i915: Add GEM ioctl to get available aperture size.

This will let userland know when to submit its batchbuffers, before they get
too big to fit in the aperture.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 17ae330ff269..c1733ac4a7f5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -79,6 +79,28 @@ i915_gem_init_ioctl(struct drm_device *dev, void *data,
         return 0;
 }
 
+int
+i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
+                            struct drm_file *file_priv)
+{
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        struct drm_i915_gem_get_aperture *args = data;
+        struct drm_i915_gem_object *obj_priv;
+
+        if (!(dev->driver->driver_features & DRIVER_GEM))
+                return -ENODEV;
+
+        args->aper_size = dev->gtt_total;
+        args->aper_available_size = args->aper_size;
+
+        list_for_each_entry(obj_priv, &dev_priv->mm.active_list, list) {
+                if (obj_priv->pin_count > 0)
+                        args->aper_available_size -= obj_priv->obj->size;
+        }
+
+        return 0;
+}
+
 
 /**
  * Creates a new mm object and returns a handle to it.