[Intel-xe] [PATCH v3 4/4] drm/xe/bo: Evict VRAM to TT rather than to system

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

The main difference is that we don't bounce and sync on eviction, allowing
for pipelined eviction. Moving forward we also need to be careful with
dma mappings which can be released in SYSTEM but may remain in TT.

v2:
- Remove a stale comment (Matthew Brost)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 03b83150e8cd..21fca198a882 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -40,6 +40,20 @@ static struct ttm_placement sys_placement = {
 	.busy_placement = &sys_placement_flags,
 };
 
+static const struct ttm_place tt_placement_flags = {
+	.fpfn = 0,
+	.lpfn = 0,
+	.mem_type = XE_PL_TT,
+	.flags = 0,
+};
+
+static struct ttm_placement tt_placement = {
+	.num_placement = 1,
+	.placement = &tt_placement_flags,
+	.num_busy_placement = 1,
+	.busy_placement = &sys_placement_flags,
+};
+
 bool mem_type_is_vram(u32 mem_type)
 {
 	return mem_type >= XE_PL_VRAM0 && mem_type != XE_PL_STOLEN;
@@ -225,9 +239,10 @@ static void xe_evict_flags(struct ttm_buffer_object *tbo,
 	case XE_PL_VRAM0:
 	case XE_PL_VRAM1:
 	case XE_PL_STOLEN:
+		*placement = tt_placement;
+		break;
 	case XE_PL_TT:
 	default:
-		/* for now kick out to system */
 		*placement = sys_placement;
 		break;
 	}
-- 
2.40.1