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 > 1)		\
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 > 0)		\
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_CMD_PER_LUN		ISCSI_DEF_XMIT_CMDS_MAX
106 
107 /* QP settings */
108 /* Maximal bounds on received asynchronous PDUs */
109 #define ISER_MAX_RX_MISC_PDUS		4 /* NOOP_IN(2) , ASYNC_EVENT(2)   */
110 
111 #define ISER_MAX_TX_MISC_PDUS		6 /* NOOP_OUT(2), TEXT(1),         *
112 					   * SCSI_TMFUNC(2), LOGOUT(1) */
113 
114 #define ISER_QP_MAX_RECV_DTOS		(ISCSI_DEF_XMIT_CMDS_MAX)
115 
116 #define ISER_MIN_POSTED_RX		(ISCSI_DEF_XMIT_CMDS_MAX >> 2)
117 
118 /* the max TX (send) WR supported by the iSER QP is defined by                 *
119  * max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect   *
120  * to have at max for SCSI command. The tx posting & completion handling code  *
121  * supports -EAGAIN scheme where tx is suspended till the QP has room for more *
122  * send WR. D=8 comes from 64K/8K                                              */
123 
124 #define ISER_INFLIGHT_DATAOUTS		8
125 
126 #define ISER_QP_MAX_REQ_DTOS		(ISCSI_DEF_XMIT_CMDS_MAX *    \
127 					(1 + ISER_INFLIGHT_DATAOUTS) + \
128 					ISER_MAX_TX_MISC_PDUS        + \
129 					ISER_MAX_RX_MISC_PDUS)
130 
131 #define ISER_VER			0x10
132 #define ISER_WSV			0x08
133 #define ISER_RSV			0x04
134 
135 struct iser_hdr {
136 	u8      flags;
137 	u8      rsvd[3];
138 	__be32  write_stag; /* write rkey */
139 	__be64  write_va;
140 	__be32  read_stag;  /* read rkey */
141 	__be64  read_va;
142 } __attribute__((packed));
143 
144 
145 #define ISER_ZBVA_NOT_SUPPORTED		0x80
146 #define ISER_SEND_W_INV_NOT_SUPPORTED	0x40
147 
148 struct iser_cm_hdr {
149 	u8      flags;
150 	u8      rsvd[3];
151 } __packed;
152 
153 /* Constant PDU lengths calculations */
154 #define ISER_HEADERS_LEN  (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))
155 
156 #define ISER_RECV_DATA_SEG_LEN	128
157 #define ISER_RX_PAYLOAD_SIZE	(ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
158 #define ISER_RX_LOGIN_SIZE	(ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)
159 
160 /* Length of an object name string */
161 #define ISER_OBJECT_NAME_SIZE		    64
162 
163 enum iser_ib_conn_state {
164 	ISER_CONN_INIT,		   /* descriptor allocd, no conn          */
165 	ISER_CONN_PENDING,	   /* in the process of being established */
166 	ISER_CONN_UP,		   /* up and running                      */
167 	ISER_CONN_TERMINATING,	   /* in the process of being terminated  */
168 	ISER_CONN_DOWN,		   /* shut down                           */
169 	ISER_CONN_STATES_NUM
170 };
171 
172 enum iser_task_status {
173 	ISER_TASK_STATUS_INIT = 0,
174 	ISER_TASK_STATUS_STARTED,
175 	ISER_TASK_STATUS_COMPLETED
176 };
177 
178 enum iser_data_dir {
179 	ISER_DIR_IN = 0,	   /* to initiator */
180 	ISER_DIR_OUT,		   /* from initiator */
181 	ISER_DIRS_NUM
182 };
183 
184 struct iser_data_buf {
185 	void               *buf;      /* pointer to the sg list               */
186 	unsigned int       size;      /* num entries of this sg               */
187 	unsigned long      data_len;  /* total data len                       */
188 	unsigned int       dma_nents; /* returned by dma_map_sg               */
189 	char       	   *copy_buf; /* allocated copy buf for SGs unaligned *
190 	                               * for rdma which are copied            */
191 	struct scatterlist sg_single; /* SG-ified clone of a non SG SC or     *
192 				       * unaligned SG                         */
193   };
194 
195 /* fwd declarations */
196 struct iser_device;
197 struct iser_cq_desc;
198 struct iscsi_iser_conn;
199 struct iscsi_iser_task;
200 struct iscsi_endpoint;
201 
202 struct iser_mem_reg {
203 	u32  lkey;
204 	u32  rkey;
205 	u64  va;
206 	u64  len;
207 	void *mem_h;
208 	int  is_fmr;
209 };
210 
211 struct iser_regd_buf {
212 	struct iser_mem_reg     reg;        /* memory registration info        */
213 	void                    *virt_addr;
214 	struct iser_device      *device;    /* device->device for dma_unmap    */
215 	enum dma_data_direction direction;  /* direction for dma_unmap	       */
216 	unsigned int            data_size;
217 };
218 
219 enum iser_desc_type {
220 	ISCSI_TX_CONTROL ,
221 	ISCSI_TX_SCSI_COMMAND,
222 	ISCSI_TX_DATAOUT
223 };
224 
225 struct iser_tx_desc {
226 	struct iser_hdr              iser_header;
227 	struct iscsi_hdr             iscsi_header;
228 	enum   iser_desc_type        type;
229 	u64		             dma_addr;
230 	/* sg[0] points to iser/iscsi headers, sg[1] optionally points to either
231 	of immediate data, unsolicited data-out or control (login,text) */
232 	struct ib_sge		     tx_sg[2];
233 	int                          num_sge;
234 };
235 
236 #define ISER_RX_PAD_SIZE	(256 - (ISER_RX_PAYLOAD_SIZE + \
237 					sizeof(u64) + sizeof(struct ib_sge)))
238 struct iser_rx_desc {
239 	struct iser_hdr              iser_header;
240 	struct iscsi_hdr             iscsi_header;
241 	char		             data[ISER_RECV_DATA_SEG_LEN];
242 	u64		             dma_addr;
243 	struct ib_sge		     rx_sg;
244 	char		             pad[ISER_RX_PAD_SIZE];
245 } __attribute__((packed));
246 
247 #define ISER_MAX_CQ 4
248 
249 struct iser_device {
250 	struct ib_device             *ib_device;
251 	struct ib_pd	             *pd;
252 	struct ib_cq	             *rx_cq[ISER_MAX_CQ];
253 	struct ib_cq	             *tx_cq[ISER_MAX_CQ];
254 	struct ib_mr	             *mr;
255 	struct tasklet_struct	     cq_tasklet[ISER_MAX_CQ];
256 	struct ib_event_handler      event_handler;
257 	struct list_head             ig_list; /* entry in ig devices list */
258 	int                          refcount;
259 	int                          cq_active_qps[ISER_MAX_CQ];
260 	int			     cqs_used;
261 	struct iser_cq_desc	     *cq_desc;
262 };
263 
264 struct iser_conn {
265 	struct iscsi_iser_conn       *iser_conn; /* iser conn for upcalls  */
266 	struct iscsi_endpoint	     *ep;
267 	enum iser_ib_conn_state	     state;	    /* rdma connection state   */
268 	atomic_t		     refcount;
269 	spinlock_t		     lock;	    /* used for state changes  */
270 	struct iser_device           *device;       /* device context          */
271 	struct rdma_cm_id            *cma_id;       /* CMA ID		       */
272 	struct ib_qp	             *qp;           /* QP 		       */
273 	struct ib_fmr_pool           *fmr_pool;     /* pool of IB FMRs         */
274 	wait_queue_head_t	     wait;          /* waitq for conn/disconn  */
275 	int                          post_recv_buf_count; /* posted rx count  */
276 	atomic_t                     post_send_buf_count; /* posted tx count   */
277 	char 			     name[ISER_OBJECT_NAME_SIZE];
278 	struct iser_page_vec         *page_vec;     /* represents SG to fmr maps*
279 						     * maps serialized as tx is*/
280 	struct list_head	     conn_list;       /* entry in ig conn list */
281 
282 	char  			     *login_buf;
283 	char			     *login_req_buf, *login_resp_buf;
284 	u64			     login_req_dma, login_resp_dma;
285 	unsigned int 		     rx_desc_head;
286 	struct iser_rx_desc	     *rx_descs;
287 	struct ib_recv_wr	     rx_wr[ISER_MIN_POSTED_RX];
288 };
289 
290 struct iscsi_iser_conn {
291 	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
292 	struct iser_conn             *ib_conn;   /* iSER IB conn      */
293 };
294 
295 struct iscsi_iser_task {
296 	struct iser_tx_desc          desc;
297 	struct iscsi_iser_conn	     *iser_conn;
298 	enum iser_task_status 	     status;
299 	int                          command_sent;  /* set if command  sent  */
300 	int                          dir[ISER_DIRS_NUM];      /* set if dir use*/
301 	struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
302 	struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
303 	struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
304 };
305 
306 struct iser_page_vec {
307 	u64 *pages;
308 	int length;
309 	int offset;
310 	int data_size;
311 };
312 
313 struct iser_cq_desc {
314 	struct iser_device           *device;
315 	int                          cq_index;
316 };
317 
318 struct iser_global {
319 	struct mutex      device_list_mutex;/*                   */
320 	struct list_head  device_list;	     /* all iSER devices */
321 	struct mutex      connlist_mutex;
322 	struct list_head  connlist;		/* all iSER IB connections */
323 
324 	struct kmem_cache *desc_cache;
325 };
326 
327 extern struct iser_global ig;
328 extern int iser_debug_level;
329 
330 /* allocate connection resources needed for rdma functionality */
331 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn);
332 
333 int iser_send_control(struct iscsi_conn *conn,
334 		      struct iscsi_task *task);
335 
336 int iser_send_command(struct iscsi_conn *conn,
337 		      struct iscsi_task *task);
338 
339 int iser_send_data_out(struct iscsi_conn *conn,
340 		       struct iscsi_task *task,
341 		       struct iscsi_data *hdr);
342 
343 void iscsi_iser_recv(struct iscsi_conn *conn,
344 		     struct iscsi_hdr       *hdr,
345 		     char                   *rx_data,
346 		     int                    rx_data_len);
347 
348 void iser_conn_init(struct iser_conn *ib_conn);
349 
350 void iser_conn_get(struct iser_conn *ib_conn);
351 
352 int iser_conn_put(struct iser_conn *ib_conn, int destroy_cma_id_allowed);
353 
354 void iser_conn_terminate(struct iser_conn *ib_conn);
355 
356 void iser_rcv_completion(struct iser_rx_desc *desc,
357 			 unsigned long    dto_xfer_len,
358 			struct iser_conn *ib_conn);
359 
360 void iser_snd_completion(struct iser_tx_desc *desc, struct iser_conn *ib_conn);
361 
362 void iser_task_rdma_init(struct iscsi_iser_task *task);
363 
364 void iser_task_rdma_finalize(struct iscsi_iser_task *task);
365 
366 void iser_free_rx_descriptors(struct iser_conn *ib_conn);
367 
368 void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *task,
369 				     enum iser_data_dir         cmd_dir);
370 
371 int  iser_reg_rdma_mem(struct iscsi_iser_task *task,
372 		       enum   iser_data_dir        cmd_dir);
373 
374 int  iser_connect(struct iser_conn   *ib_conn,
375 		  struct sockaddr_in *src_addr,
376 		  struct sockaddr_in *dst_addr,
377 		  int                non_blocking);
378 
379 int  iser_reg_page_vec(struct iser_conn     *ib_conn,
380 		       struct iser_page_vec *page_vec,
381 		       struct iser_mem_reg  *mem_reg);
382 
383 void iser_unreg_mem(struct iser_mem_reg *mem_reg);
384 
385 int  iser_post_recvl(struct iser_conn *ib_conn);
386 int  iser_post_recvm(struct iser_conn *ib_conn, int count);
387 int  iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc);
388 
389 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
390 			    struct iser_data_buf       *data,
391 			    enum   iser_data_dir       iser_dir,
392 			    enum   dma_data_direction  dma_dir);
393 
394 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task);
395 int  iser_initialize_task_headers(struct iscsi_task *task,
396 			struct iser_tx_desc *tx_desc);
397 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn);
398 #endif
399