Capture the eviction details for Flat-CCS capable lmem only objects and lmem objects with smem residency. This also captures the impact of eviction on object's memory residency and Flat-CCS compression state. Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_migrate.c | 36 ++++++++++++++++++------- 1 file changed, 27 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c index 463a6a14b5f9..9d0d18950e76 100644 --- a/drivers/gpu/drm/i915/gt/intel_migrate.c +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c @@ -485,16 +485,34 @@ static bool wa_1209644611_applies(int ver, u32 size) * And CCS data can be copied in and out of CCS region through * XY_CTRL_SURF_COPY_BLT. CPU can't access the CCS data directly. * - * When we exhaust the lmem, if the object's placements support smem, then we can - * directly decompress the compressed lmem object into smem and start using it - * from smem itself. + * when we exhaust the lmem, we need to handle two types of flat-ccs capable + * objects for its eviction. + * 1) lmem only objects + * 2) lmem objects with smem residency option * - * But when we need to swapout the compressed lmem object into a smem region - * though objects' placement doesn't support smem, then we copy the lmem content - * as it is into smem region along with ccs data (using XY_CTRL_SURF_COPY_BLT). - * When the object is referred, lmem content will be swaped in along with - * restoration of the CCS data (using XY_CTRL_SURF_COPY_BLT) at corresponding - * location. + * 1) lmem only objects: + * + * lmem backing memory can be temporarily evicted to smem, along with the + * auxiliary CCS state, where it can be potentially swapped-out at a later point, + * if required. If userspace later touches the evicted pages, then we always move + * the backing memory back to lmem, which includes restoring the saved CCS state, + * and potentially performing any required swap-in. + * + * In this scenario, objects' backing memory class and Flat-CCS state doesn't + * change. + * + * 2) lmem objects with smem residency option + * + * Lmem object with smem region in it's placement list, will be migrated into + * smem by decompressing the content. I915 doesn't handle this kind of + * migration for Flat-CCS compressed objects yet. + * + * In this scenario, objects' backing memory class and Flat-CCS state changed, + * and userspace is not aware of it. + * + * In summary, when a userspace wants to be sure about the objects memory + * residency and flat-ccs compression state, then placement list can't have + * the lmem and smem together. Instead, object has to be lmem resident only. */ static inline u32 *i915_flush_dw(u32 *cmd, u32 flags) -- 2.20.1
