/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  Definitions for the SMC module (socket related)
 *
 *  Copyright IBM Corp. 2016
 *
 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */
#ifndef _SMC_H
#define _SMC_H

#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <linux/dibs.h>

struct tcp_sock;
struct inet_request_sock;
struct sock;

#define SMC_MAX_PNETID_LEN      16      /* Max. length of PNET id */

struct smc_hashinfo {
        rwlock_t lock;
        struct hlist_head ht;
};

/* SMCD/ISM device driver interface */
#define ISM_RESERVED_VLANID     0x1FFF

struct smcd_gid {
        u64     gid;
        u64     gid_ext;
};

struct smcd_dev {
        struct dibs_dev *dibs;
        struct list_head list;
        spinlock_t lock;
        struct smc_connection **conn;
        struct list_head vlan;
        struct workqueue_struct *event_wq;
        u8 pnetid[SMC_MAX_PNETID_LEN];
        bool pnetid_by_user;
        struct list_head lgr_list;
        spinlock_t lgr_lock;
        atomic_t lgr_cnt;
        wait_queue_head_t lgrs_deleted;
        u8 going_away : 1;
};

#define SMC_HS_CTRL_NAME_MAX 16

enum {
        /* ops can be inherit from init_net */
        SMC_HS_CTRL_FLAG_INHERITABLE = 0x1,

        SMC_HS_CTRL_ALL_FLAGS = SMC_HS_CTRL_FLAG_INHERITABLE,
};

struct smc_hs_ctrl {
        /* private */

        struct list_head list;
        struct module *owner;

        /* public */

        /* unique name */
        char name[SMC_HS_CTRL_NAME_MAX];
        int flags;

        /* Invoked before computing SMC option for SYN packets.
         * We can control whether to set SMC options by returning various value.
         * Return 0 to disable SMC, or return any other value to enable it.
         */
        int (*syn_option)(struct tcp_sock *tp);

        /* Invoked before Set up SMC options for SYN-ACK packets
         * We can control whether to respond SMC options by returning various
         * value. Return 0 to disable SMC, or return any other value to enable
         * it.
         */
        int (*synack_option)(const struct tcp_sock *tp,
                             struct inet_request_sock *ireq);
};

#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
#define smc_call_hsbpf(init_val, tp, func, ...) ({                              \
        typeof(init_val) __ret = (init_val);                                    \
        struct smc_hs_ctrl *ctrl;                                               \
        rcu_read_lock();                                                        \
        ctrl = rcu_dereference(sock_net((struct sock *)(tp))->smc.hs_ctrl);     \
        if (ctrl && ctrl->func)                                                 \
                __ret = ctrl->func(tp, ##__VA_ARGS__);                          \
        rcu_read_unlock();                                                      \
        __ret;                                                                  \
})
#else
#define smc_call_hsbpf(init_val, tp, ...)  ({ (void)(tp); (init_val); })
#endif /* CONFIG_SMC_HS_CTRL_BPF */

#endif  /* _SMC_H */