1 /*
2  * iSER transport for the Open iSCSI Initiator & iSER transport internals
3  *
4  * Copyright (C) 2004 Dmitry Yusupov
5  * Copyright (C) 2004 Alex Aizman
6  * Copyright (C) 2005 Mike Christie
7  * based on code maintained by open-iscsi@googlegroups.com
8  *
9  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
10  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
11  *
12  * This software is available to you under a choice of one of two
13  * licenses.  You may choose to be licensed under the terms of the GNU
14  * General Public License (GPL) Version 2, available from the file
15  * COPYING in the main directory of this source tree, or the
16  * OpenIB.org BSD license below:
17  *
18  *     Redistribution and use in source and binary forms, with or
19  *     without modification, are permitted provided that the following
20  *     conditions are met:
21  *
22  *	- Redistributions of source code must retain the above
23  *	  copyright notice, this list of conditions and the following
24  *	  disclaimer.
25  *
26  *	- Redistributions in binary form must reproduce the above
27  *	  copyright notice, this list of conditions and the following
28  *	  disclaimer in the documentation and/or other materials
29  *	  provided with the distribution.
30  *
31  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
35  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
36  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
37  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
38  * SOFTWARE.
39  *
40  * $Id: iscsi_iser.h 7051 2006-05-10 12:29:11Z ogerlitz $
41  */
42 #ifndef __ISCSI_ISER_H__
43 #define __ISCSI_ISER_H__
44 
45 #include <linux/types.h>
46 #include <linux/net.h>
47 #include <scsi/libiscsi.h>
48 #include <scsi/scsi_transport_iscsi.h>
49 
50 #include <linux/wait.h>
51 #include <linux/sched.h>
52 #include <linux/list.h>
53 #include <linux/slab.h>
54 #include <linux/dma-mapping.h>
55 #include <linux/mutex.h>
56 #include <linux/mempool.h>
57 #include <linux/uio.h>
58 
59 #include <linux/socket.h>
60 #include <linux/in.h>
61 #include <linux/in6.h>
62 
63 #include <rdma/ib_verbs.h>
64 #include <rdma/ib_fmr_pool.h>
65 #include <rdma/rdma_cm.h>
66 
67 #define DRV_NAME	"iser"
68 #define PFX		DRV_NAME ": "
69 #define DRV_VER		"0.1"
70 #define DRV_DATE	"May 7th, 2006"
71 
72 #define iser_dbg(fmt, arg...)				\
73 	do {						\
74 		if (iser_debug_level > 0)		\
75 			printk(KERN_DEBUG PFX "%s:" fmt,\
76 				__func__ , ## arg);	\
77 	} while (0)
78 
79 #define iser_err(fmt, arg...)				\
80 	do {						\
81 		printk(KERN_ERR PFX "%s:" fmt,          \
82 		       __func__ , ## arg);		\
83 	} while (0)
84 
85 #define SHIFT_4K	12
86 #define SIZE_4K	(1UL << SHIFT_4K)
87 #define MASK_4K	(~(SIZE_4K-1))
88 
89 					/* support upto 512KB in one RDMA */
90 #define ISCSI_ISER_SG_TABLESIZE         (0x80000 >> SHIFT_4K)
91 #define ISCSI_ISER_MAX_LUN		256
92 #define ISCSI_ISER_MAX_CMD_LEN		16
93 
94 /* QP settings */
95 /* Maximal bounds on received asynchronous PDUs */
96 #define ISER_MAX_RX_MISC_PDUS		4 /* NOOP_IN(2) , ASYNC_EVENT(2)   */
97 
98 #define ISER_MAX_TX_MISC_PDUS		6 /* NOOP_OUT(2), TEXT(1),         *
99 					   * SCSI_TMFUNC(2), LOGOUT(1) */
100 
101 #define ISER_QP_MAX_RECV_DTOS		(ISCSI_XMIT_CMDS_MAX + \
102 					ISER_MAX_RX_MISC_PDUS    +  \
103 					ISER_MAX_TX_MISC_PDUS)
104 
105 /* the max TX (send) WR supported by the iSER QP is defined by                 *
106  * max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect   *
107  * to have at max for SCSI command. The tx posting & completion handling code  *
108  * supports -EAGAIN scheme where tx is suspended till the QP has room for more *
109  * send WR. D=8 comes from 64K/8K                                              */
110 
111 #define ISER_INFLIGHT_DATAOUTS		8
112 
113 #define ISER_QP_MAX_REQ_DTOS		(ISCSI_XMIT_CMDS_MAX *    \
114 					(1 + ISER_INFLIGHT_DATAOUTS) + \
115 					ISER_MAX_TX_MISC_PDUS        + \
116 					ISER_MAX_RX_MISC_PDUS)
117 
118 #define ISER_VER			0x10
119 #define ISER_WSV			0x08
120 #define ISER_RSV			0x04
121 
122 struct iser_hdr {
123 	u8      flags;
124 	u8      rsvd[3];
125 	__be32  write_stag; /* write rkey */
126 	__be64  write_va;
127 	__be32  read_stag;  /* read rkey */
128 	__be64  read_va;
129 } __attribute__((packed));
130 
131 
132 /* Length of an object name string */
133 #define ISER_OBJECT_NAME_SIZE		    64
134 
135 enum iser_ib_conn_state {
136 	ISER_CONN_INIT,		   /* descriptor allocd, no conn          */
137 	ISER_CONN_PENDING,	   /* in the process of being established */
138 	ISER_CONN_UP,		   /* up and running                      */
139 	ISER_CONN_TERMINATING,	   /* in the process of being terminated  */
140 	ISER_CONN_DOWN,		   /* shut down                           */
141 	ISER_CONN_STATES_NUM
142 };
143 
144 enum iser_task_status {
145 	ISER_TASK_STATUS_INIT = 0,
146 	ISER_TASK_STATUS_STARTED,
147 	ISER_TASK_STATUS_COMPLETED
148 };
149 
150 enum iser_data_dir {
151 	ISER_DIR_IN = 0,	   /* to initiator */
152 	ISER_DIR_OUT,		   /* from initiator */
153 	ISER_DIRS_NUM
154 };
155 
156 struct iser_data_buf {
157 	void               *buf;      /* pointer to the sg list               */
158 	unsigned int       size;      /* num entries of this sg               */
159 	unsigned long      data_len;  /* total data len                       */
160 	unsigned int       dma_nents; /* returned by dma_map_sg               */
161 	char       	   *copy_buf; /* allocated copy buf for SGs unaligned *
162 	                               * for rdma which are copied            */
163 	struct scatterlist sg_single; /* SG-ified clone of a non SG SC or     *
164 				       * unaligned SG                         */
165   };
166 
167 /* fwd declarations */
168 struct iser_device;
169 struct iscsi_iser_conn;
170 struct iscsi_iser_cmd_task;
171 
172 struct iser_mem_reg {
173 	u32  lkey;
174 	u32  rkey;
175 	u64  va;
176 	u64  len;
177 	void *mem_h;
178 	int  is_fmr;
179 };
180 
181 struct iser_regd_buf {
182 	struct iser_mem_reg     reg;        /* memory registration info        */
183 	void                    *virt_addr;
184 	struct iser_device      *device;    /* device->device for dma_unmap    */
185 	u64                     dma_addr;   /* if non zero, addr for dma_unmap */
186 	enum dma_data_direction direction;  /* direction for dma_unmap	       */
187 	unsigned int            data_size;
188 	atomic_t                ref_count;  /* refcount, freed when dec to 0   */
189 };
190 
191 #define MAX_REGD_BUF_VECTOR_LEN	2
192 
193 struct iser_dto {
194 	struct iscsi_iser_cmd_task *ctask;
195 	struct iser_conn *ib_conn;
196 	int                        notify_enable;
197 
198 	/* vector of registered buffers */
199 	unsigned int               regd_vector_len;
200 	struct iser_regd_buf       *regd[MAX_REGD_BUF_VECTOR_LEN];
201 
202 	/* offset into the registered buffer may be specified */
203 	unsigned int               offset[MAX_REGD_BUF_VECTOR_LEN];
204 
205 	/* a smaller size may be specified, if 0, then full size is used */
206 	unsigned int               used_sz[MAX_REGD_BUF_VECTOR_LEN];
207 };
208 
209 enum iser_desc_type {
210 	ISCSI_RX,
211 	ISCSI_TX_CONTROL ,
212 	ISCSI_TX_SCSI_COMMAND,
213 	ISCSI_TX_DATAOUT
214 };
215 
216 struct iser_desc {
217 	struct iser_hdr              iser_header;
218 	struct iscsi_hdr             iscsi_header;
219 	struct iser_regd_buf         hdr_regd_buf;
220 	void                         *data;         /* used by RX & TX_CONTROL */
221 	struct iser_regd_buf         data_regd_buf; /* used by RX & TX_CONTROL */
222 	enum   iser_desc_type        type;
223 	struct iser_dto              dto;
224 };
225 
226 struct iser_device {
227 	struct ib_device             *ib_device;
228 	struct ib_pd	             *pd;
229 	struct ib_cq	             *cq;
230 	struct ib_mr	             *mr;
231 	struct tasklet_struct	     cq_tasklet;
232 	struct list_head             ig_list; /* entry in ig devices list */
233 	int                          refcount;
234 };
235 
236 struct iser_conn {
237 	struct iscsi_iser_conn       *iser_conn; /* iser conn for upcalls  */
238 	enum iser_ib_conn_state	     state;	    /* rdma connection state   */
239 	spinlock_t		     lock;	    /* used for state changes  */
240 	struct iser_device           *device;       /* device context          */
241 	struct rdma_cm_id            *cma_id;       /* CMA ID		       */
242 	struct ib_qp	             *qp;           /* QP 		       */
243 	struct ib_fmr_pool           *fmr_pool;     /* pool of IB FMRs         */
244 	int                          disc_evt_flag; /* disconn event delivered */
245 	wait_queue_head_t	     wait;          /* waitq for conn/disconn  */
246 	atomic_t                     post_recv_buf_count; /* posted rx count   */
247 	atomic_t                     post_send_buf_count; /* posted tx count   */
248 	char 			     name[ISER_OBJECT_NAME_SIZE];
249 	struct iser_page_vec         *page_vec;     /* represents SG to fmr maps*
250 						     * maps serialized as tx is*/
251 	struct list_head	     conn_list;       /* entry in ig conn list */
252 };
253 
254 struct iscsi_iser_conn {
255 	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
256 	struct iser_conn             *ib_conn;   /* iSER IB conn      */
257 
258 	rwlock_t		     lock;
259 };
260 
261 struct iscsi_iser_cmd_task {
262 	struct iser_desc             desc;
263 	struct iscsi_iser_conn	     *iser_conn;
264 	enum iser_task_status 	     status;
265 	int                          command_sent;  /* set if command  sent  */
266 	int                          dir[ISER_DIRS_NUM];      /* set if dir use*/
267 	struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
268 	struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
269 	struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
270 };
271 
272 struct iser_page_vec {
273 	u64 *pages;
274 	int length;
275 	int offset;
276 	int data_size;
277 };
278 
279 struct iser_global {
280 	struct mutex      device_list_mutex;/*                   */
281 	struct list_head  device_list;	     /* all iSER devices */
282 	struct mutex      connlist_mutex;
283 	struct list_head  connlist;		/* all iSER IB connections */
284 
285 	struct kmem_cache *desc_cache;
286 };
287 
288 extern struct iser_global ig;
289 extern int iser_debug_level;
290 
291 /* allocate connection resources needed for rdma functionality */
292 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn);
293 
294 int iser_send_control(struct iscsi_conn      *conn,
295 		      struct iscsi_mgmt_task *mtask);
296 
297 int iser_send_command(struct iscsi_conn      *conn,
298 		      struct iscsi_cmd_task  *ctask);
299 
300 int iser_send_data_out(struct iscsi_conn     *conn,
301 		       struct iscsi_cmd_task *ctask,
302 		       struct iscsi_data          *hdr);
303 
304 void iscsi_iser_recv(struct iscsi_conn *conn,
305 		     struct iscsi_hdr       *hdr,
306 		     char                   *rx_data,
307 		     int                    rx_data_len);
308 
309 int  iser_conn_init(struct iser_conn **ib_conn);
310 
311 void iser_conn_terminate(struct iser_conn *ib_conn);
312 
313 void iser_conn_release(struct iser_conn *ib_conn);
314 
315 void iser_rcv_completion(struct iser_desc *desc,
316 			 unsigned long    dto_xfer_len);
317 
318 void iser_snd_completion(struct iser_desc *desc);
319 
320 void iser_ctask_rdma_init(struct iscsi_iser_cmd_task     *ctask);
321 
322 void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *ctask);
323 
324 void iser_dto_buffs_release(struct iser_dto *dto);
325 
326 int  iser_regd_buff_release(struct iser_regd_buf *regd_buf);
327 
328 void iser_reg_single(struct iser_device      *device,
329 		     struct iser_regd_buf    *regd_buf,
330 		     enum dma_data_direction direction);
331 
332 int  iser_start_rdma_unaligned_sg(struct iscsi_iser_cmd_task    *ctask,
333 				  enum iser_data_dir            cmd_dir);
334 
335 void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *ctask,
336 				     enum iser_data_dir         cmd_dir);
337 
338 int  iser_reg_rdma_mem(struct iscsi_iser_cmd_task *ctask,
339 		       enum   iser_data_dir        cmd_dir);
340 
341 int  iser_connect(struct iser_conn   *ib_conn,
342 		  struct sockaddr_in *src_addr,
343 		  struct sockaddr_in *dst_addr,
344 		  int                non_blocking);
345 
346 int  iser_reg_page_vec(struct iser_conn     *ib_conn,
347 		       struct iser_page_vec *page_vec,
348 		       struct iser_mem_reg  *mem_reg);
349 
350 void iser_unreg_mem(struct iser_mem_reg *mem_reg);
351 
352 int  iser_post_recv(struct iser_desc *rx_desc);
353 int  iser_post_send(struct iser_desc *tx_desc);
354 
355 int iser_conn_state_comp(struct iser_conn *ib_conn,
356 			 enum iser_ib_conn_state comp);
357 
358 int iser_dma_map_task_data(struct iscsi_iser_cmd_task *iser_ctask,
359 			    struct iser_data_buf       *data,
360 			    enum   iser_data_dir       iser_dir,
361 			    enum   dma_data_direction  dma_dir);
362 
363 void iser_dma_unmap_task_data(struct iscsi_iser_cmd_task *iser_ctask);
364 #endif
365