1 /*
2  * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
3  * Copyright (C) 2009 - 2010 Bart Van Assche <bvanassche@acm.org>.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  *
33  */
34 
35 #ifndef IB_SRPT_H
36 #define IB_SRPT_H
37 
38 #include <linux/types.h>
39 #include <linux/list.h>
40 #include <linux/wait.h>
41 
42 #include <rdma/ib_verbs.h>
43 #include <rdma/ib_sa.h>
44 #include <rdma/ib_cm.h>
45 #include <rdma/rdma_cm.h>
46 #include <rdma/rw.h>
47 
48 #include <scsi/srp.h>
49 
50 #include "ib_dm_mad.h"
51 
52 /*
53  * The prefix the ServiceName field must start with in the device management
54  * ServiceEntries attribute pair. See also the SRP specification.
55  */
56 #define SRP_SERVICE_NAME_PREFIX		"SRP.T10:"
57 
58 struct srpt_nexus;
59 
60 enum {
61 	/*
62 	 * SRP IOControllerProfile attributes for SRP target ports that have
63 	 * not been defined in <scsi/srp.h>. Source: section B.7, table B.7
64 	 * in the SRP specification.
65 	 */
66 	SRP_PROTOCOL = 0x0108,
67 	SRP_PROTOCOL_VERSION = 0x0001,
68 	SRP_IO_SUBCLASS = 0x609e,
69 	SRP_SEND_TO_IOC = 0x01,
70 	SRP_SEND_FROM_IOC = 0x02,
71 	SRP_RDMA_READ_FROM_IOC = 0x08,
72 	SRP_RDMA_WRITE_FROM_IOC = 0x20,
73 
74 	/*
75 	 * srp_login_cmd.req_flags bitmasks. See also table 9 in the SRP
76 	 * specification.
77 	 */
78 	SRP_MTCH_ACTION = 0x03, /* MULTI-CHANNEL ACTION */
79 	SRP_LOSOLNT = 0x10, /* logout solicited notification */
80 	SRP_CRSOLNT = 0x20, /* credit request solicited notification */
81 	SRP_AESOLNT = 0x40, /* asynchronous event solicited notification */
82 
83 	/*
84 	 * srp_cmd.sol_nt / srp_tsk_mgmt.sol_not bitmasks. See also tables
85 	 * 18 and 20 in the SRP specification.
86 	 */
87 	SRP_SCSOLNT = 0x02, /* SCSOLNT = successful solicited notification */
88 	SRP_UCSOLNT = 0x04, /* UCSOLNT = unsuccessful solicited notification */
89 
90 	/*
91 	 * srp_rsp.sol_not / srp_t_logout.sol_not bitmasks. See also tables
92 	 * 16 and 22 in the SRP specification.
93 	 */
94 	SRP_SOLNT = 0x01, /* SOLNT = solicited notification */
95 
96 	/* See also table 24 in the SRP specification. */
97 	SRP_TSK_MGMT_SUCCESS = 0x00,
98 	SRP_TSK_MGMT_FUNC_NOT_SUPP = 0x04,
99 	SRP_TSK_MGMT_FAILED = 0x05,
100 
101 	/* See also table 21 in the SRP specification. */
102 	SRP_CMD_SIMPLE_Q = 0x0,
103 	SRP_CMD_HEAD_OF_Q = 0x1,
104 	SRP_CMD_ORDERED_Q = 0x2,
105 	SRP_CMD_ACA = 0x4,
106 
107 	SRPT_DEF_SG_TABLESIZE = 128,
108 	/*
109 	 * An experimentally determined value that avoids that QP creation
110 	 * fails due to "swiotlb buffer is full" on systems using the swiotlb.
111 	 */
112 	SRPT_MAX_SG_PER_WQE = 16,
113 
114 	MIN_SRPT_SQ_SIZE = 16,
115 	DEF_SRPT_SQ_SIZE = 4096,
116 	MAX_SRPT_RQ_SIZE = 128,
117 	MIN_SRPT_SRQ_SIZE = 4,
118 	DEFAULT_SRPT_SRQ_SIZE = 4095,
119 	MAX_SRPT_SRQ_SIZE = 65535,
120 	MAX_SRPT_RDMA_SIZE = 1U << 24,
121 	MAX_SRPT_RSP_SIZE = 1024,
122 
123 	SRP_MAX_ADD_CDB_LEN = 16,
124 	SRP_MAX_IMM_DATA_OFFSET = 80,
125 	SRP_MAX_IMM_DATA = 8 * 1024,
126 	MIN_MAX_REQ_SIZE = 996,
127 	DEFAULT_MAX_REQ_SIZE_1 = sizeof(struct srp_cmd)/*48*/ +
128 				 SRP_MAX_ADD_CDB_LEN +
129 				 sizeof(struct srp_indirect_buf)/*20*/ +
130 				 128 * sizeof(struct srp_direct_buf)/*16*/,
131 	DEFAULT_MAX_REQ_SIZE_2 = SRP_MAX_IMM_DATA_OFFSET +
132 				 sizeof(struct srp_imm_buf) + SRP_MAX_IMM_DATA,
133 	DEFAULT_MAX_REQ_SIZE = DEFAULT_MAX_REQ_SIZE_1 > DEFAULT_MAX_REQ_SIZE_2 ?
134 			       DEFAULT_MAX_REQ_SIZE_1 : DEFAULT_MAX_REQ_SIZE_2,
135 
136 	MIN_MAX_RSP_SIZE = sizeof(struct srp_rsp)/*36*/ + 4,
137 	DEFAULT_MAX_RSP_SIZE = 256, /* leaves 220 bytes for sense data */
138 
139 	DEFAULT_MAX_RDMA_SIZE = 65536,
140 };
141 
142 /**
143  * enum srpt_command_state - SCSI command state managed by SRPT
144  * @SRPT_STATE_NEW:           New command arrived and is being processed.
145  * @SRPT_STATE_NEED_DATA:     Processing a write or bidir command and waiting
146  *                            for data arrival.
147  * @SRPT_STATE_DATA_IN:       Data for the write or bidir command arrived and is
148  *                            being processed.
149  * @SRPT_STATE_CMD_RSP_SENT:  SRP_RSP for SRP_CMD has been sent.
150  * @SRPT_STATE_MGMT:          Processing a SCSI task management command.
151  * @SRPT_STATE_MGMT_RSP_SENT: SRP_RSP for SRP_TSK_MGMT has been sent.
152  * @SRPT_STATE_DONE:          Command processing finished successfully, command
153  *                            processing has been aborted or command processing
154  *                            failed.
155  */
156 enum srpt_command_state {
157 	SRPT_STATE_NEW		 = 0,
158 	SRPT_STATE_NEED_DATA	 = 1,
159 	SRPT_STATE_DATA_IN	 = 2,
160 	SRPT_STATE_CMD_RSP_SENT	 = 3,
161 	SRPT_STATE_MGMT		 = 4,
162 	SRPT_STATE_MGMT_RSP_SENT = 5,
163 	SRPT_STATE_DONE		 = 6,
164 };
165 
166 /**
167  * struct srpt_ioctx - shared SRPT I/O context information
168  * @cqe:   Completion queue element.
169  * @buf:   Pointer to the buffer.
170  * @dma:   DMA address of the buffer.
171  * @offset: Offset of the first byte in @buf and @dma that is actually used.
172  * @index: Index of the I/O context in its ioctx_ring array.
173  */
174 struct srpt_ioctx {
175 	struct ib_cqe		cqe;
176 	void			*buf;
177 	dma_addr_t		dma;
178 	uint32_t		offset;
179 	uint32_t		index;
180 };
181 
182 /**
183  * struct srpt_recv_ioctx - SRPT receive I/O context
184  * @ioctx:     See above.
185  * @wait_list: Node for insertion in srpt_rdma_ch.cmd_wait_list.
186  * @byte_len:  Number of bytes in @ioctx.buf.
187  */
188 struct srpt_recv_ioctx {
189 	struct srpt_ioctx	ioctx;
190 	struct list_head	wait_list;
191 	int			byte_len;
192 };
193 
194 struct srpt_rw_ctx {
195 	struct rdma_rw_ctx	rw;
196 	struct scatterlist	*sg;
197 	unsigned int		nents;
198 };
199 
200 /**
201  * struct srpt_send_ioctx - SRPT send I/O context
202  * @ioctx:       See above.
203  * @ch:          Channel pointer.
204  * @recv_ioctx:  Receive I/O context associated with this send I/O context.
205  *		 Only used for processing immediate data.
206  * @s_rw_ctx:    @rw_ctxs points here if only a single rw_ctx is needed.
207  * @rw_ctxs:     RDMA read/write contexts.
208  * @imm_sg:      Scatterlist for immediate data.
209  * @rdma_cqe:    RDMA completion queue element.
210  * @state:       I/O context state.
211  * @cmd:         Target core command data structure.
212  * @sense_data:  SCSI sense data.
213  * @n_rdma:      Number of work requests needed to transfer this ioctx.
214  * @n_rw_ctx:    Size of rw_ctxs array.
215  * @queue_status_only: Send a SCSI status back to the initiator but no data.
216  * @sense_data:  Sense data to be sent to the initiator.
217  */
218 struct srpt_send_ioctx {
219 	struct srpt_ioctx	ioctx;
220 	struct srpt_rdma_ch	*ch;
221 	struct srpt_recv_ioctx	*recv_ioctx;
222 
223 	struct srpt_rw_ctx	s_rw_ctx;
224 	struct srpt_rw_ctx	*rw_ctxs;
225 
226 	struct scatterlist	imm_sg;
227 
228 	struct ib_cqe		rdma_cqe;
229 	enum srpt_command_state	state;
230 	struct se_cmd		cmd;
231 	u8			n_rdma;
232 	u8			n_rw_ctx;
233 	bool			queue_status_only;
234 	u8			sense_data[TRANSPORT_SENSE_BUFFER];
235 };
236 
237 /**
238  * enum rdma_ch_state - SRP channel state
239  * @CH_CONNECTING:    QP is in RTR state; waiting for RTU.
240  * @CH_LIVE:	      QP is in RTS state.
241  * @CH_DISCONNECTING: DREQ has been sent and waiting for DREP or DREQ has
242  *                    been received.
243  * @CH_DRAINING:      DREP has been received or waiting for DREP timed out
244  *                    and last work request has been queued.
245  * @CH_DISCONNECTED:  Last completion has been received.
246  */
247 enum rdma_ch_state {
248 	CH_CONNECTING,
249 	CH_LIVE,
250 	CH_DISCONNECTING,
251 	CH_DRAINING,
252 	CH_DISCONNECTED,
253 };
254 
255 /**
256  * struct srpt_rdma_ch - RDMA channel
257  * @nexus:         I_T nexus this channel is associated with.
258  * @qp:            IB queue pair used for communicating over this channel.
259  * @ib_cm:	   See below.
260  * @ib_cm.cm_id:   IB CM ID associated with the channel.
261  * @rdma_cm:	   See below.
262  * @rdma_cm.cm_id: RDMA CM ID associated with the channel.
263  * @cq:            IB completion queue for this channel.
264  * @zw_cqe:	   Zero-length write CQE.
265  * @rcu:           RCU head.
266  * @kref:	   kref for this channel.
267  * @closed:	   Completion object that will be signaled as soon as a new
268  *		   channel object with the same identity can be created.
269  * @rq_size:       IB receive queue size.
270  * @max_rsp_size:  Maximum size of an RSP response message in bytes.
271  * @sq_wr_avail:   number of work requests available in the send queue.
272  * @sport:         pointer to the information of the HCA port used by this
273  *                 channel.
274  * @max_ti_iu_len: maximum target-to-initiator information unit length.
275  * @req_lim:       request limit: maximum number of requests that may be sent
276  *                 by the initiator without having received a response.
277  * @req_lim_delta: Number of credits not yet sent back to the initiator.
278  * @imm_data_offset: Offset from start of SRP_CMD for immediate data.
279  * @spinlock:      Protects free_list and state.
280  * @state:         channel state. See also enum rdma_ch_state.
281  * @using_rdma_cm: Whether the RDMA/CM or IB/CM is used for this channel.
282  * @processing_wait_list: Whether or not cmd_wait_list is being processed.
283  * @rsp_buf_cache: kmem_cache for @ioctx_ring.
284  * @ioctx_ring:    Send ring.
285  * @req_buf_cache: kmem_cache for @ioctx_recv_ring.
286  * @ioctx_recv_ring: Receive I/O context ring.
287  * @list:          Node in srpt_nexus.ch_list.
288  * @cmd_wait_list: List of SCSI commands that arrived before the RTU event. This
289  *                 list contains struct srpt_ioctx elements and is protected
290  *                 against concurrent modification by the cm_id spinlock.
291  * @pkey:          P_Key of the IB partition for this SRP channel.
292  * @sess:          Session information associated with this SRP channel.
293  * @sess_name:     Session name.
294  * @release_work:  Allows scheduling of srpt_release_channel().
295  */
296 struct srpt_rdma_ch {
297 	struct srpt_nexus	*nexus;
298 	struct ib_qp		*qp;
299 	union {
300 		struct {
301 			struct ib_cm_id		*cm_id;
302 		} ib_cm;
303 		struct {
304 			struct rdma_cm_id	*cm_id;
305 		} rdma_cm;
306 	};
307 	struct ib_cq		*cq;
308 	struct ib_cqe		zw_cqe;
309 	struct rcu_head		rcu;
310 	struct kref		kref;
311 	struct completion	*closed;
312 	int			rq_size;
313 	u32			max_rsp_size;
314 	atomic_t		sq_wr_avail;
315 	struct srpt_port	*sport;
316 	int			max_ti_iu_len;
317 	atomic_t		req_lim;
318 	atomic_t		req_lim_delta;
319 	u16			imm_data_offset;
320 	spinlock_t		spinlock;
321 	enum rdma_ch_state	state;
322 	struct kmem_cache	*rsp_buf_cache;
323 	struct srpt_send_ioctx	**ioctx_ring;
324 	struct kmem_cache	*req_buf_cache;
325 	struct srpt_recv_ioctx	**ioctx_recv_ring;
326 	struct list_head	list;
327 	struct list_head	cmd_wait_list;
328 	uint16_t		pkey;
329 	bool			using_rdma_cm;
330 	bool			processing_wait_list;
331 	struct se_session	*sess;
332 	u8			sess_name[40];
333 	struct work_struct	release_work;
334 };
335 
336 /**
337  * struct srpt_nexus - I_T nexus
338  * @rcu:       RCU head for this data structure.
339  * @entry:     srpt_port.nexus_list list node.
340  * @ch_list:   struct srpt_rdma_ch list. Protected by srpt_port.mutex.
341  * @i_port_id: 128-bit initiator port identifier copied from SRP_LOGIN_REQ.
342  * @t_port_id: 128-bit target port identifier copied from SRP_LOGIN_REQ.
343  */
344 struct srpt_nexus {
345 	struct rcu_head		rcu;
346 	struct list_head	entry;
347 	struct list_head	ch_list;
348 	u8			i_port_id[16];
349 	u8			t_port_id[16];
350 };
351 
352 /**
353  * struct srpt_port_attib - attributes for SRPT port
354  * @srp_max_rdma_size: Maximum size of SRP RDMA transfers for new connections.
355  * @srp_max_rsp_size: Maximum size of SRP response messages in bytes.
356  * @srp_sq_size: Shared receive queue (SRQ) size.
357  * @use_srq: Whether or not to use SRQ.
358  */
359 struct srpt_port_attrib {
360 	u32			srp_max_rdma_size;
361 	u32			srp_max_rsp_size;
362 	u32			srp_sq_size;
363 	bool			use_srq;
364 };
365 
366 /**
367  * struct srpt_tpg - information about a single "target portal group"
368  * @entry:	Entry in @sport_id->tpg_list.
369  * @sport_id:	Port name this TPG is associated with.
370  * @tpg:	LIO TPG data structure.
371  *
372  * Zero or more target portal groups are associated with each port name
373  * (srpt_port_id). With each TPG an ACL list is associated.
374  */
375 struct srpt_tpg {
376 	struct list_head	entry;
377 	struct srpt_port_id	*sport_id;
378 	struct se_portal_group	tpg;
379 };
380 
381 /**
382  * struct srpt_port_id - information about an RDMA port name
383  * @mutex:	Protects @tpg_list changes.
384  * @tpg_list:	TPGs associated with the RDMA port name.
385  * @wwn:	WWN associated with the RDMA port name.
386  * @name:	ASCII representation of the port name.
387  *
388  * Multiple sysfs directories can be associated with a single RDMA port. This
389  * data structure represents a single (port, name) pair.
390  */
391 struct srpt_port_id {
392 	struct mutex		mutex;
393 	struct list_head	tpg_list;
394 	struct se_wwn		wwn;
395 	char			name[64];
396 };
397 
398 /**
399  * struct srpt_port - information associated by SRPT with a single IB port
400  * @sdev:      backpointer to the HCA information.
401  * @mad_agent: per-port management datagram processing information.
402  * @enabled:   Whether or not this target port is enabled.
403  * @port:      one-based port number.
404  * @sm_lid:    cached value of the port's sm_lid.
405  * @lid:       cached value of the port's lid.
406  * @gid:       cached value of the port's gid.
407  * @work:      work structure for refreshing the aforementioned cached values.
408  * @port_guid_id: target port GUID
409  * @port_gid_id: target port GID
410  * @port_attrib:   Port attributes that can be accessed through configfs.
411  * @refcount:	   Number of objects associated with this port.
412  * @freed_channels: Completion that will be signaled once @refcount becomes 0.
413  * @mutex:	   Protects nexus_list.
414  * @nexus_list:	   Nexus list. See also srpt_nexus.entry.
415  */
416 struct srpt_port {
417 	struct srpt_device	*sdev;
418 	struct ib_mad_agent	*mad_agent;
419 	bool			enabled;
420 	u8			port;
421 	u32			sm_lid;
422 	u32			lid;
423 	union ib_gid		gid;
424 	struct work_struct	work;
425 	struct srpt_port_id	port_guid_id;
426 	struct srpt_port_id	port_gid_id;
427 	struct srpt_port_attrib port_attrib;
428 	atomic_t		refcount;
429 	struct completion	*freed_channels;
430 	struct mutex		mutex;
431 	struct list_head	nexus_list;
432 };
433 
434 /**
435  * struct srpt_device - information associated by SRPT with a single HCA
436  * @device:        Backpointer to the struct ib_device managed by the IB core.
437  * @pd:            IB protection domain.
438  * @lkey:          L_Key (local key) with write access to all local memory.
439  * @srq:           Per-HCA SRQ (shared receive queue).
440  * @cm_id:         Connection identifier.
441  * @srq_size:      SRQ size.
442  * @sdev_mutex:	   Serializes use_srq changes.
443  * @use_srq:       Whether or not to use SRQ.
444  * @req_buf_cache: kmem_cache for @ioctx_ring buffers.
445  * @ioctx_ring:    Per-HCA SRQ.
446  * @event_handler: Per-HCA asynchronous IB event handler.
447  * @list:          Node in srpt_dev_list.
448  * @port:          Information about the ports owned by this HCA.
449  */
450 struct srpt_device {
451 	struct ib_device	*device;
452 	struct ib_pd		*pd;
453 	u32			lkey;
454 	struct ib_srq		*srq;
455 	struct ib_cm_id		*cm_id;
456 	int			srq_size;
457 	struct mutex		sdev_mutex;
458 	bool			use_srq;
459 	struct kmem_cache	*req_buf_cache;
460 	struct srpt_recv_ioctx	**ioctx_ring;
461 	struct ib_event_handler	event_handler;
462 	struct list_head	list;
463 	struct srpt_port        port[];
464 };
465 
466 #endif				/* IB_SRPT_H */
467