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