On Thu, 24 Jun 2021 at 20:31, Thomas Hellström thomas.hellstrom@linux.intel.com wrote:
In order to make the code a bit more readable and to facilitate async memcpy moves, reorganize the move code a little. Determine at an early stage whether to copy or to clear.
Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 70 ++++++++++++++----------- 1 file changed, 40 insertions(+), 30 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index c39d982c4fa6..4e529adcdfc7 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -431,6 +431,7 @@ i915_ttm_resource_get_st(struct drm_i915_gem_object *obj, }
static int i915_ttm_accel_move(struct ttm_buffer_object *bo,
bool clear, struct ttm_resource *dst_mem, struct sg_table *dst_st){ @@ -449,13 +450,10 @@ static int i915_ttm_accel_move(struct ttm_buffer_object *bo, return -EINVAL;
dst_level = i915_ttm_cache_level(i915, dst_mem, ttm);
if (!ttm || !ttm_tt_is_populated(ttm)) {
if (clear) { if (bo->type == ttm_bo_type_kernel) return -EINVAL;
Was that meant to be: return 0:
?
Also does that mean we are incorrectly falling back to memset, for non-userspace objects, instead of making it a noop?
if (ttm && !(ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC))return 0;intel_engine_pm_get(i915->gt.migrate.context->engine); ret = intel_context_migrate_clear(i915->gt.migrate.context, NULL, dst_st->sgl, dst_level,@@ -489,27 +487,53 @@ static int i915_ttm_accel_move(struct ttm_buffer_object *bo, return ret; }
-static int i915_ttm_move(struct ttm_buffer_object *bo, bool evict,
struct ttm_operation_ctx *ctx,struct ttm_resource *dst_mem,struct ttm_place *hop)+static void __i915_ttm_move(struct ttm_buffer_object *bo, bool clear,
struct ttm_resource *dst_mem,struct sg_table *dst_st){ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
struct ttm_resource_manager *dst_man =ttm_manager_type(bo->bdev, dst_mem->mem_type); struct intel_memory_region *dst_reg, *src_reg; union { struct ttm_kmap_iter_tt tt; struct ttm_kmap_iter_iomap io; } _dst_iter, _src_iter; struct ttm_kmap_iter *dst_iter, *src_iter;struct sg_table *dst_st; int ret; dst_reg = i915_ttm_region(bo->bdev, dst_mem->mem_type); src_reg = i915_ttm_region(bo->bdev, bo->resource->mem_type); GEM_BUG_ON(!dst_reg || !src_reg);
ret = i915_ttm_accel_move(bo, clear, dst_mem, dst_st);if (ret) {
One future consideration is flat CCS where I don't think we can easily fall back to memcpy for userspace objects. Maybe we can make this fallback conditional on DG1 or !ALLOC_USER for now, or just add a TODO?
dst_iter = !cpu_maps_iomem(dst_mem) ?ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm) :ttm_kmap_iter_iomap_init(&_dst_iter.io, &dst_reg->iomap,dst_st, dst_reg->region.start);src_iter = !cpu_maps_iomem(bo->resource) ?ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm) :ttm_kmap_iter_iomap_init(&_src_iter.io, &src_reg->iomap,obj->ttm.cached_io_st,src_reg->region.start);ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);}+}
+static int i915_ttm_move(struct ttm_buffer_object *bo, bool evict,
struct ttm_operation_ctx *ctx,struct ttm_resource *dst_mem,struct ttm_place *hop)+{
struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);struct ttm_resource_manager *dst_man =ttm_manager_type(bo->bdev, dst_mem->mem_type);struct ttm_tt *ttm = bo->ttm;struct sg_table *dst_st;bool clear;int ret;/* Sync for now. We could do the actual copy async. */ ret = ttm_bo_wait_ctx(bo, ctx); if (ret)@@ -526,9 +550,8 @@ static int i915_ttm_move(struct ttm_buffer_object *bo, bool evict, }
/* Populate ttm with pages if needed. Typically system memory. */
if (bo->ttm && (dst_man->use_tt ||(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED))) {ret = ttm_tt_populate(bo->bdev, bo->ttm, ctx);
if (ttm && (dst_man->use_tt || (ttm->page_flags & TTM_PAGE_FLAG_SWAPPED))) {ret = ttm_tt_populate(bo->bdev, ttm, ctx); if (ret) return ret; }@@ -537,23 +560,10 @@ static int i915_ttm_move(struct ttm_buffer_object *bo, bool evict, if (IS_ERR(dst_st)) return PTR_ERR(dst_st);
ret = i915_ttm_accel_move(bo, dst_mem, dst_st);if (ret) {/* If we start mapping GGTT, we can no longer use man::use_tt here. */dst_iter = !cpu_maps_iomem(dst_mem) ?ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm) :ttm_kmap_iter_iomap_init(&_dst_iter.io, &dst_reg->iomap,dst_st, dst_reg->region.start);src_iter = !cpu_maps_iomem(bo->resource) ?ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm) :ttm_kmap_iter_iomap_init(&_src_iter.io, &src_reg->iomap,obj->ttm.cached_io_st,src_reg->region.start);
clear = !cpu_maps_iomem(bo->resource) && (!ttm || !ttm_tt_is_populated(ttm));if (!(clear && ttm && !(ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)))
Seems quite hard to read?
Reviewed-by: Matthew Auld matthew.auld@intel.com
__i915_ttm_move(bo, clear, dst_mem, dst_st);
ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);}/* Below dst_mem becomes bo->resource. */ ttm_bo_move_sync_cleanup(bo, dst_mem); i915_ttm_adjust_domains_after_move(obj); i915_ttm_free_cached_io_st(obj);-- 2.31.1