iscsi_iser.h

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/*
 * iSER transport for the Open iSCSI Initiator & iSER transport internals
 *
 * Copyright (C) 2004 Dmitry Yusupov
 * Copyright (C) 2004 Alex Aizman
 * Copyright (C) 2005 Mike Christie
 * based on code maintained by [email protected]
 *
 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
 * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *  - Redistributions of source code must retain the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef __ISCSI_ISER_H__
#define __ISCSI_ISER_H__

#include <linux/types.h>
#include <linux/net.h>
#include <scsi/libiscsi.h>
#include <scsi/scsi_transport_iscsi.h>

#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/mutex.h>
#include <linux/mempool.h>
#include <linux/uio.h>

#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>

#include <rdma/ib_verbs.h>
#include <rdma/ib_fmr_pool.h>
#include <rdma/rdma_cm.h>

#define DRV_NAME    "iser"
#define PFX     DRV_NAME ": "
#define DRV_VER     "0.1"
#define DRV_DATE    "May 7th, 2006"

#define iser_dbg(fmt, arg...)               \
    do {                        \
        if (iser_debug_level > 1)       \
            printk(KERN_DEBUG PFX "%s:" fmt,\
                __func__ , ## arg); \
    } while (0)

#define iser_warn(fmt, arg...)              \
    do {                        \
        if (iser_debug_level > 0)       \
            printk(KERN_DEBUG PFX "%s:" fmt,\
                __func__ , ## arg); \
    } while (0)

#define iser_err(fmt, arg...)               \
    do {                        \
        printk(KERN_ERR PFX "%s:" fmt,          \
               __func__ , ## arg);      \
    } while (0)

#define SHIFT_4K    12
#define SIZE_4K (1ULL << SHIFT_4K)
#define MASK_4K (~(SIZE_4K-1))

                    /* support up to 512KB in one RDMA */
#define ISCSI_ISER_SG_TABLESIZE         (0x80000 >> SHIFT_4K)
#define ISER_DEF_CMD_PER_LUN        128

/* QP settings */
/* Maximal bounds on received asynchronous PDUs */
#define ISER_MAX_RX_MISC_PDUS       4 /* NOOP_IN(2) , ASYNC_EVENT(2)   */

#define ISER_MAX_TX_MISC_PDUS       6 /* NOOP_OUT(2), TEXT(1),         *
                       * SCSI_TMFUNC(2), LOGOUT(1) */

#define ISER_QP_MAX_RECV_DTOS       (ISCSI_DEF_XMIT_CMDS_MAX)

#define ISER_MIN_POSTED_RX      (ISCSI_DEF_XMIT_CMDS_MAX >> 2)

/* the max TX (send) WR supported by the iSER QP is defined by                 *
 * max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect   *
 * to have at max for SCSI command. The tx posting & completion handling code  *
 * supports -EAGAIN scheme where tx is suspended till the QP has room for more *
 * send WR. D=8 comes from 64K/8K                                              */

#define ISER_INFLIGHT_DATAOUTS      8

#define ISER_QP_MAX_REQ_DTOS        (ISCSI_DEF_XMIT_CMDS_MAX *    \
                    (1 + ISER_INFLIGHT_DATAOUTS) + \
                    ISER_MAX_TX_MISC_PDUS        + \
                    ISER_MAX_RX_MISC_PDUS)

#define ISER_VER            0x10
#define ISER_WSV            0x08
#define ISER_RSV            0x04

struct iser_hdr {
    u8      flags;
    u8      rsvd[3];
    __be32  write_stag; /* write rkey */
    __be64  write_va;
    __be32  read_stag;  /* read rkey */
    __be64  read_va;
} __attribute__((packed));

/* Constant PDU lengths calculations */
#define ISER_HEADERS_LEN  (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))

#define ISER_RECV_DATA_SEG_LEN  128
#define ISER_RX_PAYLOAD_SIZE    (ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
#define ISER_RX_LOGIN_SIZE  (ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)

/* Length of an object name string */
#define ISER_OBJECT_NAME_SIZE           64

enum iser_ib_conn_state {
    ISER_CONN_INIT,        /* descriptor allocd, no conn          */
    ISER_CONN_PENDING,     /* in the process of being established */
    ISER_CONN_UP,          /* up and running                      */
    ISER_CONN_TERMINATING,     /* in the process of being terminated  */
    ISER_CONN_DOWN,        /* shut down                           */
    ISER_CONN_STATES_NUM
};

enum iser_task_status {
    ISER_TASK_STATUS_INIT = 0,
    ISER_TASK_STATUS_STARTED,
    ISER_TASK_STATUS_COMPLETED
};

enum iser_data_dir {
    ISER_DIR_IN = 0,       /* to initiator */
    ISER_DIR_OUT,          /* from initiator */
    ISER_DIRS_NUM
};

struct iser_data_buf {
    void               *buf;      /* pointer to the sg list               */
    unsigned int       size;      /* num entries of this sg               */
    unsigned long      data_len;  /* total data len                       */
    unsigned int       dma_nents; /* returned by dma_map_sg               */
    char           *copy_buf; /* allocated copy buf for SGs unaligned *
                                   * for rdma which are copied            */
    struct scatterlist sg_single; /* SG-ified clone of a non SG SC or     *
                       * unaligned SG                         */
  };

/* fwd declarations */
struct iser_device;
struct iser_cq_desc;
struct iscsi_iser_conn;
struct iscsi_iser_task;
struct iscsi_endpoint;

struct iser_mem_reg {
    u32  lkey;
    u32  rkey;
    u64  va;
    u64  len;
    void *mem_h;
    int  is_fmr;
};

struct iser_regd_buf {
    struct iser_mem_reg     reg;        /* memory registration info        */
    void                    *virt_addr;
    struct iser_device      *device;    /* device->device for dma_unmap    */
    enum dma_data_direction direction;  /* direction for dma_unmap         */
    unsigned int            data_size;
};

enum iser_desc_type {
    ISCSI_TX_CONTROL ,
    ISCSI_TX_SCSI_COMMAND,
    ISCSI_TX_DATAOUT
};

struct iser_tx_desc {
    struct iser_hdr              iser_header;
    struct iscsi_hdr             iscsi_header;
    enum   iser_desc_type        type;
    u64                  dma_addr;
    /* sg[0] points to iser/iscsi headers, sg[1] optionally points to either
    of immediate data, unsolicited data-out or control (login,text) */
    struct ib_sge            tx_sg[2];
    int                          num_sge;
};

#define ISER_RX_PAD_SIZE    (256 - (ISER_RX_PAYLOAD_SIZE + \
                    sizeof(u64) + sizeof(struct ib_sge)))
struct iser_rx_desc {
    struct iser_hdr              iser_header;
    struct iscsi_hdr             iscsi_header;
    char                     data[ISER_RECV_DATA_SEG_LEN];
    u64                  dma_addr;
    struct ib_sge            rx_sg;
    char                     pad[ISER_RX_PAD_SIZE];
} __attribute__((packed));

#define ISER_MAX_CQ 4

struct iser_device {
    struct ib_device             *ib_device;
    struct ib_pd                 *pd;
    struct ib_cq                 *rx_cq[ISER_MAX_CQ];
    struct ib_cq                 *tx_cq[ISER_MAX_CQ];
    struct ib_mr                 *mr;
    struct tasklet_struct        cq_tasklet[ISER_MAX_CQ];
    struct ib_event_handler      event_handler;
    struct list_head             ig_list; /* entry in ig devices list */
    int                          refcount;
    int                          cq_active_qps[ISER_MAX_CQ];
    int              cqs_used;
    struct iser_cq_desc      *cq_desc;
};

struct iser_conn {
    struct iscsi_iser_conn       *iser_conn; /* iser conn for upcalls  */
    struct iscsi_endpoint        *ep;
    enum iser_ib_conn_state      state;     /* rdma connection state   */
    atomic_t             refcount;
    spinlock_t           lock;      /* used for state changes  */
    struct iser_device           *device;       /* device context          */
    struct rdma_cm_id            *cma_id;       /* CMA ID              */
    struct ib_qp                 *qp;           /* QP              */
    struct ib_fmr_pool           *fmr_pool;     /* pool of IB FMRs         */
    wait_queue_head_t        wait;          /* waitq for conn/disconn  */
    int                          post_recv_buf_count; /* posted rx count  */
    atomic_t                     post_send_buf_count; /* posted tx count   */
    char                 name[ISER_OBJECT_NAME_SIZE];
    struct iser_page_vec         *page_vec;     /* represents SG to fmr maps*
                             * maps serialized as tx is*/
    struct list_head         conn_list;       /* entry in ig conn list */

    char                 *login_buf;
    char                 *login_req_buf, *login_resp_buf;
    u64              login_req_dma, login_resp_dma;
    unsigned int             rx_desc_head;
    struct iser_rx_desc      *rx_descs;
    struct ib_recv_wr        rx_wr[ISER_MIN_POSTED_RX];
};

struct iscsi_iser_conn {
    struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
    struct iser_conn             *ib_conn;   /* iSER IB conn      */
};

struct iscsi_iser_task {
    struct iser_tx_desc          desc;
    struct iscsi_iser_conn       *iser_conn;
    enum iser_task_status        status;
    int                          command_sent;  /* set if command  sent  */
    int                          dir[ISER_DIRS_NUM];      /* set if dir use*/
    struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
    struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
    struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
};

struct iser_page_vec {
    u64 *pages;
    int length;
    int offset;
    int data_size;
};

struct iser_cq_desc {
    struct iser_device           *device;
    int                          cq_index;
};

struct iser_global {
    struct mutex      device_list_mutex;/*                   */
    struct list_head  device_list;       /* all iSER devices */
    struct mutex      connlist_mutex;
    struct list_head  connlist;     /* all iSER IB connections */

    struct kmem_cache *desc_cache;
};

extern struct iser_global ig;
extern int iser_debug_level;

/* allocate connection resources needed for rdma functionality */
int iser_conn_set_full_featured_mode(struct iscsi_conn *conn);

int iser_send_control(struct iscsi_conn *conn,
              struct iscsi_task *task);

int iser_send_command(struct iscsi_conn *conn,
              struct iscsi_task *task);

int iser_send_data_out(struct iscsi_conn *conn,
               struct iscsi_task *task,
               struct iscsi_data *hdr);

void iscsi_iser_recv(struct iscsi_conn *conn,
             struct iscsi_hdr       *hdr,
             char                   *rx_data,
             int                    rx_data_len);

void iser_conn_init(struct iser_conn *ib_conn);

void iser_conn_get(struct iser_conn *ib_conn);

int iser_conn_put(struct iser_conn *ib_conn, int destroy_cma_id_allowed);

void iser_conn_terminate(struct iser_conn *ib_conn);

void iser_rcv_completion(struct iser_rx_desc *desc,
             unsigned long    dto_xfer_len,
            struct iser_conn *ib_conn);

void iser_snd_completion(struct iser_tx_desc *desc, struct iser_conn *ib_conn);

void iser_task_rdma_init(struct iscsi_iser_task *task);

void iser_task_rdma_finalize(struct iscsi_iser_task *task);

void iser_free_rx_descriptors(struct iser_conn *ib_conn);

void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *task,
                     enum iser_data_dir         cmd_dir);

int  iser_reg_rdma_mem(struct iscsi_iser_task *task,
               enum   iser_data_dir        cmd_dir);

int  iser_connect(struct iser_conn   *ib_conn,
          struct sockaddr_in *src_addr,
          struct sockaddr_in *dst_addr,
          int                non_blocking);

int  iser_reg_page_vec(struct iser_conn     *ib_conn,
               struct iser_page_vec *page_vec,
               struct iser_mem_reg  *mem_reg);

void iser_unreg_mem(struct iser_mem_reg *mem_reg);

int  iser_post_recvl(struct iser_conn *ib_conn);
int  iser_post_recvm(struct iser_conn *ib_conn, int count);
int  iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc);

int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
                struct iser_data_buf       *data,
                enum   iser_data_dir       iser_dir,
                enum   dma_data_direction  dma_dir);

void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task);
int  iser_initialize_task_headers(struct iscsi_task *task,
            struct iser_tx_desc *tx_desc);
int iser_alloc_rx_descriptors(struct iser_conn *ib_conn);
#endif