[PATCH 3/4] drm/i915: allow volatile buffers to use ttm pool allocator

From: Robert Beckett
Date: Tue May 03 2022 - 15:13:50 EST


internal buffers should be shmem backed.
if a volatile buffer is requested, allow ttm to use the pool allocator
to provide volatile pages as backing

Signed-off-by: Robert Beckett <bob.beckett@xxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 4c25d9b2f138..fdb3a1c18cb6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -309,7 +309,8 @@ static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
page_flags |= TTM_TT_FLAG_ZERO_ALLOC;

caching = i915_ttm_select_tt_caching(obj);
- if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) {
+ if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached &&
+ !i915_gem_object_is_volatile(obj)) {
page_flags |= TTM_TT_FLAG_EXTERNAL |
TTM_TT_FLAG_EXTERNAL_MAPPABLE;
i915_tt->is_shmem = true;
--
2.25.1