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) 2013-2014 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#include <scsi/scsi_cmnd.h>
50#include <scsi/scsi_device.h>
51#include <scsi/iser.h>
52
53#include <linux/interrupt.h>
54#include <linux/wait.h>
55#include <linux/sched.h>
56#include <linux/list.h>
57#include <linux/slab.h>
58#include <linux/dma-mapping.h>
59#include <linux/mutex.h>
60#include <linux/mempool.h>
61#include <linux/uio.h>
62
63#include <linux/socket.h>
64#include <linux/in.h>
65#include <linux/in6.h>
66
67#include <rdma/ib_verbs.h>
68#include <rdma/rdma_cm.h>
69
70#define DRV_NAME	"iser"
71#define PFX		DRV_NAME ": "
72#define DRV_VER		"1.6"
73
74#define iser_dbg(fmt, arg...)				 \
75	do {						 \
76		if (unlikely(iser_debug_level > 2))	 \
77			printk(KERN_DEBUG PFX "%s: " fmt,\
78				__func__ , ## arg);	 \
79	} while (0)
80
81#define iser_warn(fmt, arg...)				\
82	do {						\
83		if (unlikely(iser_debug_level > 0))	\
84			pr_warn(PFX "%s: " fmt,		\
85				__func__ , ## arg);	\
86	} while (0)
87
88#define iser_info(fmt, arg...)				\
89	do {						\
90		if (unlikely(iser_debug_level > 1))	\
91			pr_info(PFX "%s: " fmt,		\
92				__func__ , ## arg);	\
93	} while (0)
94
95#define iser_err(fmt, arg...) \
96	pr_err(PFX "%s: " fmt, __func__ , ## arg)
97
98/* Default support is 512KB I/O size */
99#define ISER_DEF_MAX_SECTORS		1024
100#define ISCSI_ISER_DEF_SG_TABLESIZE                                            \
101	((ISER_DEF_MAX_SECTORS * SECTOR_SIZE) >> ilog2(SZ_4K))
102/* Maximum support is 16MB I/O size */
103#define ISCSI_ISER_MAX_SG_TABLESIZE ((32768 * SECTOR_SIZE) >> ilog2(SZ_4K))
104
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/* Max registration work requests per command */
138#define ISER_MAX_REG_WR_PER_CMD		5
139
140/* For Signature we don't support DATAOUTs so no need to make room for them */
141#define ISER_QP_SIG_MAX_REQ_DTOS	(ISER_DEF_XMIT_CMDS_MAX	*       \
142					(1 + ISER_MAX_REG_WR_PER_CMD) + \
143					ISER_MAX_TX_MISC_PDUS         + \
144					ISER_MAX_RX_MISC_PDUS)
145
146#define ISER_GET_MAX_XMIT_CMDS(send_wr) ((send_wr			\
147					 - ISER_MAX_TX_MISC_PDUS	\
148					 - ISER_MAX_RX_MISC_PDUS) /	\
149					 (1 + ISER_INFLIGHT_DATAOUTS))
150
151#define ISER_SIGNAL_CMD_COUNT 32
152
153/* Constant PDU lengths calculations */
154#define ISER_HEADERS_LEN	(sizeof(struct iser_ctrl) + 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
163enum iser_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
172enum iser_task_status {
173	ISER_TASK_STATUS_INIT = 0,
174	ISER_TASK_STATUS_STARTED,
175	ISER_TASK_STATUS_COMPLETED
176};
177
178enum iser_data_dir {
179	ISER_DIR_IN = 0,	   /* to initiator */
180	ISER_DIR_OUT,		   /* from initiator */
181	ISER_DIRS_NUM
182};
183
184/**
185 * struct iser_data_buf - iSER data buffer
186 *
187 * @sg:           pointer to the sg list
188 * @size:         num entries of this sg
189 * @data_len:     total beffer byte len
190 * @dma_nents:    returned by dma_map_sg
191 */
192struct iser_data_buf {
193	struct scatterlist *sg;
194	int                size;
195	unsigned long      data_len;
196	int                dma_nents;
197};
198
199/* fwd declarations */
200struct iser_device;
201struct iscsi_iser_task;
202struct iscsi_endpoint;
203struct iser_reg_resources;
204
205/**
206 * struct iser_mem_reg - iSER memory registration info
207 *
208 * @sge:          memory region sg element
209 * @rkey:         memory region remote key
210 * @mem_h:        pointer to registration context (FMR/Fastreg)
211 */
212struct iser_mem_reg {
213	struct ib_sge	 sge;
214	u32		 rkey;
215	void		*mem_h;
216};
217
218enum iser_desc_type {
219	ISCSI_TX_CONTROL ,
220	ISCSI_TX_SCSI_COMMAND,
221	ISCSI_TX_DATAOUT
222};
223
224/**
225 * struct iser_tx_desc - iSER TX descriptor
226 *
227 * @iser_header:   iser header
228 * @iscsi_header:  iscsi header
229 * @type:          command/control/dataout
230 * @dma_addr:      header buffer dma_address
231 * @tx_sg:         sg[0] points to iser/iscsi headers
232 *                 sg[1] optionally points to either of immediate data
233 *                 unsolicited data-out or control
234 * @num_sge:       number sges used on this TX task
235 * @cqe:           completion handler
236 * @mapped:        Is the task header mapped
237 * @reg_wr:        registration WR
238 * @send_wr:       send WR
239 * @inv_wr:        invalidate WR
240 */
241struct iser_tx_desc {
242	struct iser_ctrl             iser_header;
243	struct iscsi_hdr             iscsi_header;
244	enum   iser_desc_type        type;
245	u64		             dma_addr;
246	struct ib_sge		     tx_sg[2];
247	int                          num_sge;
248	struct ib_cqe		     cqe;
249	bool			     mapped;
250	struct ib_reg_wr	     reg_wr;
251	struct ib_send_wr	     send_wr;
252	struct ib_send_wr	     inv_wr;
253};
254
255#define ISER_RX_PAD_SIZE	(256 - (ISER_RX_PAYLOAD_SIZE + \
256				 sizeof(u64) + sizeof(struct ib_sge) + \
257				 sizeof(struct ib_cqe)))
258/**
259 * struct iser_rx_desc - iSER RX descriptor
260 *
261 * @iser_header:   iser header
262 * @iscsi_header:  iscsi header
263 * @data:          received data segment
264 * @dma_addr:      receive buffer dma address
265 * @rx_sg:         ib_sge of receive buffer
266 * @cqe:           completion handler
267 * @pad:           for sense data TODO: Modify to maximum sense length supported
268 */
269struct iser_rx_desc {
270	struct iser_ctrl             iser_header;
271	struct iscsi_hdr             iscsi_header;
272	char		             data[ISER_RECV_DATA_SEG_LEN];
273	u64		             dma_addr;
274	struct ib_sge		     rx_sg;
275	struct ib_cqe		     cqe;
276	char		             pad[ISER_RX_PAD_SIZE];
277} __packed;
278
279/**
280 * struct iser_login_desc - iSER login descriptor
281 *
282 * @req:           pointer to login request buffer
283 * @rsp:           pointer to login response buffer
284 * @req_dma:       DMA address of login request buffer
285 * @rsp_dma:       DMA address of login response buffer
286 * @sge:           IB sge for login post recv
287 * @cqe:           completion handler
288 */
289struct iser_login_desc {
290	void                         *req;
291	void                         *rsp;
292	u64                          req_dma;
293	u64                          rsp_dma;
294	struct ib_sge                sge;
295	struct ib_cqe		     cqe;
296} __packed;
297
298struct iser_conn;
299struct ib_conn;
300struct iscsi_iser_task;
301
302/**
303 * struct iser_device - iSER device handle
304 *
305 * @ib_device:     RDMA device
306 * @pd:            Protection Domain for this device
307 * @mr:            Global DMA memory region
308 * @event_handler: IB events handle routine
309 * @ig_list:	   entry in devices list
310 * @refcount:      Reference counter, dominated by open iser connections
311 */
312struct iser_device {
313	struct ib_device             *ib_device;
314	struct ib_pd	             *pd;
315	struct ib_event_handler      event_handler;
316	struct list_head             ig_list;
317	int                          refcount;
318};
319
320/**
321 * struct iser_reg_resources - Fast registration resources
322 *
323 * @mr:         memory region
324 * @sig_mr:     signature memory region
325 */
326struct iser_reg_resources {
327	struct ib_mr                     *mr;
328	struct ib_mr                     *sig_mr;
329};
330
331/**
332 * struct iser_fr_desc - Fast registration descriptor
333 *
334 * @list:           entry in connection fastreg pool
335 * @rsc:            data buffer registration resources
336 * @sig_protected:  is region protected indicator
337 * @all_list:       first and last list members
338 */
339struct iser_fr_desc {
340	struct list_head		  list;
341	struct iser_reg_resources	  rsc;
342	bool				  sig_protected;
343	struct list_head                  all_list;
344};
345
346/**
347 * struct iser_fr_pool - connection fast registration pool
348 *
349 * @list:                list of fastreg descriptors
350 * @lock:                protects fastreg pool
351 * @size:                size of the pool
352 * @all_list:            first and last list members
353 */
354struct iser_fr_pool {
355	struct list_head        list;
356	spinlock_t              lock;
357	int                     size;
358	struct list_head        all_list;
359};
360
361/**
362 * struct ib_conn - Infiniband related objects
363 *
364 * @cma_id:              rdma_cm connection maneger handle
365 * @qp:                  Connection Queue-pair
366 * @cq:                  Connection completion queue
367 * @cq_size:             The number of max outstanding completions
368 * @post_recv_buf_count: post receive counter
369 * @sig_count:           send work request signal count
370 * @rx_wr:               receive work request for batch posts
371 * @device:              reference to iser device
372 * @fr_pool:             connection fast registration poool
373 * @pi_support:          Indicate device T10-PI support
374 * @reg_cqe:             completion handler
375 */
376struct ib_conn {
377	struct rdma_cm_id           *cma_id;
378	struct ib_qp	            *qp;
379	struct ib_cq		    *cq;
380	u32			    cq_size;
381	int                          post_recv_buf_count;
382	u8                           sig_count;
383	struct ib_recv_wr	     rx_wr[ISER_MIN_POSTED_RX];
384	struct iser_device          *device;
385	struct iser_fr_pool          fr_pool;
386	bool			     pi_support;
387	struct ib_cqe		     reg_cqe;
388};
389
390/**
391 * struct iser_conn - iSER connection context
392 *
393 * @ib_conn:          connection RDMA resources
394 * @iscsi_conn:       link to matching iscsi connection
395 * @ep:               transport handle
396 * @state:            connection logical state
397 * @qp_max_recv_dtos: maximum number of data outs, corresponds
398 *                    to max number of post recvs
399 * @qp_max_recv_dtos_mask: (qp_max_recv_dtos - 1)
400 * @min_posted_rx:    (qp_max_recv_dtos >> 2)
401 * @max_cmds:         maximum cmds allowed for this connection
402 * @name:             connection peer portal
403 * @release_work:     deffered work for release job
404 * @state_mutex:      protects iser onnection state
405 * @stop_completion:  conn_stop completion
406 * @ib_completion:    RDMA cleanup completion
407 * @up_completion:    connection establishment completed
408 *                    (state is ISER_CONN_UP)
409 * @conn_list:        entry in ig conn list
410 * @login_desc:       login descriptor
411 * @rx_desc_head:     head of rx_descs cyclic buffer
412 * @rx_descs:         rx buffers array (cyclic buffer)
413 * @num_rx_descs:     number of rx descriptors
414 * @scsi_sg_tablesize: scsi host sg_tablesize
415 * @pages_per_mr:     maximum pages available for registration
416 * @snd_w_inv:        connection uses remote invalidation
417 */
418struct iser_conn {
419	struct ib_conn		     ib_conn;
420	struct iscsi_conn	     *iscsi_conn;
421	struct iscsi_endpoint	     *ep;
422	enum iser_conn_state	     state;
423	unsigned		     qp_max_recv_dtos;
424	unsigned		     qp_max_recv_dtos_mask;
425	unsigned		     min_posted_rx;
426	u16                          max_cmds;
427	char 			     name[ISER_OBJECT_NAME_SIZE];
428	struct work_struct	     release_work;
429	struct mutex		     state_mutex;
430	struct completion	     stop_completion;
431	struct completion	     ib_completion;
432	struct completion	     up_completion;
433	struct list_head	     conn_list;
434	struct iser_login_desc       login_desc;
435	unsigned int 		     rx_desc_head;
436	struct iser_rx_desc	     *rx_descs;
437	u32                          num_rx_descs;
438	unsigned short               scsi_sg_tablesize;
439	unsigned short               pages_per_mr;
440	bool			     snd_w_inv;
441};
442
443/**
444 * struct iscsi_iser_task - iser task context
445 *
446 * @desc:     TX descriptor
447 * @iser_conn:        link to iser connection
448 * @status:           current task status
449 * @sc:               link to scsi command
450 * @command_sent:     indicate if command was sent
451 * @dir:              iser data direction
452 * @rdma_reg:         task rdma registration desc
453 * @data:             iser data buffer desc
454 * @prot:             iser protection buffer desc
455 */
456struct iscsi_iser_task {
457	struct iser_tx_desc          desc;
458	struct iser_conn	     *iser_conn;
459	enum iser_task_status 	     status;
460	struct scsi_cmnd	     *sc;
461	int                          command_sent;
462	int                          dir[ISER_DIRS_NUM];
463	struct iser_mem_reg          rdma_reg[ISER_DIRS_NUM];
464	struct iser_data_buf         data[ISER_DIRS_NUM];
465	struct iser_data_buf         prot[ISER_DIRS_NUM];
466};
467
468/**
469 * struct iser_global - iSER global context
470 *
471 * @device_list_mutex:    protects device_list
472 * @device_list:          iser devices global list
473 * @connlist_mutex:       protects connlist
474 * @connlist:             iser connections global list
475 * @desc_cache:           kmem cache for tx dataout
476 */
477struct iser_global {
478	struct mutex      device_list_mutex;
479	struct list_head  device_list;
480	struct mutex      connlist_mutex;
481	struct list_head  connlist;
482	struct kmem_cache *desc_cache;
483};
484
485extern struct iser_global ig;
486extern int iser_debug_level;
487extern bool iser_pi_enable;
488extern int iser_pi_guard;
489extern unsigned int iser_max_sectors;
490extern bool iser_always_reg;
491
492int iser_send_control(struct iscsi_conn *conn,
493		      struct iscsi_task *task);
494
495int iser_send_command(struct iscsi_conn *conn,
496		      struct iscsi_task *task);
497
498int iser_send_data_out(struct iscsi_conn *conn,
499		       struct iscsi_task *task,
500		       struct iscsi_data *hdr);
501
502void iscsi_iser_recv(struct iscsi_conn *conn,
503		     struct iscsi_hdr *hdr,
504		     char *rx_data,
505		     int rx_data_len);
506
507void iser_conn_init(struct iser_conn *iser_conn);
508
509void iser_conn_release(struct iser_conn *iser_conn);
510
511int iser_conn_terminate(struct iser_conn *iser_conn);
512
513void iser_release_work(struct work_struct *work);
514
515void iser_err_comp(struct ib_wc *wc, const char *type);
516void iser_login_rsp(struct ib_cq *cq, struct ib_wc *wc);
517void iser_task_rsp(struct ib_cq *cq, struct ib_wc *wc);
518void iser_cmd_comp(struct ib_cq *cq, struct ib_wc *wc);
519void iser_ctrl_comp(struct ib_cq *cq, struct ib_wc *wc);
520void iser_dataout_comp(struct ib_cq *cq, struct ib_wc *wc);
521void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc);
522
523void iser_task_rdma_init(struct iscsi_iser_task *task);
524
525void iser_task_rdma_finalize(struct iscsi_iser_task *task);
526
527void iser_free_rx_descriptors(struct iser_conn *iser_conn);
528
529void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
530				     struct iser_data_buf *mem,
531				     enum iser_data_dir cmd_dir);
532
533int iser_reg_mem_fastreg(struct iscsi_iser_task *task,
534			 enum iser_data_dir dir,
535			 bool all_imm);
536void iser_unreg_mem_fastreg(struct iscsi_iser_task *task,
537			    enum iser_data_dir dir);
538
539int  iser_connect(struct iser_conn *iser_conn,
540		  struct sockaddr *src_addr,
541		  struct sockaddr *dst_addr,
542		  int non_blocking);
543
544int  iser_post_recvl(struct iser_conn *iser_conn);
545int  iser_post_recvm(struct iser_conn *iser_conn, int count);
546int  iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
547		    bool signal);
548
549int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
550			   struct iser_data_buf *data,
551			   enum iser_data_dir iser_dir,
552			   enum dma_data_direction dma_dir);
553
554void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
555			      struct iser_data_buf *data,
556			      enum dma_data_direction dir);
557
558int  iser_initialize_task_headers(struct iscsi_task *task,
559			struct iser_tx_desc *tx_desc);
560int iser_alloc_rx_descriptors(struct iser_conn *iser_conn,
561			      struct iscsi_session *session);
562int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
563			    unsigned cmds_max,
564			    unsigned int size);
565void iser_free_fastreg_pool(struct ib_conn *ib_conn);
566u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
567			     enum iser_data_dir cmd_dir, sector_t *sector);
568
569static inline struct iser_conn *
570to_iser_conn(struct ib_conn *ib_conn)
571{
572	return container_of(ib_conn, struct iser_conn, ib_conn);
573}
574
575static inline struct iser_rx_desc *
576iser_rx(struct ib_cqe *cqe)
577{
578	return container_of(cqe, struct iser_rx_desc, cqe);
579}
580
581static inline struct iser_tx_desc *
582iser_tx(struct ib_cqe *cqe)
583{
584	return container_of(cqe, struct iser_tx_desc, cqe);
585}
586
587static inline struct iser_login_desc *
588iser_login(struct ib_cqe *cqe)
589{
590	return container_of(cqe, struct iser_login_desc, cqe);
591}
592
593#endif
594