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 #ifndef __ISCSI_ISER_H__
41 #define __ISCSI_ISER_H__
42 
43 #include <linux/types.h>
44 #include <linux/net.h>
45 #include <scsi/libiscsi.h>
46 #include <scsi/scsi_transport_iscsi.h>
47 
48 #include <linux/wait.h>
49 #include <linux/sched.h>
50 #include <linux/list.h>
51 #include <linux/slab.h>
52 #include <linux/dma-mapping.h>
53 #include <linux/mutex.h>
54 #include <linux/mempool.h>
55 #include <linux/uio.h>
56 
57 #include <linux/socket.h>
58 #include <linux/in.h>
59 #include <linux/in6.h>
60 
61 #include <rdma/ib_verbs.h>
62 #include <rdma/ib_fmr_pool.h>
63 #include <rdma/rdma_cm.h>
64 
65 #define DRV_NAME	"iser"
66 #define PFX		DRV_NAME ": "
67 #define DRV_VER		"0.1"
68 #define DRV_DATE	"May 7th, 2006"
69 
70 #define iser_dbg(fmt, arg...)				\
71 	do {						\
72 		if (iser_debug_level > 1)		\
73 			printk(KERN_DEBUG PFX "%s:" fmt,\
74 				__func__ , ## arg);	\
75 	} while (0)
76 
77 #define iser_warn(fmt, arg...)				\
78 	do {						\
79 		if (iser_debug_level > 0)		\
80 			printk(KERN_DEBUG PFX "%s:" fmt,\
81 				__func__ , ## arg);	\
82 	} while (0)
83 
84 #define iser_err(fmt, arg...)				\
85 	do {						\
86 		printk(KERN_ERR PFX "%s:" fmt,          \
87 		       __func__ , ## arg);		\
88 	} while (0)
89 
90 #define SHIFT_4K	12
91 #define SIZE_4K	(1UL << SHIFT_4K)
92 #define MASK_4K	(~(SIZE_4K-1))
93 
94 					/* support up to 512KB in one RDMA */
95 #define ISCSI_ISER_SG_TABLESIZE         (0x80000 >> SHIFT_4K)
96 #define ISER_DEF_CMD_PER_LUN		128
97 
98 /* QP settings */
99 /* Maximal bounds on received asynchronous PDUs */
100 #define ISER_MAX_RX_MISC_PDUS		4 /* NOOP_IN(2) , ASYNC_EVENT(2)   */
101 
102 #define ISER_MAX_TX_MISC_PDUS		6 /* NOOP_OUT(2), TEXT(1),         *
103 					   * SCSI_TMFUNC(2), LOGOUT(1) */
104 
105 #define ISER_QP_MAX_RECV_DTOS		(ISCSI_DEF_XMIT_CMDS_MAX)
106 
107 #define ISER_MIN_POSTED_RX		(ISCSI_DEF_XMIT_CMDS_MAX >> 2)
108 
109 /* the max TX (send) WR supported by the iSER QP is defined by                 *
110  * max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect   *
111  * to have at max for SCSI command. The tx posting & completion handling code  *
112  * supports -EAGAIN scheme where tx is suspended till the QP has room for more *
113  * send WR. D=8 comes from 64K/8K                                              */
114 
115 #define ISER_INFLIGHT_DATAOUTS		8
116 
117 #define ISER_QP_MAX_REQ_DTOS		(ISCSI_DEF_XMIT_CMDS_MAX *    \
118 					(1 + ISER_INFLIGHT_DATAOUTS) + \
119 					ISER_MAX_TX_MISC_PDUS        + \
120 					ISER_MAX_RX_MISC_PDUS)
121 
122 #define ISER_VER			0x10
123 #define ISER_WSV			0x08
124 #define ISER_RSV			0x04
125 
126 struct iser_hdr {
127 	u8      flags;
128 	u8      rsvd[3];
129 	__be32  write_stag; /* write rkey */
130 	__be64  write_va;
131 	__be32  read_stag;  /* read rkey */
132 	__be64  read_va;
133 } __attribute__((packed));
134 
135 /* Constant PDU lengths calculations */
136 #define ISER_HEADERS_LEN  (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))
137 
138 #define ISER_RECV_DATA_SEG_LEN	128
139 #define ISER_RX_PAYLOAD_SIZE	(ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
140 #define ISER_RX_LOGIN_SIZE	(ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)
141 
142 /* Length of an object name string */
143 #define ISER_OBJECT_NAME_SIZE		    64
144 
145 enum iser_ib_conn_state {
146 	ISER_CONN_INIT,		   /* descriptor allocd, no conn          */
147 	ISER_CONN_PENDING,	   /* in the process of being established */
148 	ISER_CONN_UP,		   /* up and running                      */
149 	ISER_CONN_TERMINATING,	   /* in the process of being terminated  */
150 	ISER_CONN_DOWN,		   /* shut down                           */
151 	ISER_CONN_STATES_NUM
152 };
153 
154 enum iser_task_status {
155 	ISER_TASK_STATUS_INIT = 0,
156 	ISER_TASK_STATUS_STARTED,
157 	ISER_TASK_STATUS_COMPLETED
158 };
159 
160 enum iser_data_dir {
161 	ISER_DIR_IN = 0,	   /* to initiator */
162 	ISER_DIR_OUT,		   /* from initiator */
163 	ISER_DIRS_NUM
164 };
165 
166 struct iser_data_buf {
167 	void               *buf;      /* pointer to the sg list               */
168 	unsigned int       size;      /* num entries of this sg               */
169 	unsigned long      data_len;  /* total data len                       */
170 	unsigned int       dma_nents; /* returned by dma_map_sg               */
171 	char       	   *copy_buf; /* allocated copy buf for SGs unaligned *
172 	                               * for rdma which are copied            */
173 	struct scatterlist sg_single; /* SG-ified clone of a non SG SC or     *
174 				       * unaligned SG                         */
175   };
176 
177 /* fwd declarations */
178 struct iser_device;
179 struct iscsi_iser_conn;
180 struct iscsi_iser_task;
181 struct iscsi_endpoint;
182 
183 struct iser_mem_reg {
184 	u32  lkey;
185 	u32  rkey;
186 	u64  va;
187 	u64  len;
188 	void *mem_h;
189 	int  is_fmr;
190 };
191 
192 struct iser_regd_buf {
193 	struct iser_mem_reg     reg;        /* memory registration info        */
194 	void                    *virt_addr;
195 	struct iser_device      *device;    /* device->device for dma_unmap    */
196 	enum dma_data_direction direction;  /* direction for dma_unmap	       */
197 	unsigned int            data_size;
198 };
199 
200 enum iser_desc_type {
201 	ISCSI_TX_CONTROL ,
202 	ISCSI_TX_SCSI_COMMAND,
203 	ISCSI_TX_DATAOUT
204 };
205 
206 struct iser_tx_desc {
207 	struct iser_hdr              iser_header;
208 	struct iscsi_hdr             iscsi_header;
209 	enum   iser_desc_type        type;
210 	u64		             dma_addr;
211 	/* sg[0] points to iser/iscsi headers, sg[1] optionally points to either
212 	of immediate data, unsolicited data-out or control (login,text) */
213 	struct ib_sge		     tx_sg[2];
214 	int                          num_sge;
215 };
216 
217 #define ISER_RX_PAD_SIZE	(256 - (ISER_RX_PAYLOAD_SIZE + \
218 					sizeof(u64) + sizeof(struct ib_sge)))
219 struct iser_rx_desc {
220 	struct iser_hdr              iser_header;
221 	struct iscsi_hdr             iscsi_header;
222 	char		             data[ISER_RECV_DATA_SEG_LEN];
223 	u64		             dma_addr;
224 	struct ib_sge		     rx_sg;
225 	char		             pad[ISER_RX_PAD_SIZE];
226 } __attribute__((packed));
227 
228 struct iser_device {
229 	struct ib_device             *ib_device;
230 	struct ib_pd	             *pd;
231 	struct ib_cq	             *rx_cq;
232 	struct ib_cq	             *tx_cq;
233 	struct ib_mr	             *mr;
234 	struct tasklet_struct	     cq_tasklet;
235 	struct ib_event_handler      event_handler;
236 	struct list_head             ig_list; /* entry in ig devices list */
237 	int                          refcount;
238 };
239 
240 struct iser_conn {
241 	struct iscsi_iser_conn       *iser_conn; /* iser conn for upcalls  */
242 	struct iscsi_endpoint	     *ep;
243 	enum iser_ib_conn_state	     state;	    /* rdma connection state   */
244 	atomic_t		     refcount;
245 	spinlock_t		     lock;	    /* used for state changes  */
246 	struct iser_device           *device;       /* device context          */
247 	struct rdma_cm_id            *cma_id;       /* CMA ID		       */
248 	struct ib_qp	             *qp;           /* QP 		       */
249 	struct ib_fmr_pool           *fmr_pool;     /* pool of IB FMRs         */
250 	wait_queue_head_t	     wait;          /* waitq for conn/disconn  */
251 	int                          post_recv_buf_count; /* posted rx count  */
252 	atomic_t                     post_send_buf_count; /* posted tx count   */
253 	char 			     name[ISER_OBJECT_NAME_SIZE];
254 	struct iser_page_vec         *page_vec;     /* represents SG to fmr maps*
255 						     * maps serialized as tx is*/
256 	struct list_head	     conn_list;       /* entry in ig conn list */
257 
258 	char  			     *login_buf;
259 	u64 			     login_dma;
260 	unsigned int 		     rx_desc_head;
261 	struct iser_rx_desc	     *rx_descs;
262 	struct ib_recv_wr	     rx_wr[ISER_MIN_POSTED_RX];
263 };
264 
265 struct iscsi_iser_conn {
266 	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
267 	struct iser_conn             *ib_conn;   /* iSER IB conn      */
268 };
269 
270 struct iscsi_iser_task {
271 	struct iser_tx_desc          desc;
272 	struct iscsi_iser_conn	     *iser_conn;
273 	enum iser_task_status 	     status;
274 	int                          command_sent;  /* set if command  sent  */
275 	int                          dir[ISER_DIRS_NUM];      /* set if dir use*/
276 	struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
277 	struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
278 	struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
279 	int                          headers_initialized;
280 };
281 
282 struct iser_page_vec {
283 	u64 *pages;
284 	int length;
285 	int offset;
286 	int data_size;
287 };
288 
289 struct iser_global {
290 	struct mutex      device_list_mutex;/*                   */
291 	struct list_head  device_list;	     /* all iSER devices */
292 	struct mutex      connlist_mutex;
293 	struct list_head  connlist;		/* all iSER IB connections */
294 
295 	struct kmem_cache *desc_cache;
296 };
297 
298 extern struct iser_global ig;
299 extern int iser_debug_level;
300 
301 /* allocate connection resources needed for rdma functionality */
302 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn);
303 
304 int iser_send_control(struct iscsi_conn *conn,
305 		      struct iscsi_task *task);
306 
307 int iser_send_command(struct iscsi_conn *conn,
308 		      struct iscsi_task *task);
309 
310 int iser_send_data_out(struct iscsi_conn *conn,
311 		       struct iscsi_task *task,
312 		       struct iscsi_data *hdr);
313 
314 void iscsi_iser_recv(struct iscsi_conn *conn,
315 		     struct iscsi_hdr       *hdr,
316 		     char                   *rx_data,
317 		     int                    rx_data_len);
318 
319 void iser_conn_init(struct iser_conn *ib_conn);
320 
321 void iser_conn_get(struct iser_conn *ib_conn);
322 
323 int iser_conn_put(struct iser_conn *ib_conn, int destroy_cma_id_allowed);
324 
325 void iser_conn_terminate(struct iser_conn *ib_conn);
326 
327 void iser_rcv_completion(struct iser_rx_desc *desc,
328 			 unsigned long    dto_xfer_len,
329 			struct iser_conn *ib_conn);
330 
331 void iser_snd_completion(struct iser_tx_desc *desc, struct iser_conn *ib_conn);
332 
333 void iser_task_rdma_init(struct iscsi_iser_task *task);
334 
335 void iser_task_rdma_finalize(struct iscsi_iser_task *task);
336 
337 void iser_free_rx_descriptors(struct iser_conn *ib_conn);
338 
339 void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *task,
340 				     enum iser_data_dir         cmd_dir);
341 
342 int  iser_reg_rdma_mem(struct iscsi_iser_task *task,
343 		       enum   iser_data_dir        cmd_dir);
344 
345 int  iser_connect(struct iser_conn   *ib_conn,
346 		  struct sockaddr_in *src_addr,
347 		  struct sockaddr_in *dst_addr,
348 		  int                non_blocking);
349 
350 int  iser_reg_page_vec(struct iser_conn     *ib_conn,
351 		       struct iser_page_vec *page_vec,
352 		       struct iser_mem_reg  *mem_reg);
353 
354 void iser_unreg_mem(struct iser_mem_reg *mem_reg);
355 
356 int  iser_post_recvl(struct iser_conn *ib_conn);
357 int  iser_post_recvm(struct iser_conn *ib_conn, int count);
358 int  iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc);
359 
360 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
361 			    struct iser_data_buf       *data,
362 			    enum   iser_data_dir       iser_dir,
363 			    enum   dma_data_direction  dma_dir);
364 
365 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task);
366 int  iser_initialize_task_headers(struct iscsi_task *task,
367 			struct iser_tx_desc *tx_desc);
368 #endif
369