drm/ttm: nuke caching placement flags

Changing the caching on the fly never really worked
flawlessly.

So stop this completely and just let drivers specific the
desired caching in the tt or bus object.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/394256/

4 files changed, 8 insertions, 77 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_agp_backend.c b/drivers/gpu/drm/ttm/ttm_agp_backend.c
index a723062d37e7..4f76c9287159 100644
--- a/drivers/gpu/drm/ttm/ttm_agp_backend.c
+++ b/drivers/gpu/drm/ttm/ttm_agp_backend.c
@@ -54,7 +54,7 @@ int ttm_agp_bind(struct ttm_tt *ttm, struct ttm_resource *bo_mem)
 	struct page *dummy_read_page = ttm_bo_glob.dummy_read_page;
 	struct drm_mm_node *node = bo_mem->mm_node;
 	struct agp_memory *mem;
-	int ret, cached = (bo_mem->placement & TTM_PL_FLAG_CACHED);
+	int ret, cached = ttm->caching == ttm_cached;
 	unsigned i;
 
 	if (agp_be->mem)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 3732dcb58aad..b97ed6ca8765 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -252,10 +252,6 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 		if (ret)
 			goto out_err;
 
-		ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
-		if (ret)
-			goto out_err;
-
 		if (mem->mem_type != TTM_PL_SYSTEM) {
 			ret = ttm_tt_populate(bdev, bo->ttm, ctx);
 			if (ret)
@@ -843,29 +839,6 @@ static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
 	return ttm_bo_add_move_fence(bo, man, mem, ctx->no_wait_gpu);
 }
 
-static uint32_t ttm_bo_select_caching(struct ttm_resource_manager *man,
-				      uint32_t cur_placement,
-				      uint32_t proposed_placement)
-{
-	uint32_t caching = proposed_placement & TTM_PL_MASK_CACHING;
-	uint32_t result = proposed_placement & ~TTM_PL_MASK_CACHING;
-
-	/**
-	 * Keep current caching if possible.
-	 */
-
-	if ((cur_placement & caching) != 0)
-		result |= (cur_placement & caching);
-	else if ((TTM_PL_FLAG_CACHED & caching) != 0)
-		result |= TTM_PL_FLAG_CACHED;
-	else if ((TTM_PL_FLAG_WC & caching) != 0)
-		result |= TTM_PL_FLAG_WC;
-	else if ((TTM_PL_FLAG_UNCACHED & caching) != 0)
-		result |= TTM_PL_FLAG_UNCACHED;
-
-	return result;
-}
-
 /**
  * ttm_bo_mem_placement - check if placement is compatible
  * @bo: BO to find memory for
@@ -884,18 +857,13 @@ static int ttm_bo_mem_placement(struct ttm_buffer_object *bo,
 {
 	struct ttm_bo_device *bdev = bo->bdev;
 	struct ttm_resource_manager *man;
-	uint32_t cur_flags = 0;
 
 	man = ttm_manager_type(bdev, place->mem_type);
 	if (!man || !ttm_resource_manager_used(man))
 		return -EBUSY;
 
-	cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
-					  place->flags);
-	cur_flags |= place->flags & ~TTM_PL_MASK_CACHING;
-
 	mem->mem_type = place->mem_type;
-	mem->placement = cur_flags;
+	mem->placement = place->flags;
 
 	spin_lock(&ttm_bo_glob.lru_lock);
 	ttm_bo_del_from_lru(bo);
@@ -1028,8 +996,7 @@ static bool ttm_bo_places_compat(const struct ttm_place *places,
 			continue;
 
 		*new_flags = heap->flags;
-		if ((*new_flags & mem->placement & TTM_PL_MASK_CACHING) &&
-		    (mem->mem_type == heap->mem_type) &&
+		if ((mem->mem_type == heap->mem_type) &&
 		    (!(*new_flags & TTM_PL_FLAG_CONTIGUOUS) ||
 		     (mem->placement & TTM_PL_FLAG_CONTIGUOUS)))
 			return true;
@@ -1083,9 +1050,6 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
 		ret = ttm_bo_move_buffer(bo, placement, ctx);
 		if (ret)
 			return ret;
-	} else {
-		bo->mem.placement &= TTM_PL_MASK_CACHING;
-		bo->mem.placement |= new_flags & ~TTM_PL_MASK_CACHING;
 	}
 	/*
 	 * We might need to add a TTM.
@@ -1153,7 +1117,7 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
 	bo->mem.bus.offset = 0;
 	bo->mem.bus.addr = NULL;
 	bo->moving = NULL;
-	bo->mem.placement = TTM_PL_FLAG_CACHED;
+	bo->mem.placement = 0;
 	bo->acc_size = acc_size;
 	bo->pin_count = 0;
 	bo->sg = sg;
@@ -1484,7 +1448,7 @@ int ttm_bo_swapout(struct ttm_operation_ctx *ctx)
 
 		evict_mem = bo->mem;
 		evict_mem.mm_node = NULL;
-		evict_mem.placement = TTM_PL_MASK_CACHING;
+		evict_mem.placement = 0;
 		evict_mem.mem_type = TTM_PL_SYSTEM;
 
 		ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, &ctx);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 0542097dc419..ba7ab5ed85d0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -72,10 +72,6 @@ int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
 		old_mem->mem_type = TTM_PL_SYSTEM;
 	}
 
-	ret = ttm_tt_set_placement_caching(ttm, new_mem->placement);
-	if (unlikely(ret != 0))
-		return ret;
-
 	if (new_mem->mem_type != TTM_PL_SYSTEM) {
 
 		ret = ttm_tt_populate(bo->bdev, ttm, ctx);
@@ -135,7 +131,7 @@ static int ttm_resource_ioremap(struct ttm_bo_device *bdev,
 	} else {
 		size_t bus_size = (size_t)mem->num_pages << PAGE_SHIFT;
 
-		if (mem->placement & TTM_PL_FLAG_WC)
+		if (mem->bus.caching == ttm_write_combined)
 			addr = ioremap_wc(mem->bus.offset, bus_size);
 		else
 			addr = ioremap(mem->bus.offset, bus_size);
@@ -427,7 +423,7 @@ static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
 		map->virtual = (void *)(((u8 *)bo->mem.bus.addr) + offset);
 	} else {
 		map->bo_kmap_type = ttm_bo_map_iomap;
-		if (mem->placement & TTM_PL_FLAG_WC)
+		if (mem->bus.caching == ttm_write_combined)
 			map->virtual = ioremap_wc(bo->mem.bus.offset + offset,
 						  size);
 		else
@@ -457,7 +453,7 @@ static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
 	if (ret)
 		return ret;
 
-	if (num_pages == 1 && (mem->placement & TTM_PL_FLAG_CACHED)) {
+	if (num_pages == 1 && ttm->caching == ttm_cached) {
 		/*
 		 * We're mapping a single page, and the desired
 		 * page protection is consistent with the bo.
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index a465f51df027..3e5dd6271d4c 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -114,35 +114,6 @@ static int ttm_sg_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
 	return 0;
 }
 
-static int ttm_tt_set_caching(struct ttm_tt *ttm, enum ttm_caching caching)
-{
-	if (ttm->caching == caching)
-		return 0;
-
-	/* Can't change the caching state after TT is populated */
-	if (WARN_ON_ONCE(ttm_tt_is_populated(ttm)))
-		return -EINVAL;
-
-	ttm->caching = caching;
-
-	return 0;
-}
-
-int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
-{
-	enum ttm_caching state;
-
-	if (placement & TTM_PL_FLAG_WC)
-		state = ttm_write_combined;
-	else if (placement & TTM_PL_FLAG_UNCACHED)
-		state = ttm_uncached;
-	else
-		state = ttm_cached;
-
-	return ttm_tt_set_caching(ttm, state);
-}
-EXPORT_SYMBOL(ttm_tt_set_placement_caching);
-
 void ttm_tt_destroy_common(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
 {
 	ttm_tt_unpopulate(bdev, ttm);