0;