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 	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 	struct srp_request     *req_ring;
188 	int			comp_vector;
189 
190 	u64			tsk_mgmt_tag;
191 	struct completion	tsk_mgmt_done;
192 	u8			tsk_mgmt_status;
193 	bool			connected;
194 };
195 
196 /**
197  * struct srp_target_port
198  * @comp_vector: Completion vector used by the first RDMA channel created for
199  *   this target port.
200  */
201 struct srp_target_port {
202 	/* read and written in the hot path */
203 	spinlock_t		lock;
204 
205 	/* read only in the hot path */
206 	u32			global_rkey;
207 	struct srp_rdma_ch	*ch;
208 	struct net		*net;
209 	u32			ch_count;
210 	u32			lkey;
211 	enum srp_target_state	state;
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			req_ring_size;
233 	int			comp_vector;
234 	int			tl_retry_count;
235 
236 	bool			using_rdma_cm;
237 
238 	union {
239 		struct {
240 			__be64			service_id;
241 			union ib_gid		orig_dgid;
242 			__be16			pkey;
243 		} ib_cm;
244 		struct {
245 			union {
246 				struct sockaddr_in	ip4;
247 				struct sockaddr_in6	ip6;
248 				struct sockaddr_storage ss;
249 			} src;
250 			union {
251 				struct sockaddr_in	ip4;
252 				struct sockaddr_in6	ip6;
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[0];
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
319  *		    FMR or FR 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 FMR or 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 ib_pool_fmr **next;
329 			struct ib_pool_fmr **end;
330 		} fmr;
331 		struct {
332 			struct srp_fr_desc **next;
333 			struct srp_fr_desc **end;
334 		} fr;
335 		struct {
336 			void		   **next;
337 			void		   **end;
338 		} gen;
339 	};
340 	struct srp_direct_buf  *desc;
341 	union {
342 		u64			*pages;
343 		struct scatterlist	*sg;
344 	};
345 	dma_addr_t		base_dma_addr;
346 	u32			dma_len;
347 	u32			total_len;
348 	unsigned int		npages;
349 	unsigned int		nmdesc;
350 	unsigned int		ndesc;
351 };
352 
353 #endif /* IB_SRP_H */
354