IB/iser: iSCSI iSER transport provider header file

iSER (iSCSI Extensions for RDMA) transport provider driver for the iSCSI
initiator, whose other parts (under drivers/scsi) are scsi_transport_iscsi
- the transport management module, iscsi_tcp - the TCP transport provider
module and libiscsi - a kernel library (module) implementing functionality
needed by both TCP and iSER transports. iSER is both a provider of the iSCSI
transport api and a SCSI low level driver.

This file contains internal data structures and non static service functions.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/ulp/iser/iscsi_iser.h

+/*
+ * 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 open-iscsi@googlegroups.com
+ *
+ * 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.
+ *
+ * $Id: iscsi_iser.h 7051 2006-05-10 12:29:11Z ogerlitz $
+ */
+#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/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 > 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)
+
+					/* support upto 512KB in one RDMA */
+#define ISCSI_ISER_SG_TABLESIZE         (0x80000 >> PAGE_SHIFT)
+#define ISCSI_ISER_MAX_LUN		256
+#define ISCSI_ISER_MAX_CMD_LEN		16
+
+/* 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_XMIT_CMDS_MAX + \
+					ISER_MAX_RX_MISC_PDUS    +  \
+					ISER_MAX_TX_MISC_PDUS)
+
+/* 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_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));
+
+
+/* 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 iscsi_iser_conn;
+struct iscsi_iser_cmd_task;
+
+struct iser_mem_reg {
+	u32  lkey;
+	u32  rkey;
+	u64  va;
+	u64  len;
+	void *mem_h;
+};
+
+struct iser_regd_buf {
+	struct iser_mem_reg     reg;        /* memory registration info        */
+	void                    *virt_addr;
+	struct iser_device      *device;    /* device->device for dma_unmap    */
+	dma_addr_t              dma_addr;   /* if non zero, addr for dma_unmap */
+	enum dma_data_direction direction;  /* direction for dma_unmap	       */
+	unsigned int            data_size;
+	atomic_t                ref_count;  /* refcount, freed when dec to 0   */
+};
+
+#define MAX_REGD_BUF_VECTOR_LEN	2
+
+struct iser_dto {
+	struct iscsi_iser_cmd_task *ctask;
+	struct iscsi_iser_conn     *conn;
+	int                        notify_enable;
+
+	/* vector of registered buffers */
+	unsigned int               regd_vector_len;
+	struct iser_regd_buf       *regd[MAX_REGD_BUF_VECTOR_LEN];
+
+	/* offset into the registered buffer may be specified */
+	unsigned int               offset[MAX_REGD_BUF_VECTOR_LEN];
+
+	/* a smaller size may be specified, if 0, then full size is used */
+	unsigned int               used_sz[MAX_REGD_BUF_VECTOR_LEN];
+};
+
+enum iser_desc_type {
+	ISCSI_RX,
+	ISCSI_TX_CONTROL ,
+	ISCSI_TX_SCSI_COMMAND,
+	ISCSI_TX_DATAOUT
+};
+
+struct iser_desc {
+	struct iser_hdr              iser_header;
+	struct iscsi_hdr             iscsi_header;
+	struct iser_regd_buf         hdr_regd_buf;
+	void                         *data;         /* used by RX & TX_CONTROL */
+	struct iser_regd_buf         data_regd_buf; /* used by RX & TX_CONTROL */
+	enum   iser_desc_type        type;
+	struct iser_dto              dto;
+};
+
+struct iser_device {
+	struct ib_device             *ib_device;
+	struct ib_pd	             *pd;
+	struct ib_cq	             *cq;
+	struct ib_mr	             *mr;
+	struct tasklet_struct	     cq_tasklet;
+	struct list_head             ig_list; /* entry in ig devices list */
+	int                          refcount;
+};
+
+struct iser_conn {
+	struct iscsi_iser_conn       *iser_conn; /* iser conn for upcalls  */
+	enum iser_ib_conn_state	     state;	    /* rdma connection state   */
+	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         */
+	int                          disc_evt_flag; /* disconn event delivered */
+	wait_queue_head_t	     wait;          /* waitq for conn/disconn  */
+	atomic_t                     post_recv_buf_count; /* posted rx count   */
+	atomic_t                     post_send_buf_count; /* posted tx count   */
+	struct work_struct           comperror_work; /* conn term sleepable ctx*/
+	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 */
+};
+
+struct iscsi_iser_conn {
+	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
+	struct iser_conn             *ib_conn;   /* iSER IB conn      */
+
+	rwlock_t		     lock;
+};
+
+struct iscsi_iser_cmd_task {
+	struct iser_desc             desc;
+	struct iscsi_iser_conn	     *iser_conn;
+	int			     rdma_data_count;/* RDMA bytes           */
+	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_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 */
+
+	kmem_cache_t *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_mgmt_task *mtask);
+
+int iser_send_command(struct iscsi_conn      *conn,
+		      struct iscsi_cmd_task  *ctask);
+
+int iser_send_data_out(struct iscsi_conn     *conn,
+		       struct iscsi_cmd_task *ctask,
+		       struct iscsi_data          *hdr);
+
+void iscsi_iser_recv(struct iscsi_conn *conn,
+		     struct iscsi_hdr       *hdr,
+		     char                   *rx_data,
+		     int                    rx_data_len);
+
+int  iser_conn_init(struct iser_conn **ib_conn);
+
+void iser_conn_terminate(struct iser_conn *ib_conn);
+
+void iser_conn_release(struct iser_conn *ib_conn);
+
+void iser_rcv_completion(struct iser_desc *desc,
+			 unsigned long    dto_xfer_len);
+
+void iser_snd_completion(struct iser_desc *desc);
+
+void iser_ctask_rdma_init(struct iscsi_iser_cmd_task     *ctask);
+
+void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *ctask);
+
+void iser_dto_buffs_release(struct iser_dto *dto);
+
+int  iser_regd_buff_release(struct iser_regd_buf *regd_buf);
+
+void iser_reg_single(struct iser_device      *device,
+		     struct iser_regd_buf    *regd_buf,
+		     enum dma_data_direction direction);
+
+int  iser_start_rdma_unaligned_sg(struct iscsi_iser_cmd_task    *ctask,
+				  enum iser_data_dir            cmd_dir);
+
+void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *ctask,
+				     enum iser_data_dir         cmd_dir);
+
+int  iser_reg_rdma_mem(struct iscsi_iser_cmd_task *ctask,
+		       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_recv(struct iser_desc *rx_desc);
+int  iser_post_send(struct iser_desc *tx_desc);
+
+int iser_conn_state_comp(struct iser_conn *ib_conn,
+			 enum iser_ib_conn_state comp);
+#endif