drm/ttm: flip the switch for driver allocated resources v2

Instead of both driver and TTM allocating memory finalize embedding the
ttm_resource object as base into the driver backends.

v2: fix typo in vmwgfx grid mgr and double init in amdgpu_vram_mgr.c

Signed-off-by: Christian König <[e-mail]>
Reviewed-by: Matthew Auld <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c

···
 static inline struct amdgpu_gtt_node *
 to_amdgpu_gtt_node(struct ttm_resource *res)
 {
-	return container_of(res->mm_node, struct amdgpu_gtt_node,
-			    base.mm_nodes[0]);
+	return container_of(res, struct amdgpu_gtt_node, base.base);
 }
 
 /**
···
 /**
  * amdgpu_gtt_mgr_has_gart_addr - Check if mem has address space
  *
- * @mem: the mem object to check
+ * @res: the mem object to check
  *
  * Check if a mem object has already address space allocated.
  */
-bool amdgpu_gtt_mgr_has_gart_addr(struct ttm_resource *mem)
+bool amdgpu_gtt_mgr_has_gart_addr(struct ttm_resource *res)
 {
-	struct amdgpu_gtt_node *node = to_amdgpu_gtt_node(mem);
+	struct amdgpu_gtt_node *node = to_amdgpu_gtt_node(res);
 
 	return drm_mm_node_allocated(&node->base.mm_nodes[0]);
 }
···
 static int amdgpu_gtt_mgr_new(struct ttm_resource_manager *man,
 			      struct ttm_buffer_object *tbo,
 			      const struct ttm_place *place,
-			      struct ttm_resource *mem)
+			      struct ttm_resource **res)
 {
 	struct amdgpu_gtt_mgr *mgr = to_gtt_mgr(man);
+	uint32_t num_pages = PFN_UP(tbo->base.size);
 	struct amdgpu_gtt_node *node;
 	int r;
 
 	spin_lock(&mgr->lock);
-	if ((tbo->resource == mem || tbo->resource->mem_type != TTM_PL_TT) &&
-	    atomic64_read(&mgr->available) < mem->num_pages) {
+	if (tbo->resource && tbo->resource->mem_type != TTM_PL_TT &&
+	    atomic64_read(&mgr->available) < num_pages) {
 		spin_unlock(&mgr->lock);
 		return -ENOSPC;
 	}
-	atomic64_sub(mem->num_pages, &mgr->available);
+	atomic64_sub(num_pages, &mgr->available);
 	spin_unlock(&mgr->lock);
 
 	node = kzalloc(struct_size(node, base.mm_nodes, 1), GFP_KERNEL);
···
 		spin_lock(&mgr->lock);
 		r = drm_mm_insert_node_in_range(&mgr->mm,
 						&node->base.mm_nodes[0],
-						mem->num_pages,
-						tbo->page_alignment, 0,
-						place->fpfn, place->lpfn,
+						num_pages, tbo->page_alignment,
+						0, place->fpfn, place->lpfn,
 						DRM_MM_INSERT_BEST);
 		spin_unlock(&mgr->lock);
 		if (unlikely(r))
 			goto err_free;
 
-		mem->start = node->base.mm_nodes[0].start;
+		node->base.base.start = node->base.mm_nodes[0].start;
 	} else {
 		node->base.mm_nodes[0].start = 0;
-		node->base.mm_nodes[0].size = mem->num_pages;
-		mem->start = AMDGPU_BO_INVALID_OFFSET;
+		node->base.mm_nodes[0].size = node->base.base.num_pages;
+		node->base.base.start = AMDGPU_BO_INVALID_OFFSET;
 	}
 
-	mem->mm_node = &node->base.mm_nodes[0];
+	*res = &node->base.base;
 	return 0;
 
 err_free:
 	kfree(node);
 
 err_out:
-	atomic64_add(mem->num_pages, &mgr->available);
+	atomic64_add(num_pages, &mgr->available);
 
 	return r;
 }
···
  * Free the allocated GTT again.
  */
 static void amdgpu_gtt_mgr_del(struct ttm_resource_manager *man,
-			       struct ttm_resource *mem)
+			       struct ttm_resource *res)
 {
+	struct amdgpu_gtt_node *node = to_amdgpu_gtt_node(res);
 	struct amdgpu_gtt_mgr *mgr = to_gtt_mgr(man);
-	struct amdgpu_gtt_node *node;
-
-	if (!mem->mm_node)
-		return;
-
-	node = to_amdgpu_gtt_node(mem);
 
 	spin_lock(&mgr->lock);
 	if (drm_mm_node_allocated(&node->base.mm_nodes[0]))
 		drm_mm_remove_node(&node->base.mm_nodes[0]);
 	spin_unlock(&mgr->lock);
-	atomic64_add(mem->num_pages, &mgr->available);
+	atomic64_add(res->num_pages, &mgr->available);
 
 	kfree(node);
 }

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

···
 	if (bo->base.resv == &bo->base._resv)
 		amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
 
-	if (bo->resource->mem_type != TTM_PL_VRAM || !bo->resource->mm_node ||
+	if (bo->resource->mem_type != TTM_PL_VRAM ||
 	    !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
 		return;
 

drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h

···
 
 #include <drm/drm_mm.h>
 #include <drm/ttm/ttm_resource.h>
+#include <drm/ttm/ttm_range_manager.h>
 
 /* state back for walking over vram_mgr and gtt_mgr allocations */
 struct amdgpu_res_cursor {
···
 {
 	struct drm_mm_node *node;
 
-	if (!res || !res->mm_node) {
+	if (!res) {
 		cur->start = start;
 		cur->size = size;
 		cur->remaining = size;
···
 
 	BUG_ON(start + size > res->num_pages << PAGE_SHIFT);
 
-	node = res->mm_node;
+	node = to_ttm_range_mgr_node(res)->mm_nodes;
 	while (start >= node->size << PAGE_SHIFT)
 		start -= node++->size << PAGE_SHIFT;
 

drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c

···
 u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo)
 {
 	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
-	struct ttm_resource *mem = bo->tbo.resource;
-	struct drm_mm_node *nodes = mem->mm_node;
-	unsigned pages = mem->num_pages;
+	struct ttm_resource *res = bo->tbo.resource;
+	unsigned pages = res->num_pages;
+	struct drm_mm_node *mm;
 	u64 usage;
 
 	if (amdgpu_gmc_vram_full_visible(&adev->gmc))
 		return amdgpu_bo_size(bo);
 
-	if (mem->start >= adev->gmc.visible_vram_size >> PAGE_SHIFT)
+	if (res->start >= adev->gmc.visible_vram_size >> PAGE_SHIFT)
 		return 0;
 
-	for (usage = 0; nodes && pages; pages -= nodes->size, nodes++)
-		usage += amdgpu_vram_mgr_vis_size(adev, nodes);
+	mm = &container_of(res, struct ttm_range_mgr_node, base)->mm_nodes[0];
+	for (usage = 0; pages; pages -= mm->size, mm++)
+		usage += amdgpu_vram_mgr_vis_size(adev, mm);
 
 	return usage;
 }
···
 static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 			       struct ttm_buffer_object *tbo,
 			       const struct ttm_place *place,
-			       struct ttm_resource *mem)
+			       struct ttm_resource **res)
 {
 	unsigned long lpfn, num_nodes, pages_per_node, pages_left, pages;
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
···
 		max_bytes -= AMDGPU_VM_RESERVED_VRAM;
 
 	/* bail out quickly if there's likely not enough VRAM for this BO */
-	mem_bytes = (u64)mem->num_pages << PAGE_SHIFT;
+	mem_bytes = tbo->base.size;
 	if (atomic64_add_return(mem_bytes, &mgr->usage) > max_bytes) {
 		r = -ENOSPC;
 		goto error_sub;
···
 #endif
 		pages_per_node = max_t(uint32_t, pages_per_node,
 				       tbo->page_alignment);
-		num_nodes = DIV_ROUND_UP(mem->num_pages, pages_per_node);
+		num_nodes = DIV_ROUND_UP(PFN_UP(mem_bytes), pages_per_node);
 	}
 
 	node = kvmalloc(struct_size(node, mm_nodes, num_nodes),
···
 	if (place->flags & TTM_PL_FLAG_TOPDOWN)
 		mode = DRM_MM_INSERT_HIGH;
 
-	mem->start = 0;
-	pages_left = mem->num_pages;
+	pages_left = node->base.num_pages;
 
 	/* Limit maximum size to 2GB due to SG table limitations */
 	pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));
···
 		}
 
 		vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);
-		amdgpu_vram_mgr_virt_start(mem, &node->mm_nodes[i]);
+		amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);
 		pages_left -= pages;
 		++i;
 
···
 	spin_unlock(&mgr->lock);
 
 	if (i == 1)
-		mem->placement |= TTM_PL_FLAG_CONTIGUOUS;
+		node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
 
 	atomic64_add(vis_usage, &mgr->vis_usage);
-	mem->mm_node = &node->mm_nodes[0];
+	*res = &node->base;
 	return 0;
 
 error_free:
···
  * Free the allocated VRAM again.
  */
 static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
-				struct ttm_resource *mem)
+				struct ttm_resource *res)
 {
+	struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
 	struct amdgpu_device *adev = to_amdgpu_device(mgr);
-	struct ttm_range_mgr_node *node;
 	uint64_t usage = 0, vis_usage = 0;
-	unsigned pages = mem->num_pages;
-	struct drm_mm_node *nodes;
-
-	if (!mem->mm_node)
-		return;
-
-	node = to_ttm_range_mgr_node(mem);
-	nodes = &node->mm_nodes[0];
+	unsigned i, pages;
 
 	spin_lock(&mgr->lock);
-	while (pages) {
-		pages -= nodes->size;
-		drm_mm_remove_node(nodes);
-		usage += nodes->size << PAGE_SHIFT;
-		vis_usage += amdgpu_vram_mgr_vis_size(adev, nodes);
-		++nodes;
+	for (i = 0, pages = res->num_pages; pages;
+	     pages -= node->mm_nodes[i].size, ++i) {
+		struct drm_mm_node *mm = &node->mm_nodes[i];
+
+		drm_mm_remove_node(mm);
+		usage += mm->size << PAGE_SHIFT;
+		vis_usage += amdgpu_vram_mgr_vis_size(adev, mm);
 	}
 	amdgpu_vram_mgr_do_reserve(man);
 	spin_unlock(&mgr->lock);
···
  * Allocate and fill a sg table from a VRAM allocation.
  */
 int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
-			      struct ttm_resource *mem,
+			      struct ttm_resource *res,
 			      u64 offset, u64 length,
 			      struct device *dev,
 			      enum dma_data_direction dir,
···
 		return -ENOMEM;
 
 	/* Determine the number of DRM_MM nodes to export */
-	amdgpu_res_first(mem, offset, length, &cursor);
+	amdgpu_res_first(res, offset, length, &cursor);
 	while (cursor.remaining) {
 		num_entries++;
 		amdgpu_res_next(&cursor, cursor.size);
···
 	 * and the number of bytes from it. Access the following
 	 * DRM_MM node(s) if more buffer needs to exported
 	 */
-	amdgpu_res_first(mem, offset, length, &cursor);
+	amdgpu_res_first(res, offset, length, &cursor);
 	for_each_sgtable_sg((*sgt), sg, i) {
 		phys_addr_t phys = cursor.start + adev->gmc.aper_base;
 		size_t size = cursor.size;

drivers/gpu/drm/drm_gem_vram_helper.c

···
 static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
 {
 	/* Keep TTM behavior for now, remove when drivers are audited */
-	if (WARN_ON_ONCE(!gbo->bo.resource->mm_node))
+	if (WARN_ON_ONCE(!gbo->bo.resource ||
+			 gbo->bo.resource->mem_type == TTM_PL_SYSTEM))
 		return 0;
 
 	return gbo->bo.resource->start;

drivers/gpu/drm/nouveau/nouveau_bo.c

···
 		}
 	}
 
-	if (new_reg) {
-		if (new_reg->mm_node)
-			nvbo->offset = (new_reg->start << PAGE_SHIFT);
-		else
-			nvbo->offset = 0;
-	}
+	if (new_reg)
+		nvbo->offset = (new_reg->start << PAGE_SHIFT);
 
 }
 

drivers/gpu/drm/nouveau/nouveau_mem.c

···
 nouveau_mem_del(struct ttm_resource *reg)
 {
 	struct nouveau_mem *mem = nouveau_mem(reg);
-	if (!mem)
-		return;
+
 	nouveau_mem_fini(mem);
-	kfree(reg->mm_node);
-	reg->mm_node = NULL;
+	kfree(mem);
 }
 
 int
 nouveau_mem_new(struct nouveau_cli *cli, u8 kind, u8 comp,
-		struct ttm_resource *reg)
+		struct ttm_resource **res)
 {
 	struct nouveau_mem *mem;
 
 	if (!(mem = kzalloc(sizeof(*mem), GFP_KERNEL)))
 		return -ENOMEM;
+
 	mem->cli = cli;
 	mem->kind = kind;
 	mem->comp = comp;
 
-	reg->mm_node = mem;
+	*res = &mem->base;
 	return 0;
 }

drivers/gpu/drm/nouveau/nouveau_mem.h

···
 #include <nvif/mem.h>
 #include <nvif/vmm.h>
 
-static inline struct nouveau_mem *
-nouveau_mem(struct ttm_resource *reg)
-{
-	return reg->mm_node;
-}
-
 struct nouveau_mem {
 	struct ttm_resource base;
 	struct nouveau_cli *cli;
···
 	struct nvif_vma vma[2];
 };
 
+static inline struct nouveau_mem *
+nouveau_mem(struct ttm_resource *reg)
+{
+	return container_of(reg, struct nouveau_mem, base);
+}
+
 int nouveau_mem_new(struct nouveau_cli *, u8 kind, u8 comp,
-		    struct ttm_resource *);
+		    struct ttm_resource **);
 void nouveau_mem_del(struct ttm_resource *);
 int nouveau_mem_vram(struct ttm_resource *, bool contig, u8 page);
 int nouveau_mem_host(struct ttm_resource *, struct ttm_tt *);

drivers/gpu/drm/nouveau/nouveau_ttm.c

···
 nouveau_vram_manager_new(struct ttm_resource_manager *man,
 			 struct ttm_buffer_object *bo,
 			 const struct ttm_place *place,
-			 struct ttm_resource *reg)
+			 struct ttm_resource **res)
 {
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
···
 	if (drm->client.device.info.ram_size == 0)
 		return -ENOMEM;
 
-	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, reg);
+	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, res);
 	if (ret)
 		return ret;
 
-	ttm_resource_init(bo, place, reg->mm_node);
+	ttm_resource_init(bo, place, *res);
 
-	ret = nouveau_mem_vram(reg, nvbo->contig, nvbo->page);
+	ret = nouveau_mem_vram(*res, nvbo->contig, nvbo->page);
 	if (ret) {
-		nouveau_mem_del(reg);
+		nouveau_mem_del(*res);
 		return ret;
 	}
 
···
 nouveau_gart_manager_new(struct ttm_resource_manager *man,
 			 struct ttm_buffer_object *bo,
 			 const struct ttm_place *place,
-			 struct ttm_resource *reg)
+			 struct ttm_resource **res)
 {
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
 	int ret;
 
-	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, reg);
+	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, res);
 	if (ret)
 		return ret;
 
-	ttm_resource_init(bo, place, reg->mm_node);
-	reg->start = 0;
+	ttm_resource_init(bo, place, *res);
+	(*res)->start = 0;
 	return 0;
 }
 
···
 nv04_gart_manager_new(struct ttm_resource_manager *man,
 		      struct ttm_buffer_object *bo,
 		      const struct ttm_place *place,
-		      struct ttm_resource *reg)
+		      struct ttm_resource **res)
 {
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
 	struct nouveau_mem *mem;
 	int ret;
 
-	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, reg);
-	mem = nouveau_mem(reg);
+	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, res);
 	if (ret)
 		return ret;
 
-	ttm_resource_init(bo, place, reg->mm_node);
+	mem = nouveau_mem(*res);
+	ttm_resource_init(bo, place, *res);
 	ret = nvif_vmm_get(&mem->cli->vmm.vmm, PTES, false, 12, 0,
-			   (long)reg->num_pages << PAGE_SHIFT, &mem->vma[0]);
+			   (long)(*res)->num_pages << PAGE_SHIFT, &mem->vma[0]);
 	if (ret) {
-		nouveau_mem_del(reg);
+		nouveau_mem_del(*res);
 		return ret;
 	}
 
-	reg->start = mem->vma[0].addr >> PAGE_SHIFT;
+	(*res)->start = mem->vma[0].addr >> PAGE_SHIFT;
 	return 0;
 }
 

drivers/gpu/drm/ttm/ttm_range_manager.c

···
 static int ttm_range_man_alloc(struct ttm_resource_manager *man,
 			       struct ttm_buffer_object *bo,
 			       const struct ttm_place *place,
-			       struct ttm_resource *mem)
+			       struct ttm_resource **res)
 {
 	struct ttm_range_manager *rman = to_range_manager(man);
 	struct ttm_range_mgr_node *node;
···
 
 	spin_lock(&rman->lock);
 	ret = drm_mm_insert_node_in_range(mm, &node->mm_nodes[0],
-					  mem->num_pages, bo->page_alignment, 0,
+					  node->base.num_pages,
+					  bo->page_alignment, 0,
 					  place->fpfn, lpfn, mode);
 	spin_unlock(&rman->lock);
 
-	if (unlikely(ret)) {
+	if (unlikely(ret))
 		kfree(node);
-	} else {
-		mem->mm_node = &node->mm_nodes[0];
-		mem->start = node->mm_nodes[0].start;
-	}
+	else
+		node->base.start = node->mm_nodes[0].start;
 
 	return ret;
 }
 
 static void ttm_range_man_free(struct ttm_resource_manager *man,
-			       struct ttm_resource *mem)
+			       struct ttm_resource *res)
 {
+	struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
 	struct ttm_range_manager *rman = to_range_manager(man);
-	struct ttm_range_mgr_node *node;
-
-	if (!mem->mm_node)
-		return;
-
-	node = to_ttm_range_mgr_node(mem);
 
 	spin_lock(&rman->lock);
 	drm_mm_remove_node(&node->mm_nodes[0]);
 	spin_unlock(&rman->lock);
 
 	kfree(node);
-	mem->mm_node = NULL;
 }
 
 static void ttm_range_man_debug(struct ttm_resource_manager *man,

drivers/gpu/drm/ttm/ttm_resource.c

···
                        const struct ttm_place *place,
                        struct ttm_resource *res)
 {
-	res->mm_node = NULL;
 	res->start = 0;
 	res->num_pages = PFN_UP(bo->base.size);
 	res->mem_type = place->mem_type;
···
 {
 	struct ttm_resource_manager *man =
 		ttm_manager_type(bo->bdev, place->mem_type);
-	struct ttm_resource *res;
-	int r;
 
-	res = kmalloc(sizeof(*res), GFP_KERNEL);
-	if (!res)
-		return -ENOMEM;
-
-	ttm_resource_init(bo, place, res);
-	r = man->func->alloc(man, bo, place, res);
-	if (r) {
-		kfree(res);
-		return r;
-	}
-
-	*res_ptr = res;
-	return 0;
+	return man->func->alloc(man, bo, place, res_ptr);
 }
 
 void ttm_resource_free(struct ttm_buffer_object *bo, struct ttm_resource **res)
···
 
 	man = ttm_manager_type(bo->bdev, (*res)->mem_type);
 	man->func->free(man, *res);
-	kfree(*res);
 	*res = NULL;
 }
 EXPORT_SYMBOL(ttm_resource_free);

drivers/gpu/drm/ttm/ttm_sys_manager.c

···
 static int ttm_sys_man_alloc(struct ttm_resource_manager *man,
 			     struct ttm_buffer_object *bo,
 			     const struct ttm_place *place,
-			     struct ttm_resource *mem)
+			     struct ttm_resource **res)
 {
-	mem->mm_node = kzalloc(sizeof(*mem), GFP_KERNEL);
-	if (!mem->mm_node)
+	*res = kzalloc(sizeof(**res), GFP_KERNEL);
+	if (!*res)
 		return -ENOMEM;
 
-	ttm_resource_init(bo, place, mem->mm_node);
+	ttm_resource_init(bo, place, *res);
 	return 0;
 }
 
 static void ttm_sys_man_free(struct ttm_resource_manager *man,
-			     struct ttm_resource *mem)
+			     struct ttm_resource *res)
 {
-	kfree(mem->mm_node);
+	kfree(res);
 }
 
 static const struct ttm_resource_manager_func ttm_sys_manager_func = {

drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c

···
 static int vmw_gmrid_man_get_node(struct ttm_resource_manager *man,
 				  struct ttm_buffer_object *bo,
 				  const struct ttm_place *place,
-				  struct ttm_resource *mem)
+				  struct ttm_resource **res)
 {
 	struct vmwgfx_gmrid_man *gman = to_gmrid_manager(man);
 	int id;
 
-	mem->mm_node = kmalloc(sizeof(*mem), GFP_KERNEL);
-	if (!mem->mm_node)
+	*res = kmalloc(sizeof(**res), GFP_KERNEL);
+	if (!*res)
 		return -ENOMEM;
 
-	ttm_resource_init(bo, place, mem->mm_node);
+	ttm_resource_init(bo, place, *res);
 
 	id = ida_alloc_max(&gman->gmr_ida, gman->max_gmr_ids - 1, GFP_KERNEL);
 	if (id < 0)
···
 	spin_lock(&gman->lock);
 
 	if (gman->max_gmr_pages > 0) {
-		gman->used_gmr_pages += mem->num_pages;
+		gman->used_gmr_pages += (*res)->num_pages;
 		if (unlikely(gman->used_gmr_pages > gman->max_gmr_pages))
 			goto nospace;
 	}
 
-	mem->mm_node = gman;
-	mem->start = id;
+	(*res)->start = id;
 
 	spin_unlock(&gman->lock);
 	return 0;
 
 nospace:
-	gman->used_gmr_pages -= mem->num_pages;
+	gman->used_gmr_pages -= (*res)->num_pages;
 	spin_unlock(&gman->lock);
 	ida_free(&gman->gmr_ida, id);
+	kfree(*res);
 	return -ENOSPC;
 }
 
 static void vmw_gmrid_man_put_node(struct ttm_resource_manager *man,
-				   struct ttm_resource *mem)
+				   struct ttm_resource *res)
 {
 	struct vmwgfx_gmrid_man *gman = to_gmrid_manager(man);
 
-	ida_free(&gman->gmr_ida, mem->start);
+	ida_free(&gman->gmr_ida, res->start);
 	spin_lock(&gman->lock);
-	gman->used_gmr_pages -= mem->num_pages;
+	gman->used_gmr_pages -= res->num_pages;
 	spin_unlock(&gman->lock);
-	kfree(mem->mm_node);
+	kfree(res);
 }
 
 static const struct ttm_resource_manager_func vmw_gmrid_manager_func;

drivers/gpu/drm/vmwgfx/vmwgfx_thp.c

···
 static int vmw_thp_get_node(struct ttm_resource_manager *man,
 			    struct ttm_buffer_object *bo,
 			    const struct ttm_place *place,
-			    struct ttm_resource *mem)
+			    struct ttm_resource **res)
 {
 	struct vmw_thp_manager *rman = to_thp_manager(man);
 	struct drm_mm *mm = &rman->mm;
···
 	spin_lock(&rman->lock);
 	if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)) {
 		align_pages = (HPAGE_PUD_SIZE >> PAGE_SHIFT);
-		if (mem->num_pages >= align_pages) {
+		if (node->base.num_pages >= align_pages) {
 			ret = vmw_thp_insert_aligned(bo, mm, &node->mm_nodes[0],
-						     align_pages, place, mem,
-						     lpfn, mode);
+						     align_pages, place,
+						     &node->base, lpfn, mode);
 			if (!ret)
 				goto found_unlock;
 		}
 	}
 
 	align_pages = (HPAGE_PMD_SIZE >> PAGE_SHIFT);
-	if (mem->num_pages >= align_pages) {
+	if (node->base.num_pages >= align_pages) {
 		ret = vmw_thp_insert_aligned(bo, mm, &node->mm_nodes[0],
-					     align_pages, place, mem, lpfn,
-					     mode);
+					     align_pages, place, &node->base,
+					     lpfn, mode);
 		if (!ret)
 			goto found_unlock;
 	}
 
 	ret = drm_mm_insert_node_in_range(mm, &node->mm_nodes[0],
-					  mem->num_pages, bo->page_alignment, 0,
+					  node->base.num_pages,
+					  bo->page_alignment, 0,
 					  place->fpfn, lpfn, mode);
 found_unlock:
 	spin_unlock(&rman->lock);
···
 	if (unlikely(ret)) {
 		kfree(node);
 	} else {
-		mem->mm_node = &node->mm_nodes[0];
-		mem->start = node->mm_nodes[0].start;
+		node->base.start = node->mm_nodes[0].start;
+		*res = &node->base;
 	}
 
 	return ret;
 }
 
-
-
 static void vmw_thp_put_node(struct ttm_resource_manager *man,
-			     struct ttm_resource *mem)
+			     struct ttm_resource *res)
 {
+	struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
 	struct vmw_thp_manager *rman = to_thp_manager(man);
-	struct ttm_range_mgr_node * node = mem->mm_node;
 
 	spin_lock(&rman->lock);
 	drm_mm_remove_node(&node->mm_nodes[0]);

include/drm/ttm/ttm_range_manager.h

···
 static inline struct ttm_range_mgr_node *
 to_ttm_range_mgr_node(struct ttm_resource *res)
 {
-	return container_of(res->mm_node, struct ttm_range_mgr_node,
-			    mm_nodes[0]);
+	return container_of(res, struct ttm_range_mgr_node, base);
 }
 
 int ttm_range_man_init(struct ttm_device *bdev,

include/drm/ttm/ttm_resource.h

···
 	 *
 	 * @man: Pointer to a memory type manager.
 	 * @bo: Pointer to the buffer object we're allocating space for.
-	 * @placement: Placement details.
-	 * @flags: Additional placement flags.
-	 * @mem: Pointer to a struct ttm_resource to be filled in.
+	 * @place: Placement details.
+	 * @res: Resulting pointer to the ttm_resource.
 	 *
 	 * This function should allocate space in the memory type managed
-	 * by @man. Placement details if
-	 * applicable are given by @placement. If successful,
-	 * @mem::mm_node should be set to a non-null value, and
-	 * @mem::start should be set to a value identifying the beginning
+	 * by @man. Placement details if applicable are given by @place. If
+	 * successful, a filled in ttm_resource object should be returned in
+	 * @res. @res::start should be set to a value identifying the beginning
 	 * of the range allocated, and the function should return zero.
-	 * If the memory region accommodate the buffer object, @mem::mm_node
-	 * should be set to NULL, and the function should return 0.
+	 * If the manager can't fulfill the request -ENOSPC should be returned.
 	 * If a system error occurred, preventing the request to be fulfilled,
 	 * the function should return a negative error code.
 	 *
-	 * Note that @mem::mm_node will only be dereferenced by
-	 * struct ttm_resource_manager functions and optionally by the driver,
-	 * which has knowledge of the underlying type.
-	 *
-	 * This function may not be called from within atomic context, so
-	 * an implementation can and must use either a mutex or a spinlock to
-	 * protect any data structures managing the space.
+	 * This function may not be called from within atomic context and needs
+	 * to take care of its own locking to protect any data structures
+	 * managing the space.
 	 */
 	int  (*alloc)(struct ttm_resource_manager *man,
 		      struct ttm_buffer_object *bo,
 		      const struct ttm_place *place,
-		      struct ttm_resource *mem);
+		      struct ttm_resource **res);
 
 	/**
 	 * struct ttm_resource_manager_func member free
 	 *
 	 * @man: Pointer to a memory type manager.
-	 * @mem: Pointer to a struct ttm_resource to be filled in.
+	 * @res: Pointer to a struct ttm_resource to be freed.
 	 *
-	 * This function frees memory type resources previously allocated
-	 * and that are identified by @mem::mm_node and @mem::start. May not
-	 * be called from within atomic context.
+	 * This function frees memory type resources previously allocated.
+	 * May not be called from within atomic context.
 	 */
 	void (*free)(struct ttm_resource_manager *man,
-		     struct ttm_resource *mem);
+		     struct ttm_resource *res);
 
 	/**
 	 * struct ttm_resource_manager_func member debug
···
 /**
  * struct ttm_resource
  *
- * @mm_node: Memory manager node.
- * @size: Requested size of memory region.
- * @num_pages: Actual size of memory region in pages.
+ * @start: Start of the allocation.
+ * @num_pages: Actual size of resource in pages.
+ * @mem_type: Resource type of the allocation.
  * @placement: Placement flags.
  * @bus: Placement on io bus accessible to the CPU
  *
···
  * buffer object.
  */
 struct ttm_resource {
-	void *mm_node;
 	unsigned long start;
 	unsigned long num_pages;
 	uint32_t mem_type;