[PATCH v6 7/8] drm/i915/ttm: use cached system pages when evicting lmem

[Matthew Auld]

This should let us do an accelerated copy directly to the shmem pages
when temporarily moving lmem-only objects, where the i915-gem shrinker
can later kick in to swap out the pages, if needed.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 98b7ead1a008..48069b5a664e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -134,11 +134,11 @@ static enum ttm_caching
 i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj)
 {
 	/*
-	 * Objects only allowed in system get cached cpu-mappings.
-	 * Other objects get WC mapping for now. Even if in system.
+	 * Objects only allowed in system get cached cpu-mappings, or when
+	 * evicting lmem-only buffers to system for swapping. Other objects get
+	 * WC mapping for now. Even if in system.
 	 */
-	if (obj->mm.region->type == INTEL_MEMORY_SYSTEM &&
-	    obj->mm.n_placements <= 1)
+	if (obj->mm.n_placements <= 1)
 		return ttm_cached;
 
 	return ttm_write_combined;
-- 
2.26.3