/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  Definitions for SMC Connections, Link Groups and Links
 *
 *  Copyright IBM Corp. 2016
 *
 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#ifndef _SMC_CORE_H
#define _SMC_CORE_H

#include <linux/atomic.h>
#include <rdma/ib_verbs.h>

#include "smc.h"
#include "smc_ib.h"

#define SMC_RMBS_PER_LGR_MAX    255     /* max. # of RMBs per link group */

struct smc_lgr_list {                   /* list of link group definition */
        struct list_head        list;
        spinlock_t              lock;   /* protects list of link groups */
        u32                     num;    /* unique link group number */
};

enum smc_lgr_role {             /* possible roles of a link group */
        SMC_CLNT,       /* client */
        SMC_SERV        /* server */
};

enum smc_link_state {                   /* possible states of a link */
        SMC_LNK_UNUSED,         /* link is unused */
        SMC_LNK_INACTIVE,       /* link is inactive */
        SMC_LNK_ACTIVATING,     /* link is being activated */
        SMC_LNK_ACTIVE,         /* link is active */
};

#define SMC_WR_BUF_SIZE         48      /* size of work request buffer */

struct smc_wr_buf {
        u8      raw[SMC_WR_BUF_SIZE];
};

#define SMC_WR_REG_MR_WAIT_TIME (5 * HZ)/* wait time for ib_wr_reg_mr result */

enum smc_wr_reg_state {
        POSTED,         /* ib_wr_reg_mr request posted */
        CONFIRMED,      /* ib_wr_reg_mr response: successful */
        FAILED          /* ib_wr_reg_mr response: failure */
};

struct smc_rdma_sge {                           /* sges for RDMA writes */
        struct ib_sge           wr_tx_rdma_sge[SMC_IB_MAX_SEND_SGE];
};

#define SMC_MAX_RDMA_WRITES     2               /* max. # of RDMA writes per
                                                 * message send
                                                 */

struct smc_rdma_sges {                          /* sges per message send */
        struct smc_rdma_sge     tx_rdma_sge[SMC_MAX_RDMA_WRITES];
};

struct smc_rdma_wr {                            /* work requests per message
                                                 * send
                                                 */
        struct ib_rdma_wr       wr_tx_rdma[SMC_MAX_RDMA_WRITES];
};

#define SMC_LGR_ID_SIZE         4

struct smc_link {
        struct smc_ib_device    *smcibdev;      /* ib-device */
        u8                      ibport;         /* port - values 1 | 2 */
        struct ib_pd            *roce_pd;       /* IB protection domain,
                                                 * unique for every RoCE QP
                                                 */
        struct ib_qp            *roce_qp;       /* IB queue pair */
        struct ib_qp_attr       qp_attr;        /* IB queue pair attributes */

        struct smc_wr_buf       *wr_tx_bufs;    /* WR send payload buffers */
        struct ib_send_wr       *wr_tx_ibs;     /* WR send meta data */
        struct ib_sge           *wr_tx_sges;    /* WR send gather meta data */
        struct smc_rdma_sges    *wr_tx_rdma_sges;/*RDMA WRITE gather meta data*/
        struct smc_rdma_wr      *wr_tx_rdmas;   /* WR RDMA WRITE */
        struct smc_wr_tx_pend   *wr_tx_pends;   /* WR send waiting for CQE */
        struct completion       *wr_tx_compl;   /* WR send CQE completion */
        /* above four vectors have wr_tx_cnt elements and use the same index */
        dma_addr_t              wr_tx_dma_addr; /* DMA address of wr_tx_bufs */
        atomic_long_t           wr_tx_id;       /* seq # of last sent WR */
        unsigned long           *wr_tx_mask;    /* bit mask of used indexes */
        u32                     wr_tx_cnt;      /* number of WR send buffers */
        wait_queue_head_t       wr_tx_wait;     /* wait for free WR send buf */

        struct smc_wr_buf       *wr_rx_bufs;    /* WR recv payload buffers */
        struct ib_recv_wr       *wr_rx_ibs;     /* WR recv meta data */
        struct ib_sge           *wr_rx_sges;    /* WR recv scatter meta data */
        /* above three vectors have wr_rx_cnt elements and use the same index */
        dma_addr_t              wr_rx_dma_addr; /* DMA address of wr_rx_bufs */
        u64                     wr_rx_id;       /* seq # of last recv WR */
        u32                     wr_rx_cnt;      /* number of WR recv buffers */
        unsigned long           wr_rx_tstamp;   /* jiffies when last buf rx */

        struct ib_reg_wr        wr_reg;         /* WR register memory region */
        wait_queue_head_t       wr_reg_wait;    /* wait for wr_reg result */
        enum smc_wr_reg_state   wr_reg_state;   /* state of wr_reg request */

        u8                      gid[SMC_GID_SIZE];/* gid matching used vlan id*/
        u8                      sgid_index;     /* gid index for vlan id      */
        u32                     peer_qpn;       /* QP number of peer */
        enum ib_mtu             path_mtu;       /* used mtu */
        enum ib_mtu             peer_mtu;       /* mtu size of peer */
        u32                     psn_initial;    /* QP tx initial packet seqno */
        u32                     peer_psn;       /* QP rx initial packet seqno */
        u8                      peer_mac[ETH_ALEN];     /* = gid[8:10||13:15] */
        u8                      peer_gid[SMC_GID_SIZE]; /* gid of peer*/
        u8                      link_id;        /* unique # within link group */
        u8                      link_uid[SMC_LGR_ID_SIZE]; /* unique lnk id */
        u8                      peer_link_uid[SMC_LGR_ID_SIZE]; /* peer uid */
        u8                      link_idx;       /* index in lgr link array */
        u8                      link_is_asym;   /* is link asymmetric? */
        struct smc_link_group   *lgr;           /* parent link group */
        struct work_struct      link_down_wrk;  /* wrk to bring link down */

        enum smc_link_state     state;          /* state of link */
        struct delayed_work     llc_testlink_wrk; /* testlink worker */
        struct completion       llc_testlink_resp; /* wait for rx of testlink */
        int                     llc_testlink_time; /* testlink interval */
};

/* For now we just allow one parallel link per link group. The SMC protocol
 * allows more (up to 8).
 */
#define SMC_LINKS_PER_LGR_MAX   3
#define SMC_SINGLE_LINK         0

/* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
struct smc_buf_desc {
        struct list_head        list;
        void                    *cpu_addr;      /* virtual address of buffer */
        struct page             *pages;
        int                     len;            /* length of buffer */
        u32                     used;           /* currently used / unused */
        union {
                struct { /* SMC-R */
                        struct sg_table sgt[SMC_LINKS_PER_LGR_MAX];
                                        /* virtual buffer */
                        struct ib_mr    *mr_rx[SMC_LINKS_PER_LGR_MAX];
                                        /* for rmb only: memory region
                                         * incl. rkey provided to peer
                                         */
                        u32             order;  /* allocation order */

                        u8              is_conf_rkey;
                                        /* confirm_rkey done */
                        u8              is_reg_mr[SMC_LINKS_PER_LGR_MAX];
                                        /* mem region registered */
                        u8              is_map_ib[SMC_LINKS_PER_LGR_MAX];
                                        /* mem region mapped to lnk */
                        u8              is_reg_err;
                                        /* buffer registration err */
                };
                struct { /* SMC-D */
                        unsigned short  sba_idx;
                                        /* SBA index number */
                        u64             token;
                                        /* DMB token number */
                        dma_addr_t      dma_addr;
                                        /* DMA address */
                };
        };
};

struct smc_rtoken {                             /* address/key of remote RMB */
        u64                     dma_addr;
        u32                     rkey;
};

#define SMC_BUF_MIN_SIZE        16384   /* minimum size of an RMB */
#define SMC_RMBE_SIZES          16      /* number of distinct RMBE sizes */
/* theoretically, the RFC states that largest size would be 512K,
 * i.e. compressed 5 and thus 6 sizes (0..5), despite
 * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
 */

struct smcd_dev;

enum smc_lgr_type {                             /* redundancy state of lgr */
        SMC_LGR_NONE,                   /* no active links, lgr to be deleted */
        SMC_LGR_SINGLE,                 /* 1 active RNIC on each peer */
        SMC_LGR_SYMMETRIC,              /* 2 active RNICs on each peer */
        SMC_LGR_ASYMMETRIC_PEER,        /* local has 2, peer 1 active RNICs */
        SMC_LGR_ASYMMETRIC_LOCAL,       /* local has 1, peer 2 active RNICs */
};

enum smc_llc_flowtype {
        SMC_LLC_FLOW_NONE       = 0,
        SMC_LLC_FLOW_ADD_LINK   = 2,
        SMC_LLC_FLOW_DEL_LINK   = 4,
        SMC_LLC_FLOW_RKEY       = 6,
};

struct smc_llc_qentry;

struct smc_llc_flow {
        enum smc_llc_flowtype type;
        struct smc_llc_qentry *qentry;
};

struct smc_link_group {
        struct list_head        list;
        struct rb_root          conns_all;      /* connection tree */
        rwlock_t                conns_lock;     /* protects conns_all */
        unsigned int            conns_num;      /* current # of connections */
        unsigned short          vlan_id;        /* vlan id of link group */

        struct list_head        sndbufs[SMC_RMBE_SIZES];/* tx buffers */
        struct mutex            sndbufs_lock;   /* protects tx buffers */
        struct list_head        rmbs[SMC_RMBE_SIZES];   /* rx buffers */
        struct mutex            rmbs_lock;      /* protects rx buffers */

        u8                      id[SMC_LGR_ID_SIZE];    /* unique lgr id */
        struct delayed_work     free_work;      /* delayed freeing of an lgr */
        struct work_struct      terminate_work; /* abnormal lgr termination */
        struct workqueue_struct *tx_wq;         /* wq for conn. tx workers */
        u8                      sync_err : 1;   /* lgr no longer fits to peer */
        u8                      terminating : 1;/* lgr is terminating */
        u8                      freeing : 1;    /* lgr is being freed */

        bool                    is_smcd;        /* SMC-R or SMC-D */
        u8                      smc_version;
        u8                      negotiated_eid[SMC_MAX_EID_LEN];
        u8                      peer_os;        /* peer operating system */
        u8                      peer_smc_release;
        u8                      peer_hostname[SMC_MAX_HOSTNAME_LEN];
        union {
                struct { /* SMC-R */
                        enum smc_lgr_role       role;
                                                /* client or server */
                        struct smc_link         lnk[SMC_LINKS_PER_LGR_MAX];
                                                /* smc link */
                        char                    peer_systemid[SMC_SYSTEMID_LEN];
                                                /* unique system_id of peer */
                        struct smc_rtoken       rtokens[SMC_RMBS_PER_LGR_MAX]
                                                [SMC_LINKS_PER_LGR_MAX];
                                                /* remote addr/key pairs */
                        DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
                                                /* used rtoken elements */
                        u8                      next_link_id;
                        enum smc_lgr_type       type;
                                                /* redundancy state */
                        u8                      pnet_id[SMC_MAX_PNETID_LEN + 1];
                                                /* pnet id of this lgr */
                        struct list_head        llc_event_q;
                                                /* queue for llc events */
                        spinlock_t              llc_event_q_lock;
                                                /* protects llc_event_q */
                        struct mutex            llc_conf_mutex;
                                                /* protects lgr reconfig. */
                        struct work_struct      llc_add_link_work;
                        struct work_struct      llc_del_link_work;
                        struct work_struct      llc_event_work;
                                                /* llc event worker */
                        wait_queue_head_t       llc_flow_waiter;
                                                /* w4 next llc event */
                        wait_queue_head_t       llc_msg_waiter;
                                                /* w4 next llc msg */
                        struct smc_llc_flow     llc_flow_lcl;
                                                /* llc local control field */
                        struct smc_llc_flow     llc_flow_rmt;
                                                /* llc remote control field */
                        struct smc_llc_qentry   *delayed_event;
                                                /* arrived when flow active */
                        spinlock_t              llc_flow_lock;
                                                /* protects llc flow */
                        int                     llc_testlink_time;
                                                /* link keep alive time */
                        u32                     llc_termination_rsn;
                                                /* rsn code for termination */
                };
                struct { /* SMC-D */
                        u64                     peer_gid;
                                                /* Peer GID (remote) */
                        struct smcd_dev         *smcd;
                                                /* ISM device for VLAN reg. */
                        u8                      peer_shutdown : 1;
                                                /* peer triggered shutdownn */
                };
        };
};

struct smc_clc_msg_local;

struct smc_init_info {
        u8                      is_smcd;
        u8                      smc_type_v1;
        u8                      smc_type_v2;
        u8                      first_contact_peer;
        u8                      first_contact_local;
        unsigned short          vlan_id;
        /* SMC-R */
        struct smc_clc_msg_local *ib_lcl;
        struct smc_ib_device    *ib_dev;
        u8                      ib_gid[SMC_GID_SIZE];
        u8                      ib_port;
        u32                     ib_clcqpn;
        /* SMC-D */
        u64                     ism_peer_gid[SMC_MAX_ISM_DEVS + 1];
        struct smcd_dev         *ism_dev[SMC_MAX_ISM_DEVS + 1];
        u16                     ism_chid[SMC_MAX_ISM_DEVS + 1];
        u8                      ism_offered_cnt; /* # of ISM devices offered */
        u8                      ism_selected;    /* index of selected ISM dev*/
        u8                      smcd_version;
};

/* Find the connection associated with the given alert token in the link group.
 * To use rbtrees we have to implement our own search core.
 * Requires @conns_lock
 * @token       alert token to search for
 * @lgr          link group to search in
 * Returns connection associated with token if found, NULL otherwise.
 */
static inline struct smc_connection *smc_lgr_find_conn(
        u32 token, struct smc_link_group *lgr)
{
        struct smc_connection *res = NULL;
        struct rb_node *node;

        node = lgr->conns_all.rb_node;
        while (node) {
                struct smc_connection *cur = rb_entry(node,
                                        struct smc_connection, alert_node);

                if (cur->alert_token_local > token) {
                        node = node->rb_left;
                } else {
                        if (cur->alert_token_local < token) {
                                node = node->rb_right;
                        } else {
                                res = cur;
                                break;
                        }
                }
        }

        return res;
}

/* returns true if the specified link is usable */
static inline bool smc_link_usable(struct smc_link *lnk)
{
        if (lnk->state == SMC_LNK_UNUSED || lnk->state == SMC_LNK_INACTIVE)
                return false;
        return true;
}

static inline bool smc_link_active(struct smc_link *lnk)
{
        return lnk->state == SMC_LNK_ACTIVE;
}

struct smc_sock;
struct smc_clc_msg_accept_confirm;
struct smc_clc_msg_local;

void smc_lgr_cleanup_early(struct smc_connection *conn);
void smc_lgr_terminate_sched(struct smc_link_group *lgr);
void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport);
void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport);
void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
                        unsigned short vlan);
void smc_smcd_terminate_all(struct smcd_dev *dev);
void smc_smcr_terminate_all(struct smc_ib_device *smcibdev);
int smc_buf_create(struct smc_sock *smc, bool is_smcd);
int smc_uncompress_bufsize(u8 compressed);
int smc_rmb_rtoken_handling(struct smc_connection *conn, struct smc_link *link,
                            struct smc_clc_msg_accept_confirm *clc);
int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey);
int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey);
void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
                    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey);
void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
                     __be64 nw_vaddr, __be32 nw_rkey);
void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini);

void smc_conn_free(struct smc_connection *conn);
int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini);
void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
int smc_core_init(void);
void smc_core_exit(void);

int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
                   u8 link_idx, struct smc_init_info *ini);
void smcr_link_clear(struct smc_link *lnk, bool log);
int smcr_buf_map_lgr(struct smc_link *lnk);
int smcr_buf_reg_lgr(struct smc_link *lnk);
void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type);
void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
                            enum smc_lgr_type new_type, int asym_lnk_idx);
int smcr_link_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc);
struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
                                  struct smc_link *from_lnk, bool is_dev_err);
void smcr_link_down_cond(struct smc_link *lnk);
void smcr_link_down_cond_sched(struct smc_link *lnk);

static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
{
        return link->lgr;
}
#endif