// SPDX-License-Identifier: GPL-2.0
#ifndef IOU_ZC_RX_H
#define IOU_ZC_RX_H

#include <linux/io_uring_types.h>
#include <linux/dma-buf.h>
#include <linux/socket.h>
#include <net/page_pool/types.h>
#include <net/net_trackers.h>

struct io_zcrx_mem {
        unsigned long                   size;
        bool                            is_dmabuf;

        struct page                     **pages;
        unsigned long                   nr_folios;
        struct sg_table                 page_sg_table;
        unsigned long                   account_pages;
        struct sg_table                 *sgt;

        struct dma_buf_attachment       *attach;
        struct dma_buf                  *dmabuf;
};

struct io_zcrx_area {
        struct net_iov_area     nia;
        struct io_zcrx_ifq      *ifq;
        atomic_t                *user_refs;

        bool                    is_mapped;
        u16                     area_id;

        /* freelist */
        spinlock_t              freelist_lock ____cacheline_aligned_in_smp;
        u32                     free_count;
        u32                     *freelist;

        struct io_zcrx_mem      mem;
};

struct io_zcrx_ifq {
        struct io_zcrx_area             *area;
        unsigned                        niov_shift;
        struct user_struct              *user;
        struct mm_struct                *mm_account;

        spinlock_t                      rq_lock ____cacheline_aligned_in_smp;
        struct io_uring                 *rq_ring;
        struct io_uring_zcrx_rqe        *rqes;
        u32                             cached_rq_head;
        u32                             rq_entries;

        u32                             if_rxq;
        struct device                   *dev;
        struct net_device               *netdev;
        netdevice_tracker               netdev_tracker;
        refcount_t                      refs;
        /* counts userspace facing users like io_uring */
        refcount_t                      user_refs;

        /*
         * Page pool and net configuration lock, can be taken deeper in the
         * net stack.
         */
        struct mutex                    pp_lock;
        struct io_mapped_region         region;
};

#if defined(CONFIG_IO_URING_ZCRX)
int io_zcrx_ctrl(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_arg);
int io_register_zcrx_ifq(struct io_ring_ctx *ctx,
                         struct io_uring_zcrx_ifq_reg __user *arg);
void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx);
int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
                 struct socket *sock, unsigned int flags,
                 unsigned issue_flags, unsigned int *len);
struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx,
                                            unsigned int id);
#else
static inline int io_register_zcrx_ifq(struct io_ring_ctx *ctx,
                                        struct io_uring_zcrx_ifq_reg __user *arg)
{
        return -EOPNOTSUPP;
}
static inline void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx)
{
}
static inline int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
                               struct socket *sock, unsigned int flags,
                               unsigned issue_flags, unsigned int *len)
{
        return -EOPNOTSUPP;
}
static inline struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx,
                                                          unsigned int id)
{
        return NULL;
}
static inline int io_zcrx_ctrl(struct io_ring_ctx *ctx,
                                void __user *arg, unsigned nr_arg)
{
        return -EOPNOTSUPP;
}
#endif

int io_recvzc(struct io_kiocb *req, unsigned int issue_flags);
int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);

#endif