/* SPDX-License-Identifier: GPL-2.0-or-later *//* * Device memory TCP support * * Authors:	Mina Almasry <almasrymina@google.com> *		Willem de Bruijn <willemb@google.com> *		Kaiyuan Zhang <kaiyuanz@google.com> * */#ifndef _NET_DEVMEM_H#define _NET_DEVMEM_H struct netlink_ext_ack; struct net_devmem_dmabuf_binding {	struct dma_buf *dmabuf;	struct dma_buf_attachment *attachment;	struct sg_table *sgt;	struct net_device *dev;	struct gen_pool *chunk_pool; 	/* The user holds a ref (via the netlink API) for as long as they want	 * the binding to remain alive. Each page pool using this binding holds	 * a ref to keep the binding alive. Each allocated net_iov holds a	 * ref.	 *	 * The binding undos itself and unmaps the underlying dmabuf once all	 * those refs are dropped and the binding is no longer desired or in	 * use.	 */	refcount_t ref; 	/* The list of bindings currently active. Used for netlink to notify us	 * of the user dropping the bind.	 */	struct list_head list; 	/* rxq's this binding is active on. */	struct xarray bound_rxqs; 	/* ID of this binding. Globally unique to all bindings currently	 * active.	 */	u32 id;}; #if defined(CONFIG_NET_DEVMEM)/* Owner of the dma-buf chunks inserted into the gen pool. Each scatterlist * entry from the dmabuf is inserted into the genpool as a chunk, and needs * this owner struct to keep track of some metadata necessary to create * allocations from this chunk. */struct dmabuf_genpool_chunk_owner {	/* Offset into the dma-buf where this chunk starts.  */	unsigned long base_virtual; 	/* dma_addr of the start of the chunk.  */	dma_addr_t base_dma_addr; 	/* Array of net_iovs for this chunk. */	struct net_iov *niovs;	size_t num_niovs; 	struct net_devmem_dmabuf_binding *binding;}; void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding);struct net_devmem_dmabuf_binding *net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,		       struct netlink_ext_ack *extack);void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding);int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,				    struct net_devmem_dmabuf_binding *binding,				    struct netlink_ext_ack *extack);void dev_dmabuf_uninstall(struct net_device *dev); static inline struct dmabuf_genpool_chunk_owner *net_iov_owner(const struct net_iov *niov){	return niov->owner;} static inline unsigned int net_iov_idx(const struct net_iov *niov){	return niov - net_iov_owner(niov)->niovs;} static inline struct net_devmem_dmabuf_binding *net_iov_binding(const struct net_iov *niov){	return net_iov_owner(niov)->binding;} static inline unsigned long net_iov_virtual_addr(const struct net_iov *niov){	struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov); 	return owner->base_virtual +	       ((unsigned long)net_iov_idx(niov) << PAGE_SHIFT);} static inline u32 net_iov_binding_id(const struct net_iov *niov){	return net_iov_owner(niov)->binding->id;} static inline voidnet_devmem_dmabuf_binding_get(struct net_devmem_dmabuf_binding *binding){	refcount_inc(&binding->ref);} static inline voidnet_devmem_dmabuf_binding_put(struct net_devmem_dmabuf_binding *binding){	if (!refcount_dec_and_test(&binding->ref))		return; 	__net_devmem_dmabuf_binding_free(binding);} struct net_iov *net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding);void net_devmem_free_dmabuf(struct net_iov *ppiov); #elsestruct net_devmem_dmabuf_binding; static inline void__net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding){} static inline struct net_devmem_dmabuf_binding *net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,		       struct netlink_ext_ack *extack){	return ERR_PTR(-EOPNOTSUPP);} static inline voidnet_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding){} static inline intnet_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,				struct net_devmem_dmabuf_binding *binding,				struct netlink_ext_ack *extack) {	return -EOPNOTSUPP;} static inline void dev_dmabuf_uninstall(struct net_device *dev){} static inline struct net_iov *net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding){	return NULL;} static inline void net_devmem_free_dmabuf(struct net_iov *ppiov){} static inline unsigned long net_iov_virtual_addr(const struct net_iov *niov){	return 0;} static inline u32 net_iov_binding_id(const struct net_iov *niov){	return 0;}#endif #endif /* _NET_DEVMEM_H */