On Tue, Apr 24, 2012 at 03:47:42PM +0100, Chris Wilson wrote:
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 2 ++
> drivers/gpu/drm/i915/i915_gem_gtt.c | 32 +++++++++++++++++++++++++++++---
> 2 files changed, 31 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 32e6c4d..3492e20 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -827,6 +827,8 @@ enum i915_cache_level {
> I915_CACHE_LLC_MLC, /* gen6+ */
> };
>
> +#define I915_GTT_RESERVED ((struct drm_mm_node *)0x1)
> +
> struct drm_i915_gem_object {
> struct drm_gem_object base;
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 25c8bf9..b0c20a5 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -417,16 +417,42 @@ void i915_gem_init_global_gtt(struct drm_device *dev,
> unsigned long end)
> {
> drm_i915_private_t *dev_priv = dev->dev_private;
> + struct drm_mm_node *entry;
> + struct drm_i915_gem_object *obj;
>
> - /* Substract the guard page ... */
> + /* Subtract the guard page ... */
> drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE);
>
> + /* Mark any preallocated objects as occupied */
> + list_for_each_entry(obj, &dev_priv->mm.gtt_list, gtt_list) {
> + DRM_DEBUG_KMS("reserving preallocated space: %x + %zx\n",
> + obj->gtt_offset, obj->base.size);
> +
> + BUG_ON(obj->gtt_space != I915_GTT_RESERVED);
> + obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
> + obj->gtt_offset,
> + obj->base.size,
> + false);
> + obj->has_global_gtt_mapping = 1;
> + }
> +
> dev_priv->mm.gtt_start = start;
> dev_priv->mm.gtt_mappable_end = mappable_end;
> dev_priv->mm.gtt_end = end;
> dev_priv->mm.gtt_total = end - start;
> dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start;
>
> - /* ... but ensure that we clear the entire range. */
> - intel_gtt_clear_range(start / PAGE_SIZE, (end-start) / PAGE_SIZE);
> + /* Clear any non-preallocated blocks */
> + list_for_each_entry(entry, &dev_priv->mm.gtt_space.hole_stack, hole_stack) {
> + unsigned long hole_start = entry->start + entry->size;
> + unsigned long hole_end = list_entry(entry->node_list.next,
> + struct drm_mm_node,
> + node_list)->start;
> +
> + DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
> + hole_start, hole_end);
> +
> + intel_gtt_clear_range(hole_start / PAGE_SIZE,
> + (hole_end-hole_start) / PAGE_SIZE);
> + }
Assuming I'm reading the code correctly this does not clear the unmanaged
guard page at the end of the gtt.
-Daniel
--
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48
