/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _RDS_IB_H
#define _RDS_IB_H

#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include "rds.h"
#include "rdma_transport.h"

#define RDS_IB_MAX_SGE                  8
#define RDS_IB_RECV_SGE                 2

#define RDS_IB_DEFAULT_RECV_WR          1024
#define RDS_IB_DEFAULT_SEND_WR          256
#define RDS_IB_DEFAULT_FR_WR            512

#define RDS_IB_DEFAULT_RETRY_COUNT      1

#define RDS_IB_SUPPORTED_PROTOCOLS      0x00000003      /* minor versions supported */

#define RDS_IB_RECYCLE_BATCH_COUNT      32

#define RDS_IB_WC_MAX                   32

extern struct rw_semaphore rds_ib_devices_lock;
extern struct list_head rds_ib_devices;

/*
 * IB posts RDS_FRAG_SIZE fragments of pages to the receive queues to
 * try and minimize the amount of memory tied up both the device and
 * socket receive queues.
 */
struct rds_page_frag {
        struct list_head        f_item;
        struct list_head        f_cache_entry;
        struct scatterlist      f_sg;
};

struct rds_ib_incoming {
        struct list_head        ii_frags;
        struct list_head        ii_cache_entry;
        struct rds_incoming     ii_inc;
};

struct rds_ib_cache_head {
        struct list_head *first;
        unsigned long count;
};

struct rds_ib_refill_cache {
        struct rds_ib_cache_head __percpu *percpu;
        struct list_head         *xfer;
        struct list_head         *ready;
};

/* This is the common structure for the IB private data exchange in setting up
 * an RDS connection.  The exchange is different for IPv4 and IPv6 connections.
 * The reason is that the address size is different and the addresses
 * exchanged are in the beginning of the structure.  Hence it is not possible
 * for interoperability if same structure is used.
 */
struct rds_ib_conn_priv_cmn {
        u8                      ricpc_protocol_major;
        u8                      ricpc_protocol_minor;
        __be16                  ricpc_protocol_minor_mask;      /* bitmask */
        u8                      ricpc_dp_toss;
        u8                      ripc_reserved1;
        __be16                  ripc_reserved2;
        __be64                  ricpc_ack_seq;
        __be32                  ricpc_credit;   /* non-zero enables flow ctl */
};

struct rds_ib_connect_private {
        /* Add new fields at the end, and don't permute existing fields. */
        __be32                          dp_saddr;
        __be32                          dp_daddr;
        struct rds_ib_conn_priv_cmn     dp_cmn;
};

struct rds6_ib_connect_private {
        /* Add new fields at the end, and don't permute existing fields. */
        struct in6_addr                 dp_saddr;
        struct in6_addr                 dp_daddr;
        struct rds_ib_conn_priv_cmn     dp_cmn;
};

#define dp_protocol_major       dp_cmn.ricpc_protocol_major
#define dp_protocol_minor       dp_cmn.ricpc_protocol_minor
#define dp_protocol_minor_mask  dp_cmn.ricpc_protocol_minor_mask
#define dp_ack_seq              dp_cmn.ricpc_ack_seq
#define dp_credit               dp_cmn.ricpc_credit

union rds_ib_conn_priv {
        struct rds_ib_connect_private   ricp_v4;
        struct rds6_ib_connect_private  ricp_v6;
};

struct rds_ib_send_work {
        void                    *s_op;
        union {
                struct ib_send_wr       s_wr;
                struct ib_rdma_wr       s_rdma_wr;
                struct ib_atomic_wr     s_atomic_wr;
        };
        struct ib_sge           s_sge[RDS_IB_MAX_SGE];
        unsigned long           s_queued;
};

struct rds_ib_recv_work {
        struct rds_ib_incoming  *r_ibinc;
        struct rds_page_frag    *r_frag;
        struct ib_recv_wr       r_wr;
        struct ib_sge           r_sge[2];
};

struct rds_ib_work_ring {
        u32             w_nr;
        u32             w_alloc_ptr;
        u32             w_alloc_ctr;
        u32             w_free_ptr;
        atomic_t        w_free_ctr;
};

/* Rings are posted with all the allocations they'll need to queue the
 * incoming message to the receiving socket so this can't fail.
 * All fragments start with a header, so we can make sure we're not receiving
 * garbage, and we can tell a small 8 byte fragment from an ACK frame.
 */
struct rds_ib_ack_state {
        u64             ack_next;
        u64             ack_recv;
        unsigned int    ack_required:1;
        unsigned int    ack_next_valid:1;
        unsigned int    ack_recv_valid:1;
};


struct rds_ib_device;

struct rds_ib_connection {

        struct list_head        ib_node;
        struct rds_ib_device    *rds_ibdev;
        struct rds_connection   *conn;

        /* alphabet soup, IBTA style */
        struct rdma_cm_id       *i_cm_id;
        struct ib_pd            *i_pd;
        struct ib_cq            *i_send_cq;
        struct ib_cq            *i_recv_cq;
        struct ib_wc            i_send_wc[RDS_IB_WC_MAX];
        struct ib_wc            i_recv_wc[RDS_IB_WC_MAX];

        /* To control the number of wrs from fastreg */
        atomic_t                i_fastreg_wrs;
        atomic_t                i_fastreg_inuse_count;

        /* interrupt handling */
        struct tasklet_struct   i_send_tasklet;
        struct tasklet_struct   i_recv_tasklet;

        /* tx */
        struct rds_ib_work_ring i_send_ring;
        struct rm_data_op       *i_data_op;
        struct rds_header       **i_send_hdrs;
        dma_addr_t              *i_send_hdrs_dma;
        struct rds_ib_send_work *i_sends;
        atomic_t                i_signaled_sends;

        /* rx */
        struct mutex            i_recv_mutex;
        struct rds_ib_work_ring i_recv_ring;
        struct rds_ib_incoming  *i_ibinc;
        u32                     i_recv_data_rem;
        struct rds_header       **i_recv_hdrs;
        dma_addr_t              *i_recv_hdrs_dma;
        struct rds_ib_recv_work *i_recvs;
        u64                     i_ack_recv;     /* last ACK received */
        struct rds_ib_refill_cache i_cache_incs;
        struct rds_ib_refill_cache i_cache_frags;
        atomic_t                i_cache_allocs;

        /* sending acks */
        unsigned long           i_ack_flags;
#ifdef KERNEL_HAS_ATOMIC64
        atomic64_t              i_ack_next;     /* next ACK to send */
#else
        spinlock_t              i_ack_lock;     /* protect i_ack_next */
        u64                     i_ack_next;     /* next ACK to send */
#endif
        struct rds_header       *i_ack;
        struct ib_send_wr       i_ack_wr;
        struct ib_sge           i_ack_sge;
        dma_addr_t              i_ack_dma;
        unsigned long           i_ack_queued;

        /* Flow control related information
         *
         * Our algorithm uses a pair variables that we need to access
         * atomically - one for the send credits, and one posted
         * recv credits we need to transfer to remote.
         * Rather than protect them using a slow spinlock, we put both into
         * a single atomic_t and update it using cmpxchg
         */
        atomic_t                i_credits;

        /* Protocol version specific information */
        unsigned int            i_flowctl:1;    /* enable/disable flow ctl */

        /* Batched completions */
        unsigned int            i_unsignaled_wrs;

        /* Endpoint role in connection */
        bool                    i_active_side;
        atomic_t                i_cq_quiesce;

        /* Send/Recv vectors */
        int                     i_scq_vector;
        int                     i_rcq_vector;
        u8                      i_sl;
};

/* This assumes that atomic_t is at least 32 bits */
#define IB_GET_SEND_CREDITS(v)  ((v) & 0xffff)
#define IB_GET_POST_CREDITS(v)  ((v) >> 16)
#define IB_SET_SEND_CREDITS(v)  ((v) & 0xffff)
#define IB_SET_POST_CREDITS(v)  ((v) << 16)

struct rds_ib_ipaddr {
        struct list_head        list;
        __be32                  ipaddr;
        struct rcu_head         rcu;
};

enum {
        RDS_IB_MR_8K_POOL,
        RDS_IB_MR_1M_POOL,
};

struct rds_ib_device {
        struct list_head        list;
        struct list_head        ipaddr_list;
        struct list_head        conn_list;
        struct ib_device        *dev;
        struct ib_pd            *pd;
        u8                      odp_capable:1;

        unsigned int            max_mrs;
        struct rds_ib_mr_pool   *mr_1m_pool;
        struct rds_ib_mr_pool   *mr_8k_pool;
        unsigned int            max_8k_mrs;
        unsigned int            max_1m_mrs;
        int                     max_sge;
        unsigned int            max_wrs;
        unsigned int            max_initiator_depth;
        unsigned int            max_responder_resources;
        spinlock_t              spinlock;       /* protect the above */
        refcount_t              refcount;
        struct work_struct      free_work;
        int                     *vector_load;
};

#define rdsibdev_to_node(rdsibdev) ibdev_to_node(rdsibdev->dev)

/* bits for i_ack_flags */
#define IB_ACK_IN_FLIGHT        0
#define IB_ACK_REQUESTED        1

/* Magic WR_ID for ACKs */
#define RDS_IB_ACK_WR_ID        (~(u64) 0)

struct rds_ib_statistics {
        uint64_t        s_ib_connect_raced;
        uint64_t        s_ib_listen_closed_stale;
        uint64_t        s_ib_evt_handler_call;
        uint64_t        s_ib_tasklet_call;
        uint64_t        s_ib_tx_cq_event;
        uint64_t        s_ib_tx_ring_full;
        uint64_t        s_ib_tx_throttle;
        uint64_t        s_ib_tx_sg_mapping_failure;
        uint64_t        s_ib_tx_stalled;
        uint64_t        s_ib_tx_credit_updates;
        uint64_t        s_ib_rx_cq_event;
        uint64_t        s_ib_rx_ring_empty;
        uint64_t        s_ib_rx_refill_from_cq;
        uint64_t        s_ib_rx_refill_from_thread;
        uint64_t        s_ib_rx_alloc_limit;
        uint64_t        s_ib_rx_total_frags;
        uint64_t        s_ib_rx_total_incs;
        uint64_t        s_ib_rx_credit_updates;
        uint64_t        s_ib_ack_sent;
        uint64_t        s_ib_ack_send_failure;
        uint64_t        s_ib_ack_send_delayed;
        uint64_t        s_ib_ack_send_piggybacked;
        uint64_t        s_ib_ack_received;
        uint64_t        s_ib_rdma_mr_8k_alloc;
        uint64_t        s_ib_rdma_mr_8k_free;
        uint64_t        s_ib_rdma_mr_8k_used;
        uint64_t        s_ib_rdma_mr_8k_pool_flush;
        uint64_t        s_ib_rdma_mr_8k_pool_wait;
        uint64_t        s_ib_rdma_mr_8k_pool_depleted;
        uint64_t        s_ib_rdma_mr_1m_alloc;
        uint64_t        s_ib_rdma_mr_1m_free;
        uint64_t        s_ib_rdma_mr_1m_used;
        uint64_t        s_ib_rdma_mr_1m_pool_flush;
        uint64_t        s_ib_rdma_mr_1m_pool_wait;
        uint64_t        s_ib_rdma_mr_1m_pool_depleted;
        uint64_t        s_ib_rdma_mr_8k_reused;
        uint64_t        s_ib_rdma_mr_1m_reused;
        uint64_t        s_ib_atomic_cswp;
        uint64_t        s_ib_atomic_fadd;
        uint64_t        s_ib_recv_added_to_cache;
        uint64_t        s_ib_recv_removed_from_cache;
};

extern struct workqueue_struct *rds_ib_wq;

/*
 * Fake ib_dma_sync_sg_for_{cpu,device} as long as ib_verbs.h
 * doesn't define it.
 */
static inline void rds_ib_dma_sync_sg_for_cpu(struct ib_device *dev,
                                              struct scatterlist *sglist,
                                              unsigned int sg_dma_len,
                                              int direction)
{
        struct scatterlist *sg;
        unsigned int i;

        for_each_sg(sglist, sg, sg_dma_len, i) {
                ib_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
                                           sg_dma_len(sg), direction);
        }
}
#define ib_dma_sync_sg_for_cpu  rds_ib_dma_sync_sg_for_cpu

static inline void rds_ib_dma_sync_sg_for_device(struct ib_device *dev,
                                                 struct scatterlist *sglist,
                                                 unsigned int sg_dma_len,
                                                 int direction)
{
        struct scatterlist *sg;
        unsigned int i;

        for_each_sg(sglist, sg, sg_dma_len, i) {
                ib_dma_sync_single_for_device(dev, sg_dma_address(sg),
                                              sg_dma_len(sg), direction);
        }
}
#define ib_dma_sync_sg_for_device       rds_ib_dma_sync_sg_for_device


/* ib.c */
extern struct rds_transport rds_ib_transport;
struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device);
void rds_ib_dev_put(struct rds_ib_device *rds_ibdev);
extern struct ib_client rds_ib_client;

extern unsigned int rds_ib_retry_count;

extern spinlock_t ib_nodev_conns_lock;
extern struct list_head ib_nodev_conns;

/* ib_cm.c */
int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp);
void rds_ib_conn_free(void *arg);
int rds_ib_conn_path_connect(struct rds_conn_path *cp);
void rds_ib_conn_path_shutdown(struct rds_conn_path *cp);
void rds_ib_state_change(struct sock *sk);
int rds_ib_listen_init(void);
void rds_ib_listen_stop(void);
__printf(2, 3)
void __rds_ib_conn_error(struct rds_connection *conn, const char *, ...);
int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
                             struct rdma_cm_event *event, bool isv6);
int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id, bool isv6);
void rds_ib_cm_connect_complete(struct rds_connection *conn,
                                struct rdma_cm_event *event);

#define rds_ib_conn_error(conn, fmt...) \
        __rds_ib_conn_error(conn, KERN_WARNING "RDS/IB: " fmt)

/* ib_rdma.c */
int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
                         struct in6_addr *ipaddr);
void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
void rds_ib_destroy_nodev_conns(void);
void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc);

/* ib_recv.c */
int rds_ib_recv_init(void);
void rds_ib_recv_exit(void);
int rds_ib_recv_path(struct rds_conn_path *conn);
int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic, gfp_t gfp);
void rds_ib_recv_free_caches(struct rds_ib_connection *ic);
void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp);
void rds_ib_inc_free(struct rds_incoming *inc);
int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
void rds_ib_recv_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc,
                             struct rds_ib_ack_state *state);
void rds_ib_recv_tasklet_fn(unsigned long data);
void rds_ib_recv_init_ring(struct rds_ib_connection *ic);
void rds_ib_recv_clear_ring(struct rds_ib_connection *ic);
void rds_ib_recv_init_ack(struct rds_ib_connection *ic);
void rds_ib_attempt_ack(struct rds_ib_connection *ic);
void rds_ib_ack_send_complete(struct rds_ib_connection *ic);
u64 rds_ib_piggyb_ack(struct rds_ib_connection *ic);
void rds_ib_set_ack(struct rds_ib_connection *ic, u64 seq, int ack_required);

/* ib_ring.c */
void rds_ib_ring_init(struct rds_ib_work_ring *ring, u32 nr);
void rds_ib_ring_resize(struct rds_ib_work_ring *ring, u32 nr);
u32 rds_ib_ring_alloc(struct rds_ib_work_ring *ring, u32 val, u32 *pos);
void rds_ib_ring_free(struct rds_ib_work_ring *ring, u32 val);
void rds_ib_ring_unalloc(struct rds_ib_work_ring *ring, u32 val);
int rds_ib_ring_empty(struct rds_ib_work_ring *ring);
int rds_ib_ring_low(struct rds_ib_work_ring *ring);
u32 rds_ib_ring_oldest(struct rds_ib_work_ring *ring);
u32 rds_ib_ring_completed(struct rds_ib_work_ring *ring, u32 wr_id, u32 oldest);
extern wait_queue_head_t rds_ib_ring_empty_wait;

/* ib_send.c */
void rds_ib_xmit_path_complete(struct rds_conn_path *cp);
int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
                unsigned int hdr_off, unsigned int sg, unsigned int off);
void rds_ib_send_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc);
void rds_ib_send_init_ring(struct rds_ib_connection *ic);
void rds_ib_send_clear_ring(struct rds_ib_connection *ic);
int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op);
void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits);
void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted);
int rds_ib_send_grab_credits(struct rds_ib_connection *ic, u32 wanted,
                             u32 *adv_credits, int need_posted, int max_posted);
int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op);

/* ib_stats.c */
DECLARE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);
#define rds_ib_stats_inc(member) rds_stats_inc_which(rds_ib_stats, member)
#define rds_ib_stats_add(member, count) \
                rds_stats_add_which(rds_ib_stats, member, count)
unsigned int rds_ib_stats_info_copy(struct rds_info_iterator *iter,
                                    unsigned int avail);

/* ib_sysctl.c */
int rds_ib_sysctl_init(void);
void rds_ib_sysctl_exit(void);
extern unsigned long rds_ib_sysctl_max_send_wr;
extern unsigned long rds_ib_sysctl_max_recv_wr;
extern unsigned long rds_ib_sysctl_max_unsig_wrs;
extern unsigned long rds_ib_sysctl_max_unsig_bytes;
extern unsigned long rds_ib_sysctl_max_recv_allocation;
extern unsigned int rds_ib_sysctl_flow_control;

#endif