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