text: /*
   * Copyright (c) 2005 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 IB_SRP_H
  #define IB_SRP_H
  
  #include <linux/types.h>
  #include <linux/list.h>
  #include <linux/mutex.h>
  #include <linux/scatterlist.h>
  
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_cmnd.h>
  
  #include <rdma/ib_verbs.h>
  #include <rdma/ib_sa.h>
  #include <rdma/ib_cm.h>
  #include <rdma/ib_fmr_pool.h>
  
  enum {
  	SRP_PATH_REC_TIMEOUT_MS	= 1000,
  	SRP_ABORT_TIMEOUT_MS	= 5000,
  
  	SRP_PORT_REDIRECT	= 1,
  	SRP_DLID_REDIRECT	= 2,
  	SRP_STALE_CONN		= 3,
  
  	SRP_DEF_SG_TABLESIZE	= 12,
  
  	SRP_DEFAULT_QUEUE_SIZE	= 1 << 6,
  	SRP_RSP_SQ_SIZE		= 1,
  	SRP_TSK_MGMT_SQ_SIZE	= 1,
  	SRP_DEFAULT_CMD_SQ_SIZE = SRP_DEFAULT_QUEUE_SIZE - SRP_RSP_SQ_SIZE -
  				  SRP_TSK_MGMT_SQ_SIZE,
  
  	SRP_TAG_NO_REQ		= ~0U,
  	SRP_TAG_TSK_MGMT	= 1U << 31,
  
  	SRP_MAX_PAGES_PER_MR	= 512,
  };
  
  enum srp_target_state {
  	SRP_TARGET_SCANNING,
  	SRP_TARGET_LIVE,
  	SRP_TARGET_REMOVED,
  };
  
  enum srp_iu_type {
  	SRP_IU_CMD,
  	SRP_IU_TSK_MGMT,
  	SRP_IU_RSP,
  };
  
  /*
   * @mr_page_mask: HCA memory registration page mask.
   * @mr_page_size: HCA memory registration page size.
   * @mr_max_size: Maximum size in bytes of a single FMR / FR registration
   *   request.
   */
  struct srp_device {
  	struct list_head	dev_list;
  	struct ib_device       *dev;
  	struct ib_pd	       *pd;
  	u32			global_rkey;
  	u64			mr_page_mask;
  	int			mr_page_size;
  	int			mr_max_size;
  	int			max_pages_per_mr;
  	bool			has_fmr;
  	bool			has_fr;
  	bool			use_fmr;
  	bool			use_fast_reg;
  };
  
  struct srp_host {
  	struct srp_device      *srp_dev;
  	u8			port;
  	struct device		dev;
  	struct list_head	target_list;
  	spinlock_t		target_lock;
  	struct completion	released;
  	struct list_head	list;
  	struct mutex		add_target_mutex;
  };
  
  struct srp_request {
  	struct scsi_cmnd       *scmnd;
  	struct srp_iu	       *cmd;
  	union {
  		struct ib_pool_fmr **fmr_list;
  		struct srp_fr_desc **fr_list;
  	};
  	u64		       *map_page;
  	struct srp_direct_buf  *indirect_desc;
  	dma_addr_t		indirect_dma_addr;
  	short			nmdesc;
  	struct ib_cqe		reg_cqe;
  };
  
  /**
   * struct srp_rdma_ch
   * @comp_vector: Completion vector used by this RDMA channel.
   */
  struct srp_rdma_ch {
  	/* These are RW in the hot path, and commonly used together */
  	struct list_head	free_tx;
  	spinlock_t		lock;
  	s32			req_lim;
  
  	/* These are read-only in the hot path */
  	struct srp_target_port *target ____cacheline_aligned_in_smp;
  	struct ib_cq	       *send_cq;
  	struct ib_cq	       *recv_cq;
  	struct ib_qp	       *qp;
  	union {
  		struct ib_fmr_pool     *fmr_pool;
  		struct srp_fr_pool     *fr_pool;
  	};
  
  	/* Everything above this point is used in the hot path of
  	 * command processing. Try to keep them packed into cachelines.
  	 */
  
  	struct completion	done;
  	int			status;
  
  	struct sa_path_rec	path;
  	struct ib_sa_query     *path_query;
  	int			path_query_id;
  
  	struct ib_cm_id	       *cm_id;
  	struct srp_iu	      **tx_ring;
  	struct srp_iu	      **rx_ring;
  	struct srp_request     *req_ring;
  	int			max_ti_iu_len;
  	int			comp_vector;
  
  	u64			tsk_mgmt_tag;
  	struct completion	tsk_mgmt_done;
  	u8			tsk_mgmt_status;
  	bool			connected;
  };
  
  /**
   * struct srp_target_port
   * @comp_vector: Completion vector used by the first RDMA channel created for
   *   this target port.
   */
  struct srp_target_port {
  	/* read and written in the hot path */
  	spinlock_t		lock;
  
  	/* read only in the hot path */
  	u32			global_rkey;
  	struct srp_rdma_ch	*ch;
  	u32			ch_count;
  	u32			lkey;
  	enum srp_target_state	state;
  	unsigned int		max_iu_len;
  	unsigned int		cmd_sg_cnt;
  	unsigned int		indirect_size;
  	bool			allow_ext_sg;
  
  	/* other member variables */
  	union ib_gid		sgid;
  	__be64			id_ext;
  	__be64			ioc_guid;
  	__be64			service_id;
  	__be64			initiator_ext;
  	u16			io_class;
  	struct srp_host	       *srp_host;
  	struct Scsi_Host       *scsi_host;
  	struct srp_rport       *rport;
  	char			target_name[32];
  	unsigned int		scsi_id;
  	unsigned int		sg_tablesize;
  	int			mr_pool_size;
  	int			mr_per_cmd;
  	int			queue_size;
  	int			req_ring_size;
  	int			comp_vector;
  	int			tl_retry_count;
  
  	union ib_gid		orig_dgid;
  	__be16			pkey;
  
  	u32			rq_tmo_jiffies;
  
  	int			zero_req_lim;
  
  	struct work_struct	tl_err_work;
  	struct work_struct	remove_work;
  
  	struct list_head	list;
  	bool			qp_in_error;
  };
  
  struct srp_iu {
  	struct list_head	list;
  	u64			dma;
  	void		       *buf;
  	size_t			size;
  	enum dma_data_direction	direction;
  	struct ib_cqe		cqe;
  };
  
  /**
   * struct srp_fr_desc - fast registration work request arguments
   * @entry: Entry in srp_fr_pool.free_list.
   * @mr:    Memory region.
   * @frpl:  Fast registration page list.
   */
  struct srp_fr_desc {
  	struct list_head		entry;
  	struct ib_mr			*mr;
  };
  
  /**
   * struct srp_fr_pool - pool of fast registration descriptors
   *
   * An entry is available for allocation if and only if it occurs in @free_list.
   *
   * @size:      Number of descriptors in this pool.
   * @max_page_list_len: Maximum fast registration work request page list length.
   * @lock:      Protects free_list.
   * @free_list: List of free descriptors.
   * @desc:      Fast registration descriptor pool.
   */
  struct srp_fr_pool {
  	int			size;
  	int			max_page_list_len;
  	spinlock_t		lock;
  	struct list_head	free_list;
  	struct srp_fr_desc	desc[0];
  };
  
  /**
   * struct srp_map_state - per-request DMA memory mapping state
   * @desc:	    Pointer to the element of the SRP buffer descriptor array
   *		    that is being filled in.
   * @pages:	    Array with DMA addresses of pages being considered for
   *		    memory registration.
   * @base_dma_addr:  DMA address of the first page that has not yet been mapped.
   * @dma_len:	    Number of bytes that will be registered with the next
   *		    FMR or FR memory registration call.
   * @total_len:	    Total number of bytes in the sg-list being mapped.
   * @npages:	    Number of page addresses in the pages[] array.
   * @nmdesc:	    Number of FMR or FR memory descriptors used for mapping.
   * @ndesc:	    Number of SRP buffer descriptors that have been filled in.
   */
  struct srp_map_state {
  	union {
  		struct {
  			struct ib_pool_fmr **next;
  			struct ib_pool_fmr **end;
  		} fmr;
  		struct {
  			struct srp_fr_desc **next;
  			struct srp_fr_desc **end;
  		} fr;
  		struct {
  			void		   **next;
  			void		   **end;
  		} gen;
  	};
  	struct srp_direct_buf  *desc;
  	union {
  		u64			*pages;
  		struct scatterlist	*sg;
  	};
  	dma_addr_t		base_dma_addr;
  	u32			dma_len;
  	u32			total_len;
  	unsigned int		npages;
  	unsigned int		nmdesc;
  	unsigned int		ndesc;
  };
  
  #endif /* IB_SRP_H */
  