1 /*
2  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #ifndef IB_SRP_H
34 #define IB_SRP_H
35 
36 #include <linux/types.h>
37 #include <linux/list.h>
38 #include <linux/mutex.h>
39 #include <linux/scatterlist.h>
40 
41 #include <scsi/scsi_host.h>
42 #include <scsi/scsi_cmnd.h>
43 
44 #include <rdma/ib_verbs.h>
45 #include <rdma/ib_sa.h>
46 #include <rdma/ib_cm.h>
47 #include <rdma/rdma_cm.h>
48 
49 enum {
50 	SRP_PATH_REC_TIMEOUT_MS	= 1000,
51 	SRP_ABORT_TIMEOUT_MS	= 5000,
52 
53 	SRP_PORT_REDIRECT	= 1,
54 	SRP_DLID_REDIRECT	= 2,
55 	SRP_STALE_CONN		= 3,
56 
57 	SRP_DEF_SG_TABLESIZE	= 12,
58 
59 	SRP_DEFAULT_QUEUE_SIZE	= 1 << 6,
60 	SRP_RSP_SQ_SIZE		= 1,
61 	SRP_TSK_MGMT_SQ_SIZE	= 1,
62 	SRP_DEFAULT_CMD_SQ_SIZE = SRP_DEFAULT_QUEUE_SIZE - SRP_RSP_SQ_SIZE -
63 				  SRP_TSK_MGMT_SQ_SIZE,
64 
65 	SRP_MAX_PAGES_PER_MR	= 512,
66 
67 	SRP_MAX_ADD_CDB_LEN	= 16,
68 
69 	SRP_MAX_IMM_SGE		= 2,
70 	SRP_MAX_SGE		= SRP_MAX_IMM_SGE + 1,
71 	/*
72 	 * Choose the immediate data offset such that a 32 byte CDB still fits.
73 	 */
74 	SRP_IMM_DATA_OFFSET	= sizeof(struct srp_cmd) +
75 				  SRP_MAX_ADD_CDB_LEN +
76 				  sizeof(struct srp_imm_buf),
77 };
78 
79 enum {
80 	SRP_TAG_NO_REQ		= ~0U,
81 	SRP_TAG_TSK_MGMT	= BIT(31),
82 };
83 
84 enum srp_target_state {
85 	SRP_TARGET_SCANNING,
86 	SRP_TARGET_LIVE,
87 	SRP_TARGET_REMOVED,
88 };
89 
90 enum srp_iu_type {
91 	SRP_IU_CMD,
92 	SRP_IU_TSK_MGMT,
93 	SRP_IU_RSP,
94 };
95 
96 /*
97  * RDMA adapter in the initiator system.
98  *
99  * @dev_list: List of RDMA ports associated with this RDMA adapter (srp_host).
100  * @mr_page_mask: HCA memory registration page mask.
101  * @mr_page_size: HCA memory registration page size.
102  * @mr_max_size: Maximum size in bytes of a single FR registration request.
103  */
104 struct srp_device {
105 	struct list_head	dev_list;
106 	struct ib_device       *dev;
107 	struct ib_pd	       *pd;
108 	u32			global_rkey;
109 	u64			mr_page_mask;
110 	int			mr_page_size;
111 	int			mr_max_size;
112 	int			max_pages_per_mr;
113 	bool			has_fr;
114 	bool			use_fast_reg;
115 };
116 
117 /*
118  * One port of an RDMA adapter in the initiator system.
119  *
120  * @target_list: List of connected target ports (struct srp_target_port).
121  * @target_lock: Protects @target_list.
122  */
123 struct srp_host {
124 	struct srp_device      *srp_dev;
125 	u32			port;
126 	struct device		dev;
127 	struct list_head	target_list;
128 	spinlock_t		target_lock;
129 	struct list_head	list;
130 	struct mutex		add_target_mutex;
131 };
132 
133 struct srp_request {
134 	struct scsi_cmnd       *scmnd;
135 	struct srp_iu	       *cmd;
136 	struct srp_fr_desc     **fr_list;
137 	struct srp_direct_buf  *indirect_desc;
138 	dma_addr_t		indirect_dma_addr;
139 	short			nmdesc;
140 	struct ib_cqe		reg_cqe;
141 };
142 
143 /**
144  * struct srp_rdma_ch
145  * @comp_vector: Completion vector used by this RDMA channel.
146  * @max_it_iu_len: Maximum initiator-to-target information unit length.
147  * @max_ti_iu_len: Maximum target-to-initiator information unit length.
148  */
149 struct srp_rdma_ch {
150 	/* These are RW in the hot path, and commonly used together */
151 	struct list_head	free_tx;
152 	spinlock_t		lock;
153 	s32			req_lim;
154 
155 	/* These are read-only in the hot path */
156 	struct srp_target_port *target ____cacheline_aligned_in_smp;
157 	struct ib_cq	       *send_cq;
158 	struct ib_cq	       *recv_cq;
159 	struct ib_qp	       *qp;
160 	struct srp_fr_pool     *fr_pool;
161 	uint32_t		max_it_iu_len;
162 	uint32_t		max_ti_iu_len;
163 	u8			max_imm_sge;
164 	bool			use_imm_data;
165 
166 	/* Everything above this point is used in the hot path of
167 	 * command processing. Try to keep them packed into cachelines.
168 	 */
169 
170 	struct completion	done;
171 	int			status;
172 
173 	union {
174 		struct ib_cm {
175 			struct sa_path_rec	path;
176 			struct ib_sa_query	*path_query;
177 			int			path_query_id;
178 			struct ib_cm_id		*cm_id;
179 		} ib_cm;
180 		struct rdma_cm {
181 			struct rdma_cm_id	*cm_id;
182 		} rdma_cm;
183 	};
184 
185 	struct srp_iu	      **tx_ring;
186 	struct srp_iu	      **rx_ring;
187 	int			comp_vector;
188 
189 	u64			tsk_mgmt_tag;
190 	struct completion	tsk_mgmt_done;
191 	u8			tsk_mgmt_status;
192 	bool			connected;
193 };
194 
195 /**
196  * struct srp_target_port - RDMA port in the SRP target system
197  * @comp_vector: Completion vector used by the first RDMA channel created for
198  *   this target port.
199  */
200 struct srp_target_port {
201 	/* read and written in the hot path */
202 	spinlock_t		lock;
203 
204 	/* read only in the hot path */
205 	u32			global_rkey;
206 	struct srp_rdma_ch	*ch;
207 	struct net		*net;
208 	u32			ch_count;
209 	u32			lkey;
210 	enum srp_target_state	state;
211 	uint32_t		max_it_iu_size;
212 	unsigned int		cmd_sg_cnt;
213 	unsigned int		indirect_size;
214 	bool			allow_ext_sg;
215 
216 	/* other member variables */
217 	union ib_gid		sgid;
218 	__be64			id_ext;
219 	__be64			ioc_guid;
220 	__be64			initiator_ext;
221 	u16			io_class;
222 	struct srp_host	       *srp_host;
223 	struct Scsi_Host       *scsi_host;
224 	struct srp_rport       *rport;
225 	char			target_name[32];
226 	unsigned int		scsi_id;
227 	unsigned int		sg_tablesize;
228 	unsigned int		target_can_queue;
229 	int			mr_pool_size;
230 	int			mr_per_cmd;
231 	int			queue_size;
232 	int			comp_vector;
233 	int			tl_retry_count;
234 
235 	bool			using_rdma_cm;
236 
237 	union {
238 		struct {
239 			__be64			service_id;
240 			union ib_gid		orig_dgid;
241 			__be16			pkey;
242 		} ib_cm;
243 		struct {
244 			union {
245 				struct sockaddr_in	ip4;
246 				struct sockaddr_in6	ip6;
247 				struct sockaddr		sa;
248 				struct sockaddr_storage ss;
249 			} src;
250 			union {
251 				struct sockaddr_in	ip4;
252 				struct sockaddr_in6	ip6;
253 				struct sockaddr		sa;
254 				struct sockaddr_storage ss;
255 			} dst;
256 			bool src_specified;
257 		} rdma_cm;
258 	};
259 
260 	u32			rq_tmo_jiffies;
261 
262 	int			zero_req_lim;
263 
264 	struct work_struct	tl_err_work;
265 	struct work_struct	remove_work;
266 
267 	struct list_head	list;
268 	bool			qp_in_error;
269 };
270 
271 struct srp_iu {
272 	struct list_head	list;
273 	u64			dma;
274 	void		       *buf;
275 	size_t			size;
276 	enum dma_data_direction	direction;
277 	u32			num_sge;
278 	struct ib_sge		sge[SRP_MAX_SGE];
279 	struct ib_cqe		cqe;
280 };
281 
282 /**
283  * struct srp_fr_desc - fast registration work request arguments
284  * @entry: Entry in srp_fr_pool.free_list.
285  * @mr:    Memory region.
286  * @frpl:  Fast registration page list.
287  */
288 struct srp_fr_desc {
289 	struct list_head		entry;
290 	struct ib_mr			*mr;
291 };
292 
293 /**
294  * struct srp_fr_pool - pool of fast registration descriptors
295  *
296  * An entry is available for allocation if and only if it occurs in @free_list.
297  *
298  * @size:      Number of descriptors in this pool.
299  * @max_page_list_len: Maximum fast registration work request page list length.
300  * @lock:      Protects free_list.
301  * @free_list: List of free descriptors.
302  * @desc:      Fast registration descriptor pool.
303  */
304 struct srp_fr_pool {
305 	int			size;
306 	int			max_page_list_len;
307 	spinlock_t		lock;
308 	struct list_head	free_list;
309 	struct srp_fr_desc	desc[];
310 };
311 
312 /**
313  * struct srp_map_state - per-request DMA memory mapping state
314  * @desc:	    Pointer to the element of the SRP buffer descriptor array
315  *		    that is being filled in.
316  * @pages:	    Array with DMA addresses of pages being considered for
317  *		    memory registration.
318  * @base_dma_addr:  DMA address of the first page that has not yet been mapped.
319  * @dma_len:	    Number of bytes that will be registered with the next FR
320  *                  memory registration call.
321  * @total_len:	    Total number of bytes in the sg-list being mapped.
322  * @npages:	    Number of page addresses in the pages[] array.
323  * @nmdesc:	    Number of FR memory descriptors used for mapping.
324  * @ndesc:	    Number of SRP buffer descriptors that have been filled in.
325  */
326 struct srp_map_state {
327 	union {
328 		struct {
329 			struct srp_fr_desc **next;
330 			struct srp_fr_desc **end;
331 		} fr;
332 		struct {
333 			void		   **next;
334 			void		   **end;
335 		} gen;
336 	};
337 	struct srp_direct_buf  *desc;
338 	union {
339 		u64			*pages;
340 		struct scatterlist	*sg;
341 	};
342 	dma_addr_t		base_dma_addr;
343 	u32			dma_len;
344 	u32			total_len;
345 	unsigned int		npages;
346 	unsigned int		nmdesc;
347 	unsigned int		ndesc;
348 };
349 
350 #endif /* IB_SRP_H */
351