xref: /linux/drivers/infiniband/ulp/srp/ib_srp.h (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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_TAG_NO_REQ		= ~0U,
66 	SRP_TAG_TSK_MGMT	= 1U << 31,
67 
68 	SRP_MAX_PAGES_PER_MR	= 512,
69 
70 	SRP_MAX_ADD_CDB_LEN	= 16,
71 
72 	SRP_MAX_IMM_SGE		= 2,
73 	SRP_MAX_SGE		= SRP_MAX_IMM_SGE + 1,
74 	/*
75 	 * Choose the immediate data offset such that a 32 byte CDB still fits.
76 	 */
77 	SRP_IMM_DATA_OFFSET	= sizeof(struct srp_cmd) +
78 				  SRP_MAX_ADD_CDB_LEN +
79 				  sizeof(struct srp_imm_buf),
80 };
81 
82 enum srp_target_state {
83 	SRP_TARGET_SCANNING,
84 	SRP_TARGET_LIVE,
85 	SRP_TARGET_REMOVED,
86 };
87 
88 enum srp_iu_type {
89 	SRP_IU_CMD,
90 	SRP_IU_TSK_MGMT,
91 	SRP_IU_RSP,
92 };
93 
94 /*
95  * RDMA adapter in the initiator system.
96  *
97  * @dev_list: List of RDMA ports associated with this RDMA adapter (srp_host).
98  * @mr_page_mask: HCA memory registration page mask.
99  * @mr_page_size: HCA memory registration page size.
100  * @mr_max_size: Maximum size in bytes of a single FR registration request.
101  */
102 struct srp_device {
103 	struct list_head	dev_list;
104 	struct ib_device       *dev;
105 	struct ib_pd	       *pd;
106 	u32			global_rkey;
107 	u64			mr_page_mask;
108 	int			mr_page_size;
109 	int			mr_max_size;
110 	int			max_pages_per_mr;
111 	bool			has_fr;
112 	bool			use_fast_reg;
113 };
114 
115 /*
116  * One port of an RDMA adapter in the initiator system.
117  *
118  * @target_list: List of connected target ports (struct srp_target_port).
119  * @target_lock: Protects @target_list.
120  */
121 struct srp_host {
122 	struct srp_device      *srp_dev;
123 	u8			port;
124 	struct device		dev;
125 	struct list_head	target_list;
126 	spinlock_t		target_lock;
127 	struct completion	released;
128 	struct list_head	list;
129 	struct mutex		add_target_mutex;
130 };
131 
132 struct srp_request {
133 	struct scsi_cmnd       *scmnd;
134 	struct srp_iu	       *cmd;
135 	struct srp_fr_desc     **fr_list;
136 	struct srp_direct_buf  *indirect_desc;
137 	dma_addr_t		indirect_dma_addr;
138 	short			nmdesc;
139 	struct ib_cqe		reg_cqe;
140 };
141 
142 /**
143  * struct srp_rdma_ch
144  * @comp_vector: Completion vector used by this RDMA channel.
145  * @max_it_iu_len: Maximum initiator-to-target information unit length.
146  * @max_ti_iu_len: Maximum target-to-initiator information unit length.
147  */
148 struct srp_rdma_ch {
149 	/* These are RW in the hot path, and commonly used together */
150 	struct list_head	free_tx;
151 	spinlock_t		lock;
152 	s32			req_lim;
153 
154 	/* These are read-only in the hot path */
155 	struct srp_target_port *target ____cacheline_aligned_in_smp;
156 	struct ib_cq	       *send_cq;
157 	struct ib_cq	       *recv_cq;
158 	struct ib_qp	       *qp;
159 	struct srp_fr_pool     *fr_pool;
160 	uint32_t		max_it_iu_len;
161 	uint32_t		max_ti_iu_len;
162 	u8			max_imm_sge;
163 	bool			use_imm_data;
164 
165 	/* Everything above this point is used in the hot path of
166 	 * command processing. Try to keep them packed into cachelines.
167 	 */
168 
169 	struct completion	done;
170 	int			status;
171 
172 	union {
173 		struct ib_cm {
174 			struct sa_path_rec	path;
175 			struct ib_sa_query	*path_query;
176 			int			path_query_id;
177 			struct ib_cm_id		*cm_id;
178 		} ib_cm;
179 		struct rdma_cm {
180 			struct rdma_cm_id	*cm_id;
181 		} rdma_cm;
182 	};
183 
184 	struct srp_iu	      **tx_ring;
185 	struct srp_iu	      **rx_ring;
186 	int			comp_vector;
187 
188 	u64			tsk_mgmt_tag;
189 	struct completion	tsk_mgmt_done;
190 	u8			tsk_mgmt_status;
191 	bool			connected;
192 };
193 
194 /**
195  * struct srp_target_port - RDMA port in the SRP target system
196  * @comp_vector: Completion vector used by the first RDMA channel created for
197  *   this target port.
198  */
199 struct srp_target_port {
200 	/* read and written in the hot path */
201 	spinlock_t		lock;
202 
203 	/* read only in the hot path */
204 	u32			global_rkey;
205 	struct srp_rdma_ch	*ch;
206 	struct net		*net;
207 	u32			ch_count;
208 	u32			lkey;
209 	enum srp_target_state	state;
210 	uint32_t		max_it_iu_size;
211 	unsigned int		cmd_sg_cnt;
212 	unsigned int		indirect_size;
213 	bool			allow_ext_sg;
214 
215 	/* other member variables */
216 	union ib_gid		sgid;
217 	__be64			id_ext;
218 	__be64			ioc_guid;
219 	__be64			initiator_ext;
220 	u16			io_class;
221 	struct srp_host	       *srp_host;
222 	struct Scsi_Host       *scsi_host;
223 	struct srp_rport       *rport;
224 	char			target_name[32];
225 	unsigned int		scsi_id;
226 	unsigned int		sg_tablesize;
227 	unsigned int		target_can_queue;
228 	int			mr_pool_size;
229 	int			mr_per_cmd;
230 	int			queue_size;
231 	int			comp_vector;
232 	int			tl_retry_count;
233 
234 	bool			using_rdma_cm;
235 
236 	union {
237 		struct {
238 			__be64			service_id;
239 			union ib_gid		orig_dgid;
240 			__be16			pkey;
241 		} ib_cm;
242 		struct {
243 			union {
244 				struct sockaddr_in	ip4;
245 				struct sockaddr_in6	ip6;
246 				struct sockaddr		sa;
247 				struct sockaddr_storage ss;
248 			} src;
249 			union {
250 				struct sockaddr_in	ip4;
251 				struct sockaddr_in6	ip6;
252 				struct sockaddr		sa;
253 				struct sockaddr_storage ss;
254 			} dst;
255 			bool src_specified;
256 		} rdma_cm;
257 	};
258 
259 	u32			rq_tmo_jiffies;
260 
261 	int			zero_req_lim;
262 
263 	struct work_struct	tl_err_work;
264 	struct work_struct	remove_work;
265 
266 	struct list_head	list;
267 	bool			qp_in_error;
268 };
269 
270 struct srp_iu {
271 	struct list_head	list;
272 	u64			dma;
273 	void		       *buf;
274 	size_t			size;
275 	enum dma_data_direction	direction;
276 	u32			num_sge;
277 	struct ib_sge		sge[SRP_MAX_SGE];
278 	struct ib_cqe		cqe;
279 };
280 
281 /**
282  * struct srp_fr_desc - fast registration work request arguments
283  * @entry: Entry in srp_fr_pool.free_list.
284  * @mr:    Memory region.
285  * @frpl:  Fast registration page list.
286  */
287 struct srp_fr_desc {
288 	struct list_head		entry;
289 	struct ib_mr			*mr;
290 };
291 
292 /**
293  * struct srp_fr_pool - pool of fast registration descriptors
294  *
295  * An entry is available for allocation if and only if it occurs in @free_list.
296  *
297  * @size:      Number of descriptors in this pool.
298  * @max_page_list_len: Maximum fast registration work request page list length.
299  * @lock:      Protects free_list.
300  * @free_list: List of free descriptors.
301  * @desc:      Fast registration descriptor pool.
302  */
303 struct srp_fr_pool {
304 	int			size;
305 	int			max_page_list_len;
306 	spinlock_t		lock;
307 	struct list_head	free_list;
308 	struct srp_fr_desc	desc[];
309 };
310 
311 /**
312  * struct srp_map_state - per-request DMA memory mapping state
313  * @desc:	    Pointer to the element of the SRP buffer descriptor array
314  *		    that is being filled in.
315  * @pages:	    Array with DMA addresses of pages being considered for
316  *		    memory registration.
317  * @base_dma_addr:  DMA address of the first page that has not yet been mapped.
318  * @dma_len:	    Number of bytes that will be registered with the next FR
319  *                  memory registration call.
320  * @total_len:	    Total number of bytes in the sg-list being mapped.
321  * @npages:	    Number of page addresses in the pages[] array.
322  * @nmdesc:	    Number of FR memory descriptors used for mapping.
323  * @ndesc:	    Number of SRP buffer descriptors that have been filled in.
324  */
325 struct srp_map_state {
326 	union {
327 		struct {
328 			struct srp_fr_desc **next;
329 			struct srp_fr_desc **end;
330 		} fr;
331 		struct {
332 			void		   **next;
333 			void		   **end;
334 		} gen;
335 	};
336 	struct srp_direct_buf  *desc;
337 	union {
338 		u64			*pages;
339 		struct scatterlist	*sg;
340 	};
341 	dma_addr_t		base_dma_addr;
342 	u32			dma_len;
343 	u32			total_len;
344 	unsigned int		npages;
345 	unsigned int		nmdesc;
346 	unsigned int		ndesc;
347 };
348 
349 #endif /* IB_SRP_H */
350