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