iw.h

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#ifndef _RDS_IW_H
#define _RDS_IW_H

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

#define RDS_FASTREG_SIZE        20
#define RDS_FASTREG_POOL_SIZE       2048

#define RDS_IW_MAX_SGE          8
#define RDS_IW_RECV_SGE         2

#define RDS_IW_DEFAULT_RECV_WR      1024
#define RDS_IW_DEFAULT_SEND_WR      256

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

extern struct list_head rds_iw_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.
 */
/* page offset of the final full frag that fits in the page */
#define RDS_PAGE_LAST_OFF (((PAGE_SIZE  / RDS_FRAG_SIZE) - 1) * RDS_FRAG_SIZE)
struct rds_page_frag {
    struct list_head    f_item;
    struct page     *f_page;
    unsigned long       f_offset;
    dma_addr_t      f_mapped;
};

struct rds_iw_incoming {
    struct list_head    ii_frags;
    struct rds_incoming ii_inc;
};

struct rds_iw_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_iw_scatterlist {
    struct scatterlist  *list;
    unsigned int        len;
    int         dma_len;
    unsigned int        dma_npages;
    unsigned int        bytes;
};

struct rds_iw_mapping {
    spinlock_t      m_lock; /* protect the mapping struct */
    struct list_head    m_list;
    struct rds_iw_mr    *m_mr;
    uint32_t        m_rkey;
    struct rds_iw_scatterlist m_sg;
};

struct rds_iw_send_work {
    struct rds_message  *s_rm;

    /* We should really put these into a union: */
    struct rm_rdma_op   *s_op;
    struct rds_iw_mapping   *s_mapping;
    struct ib_mr        *s_mr;
    struct ib_fast_reg_page_list *s_page_list;
    unsigned char       s_remap_count;

    struct ib_send_wr   s_wr;
    struct ib_sge       s_sge[RDS_IW_MAX_SGE];
    unsigned long       s_queued;
};

struct rds_iw_recv_work {
    struct rds_iw_incoming  *r_iwinc;
    struct rds_page_frag    *r_frag;
    struct ib_recv_wr   r_wr;
    struct ib_sge       r_sge[2];
};

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

struct rds_iw_device;

struct rds_iw_connection {

    struct list_head    iw_node;
    struct rds_iw_device    *rds_iwdev;
    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_iw_work_ring i_send_ring;
    struct rds_message  *i_rm;
    struct rds_header   *i_send_hdrs;
    u64         i_send_hdrs_dma;
    struct rds_iw_send_work *i_sends;

    /* rx */
    struct tasklet_struct   i_recv_tasklet;
    struct mutex        i_recv_mutex;
    struct rds_iw_work_ring i_recv_ring;
    struct rds_iw_incoming  *i_iwinc;
    u32         i_recv_data_rem;
    struct rds_header   *i_recv_hdrs;
    u64         i_recv_hdrs_dma;
    struct rds_iw_recv_work *i_recvs;
    struct rds_page_frag    i_frag;
    u64         i_ack_recv; /* last ACK received */

    /* 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 */
    unsigned int        i_dma_local_lkey:1;
    unsigned int        i_fastreg_posted:1; /* fastreg posted on this connection */
    /* Batched completions */
    unsigned int        i_unsignaled_wrs;
    long            i_unsignaled_bytes;
};

/* 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_iw_cm_id {
    struct list_head    list;
    struct rdma_cm_id   *cm_id;
};

struct rds_iw_device {
    struct list_head    list;
    struct list_head    cm_id_list;
    struct list_head    conn_list;
    struct ib_device    *dev;
    struct ib_pd        *pd;
    struct ib_mr        *mr;
    struct rds_iw_mr_pool   *mr_pool;
    int         max_sge;
    unsigned int        max_wrs;
    unsigned int        dma_local_lkey:1;
    spinlock_t      spinlock;   /* protect the above */
};

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

/* Magic WR_ID for ACKs */
#define RDS_IW_ACK_WR_ID    ((u64)0xffffffffffffffffULL)
#define RDS_IW_FAST_REG_WR_ID   ((u64)0xefefefefefefefefULL)
#define RDS_IW_LOCAL_INV_WR_ID  ((u64)0xdfdfdfdfdfdfdfdfULL)

struct rds_iw_statistics {
    uint64_t    s_iw_connect_raced;
    uint64_t    s_iw_listen_closed_stale;
    uint64_t    s_iw_tx_cq_call;
    uint64_t    s_iw_tx_cq_event;
    uint64_t    s_iw_tx_ring_full;
    uint64_t    s_iw_tx_throttle;
    uint64_t    s_iw_tx_sg_mapping_failure;
    uint64_t    s_iw_tx_stalled;
    uint64_t    s_iw_tx_credit_updates;
    uint64_t    s_iw_rx_cq_call;
    uint64_t    s_iw_rx_cq_event;
    uint64_t    s_iw_rx_ring_empty;
    uint64_t    s_iw_rx_refill_from_cq;
    uint64_t    s_iw_rx_refill_from_thread;
    uint64_t    s_iw_rx_alloc_limit;
    uint64_t    s_iw_rx_credit_updates;
    uint64_t    s_iw_ack_sent;
    uint64_t    s_iw_ack_send_failure;
    uint64_t    s_iw_ack_send_delayed;
    uint64_t    s_iw_ack_send_piggybacked;
    uint64_t    s_iw_ack_received;
    uint64_t    s_iw_rdma_mr_alloc;
    uint64_t    s_iw_rdma_mr_free;
    uint64_t    s_iw_rdma_mr_used;
    uint64_t    s_iw_rdma_mr_pool_flush;
    uint64_t    s_iw_rdma_mr_pool_wait;
    uint64_t    s_iw_rdma_mr_pool_depleted;
};

extern struct workqueue_struct *rds_iw_wq;

/*
 * Fake ib_dma_sync_sg_for_{cpu,device} as long as ib_verbs.h
 * doesn't define it.
 */
static inline void rds_iw_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_iw_dma_sync_sg_for_cpu

static inline void rds_iw_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_iw_dma_sync_sg_for_device

static inline u32 rds_iw_local_dma_lkey(struct rds_iw_connection *ic)
{
    return ic->i_dma_local_lkey ? ic->i_cm_id->device->local_dma_lkey : ic->i_mr->lkey;
}

/* ib.c */
extern struct rds_transport rds_iw_transport;
extern struct ib_client rds_iw_client;

extern unsigned int fastreg_pool_size;
extern unsigned int fastreg_message_size;

extern spinlock_t iw_nodev_conns_lock;
extern struct list_head iw_nodev_conns;

/* ib_cm.c */
int rds_iw_conn_alloc(struct rds_connection *conn, gfp_t gfp);
void rds_iw_conn_free(void *arg);
int rds_iw_conn_connect(struct rds_connection *conn);
void rds_iw_conn_shutdown(struct rds_connection *conn);
void rds_iw_state_change(struct sock *sk);
int rds_iw_listen_init(void);
void rds_iw_listen_stop(void);
void __rds_iw_conn_error(struct rds_connection *conn, const char *, ...);
int rds_iw_cm_handle_connect(struct rdma_cm_id *cm_id,
                 struct rdma_cm_event *event);
int rds_iw_cm_initiate_connect(struct rdma_cm_id *cm_id);
void rds_iw_cm_connect_complete(struct rds_connection *conn,
                struct rdma_cm_event *event);


#define rds_iw_conn_error(conn, fmt...) \
    __rds_iw_conn_error(conn, KERN_WARNING "RDS/IW: " fmt)

/* ib_rdma.c */
int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id);
void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn);
void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn);
void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock);
static inline void rds_iw_destroy_nodev_conns(void)
{
    __rds_iw_destroy_conns(&iw_nodev_conns, &iw_nodev_conns_lock);
}
static inline void rds_iw_destroy_conns(struct rds_iw_device *rds_iwdev)
{
    __rds_iw_destroy_conns(&rds_iwdev->conn_list, &rds_iwdev->spinlock);
}
struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *);
void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo);
void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *);
void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents,
            struct rds_sock *rs, u32 *key_ret);
void rds_iw_sync_mr(void *trans_private, int dir);
void rds_iw_free_mr(void *trans_private, int invalidate);
void rds_iw_flush_mrs(void);

/* ib_recv.c */
int rds_iw_recv_init(void);
void rds_iw_recv_exit(void);
int rds_iw_recv(struct rds_connection *conn);
int rds_iw_recv_refill(struct rds_connection *conn, gfp_t kptr_gfp,
               gfp_t page_gfp, int prefill);
void rds_iw_inc_free(struct rds_incoming *inc);
int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
                 size_t size);
void rds_iw_recv_cq_comp_handler(struct ib_cq *cq, void *context);
void rds_iw_recv_tasklet_fn(unsigned long data);
void rds_iw_recv_init_ring(struct rds_iw_connection *ic);
void rds_iw_recv_clear_ring(struct rds_iw_connection *ic);
void rds_iw_recv_init_ack(struct rds_iw_connection *ic);
void rds_iw_attempt_ack(struct rds_iw_connection *ic);
void rds_iw_ack_send_complete(struct rds_iw_connection *ic);
u64 rds_iw_piggyb_ack(struct rds_iw_connection *ic);

/* ib_ring.c */
void rds_iw_ring_init(struct rds_iw_work_ring *ring, u32 nr);
void rds_iw_ring_resize(struct rds_iw_work_ring *ring, u32 nr);
u32 rds_iw_ring_alloc(struct rds_iw_work_ring *ring, u32 val, u32 *pos);
void rds_iw_ring_free(struct rds_iw_work_ring *ring, u32 val);
void rds_iw_ring_unalloc(struct rds_iw_work_ring *ring, u32 val);
int rds_iw_ring_empty(struct rds_iw_work_ring *ring);
int rds_iw_ring_low(struct rds_iw_work_ring *ring);
u32 rds_iw_ring_oldest(struct rds_iw_work_ring *ring);
u32 rds_iw_ring_completed(struct rds_iw_work_ring *ring, u32 wr_id, u32 oldest);
extern wait_queue_head_t rds_iw_ring_empty_wait;

/* ib_send.c */
void rds_iw_xmit_complete(struct rds_connection *conn);
int rds_iw_xmit(struct rds_connection *conn, struct rds_message *rm,
        unsigned int hdr_off, unsigned int sg, unsigned int off);
void rds_iw_send_cq_comp_handler(struct ib_cq *cq, void *context);
void rds_iw_send_init_ring(struct rds_iw_connection *ic);
void rds_iw_send_clear_ring(struct rds_iw_connection *ic);
int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op);
void rds_iw_send_add_credits(struct rds_connection *conn, unsigned int credits);
void rds_iw_advertise_credits(struct rds_connection *conn, unsigned int posted);
int rds_iw_send_grab_credits(struct rds_iw_connection *ic, u32 wanted,
                 u32 *adv_credits, int need_posted, int max_posted);

/* ib_stats.c */
DECLARE_PER_CPU(struct rds_iw_statistics, rds_iw_stats);
#define rds_iw_stats_inc(member) rds_stats_inc_which(rds_iw_stats, member)
unsigned int rds_iw_stats_info_copy(struct rds_info_iterator *iter,
                    unsigned int avail);

/* ib_sysctl.c */
int rds_iw_sysctl_init(void);
void rds_iw_sysctl_exit(void);
extern unsigned long rds_iw_sysctl_max_send_wr;
extern unsigned long rds_iw_sysctl_max_recv_wr;
extern unsigned long rds_iw_sysctl_max_unsig_wrs;
extern unsigned long rds_iw_sysctl_max_unsig_bytes;
extern unsigned long rds_iw_sysctl_max_recv_allocation;
extern unsigned int rds_iw_sysctl_flow_control;

/*
 * Helper functions for getting/setting the header and data SGEs in
 * RDS packets (not RDMA)
 */
static inline struct ib_sge *
rds_iw_header_sge(struct rds_iw_connection *ic, struct ib_sge *sge)
{
    return &sge[0];
}

static inline struct ib_sge *
rds_iw_data_sge(struct rds_iw_connection *ic, struct ib_sge *sge)
{
    return &sge[1];
}

#endif