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/ib_fmr_pool.h>
48 #include <rdma/rdma_cm.h>
49 
50 enum {
51 	SRP_PATH_REC_TIMEOUT_MS	= 1000,
52 	SRP_ABORT_TIMEOUT_MS	= 5000,
53 
54 	SRP_PORT_REDIRECT	= 1,
55 	SRP_DLID_REDIRECT	= 2,
56 	SRP_STALE_CONN		= 3,
57 
58 	SRP_DEF_SG_TABLESIZE	= 12,
59 
60 	SRP_DEFAULT_QUEUE_SIZE	= 1 << 6,
61 	SRP_RSP_SQ_SIZE		= 1,
62 	SRP_TSK_MGMT_SQ_SIZE	= 1,
63 	SRP_DEFAULT_CMD_SQ_SIZE = SRP_DEFAULT_QUEUE_SIZE - SRP_RSP_SQ_SIZE -
64 				  SRP_TSK_MGMT_SQ_SIZE,
65 
66 	SRP_TAG_NO_REQ		= ~0U,
67 	SRP_TAG_TSK_MGMT	= 1U << 31,
68 
69 	SRP_MAX_PAGES_PER_MR	= 512,
70 
71 	SRP_MAX_ADD_CDB_LEN	= 16,
72 
73 	SRP_MAX_IMM_SGE		= 2,
74 	SRP_MAX_SGE		= SRP_MAX_IMM_SGE + 1,
75 	/*
76 	 * Choose the immediate data offset such that a 32 byte CDB still fits.
77 	 */
78 	SRP_IMM_DATA_OFFSET	= sizeof(struct srp_cmd) +
79 				  SRP_MAX_ADD_CDB_LEN +
80 				  sizeof(struct srp_imm_buf),
81 };
82 
83 enum srp_target_state {
84 	SRP_TARGET_SCANNING,
85 	SRP_TARGET_LIVE,
86 	SRP_TARGET_REMOVED,
87 };
88 
89 enum srp_iu_type {
90 	SRP_IU_CMD,
91 	SRP_IU_TSK_MGMT,
92 	SRP_IU_RSP,
93 };
94 
95 /*
96  * @mr_page_mask: HCA memory registration page mask.
97  * @mr_page_size: HCA memory registration page size.
98  * @mr_max_size: Maximum size in bytes of a single FMR / FR registration
99  *   request.
100  */
101 struct srp_device {
102 	struct list_head	dev_list;
103 	struct ib_device       *dev;
104 	struct ib_pd	       *pd;
105 	u32			global_rkey;
106 	u64			mr_page_mask;
107 	int			mr_page_size;
108 	int			mr_max_size;
109 	int			max_pages_per_mr;
110 	bool			has_fmr;
111 	bool			has_fr;
112 	bool			use_fmr;
113 	bool			use_fast_reg;
114 };
115 
116 struct srp_host {
117 	struct srp_device      *srp_dev;
118 	u8			port;
119 	struct device		dev;
120 	struct list_head	target_list;
121 	spinlock_t		target_lock;
122 	struct completion	released;
123 	struct list_head	list;
124 	struct mutex		add_target_mutex;
125 };
126 
127 struct srp_request {
128 	struct scsi_cmnd       *scmnd;
129 	struct srp_iu	       *cmd;
130 	union {
131 		struct ib_pool_fmr **fmr_list;
132 		struct srp_fr_desc **fr_list;
133 	};
134 	u64		       *map_page;
135 	struct srp_direct_buf  *indirect_desc;
136 	dma_addr_t		indirect_dma_addr;
137 	short			nmdesc;
138 	struct ib_cqe		reg_cqe;
139 };
140 
141 /**
142  * struct srp_rdma_ch
143  * @comp_vector: Completion vector used by this RDMA channel.
144  * @max_it_iu_len: Maximum initiator-to-target information unit length.
145  * @max_ti_iu_len: Maximum target-to-initiator information unit length.
146  */
147 struct srp_rdma_ch {
148 	/* These are RW in the hot path, and commonly used together */
149 	struct list_head	free_tx;
150 	spinlock_t		lock;
151 	s32			req_lim;
152 
153 	/* These are read-only in the hot path */
154 	struct srp_target_port *target ____cacheline_aligned_in_smp;
155 	struct ib_cq	       *send_cq;
156 	struct ib_cq	       *recv_cq;
157 	struct ib_qp	       *qp;
158 	union {
159 		struct ib_fmr_pool     *fmr_pool;
160 		struct srp_fr_pool     *fr_pool;
161 	};
162 	uint32_t		max_it_iu_len;
163 	uint32_t		max_ti_iu_len;
164 	u8			max_imm_sge;
165 	bool			use_imm_data;
166 
167 	/* Everything above this point is used in the hot path of
168 	 * command processing. Try to keep them packed into cachelines.
169 	 */
170 
171 	struct completion	done;
172 	int			status;
173 
174 	union {
175 		struct ib_cm {
176 			struct sa_path_rec	path;
177 			struct ib_sa_query	*path_query;
178 			int			path_query_id;
179 			struct ib_cm_id		*cm_id;
180 		} ib_cm;
181 		struct rdma_cm {
182 			struct rdma_cm_id	*cm_id;
183 		} rdma_cm;
184 	};
185 
186 	struct srp_iu	      **tx_ring;
187 	struct srp_iu	      **rx_ring;
188 	struct srp_request     *req_ring;
189 	int			comp_vector;
190 
191 	u64			tsk_mgmt_tag;
192 	struct completion	tsk_mgmt_done;
193 	u8			tsk_mgmt_status;
194 	bool			connected;
195 };
196 
197 /**
198  * struct srp_target_port
199  * @comp_vector: Completion vector used by the first RDMA channel created for
200  *   this target port.
201  */
202 struct srp_target_port {
203 	/* read and written in the hot path */
204 	spinlock_t		lock;
205 
206 	/* read only in the hot path */
207 	u32			global_rkey;
208 	struct srp_rdma_ch	*ch;
209 	struct net		*net;
210 	u32			ch_count;
211 	u32			lkey;
212 	enum srp_target_state	state;
213 	uint32_t		max_it_iu_size;
214 	unsigned int		cmd_sg_cnt;
215 	unsigned int		indirect_size;
216 	bool			allow_ext_sg;
217 
218 	/* other member variables */
219 	union ib_gid		sgid;
220 	__be64			id_ext;
221 	__be64			ioc_guid;
222 	__be64			initiator_ext;
223 	u16			io_class;
224 	struct srp_host	       *srp_host;
225 	struct Scsi_Host       *scsi_host;
226 	struct srp_rport       *rport;
227 	char			target_name[32];
228 	unsigned int		scsi_id;
229 	unsigned int		sg_tablesize;
230 	unsigned int		target_can_queue;
231 	int			mr_pool_size;
232 	int			mr_per_cmd;
233 	int			queue_size;
234 	int			req_ring_size;
235 	int			comp_vector;
236 	int			tl_retry_count;
237 
238 	bool			using_rdma_cm;
239 
240 	union {
241 		struct {
242 			__be64			service_id;
243 			union ib_gid		orig_dgid;
244 			__be16			pkey;
245 		} ib_cm;
246 		struct {
247 			union {
248 				struct sockaddr_in	ip4;
249 				struct sockaddr_in6	ip6;
250 				struct sockaddr		sa;
251 				struct sockaddr_storage ss;
252 			} src;
253 			union {
254 				struct sockaddr_in	ip4;
255 				struct sockaddr_in6	ip6;
256 				struct sockaddr		sa;
257 				struct sockaddr_storage ss;
258 			} dst;
259 			bool src_specified;
260 		} rdma_cm;
261 	};
262 
263 	u32			rq_tmo_jiffies;
264 
265 	int			zero_req_lim;
266 
267 	struct work_struct	tl_err_work;
268 	struct work_struct	remove_work;
269 
270 	struct list_head	list;
271 	bool			qp_in_error;
272 };
273 
274 struct srp_iu {
275 	struct list_head	list;
276 	u64			dma;
277 	void		       *buf;
278 	size_t			size;
279 	enum dma_data_direction	direction;
280 	u32			num_sge;
281 	struct ib_sge		sge[SRP_MAX_SGE];
282 	struct ib_cqe		cqe;
283 };
284 
285 /**
286  * struct srp_fr_desc - fast registration work request arguments
287  * @entry: Entry in srp_fr_pool.free_list.
288  * @mr:    Memory region.
289  * @frpl:  Fast registration page list.
290  */
291 struct srp_fr_desc {
292 	struct list_head		entry;
293 	struct ib_mr			*mr;
294 };
295 
296 /**
297  * struct srp_fr_pool - pool of fast registration descriptors
298  *
299  * An entry is available for allocation if and only if it occurs in @free_list.
300  *
301  * @size:      Number of descriptors in this pool.
302  * @max_page_list_len: Maximum fast registration work request page list length.
303  * @lock:      Protects free_list.
304  * @free_list: List of free descriptors.
305  * @desc:      Fast registration descriptor pool.
306  */
307 struct srp_fr_pool {
308 	int			size;
309 	int			max_page_list_len;
310 	spinlock_t		lock;
311 	struct list_head	free_list;
312 	struct srp_fr_desc	desc[0];
313 };
314 
315 /**
316  * struct srp_map_state - per-request DMA memory mapping state
317  * @desc:	    Pointer to the element of the SRP buffer descriptor array
318  *		    that is being filled in.
319  * @pages:	    Array with DMA addresses of pages being considered for
320  *		    memory registration.
321  * @base_dma_addr:  DMA address of the first page that has not yet been mapped.
322  * @dma_len:	    Number of bytes that will be registered with the next
323  *		    FMR or FR memory registration call.
324  * @total_len:	    Total number of bytes in the sg-list being mapped.
325  * @npages:	    Number of page addresses in the pages[] array.
326  * @nmdesc:	    Number of FMR or FR memory descriptors used for mapping.
327  * @ndesc:	    Number of SRP buffer descriptors that have been filled in.
328  */
329 struct srp_map_state {
330 	union {
331 		struct {
332 			struct ib_pool_fmr **next;
333 			struct ib_pool_fmr **end;
334 		} fmr;
335 		struct {
336 			struct srp_fr_desc **next;
337 			struct srp_fr_desc **end;
338 		} fr;
339 		struct {
340 			void		   **next;
341 			void		   **end;
342 		} gen;
343 	};
344 	struct srp_direct_buf  *desc;
345 	union {
346 		u64			*pages;
347 		struct scatterlist	*sg;
348 	};
349 	dma_addr_t		base_dma_addr;
350 	u32			dma_len;
351 	u32			total_len;
352 	unsigned int		npages;
353 	unsigned int		nmdesc;
354 	unsigned int		ndesc;
355 };
356 
357 #endif /* IB_SRP_H */
358