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 	LOCAL_INV_WR_ID_MASK	= 1,
71 	FAST_REG_WR_ID_MASK	= 2,
72 
73 	SRP_LAST_WR_ID		= 0xfffffffcU,
74 };
75 
76 enum srp_target_state {
77 	SRP_TARGET_SCANNING,
78 	SRP_TARGET_LIVE,
79 	SRP_TARGET_REMOVED,
80 };
81 
82 enum srp_iu_type {
83 	SRP_IU_CMD,
84 	SRP_IU_TSK_MGMT,
85 	SRP_IU_RSP,
86 };
87 
88 /*
89  * @mr_page_mask: HCA memory registration page mask.
90  * @mr_page_size: HCA memory registration page size.
91  * @mr_max_size: Maximum size in bytes of a single FMR / FR registration
92  *   request.
93  */
94 struct srp_device {
95 	struct list_head	dev_list;
96 	struct ib_device       *dev;
97 	struct ib_pd	       *pd;
98 	struct ib_mr	       *global_mr;
99 	u64			mr_page_mask;
100 	int			mr_page_size;
101 	int			mr_max_size;
102 	int			max_pages_per_mr;
103 	bool			has_fmr;
104 	bool			has_fr;
105 	bool			use_fmr;
106 	bool			use_fast_reg;
107 };
108 
109 struct srp_host {
110 	struct srp_device      *srp_dev;
111 	u8			port;
112 	struct device		dev;
113 	struct list_head	target_list;
114 	spinlock_t		target_lock;
115 	struct completion	released;
116 	struct list_head	list;
117 	struct mutex		add_target_mutex;
118 };
119 
120 struct srp_request {
121 	struct scsi_cmnd       *scmnd;
122 	struct srp_iu	       *cmd;
123 	union {
124 		struct ib_pool_fmr **fmr_list;
125 		struct srp_fr_desc **fr_list;
126 	};
127 	u64		       *map_page;
128 	struct srp_direct_buf  *indirect_desc;
129 	dma_addr_t		indirect_dma_addr;
130 	short			nmdesc;
131 };
132 
133 /**
134  * struct srp_rdma_ch
135  * @comp_vector: Completion vector used by this RDMA channel.
136  */
137 struct srp_rdma_ch {
138 	/* These are RW in the hot path, and commonly used together */
139 	struct list_head	free_tx;
140 	spinlock_t		lock;
141 	s32			req_lim;
142 
143 	/* These are read-only in the hot path */
144 	struct srp_target_port *target ____cacheline_aligned_in_smp;
145 	struct ib_cq	       *send_cq;
146 	struct ib_cq	       *recv_cq;
147 	struct ib_qp	       *qp;
148 	union {
149 		struct ib_fmr_pool     *fmr_pool;
150 		struct srp_fr_pool     *fr_pool;
151 	};
152 
153 	/* Everything above this point is used in the hot path of
154 	 * command processing. Try to keep them packed into cachelines.
155 	 */
156 
157 	struct completion	done;
158 	int			status;
159 
160 	struct ib_sa_path_rec	path;
161 	struct ib_sa_query     *path_query;
162 	int			path_query_id;
163 
164 	struct ib_cm_id	       *cm_id;
165 	struct srp_iu	      **tx_ring;
166 	struct srp_iu	      **rx_ring;
167 	struct srp_request     *req_ring;
168 	int			max_ti_iu_len;
169 	int			comp_vector;
170 
171 	struct completion	tsk_mgmt_done;
172 	u8			tsk_mgmt_status;
173 	bool			connected;
174 };
175 
176 /**
177  * struct srp_target_port
178  * @comp_vector: Completion vector used by the first RDMA channel created for
179  *   this target port.
180  */
181 struct srp_target_port {
182 	/* read and written in the hot path */
183 	spinlock_t		lock;
184 
185 	/* read only in the hot path */
186 	struct ib_mr		*global_mr;
187 	struct srp_rdma_ch	*ch;
188 	u32			ch_count;
189 	u32			lkey;
190 	enum srp_target_state	state;
191 	unsigned int		max_iu_len;
192 	unsigned int		cmd_sg_cnt;
193 	unsigned int		indirect_size;
194 	bool			allow_ext_sg;
195 
196 	/* other member variables */
197 	union ib_gid		sgid;
198 	__be64			id_ext;
199 	__be64			ioc_guid;
200 	__be64			service_id;
201 	__be64			initiator_ext;
202 	u16			io_class;
203 	struct srp_host	       *srp_host;
204 	struct Scsi_Host       *scsi_host;
205 	struct srp_rport       *rport;
206 	char			target_name[32];
207 	unsigned int		scsi_id;
208 	unsigned int		sg_tablesize;
209 	int			queue_size;
210 	int			req_ring_size;
211 	int			comp_vector;
212 	int			tl_retry_count;
213 
214 	union ib_gid		orig_dgid;
215 	__be16			pkey;
216 
217 	u32			rq_tmo_jiffies;
218 
219 	int			zero_req_lim;
220 
221 	struct work_struct	tl_err_work;
222 	struct work_struct	remove_work;
223 
224 	struct list_head	list;
225 	bool			qp_in_error;
226 };
227 
228 struct srp_iu {
229 	struct list_head	list;
230 	u64			dma;
231 	void		       *buf;
232 	size_t			size;
233 	enum dma_data_direction	direction;
234 };
235 
236 /**
237  * struct srp_fr_desc - fast registration work request arguments
238  * @entry: Entry in srp_fr_pool.free_list.
239  * @mr:    Memory region.
240  * @frpl:  Fast registration page list.
241  */
242 struct srp_fr_desc {
243 	struct list_head		entry;
244 	struct ib_mr			*mr;
245 };
246 
247 /**
248  * struct srp_fr_pool - pool of fast registration descriptors
249  *
250  * An entry is available for allocation if and only if it occurs in @free_list.
251  *
252  * @size:      Number of descriptors in this pool.
253  * @max_page_list_len: Maximum fast registration work request page list length.
254  * @lock:      Protects free_list.
255  * @free_list: List of free descriptors.
256  * @desc:      Fast registration descriptor pool.
257  */
258 struct srp_fr_pool {
259 	int			size;
260 	int			max_page_list_len;
261 	spinlock_t		lock;
262 	struct list_head	free_list;
263 	struct srp_fr_desc	desc[0];
264 };
265 
266 /**
267  * struct srp_map_state - per-request DMA memory mapping state
268  * @desc:	    Pointer to the element of the SRP buffer descriptor array
269  *		    that is being filled in.
270  * @pages:	    Array with DMA addresses of pages being considered for
271  *		    memory registration.
272  * @base_dma_addr:  DMA address of the first page that has not yet been mapped.
273  * @dma_len:	    Number of bytes that will be registered with the next
274  *		    FMR or FR memory registration call.
275  * @total_len:	    Total number of bytes in the sg-list being mapped.
276  * @npages:	    Number of page addresses in the pages[] array.
277  * @nmdesc:	    Number of FMR or FR memory descriptors used for mapping.
278  * @ndesc:	    Number of SRP buffer descriptors that have been filled in.
279  */
280 struct srp_map_state {
281 	union {
282 		struct {
283 			struct ib_pool_fmr **next;
284 			struct ib_pool_fmr **end;
285 		} fmr;
286 		struct {
287 			struct srp_fr_desc **next;
288 			struct srp_fr_desc **end;
289 		} fr;
290 		struct {
291 			void		   **next;
292 			void		   **end;
293 		} gen;
294 	};
295 	struct srp_direct_buf  *desc;
296 	union {
297 		u64			*pages;
298 		struct scatterlist	*sg;
299 	};
300 	dma_addr_t		base_dma_addr;
301 	u32			dma_len;
302 	u32			total_len;
303 	union {
304 		unsigned int	npages;
305 		int		sg_nents;
306 	};
307 	unsigned int		nmdesc;
308 	unsigned int		ndesc;
309 };
310 
311 #endif /* IB_SRP_H */
312