drm/i915/ttm: ensure we unmap when purging

Purging can happen during swapping out, or directly invoked with the
madvise ioctl. In such cases this doesn't involve a ttm move, which
skips umapping the object.

v2(Thomas):
- add ttm_truncate helper, and just call into i915_ttm_move_notify() to
  handle the unmapping step

Fixes: 213d50927763 ("drm/i915/ttm: Introduce a TTM i915 gem object backend")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220106174910.280616-4-matthew.auld@intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index d6d6878..84cae74 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -554,6 +554,20 @@ i915_ttm_resource_get_st(struct drm_i915_gem_object *obj,
        return intel_region_ttm_resource_to_rsgt(obj->mm.region, res);
 }
 
+static int i915_ttm_truncate(struct drm_i915_gem_object *obj)
+{
+       struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+       int err;
+
+       WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED);
+
+       err = i915_ttm_move_notify(bo);
+       if (err)
+               return err;
+
+       return i915_ttm_purge(obj);
+}
+
 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo)
 {
        struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
@@ -960,7 +974,7 @@ static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
 
        .get_pages = i915_ttm_get_pages,
        .put_pages = i915_ttm_put_pages,
-       .truncate = i915_ttm_purge,
+       .truncate = i915_ttm_truncate,
        .shrink = i915_ttm_shrink,
 
        .adjust_lru = i915_ttm_adjust_lru,