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  * Copyright (c) 2013 Mellanox Technologies. All rights reserved.
12  *
13  * This software is available to you under a choice of one of two
14  * licenses.  You may choose to be licensed under the terms of the GNU
15  * General Public License (GPL) Version 2, available from the file
16  * COPYING in the main directory of this source tree, or the
17  * OpenIB.org BSD license below:
18  *
19  *     Redistribution and use in source and binary forms, with or
20  *     without modification, are permitted provided that the following
21  *     conditions are met:
22  *
23  *	- Redistributions of source code must retain the above
24  *	  copyright notice, this list of conditions and the following
25  *	  disclaimer.
26  *
27  *	- Redistributions in binary form must reproduce the above
28  *	  copyright notice, this list of conditions and the following
29  *	  disclaimer in the documentation and/or other materials
30  *	  provided with the distribution.
31  *
32  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
33  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
34  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
35  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
36  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
37  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
38  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
39  * SOFTWARE.
40  */
41 #ifndef __ISCSI_ISER_H__
42 #define __ISCSI_ISER_H__
43 
44 #include <linux/types.h>
45 #include <linux/net.h>
46 #include <linux/printk.h>
47 #include <scsi/libiscsi.h>
48 #include <scsi/scsi_transport_iscsi.h>
49 
50 #include <linux/interrupt.h>
51 #include <linux/wait.h>
52 #include <linux/sched.h>
53 #include <linux/list.h>
54 #include <linux/slab.h>
55 #include <linux/dma-mapping.h>
56 #include <linux/mutex.h>
57 #include <linux/mempool.h>
58 #include <linux/uio.h>
59 
60 #include <linux/socket.h>
61 #include <linux/in.h>
62 #include <linux/in6.h>
63 
64 #include <rdma/ib_verbs.h>
65 #include <rdma/ib_fmr_pool.h>
66 #include <rdma/rdma_cm.h>
67 
68 #define DRV_NAME	"iser"
69 #define PFX		DRV_NAME ": "
70 #define DRV_VER		"1.1"
71 
72 #define iser_dbg(fmt, arg...)				\
73 	do {						\
74 		if (iser_debug_level > 2)		\
75 			printk(KERN_DEBUG PFX "%s:" fmt,\
76 				__func__ , ## arg);	\
77 	} while (0)
78 
79 #define iser_warn(fmt, arg...)				\
80 	do {						\
81 		if (iser_debug_level > 0)		\
82 			pr_warn(PFX "%s:" fmt,          \
83 				__func__ , ## arg);	\
84 	} while (0)
85 
86 #define iser_info(fmt, arg...)				\
87 	do {						\
88 		if (iser_debug_level > 1)		\
89 			pr_info(PFX "%s:" fmt,          \
90 				__func__ , ## arg);	\
91 	} while (0)
92 
93 #define iser_err(fmt, arg...)				\
94 	do {						\
95 		printk(KERN_ERR PFX "%s:" fmt,          \
96 		       __func__ , ## arg);		\
97 	} while (0)
98 
99 #define SHIFT_4K	12
100 #define SIZE_4K	(1ULL << SHIFT_4K)
101 #define MASK_4K	(~(SIZE_4K-1))
102 
103 					/* support up to 512KB in one RDMA */
104 #define ISCSI_ISER_SG_TABLESIZE         (0x80000 >> SHIFT_4K)
105 #define ISER_DEF_XMIT_CMDS_DEFAULT		512
106 #if ISCSI_DEF_XMIT_CMDS_MAX > ISER_DEF_XMIT_CMDS_DEFAULT
107 	#define ISER_DEF_XMIT_CMDS_MAX		ISCSI_DEF_XMIT_CMDS_MAX
108 #else
109 	#define ISER_DEF_XMIT_CMDS_MAX		ISER_DEF_XMIT_CMDS_DEFAULT
110 #endif
111 #define ISER_DEF_CMD_PER_LUN		ISER_DEF_XMIT_CMDS_MAX
112 
113 /* QP settings */
114 /* Maximal bounds on received asynchronous PDUs */
115 #define ISER_MAX_RX_MISC_PDUS		4 /* NOOP_IN(2) , ASYNC_EVENT(2)   */
116 
117 #define ISER_MAX_TX_MISC_PDUS		6 /* NOOP_OUT(2), TEXT(1),         *
118 					   * SCSI_TMFUNC(2), LOGOUT(1) */
119 
120 #define ISER_QP_MAX_RECV_DTOS		(ISER_DEF_XMIT_CMDS_MAX)
121 
122 #define ISER_MIN_POSTED_RX		(ISER_DEF_XMIT_CMDS_MAX >> 2)
123 
124 /* the max TX (send) WR supported by the iSER QP is defined by                 *
125  * max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect   *
126  * to have at max for SCSI command. The tx posting & completion handling code  *
127  * supports -EAGAIN scheme where tx is suspended till the QP has room for more *
128  * send WR. D=8 comes from 64K/8K                                              */
129 
130 #define ISER_INFLIGHT_DATAOUTS		8
131 
132 #define ISER_QP_MAX_REQ_DTOS		(ISER_DEF_XMIT_CMDS_MAX *    \
133 					(1 + ISER_INFLIGHT_DATAOUTS) + \
134 					ISER_MAX_TX_MISC_PDUS        + \
135 					ISER_MAX_RX_MISC_PDUS)
136 
137 #define ISER_VER			0x10
138 #define ISER_WSV			0x08
139 #define ISER_RSV			0x04
140 
141 struct iser_hdr {
142 	u8      flags;
143 	u8      rsvd[3];
144 	__be32  write_stag; /* write rkey */
145 	__be64  write_va;
146 	__be32  read_stag;  /* read rkey */
147 	__be64  read_va;
148 } __attribute__((packed));
149 
150 
151 #define ISER_ZBVA_NOT_SUPPORTED		0x80
152 #define ISER_SEND_W_INV_NOT_SUPPORTED	0x40
153 
154 struct iser_cm_hdr {
155 	u8      flags;
156 	u8      rsvd[3];
157 } __packed;
158 
159 /* Constant PDU lengths calculations */
160 #define ISER_HEADERS_LEN  (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))
161 
162 #define ISER_RECV_DATA_SEG_LEN	128
163 #define ISER_RX_PAYLOAD_SIZE	(ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
164 #define ISER_RX_LOGIN_SIZE	(ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)
165 
166 /* Length of an object name string */
167 #define ISER_OBJECT_NAME_SIZE		    64
168 
169 enum iser_ib_conn_state {
170 	ISER_CONN_INIT,		   /* descriptor allocd, no conn          */
171 	ISER_CONN_PENDING,	   /* in the process of being established */
172 	ISER_CONN_UP,		   /* up and running                      */
173 	ISER_CONN_TERMINATING,	   /* in the process of being terminated  */
174 	ISER_CONN_DOWN,		   /* shut down                           */
175 	ISER_CONN_STATES_NUM
176 };
177 
178 enum iser_task_status {
179 	ISER_TASK_STATUS_INIT = 0,
180 	ISER_TASK_STATUS_STARTED,
181 	ISER_TASK_STATUS_COMPLETED
182 };
183 
184 enum iser_data_dir {
185 	ISER_DIR_IN = 0,	   /* to initiator */
186 	ISER_DIR_OUT,		   /* from initiator */
187 	ISER_DIRS_NUM
188 };
189 
190 struct iser_data_buf {
191 	void               *buf;      /* pointer to the sg list               */
192 	unsigned int       size;      /* num entries of this sg               */
193 	unsigned long      data_len;  /* total data len                       */
194 	unsigned int       dma_nents; /* returned by dma_map_sg               */
195 	char       	   *copy_buf; /* allocated copy buf for SGs unaligned *
196 	                               * for rdma which are copied            */
197 	struct scatterlist sg_single; /* SG-ified clone of a non SG SC or     *
198 				       * unaligned SG                         */
199   };
200 
201 /* fwd declarations */
202 struct iser_device;
203 struct iser_cq_desc;
204 struct iscsi_iser_conn;
205 struct iscsi_iser_task;
206 struct iscsi_endpoint;
207 
208 struct iser_mem_reg {
209 	u32  lkey;
210 	u32  rkey;
211 	u64  va;
212 	u64  len;
213 	void *mem_h;
214 	int  is_mr;
215 };
216 
217 struct iser_regd_buf {
218 	struct iser_mem_reg     reg;        /* memory registration info        */
219 	void                    *virt_addr;
220 	struct iser_device      *device;    /* device->device for dma_unmap    */
221 	enum dma_data_direction direction;  /* direction for dma_unmap	       */
222 	unsigned int            data_size;
223 };
224 
225 enum iser_desc_type {
226 	ISCSI_TX_CONTROL ,
227 	ISCSI_TX_SCSI_COMMAND,
228 	ISCSI_TX_DATAOUT
229 };
230 
231 struct iser_tx_desc {
232 	struct iser_hdr              iser_header;
233 	struct iscsi_hdr             iscsi_header;
234 	enum   iser_desc_type        type;
235 	u64		             dma_addr;
236 	/* sg[0] points to iser/iscsi headers, sg[1] optionally points to either
237 	of immediate data, unsolicited data-out or control (login,text) */
238 	struct ib_sge		     tx_sg[2];
239 	int                          num_sge;
240 };
241 
242 #define ISER_RX_PAD_SIZE	(256 - (ISER_RX_PAYLOAD_SIZE + \
243 					sizeof(u64) + sizeof(struct ib_sge)))
244 struct iser_rx_desc {
245 	struct iser_hdr              iser_header;
246 	struct iscsi_hdr             iscsi_header;
247 	char		             data[ISER_RECV_DATA_SEG_LEN];
248 	u64		             dma_addr;
249 	struct ib_sge		     rx_sg;
250 	char		             pad[ISER_RX_PAD_SIZE];
251 } __attribute__((packed));
252 
253 #define ISER_MAX_CQ 4
254 
255 struct iser_conn;
256 struct iscsi_iser_task;
257 
258 struct iser_device {
259 	struct ib_device             *ib_device;
260 	struct ib_pd	             *pd;
261 	struct ib_cq	             *rx_cq[ISER_MAX_CQ];
262 	struct ib_cq	             *tx_cq[ISER_MAX_CQ];
263 	struct ib_mr	             *mr;
264 	struct tasklet_struct	     cq_tasklet[ISER_MAX_CQ];
265 	struct ib_event_handler      event_handler;
266 	struct list_head             ig_list; /* entry in ig devices list */
267 	int                          refcount;
268 	int                          cq_active_qps[ISER_MAX_CQ];
269 	int			     cqs_used;
270 	struct iser_cq_desc	     *cq_desc;
271 	int                          (*iser_alloc_rdma_reg_res)(struct iser_conn *ib_conn,
272 								unsigned cmds_max);
273 	void                         (*iser_free_rdma_reg_res)(struct iser_conn *ib_conn);
274 	int                          (*iser_reg_rdma_mem)(struct iscsi_iser_task *iser_task,
275 							  enum iser_data_dir cmd_dir);
276 	void                         (*iser_unreg_rdma_mem)(struct iscsi_iser_task *iser_task,
277 							    enum iser_data_dir cmd_dir);
278 };
279 
280 struct fast_reg_descriptor {
281 	struct list_head		  list;
282 	/* For fast registration - FRWR */
283 	struct ib_mr			 *data_mr;
284 	struct ib_fast_reg_page_list     *data_frpl;
285 	/* Valid for fast registration flag */
286 	bool				  valid;
287 };
288 
289 struct iser_conn {
290 	struct iscsi_iser_conn       *iser_conn; /* iser conn for upcalls  */
291 	struct iscsi_endpoint	     *ep;
292 	enum iser_ib_conn_state	     state;	    /* rdma connection state   */
293 	atomic_t		     refcount;
294 	spinlock_t		     lock;	    /* used for state changes  */
295 	struct iser_device           *device;       /* device context          */
296 	struct rdma_cm_id            *cma_id;       /* CMA ID		       */
297 	struct ib_qp	             *qp;           /* QP 		       */
298 	wait_queue_head_t	     wait;          /* waitq for conn/disconn  */
299 	unsigned		     qp_max_recv_dtos; /* num of rx buffers */
300 	unsigned		     qp_max_recv_dtos_mask; /* above minus 1 */
301 	unsigned		     min_posted_rx; /* qp_max_recv_dtos >> 2 */
302 	int                          post_recv_buf_count; /* posted rx count  */
303 	atomic_t                     post_send_buf_count; /* posted tx count   */
304 	char 			     name[ISER_OBJECT_NAME_SIZE];
305 	struct list_head	     conn_list;       /* entry in ig conn list */
306 
307 	char  			     *login_buf;
308 	char			     *login_req_buf, *login_resp_buf;
309 	u64			     login_req_dma, login_resp_dma;
310 	unsigned int 		     rx_desc_head;
311 	struct iser_rx_desc	     *rx_descs;
312 	struct ib_recv_wr	     rx_wr[ISER_MIN_POSTED_RX];
313 	union {
314 		struct {
315 			struct ib_fmr_pool      *pool;	   /* pool of IB FMRs         */
316 			struct iser_page_vec	*page_vec; /* represents SG to fmr maps*
317 							    * maps serialized as tx is*/
318 		} fmr;
319 		struct {
320 			struct list_head	pool;
321 			int			pool_size;
322 		} frwr;
323 	} fastreg;
324 };
325 
326 struct iscsi_iser_conn {
327 	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
328 	struct iser_conn             *ib_conn;   /* iSER IB conn      */
329 };
330 
331 struct iscsi_iser_task {
332 	struct iser_tx_desc          desc;
333 	struct iscsi_iser_conn	     *iser_conn;
334 	enum iser_task_status 	     status;
335 	int                          command_sent;  /* set if command  sent  */
336 	int                          dir[ISER_DIRS_NUM];      /* set if dir use*/
337 	struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
338 	struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
339 	struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
340 };
341 
342 struct iser_page_vec {
343 	u64 *pages;
344 	int length;
345 	int offset;
346 	int data_size;
347 };
348 
349 struct iser_cq_desc {
350 	struct iser_device           *device;
351 	int                          cq_index;
352 };
353 
354 struct iser_global {
355 	struct mutex      device_list_mutex;/*                   */
356 	struct list_head  device_list;	     /* all iSER devices */
357 	struct mutex      connlist_mutex;
358 	struct list_head  connlist;		/* all iSER IB connections */
359 
360 	struct kmem_cache *desc_cache;
361 };
362 
363 extern struct iser_global ig;
364 extern int iser_debug_level;
365 
366 /* allocate connection resources needed for rdma functionality */
367 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn);
368 
369 int iser_send_control(struct iscsi_conn *conn,
370 		      struct iscsi_task *task);
371 
372 int iser_send_command(struct iscsi_conn *conn,
373 		      struct iscsi_task *task);
374 
375 int iser_send_data_out(struct iscsi_conn *conn,
376 		       struct iscsi_task *task,
377 		       struct iscsi_data *hdr);
378 
379 void iscsi_iser_recv(struct iscsi_conn *conn,
380 		     struct iscsi_hdr       *hdr,
381 		     char                   *rx_data,
382 		     int                    rx_data_len);
383 
384 void iser_conn_init(struct iser_conn *ib_conn);
385 
386 void iser_conn_get(struct iser_conn *ib_conn);
387 
388 int iser_conn_put(struct iser_conn *ib_conn, int destroy_cma_id_allowed);
389 
390 void iser_conn_terminate(struct iser_conn *ib_conn);
391 
392 void iser_rcv_completion(struct iser_rx_desc *desc,
393 			 unsigned long    dto_xfer_len,
394 			struct iser_conn *ib_conn);
395 
396 void iser_snd_completion(struct iser_tx_desc *desc, struct iser_conn *ib_conn);
397 
398 void iser_task_rdma_init(struct iscsi_iser_task *task);
399 
400 void iser_task_rdma_finalize(struct iscsi_iser_task *task);
401 
402 void iser_free_rx_descriptors(struct iser_conn *ib_conn);
403 
404 void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *task,
405 				     enum iser_data_dir         cmd_dir);
406 
407 int  iser_reg_rdma_mem_fmr(struct iscsi_iser_task *task,
408 			   enum iser_data_dir cmd_dir);
409 int  iser_reg_rdma_mem_frwr(struct iscsi_iser_task *task,
410 			    enum iser_data_dir cmd_dir);
411 
412 int  iser_connect(struct iser_conn   *ib_conn,
413 		  struct sockaddr_in *src_addr,
414 		  struct sockaddr_in *dst_addr,
415 		  int                non_blocking);
416 
417 int  iser_reg_page_vec(struct iser_conn     *ib_conn,
418 		       struct iser_page_vec *page_vec,
419 		       struct iser_mem_reg  *mem_reg);
420 
421 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
422 			enum iser_data_dir cmd_dir);
423 void iser_unreg_mem_frwr(struct iscsi_iser_task *iser_task,
424 			 enum iser_data_dir cmd_dir);
425 
426 int  iser_post_recvl(struct iser_conn *ib_conn);
427 int  iser_post_recvm(struct iser_conn *ib_conn, int count);
428 int  iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc);
429 
430 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
431 			    struct iser_data_buf       *data,
432 			    enum   iser_data_dir       iser_dir,
433 			    enum   dma_data_direction  dma_dir);
434 
435 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task);
436 int  iser_initialize_task_headers(struct iscsi_task *task,
437 			struct iser_tx_desc *tx_desc);
438 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn, struct iscsi_session *session);
439 int iser_create_fmr_pool(struct iser_conn *ib_conn, unsigned cmds_max);
440 void iser_free_fmr_pool(struct iser_conn *ib_conn);
441 int iser_create_frwr_pool(struct iser_conn *ib_conn, unsigned cmds_max);
442 void iser_free_frwr_pool(struct iser_conn *ib_conn);
443 #endif
444