/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *   Copyright (C) 2025, Stefan Metzmacher
 */

#ifndef __LINUX_SMBDIRECT_H__
#define __LINUX_SMBDIRECT_H__

#include <linux/types.h>

/* SMB-DIRECT buffer descriptor V1 structure [MS-SMBD] 2.2.3.1 */
struct smbdirect_buffer_descriptor_v1 {
        __le64 offset;
        __le32 token;
        __le32 length;
} __packed;

/*
 * Connection parameters mostly from [MS-SMBD] 3.1.1.1
 *
 * These are setup and negotiated at the beginning of a
 * connection and remain constant unless explicitly changed.
 *
 * Some values are important for the upper layer.
 */
struct smbdirect_socket_parameters {
        __u64 flags;
#define SMBDIRECT_FLAG_PORT_RANGE_ONLY_IB ((__u64)0x1)
#define SMBDIRECT_FLAG_PORT_RANGE_ONLY_IW ((__u64)0x2)
        __u32 resolve_addr_timeout_msec;
        __u32 resolve_route_timeout_msec;
        __u32 rdma_connect_timeout_msec;
        __u32 negotiate_timeout_msec;
        __u16 initiator_depth;     /* limited to U8_MAX */
        __u16 responder_resources; /* limited to U8_MAX */
        __u16 recv_credit_max;
        __u16 send_credit_target;
        __u32 max_send_size;
        __u32 max_fragmented_send_size;
        __u32 max_recv_size;
        __u32 max_fragmented_recv_size;
        __u32 max_read_write_size;
        __u32 max_frmr_depth;
        __u32 keepalive_interval_msec;
        __u32 keepalive_timeout_msec;
} __packed;

#define SMBDIRECT_FLAG_PORT_RANGE_MASK ( \
                SMBDIRECT_FLAG_PORT_RANGE_ONLY_IB | \
                SMBDIRECT_FLAG_PORT_RANGE_ONLY_IW)

struct smbdirect_socket;
struct smbdirect_send_batch;
struct smbdirect_mr_io;

#include <rdma/rw.h>

u8 smbdirect_netdev_rdma_capable_node_type(struct net_device *netdev);

bool smbdirect_frwr_is_supported(const struct ib_device_attr *attrs);

int smbdirect_socket_create_kern(struct net *net, struct smbdirect_socket **_sc);

int smbdirect_socket_create_accepting(struct rdma_cm_id *id, struct smbdirect_socket **_sc);

int smbdirect_socket_set_initial_parameters(struct smbdirect_socket *sc,
                                            const struct smbdirect_socket_parameters *sp);

const struct smbdirect_socket_parameters *
smbdirect_socket_get_current_parameters(struct smbdirect_socket *sc);

int smbdirect_socket_set_kernel_settings(struct smbdirect_socket *sc,
                                         enum ib_poll_context poll_ctx,
                                         gfp_t gfp_mask);

#define SMBDIRECT_LOG_ERR               0x0
#define SMBDIRECT_LOG_INFO              0x1

#define SMBDIRECT_LOG_OUTGOING                  0x1
#define SMBDIRECT_LOG_INCOMING                  0x2
#define SMBDIRECT_LOG_READ                      0x4
#define SMBDIRECT_LOG_WRITE                     0x8
#define SMBDIRECT_LOG_RDMA_SEND                 0x10
#define SMBDIRECT_LOG_RDMA_RECV                 0x20
#define SMBDIRECT_LOG_KEEP_ALIVE                0x40
#define SMBDIRECT_LOG_RDMA_EVENT                0x80
#define SMBDIRECT_LOG_RDMA_MR                   0x100
#define SMBDIRECT_LOG_RDMA_RW                   0x200
#define SMBDIRECT_LOG_NEGOTIATE                 0x400
void smbdirect_socket_set_logging(struct smbdirect_socket *sc,
                                  void *private_ptr,
                                  bool (*needed)(struct smbdirect_socket *sc,
                                                 void *private_ptr,
                                                 unsigned int lvl,
                                                 unsigned int cls),
                                  void (*vaprintf)(struct smbdirect_socket *sc,
                                                   const char *func,
                                                   unsigned int line,
                                                   void *private_ptr,
                                                   unsigned int lvl,
                                                   unsigned int cls,
                                                   struct va_format *vaf));

bool smbdirect_connection_is_connected(struct smbdirect_socket *sc);

int smbdirect_connection_wait_for_connected(struct smbdirect_socket *sc);

int smbdirect_socket_bind(struct smbdirect_socket *sc, struct sockaddr *addr);

void smbdirect_socket_shutdown(struct smbdirect_socket *sc);

void smbdirect_socket_release(struct smbdirect_socket *sc);

int smbdirect_connection_send_batch_flush(struct smbdirect_socket *sc,
                                          struct smbdirect_send_batch *batch,
                                          bool is_last);

/*
 * This is only temporary and only needed
 * as long as the client still requires
 * to use smbdirect_connection_send_single_iter()
 */
struct smbdirect_send_batch_storage {
        union {
                struct list_head __msg_list;
                __aligned_u64 __space[5];
        };
};

struct smbdirect_send_batch *
smbdirect_init_send_batch_storage(struct smbdirect_send_batch_storage *storage,
                                  bool need_invalidate_rkey,
                                  unsigned int remote_key);

int smbdirect_connection_send_single_iter(struct smbdirect_socket *sc,
                                          struct smbdirect_send_batch *batch,
                                          struct iov_iter *iter,
                                          unsigned int flags,
                                          u32 remaining_data_length);

int smbdirect_connection_send_wait_zero_pending(struct smbdirect_socket *sc);

int smbdirect_connection_send_iter(struct smbdirect_socket *sc,
                                   struct iov_iter *iter,
                                   unsigned int flags,
                                   bool need_invalidate,
                                   unsigned int remote_key);

int smbdirect_connection_recvmsg(struct smbdirect_socket *sc,
                                 struct msghdr *msg,
                                 unsigned int flags);

int smbdirect_connect(struct smbdirect_socket *sc,
                      const struct sockaddr *dst);

int smbdirect_connect_sync(struct smbdirect_socket *sc,
                           const struct sockaddr *dst);

int smbdirect_socket_listen(struct smbdirect_socket *sc, int backlog);

struct smbdirect_socket *smbdirect_socket_accept(struct smbdirect_socket *lsc,
                                                 long timeo,
                                                 struct proto_accept_arg *arg);

int smbdirect_connection_rdma_xmit(struct smbdirect_socket *sc,
                                   void *buf, size_t buf_len,
                                   struct smbdirect_buffer_descriptor_v1 *desc,
                                   size_t desc_len,
                                   bool is_read);

struct smbdirect_mr_io *
smbdirect_connection_register_mr_io(struct smbdirect_socket *sc,
                                    struct iov_iter *iter,
                                    bool writing,
                                    bool need_invalidate);

void smbdirect_mr_io_fill_buffer_descriptor(struct smbdirect_mr_io *mr,
                                            struct smbdirect_buffer_descriptor_v1 *v1);

void smbdirect_connection_deregister_mr_io(struct smbdirect_mr_io *mr);

void smbdirect_connection_legacy_debug_proc_show(struct smbdirect_socket *sc,
                                                 unsigned int rdma_readwrite_threshold,
                                                 struct seq_file *m);

#endif /* __LINUX_SMBDIRECT_H__ */