ib.h

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#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_FMR_SIZE            256
#define RDS_FMR_POOL_SIZE       8192

#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_RETRY_COUNT  2

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

#define RDS_IB_RECYCLE_BATCH_COUNT  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;
    struct list_head     *xfer;
    struct list_head     *ready;
};

struct rds_ib_connect_private {
    /* Add new fields at the end, and don't permute existing fields. */
    __be32          dp_saddr;
    __be32          dp_daddr;
    u8          dp_protocol_major;
    u8          dp_protocol_minor;
    __be16          dp_protocol_minor_mask; /* bitmask */
    __be32          dp_reserved1;
    __be64          dp_ack_seq;
    __be32          dp_credit;      /* non-zero enables flow ctl */
};

struct rds_ib_send_work {
    void            *s_op;
    struct ib_send_wr   s_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;
};

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_mr        *i_mr;
    struct ib_cq        *i_send_cq;
    struct ib_cq        *i_recv_cq;

    /* tx */
    struct rds_ib_work_ring i_send_ring;
    struct rm_data_op   *i_data_op;
    struct rds_header   *i_send_hdrs;
    u64         i_send_hdrs_dma;
    struct rds_ib_send_work *i_sends;
    atomic_t        i_signaled_sends;

    /* rx */
    struct tasklet_struct   i_recv_tasklet;
    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;
    u64         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;

    /* 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;
    u64         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;
};

/* 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 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;
    struct ib_mr        *mr;
    struct rds_ib_mr_pool   *mr_pool;
    unsigned int        fmr_max_remaps;
    unsigned int        max_fmrs;
    int         max_sge;
    unsigned int        max_wrs;
    unsigned int        max_initiator_depth;
    unsigned int        max_responder_resources;
    spinlock_t      spinlock;   /* protect the above */
    atomic_t        refcount;
    struct work_struct  free_work;
};

#define ibdev_to_node(ibdev) dev_to_node(ibdev->dma_device)
#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_tx_cq_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_call;
    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_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_alloc;
    uint64_t    s_ib_rdma_mr_free;
    uint64_t    s_ib_rdma_mr_used;
    uint64_t    s_ib_rdma_mr_pool_flush;
    uint64_t    s_ib_rdma_mr_pool_wait;
    uint64_t    s_ib_rdma_mr_pool_depleted;
    uint64_t    s_ib_atomic_cswp;
    uint64_t    s_ib_atomic_fadd;
};

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 *sg, unsigned int sg_dma_len, int direction)
{
    unsigned int i;

    for (i = 0; i < sg_dma_len; ++i) {
        ib_dma_sync_single_for_cpu(dev,
                ib_sg_dma_address(dev, &sg[i]),
                ib_sg_dma_len(dev, &sg[i]),
                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 *sg, unsigned int sg_dma_len, int direction)
{
    unsigned int i;

    for (i = 0; i < sg_dma_len; ++i) {
        ib_dma_sync_single_for_device(dev,
                ib_sg_dma_address(dev, &sg[i]),
                ib_sg_dma_len(dev, &sg[i]),
                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 fmr_message_size;
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_connect(struct rds_connection *conn);
void rds_ib_conn_shutdown(struct rds_connection *conn);
void rds_ib_state_change(struct sock *sk);
int rds_ib_listen_init(void);
void rds_ib_listen_stop(void);
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);
int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id);
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, __be32 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);
struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *);
void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo);
void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *);
void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
            struct rds_sock *rs, u32 *key_ret);
void rds_ib_sync_mr(void *trans_private, int dir);
void rds_ib_free_mr(void *trans_private, int invalidate);
void rds_ib_flush_mrs(void);

/* ib_recv.c */
int rds_ib_recv_init(void);
void rds_ib_recv_exit(void);
int rds_ib_recv(struct rds_connection *conn);
int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic);
void rds_ib_recv_free_caches(struct rds_ib_connection *ic);
void rds_ib_recv_refill(struct rds_connection *conn, int prefill);
void rds_ib_inc_free(struct rds_incoming *inc);
int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
                 size_t size);
void rds_ib_recv_cq_comp_handler(struct ib_cq *cq, void *context);
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);

/* 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 */
char *rds_ib_wc_status_str(enum ib_wc_status status);
void rds_ib_xmit_complete(struct rds_connection *conn);
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_cq_comp_handler(struct ib_cq *cq, void *context);
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(struct rds_ib_statistics, rds_ib_stats);
#define rds_ib_stats_inc(member) rds_stats_inc_which(rds_ib_stats, member)
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