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_MAX_LUN		= 512,
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 	LOCAL_INV_WR_ID_MASK	= 1,
72 	FAST_REG_WR_ID_MASK	= 2,
73 };
74 
75 enum srp_target_state {
76 	SRP_TARGET_LIVE,
77 	SRP_TARGET_REMOVED,
78 };
79 
80 enum srp_iu_type {
81 	SRP_IU_CMD,
82 	SRP_IU_TSK_MGMT,
83 	SRP_IU_RSP,
84 };
85 
86 /*
87  * @mr_page_mask: HCA memory registration page mask.
88  * @mr_page_size: HCA memory registration page size.
89  * @mr_max_size: Maximum size in bytes of a single FMR / FR registration
90  *   request.
91  */
92 struct srp_device {
93 	struct list_head	dev_list;
94 	struct ib_device       *dev;
95 	struct ib_pd	       *pd;
96 	struct ib_mr	       *mr;
97 	u64			mr_page_mask;
98 	int			mr_page_size;
99 	int			mr_max_size;
100 	int			max_pages_per_mr;
101 	bool			has_fmr;
102 	bool			has_fr;
103 	bool			use_fast_reg;
104 };
105 
106 struct srp_host {
107 	struct srp_device      *srp_dev;
108 	u8			port;
109 	struct device		dev;
110 	struct list_head	target_list;
111 	spinlock_t		target_lock;
112 	struct completion	released;
113 	struct list_head	list;
114 	struct mutex		add_target_mutex;
115 };
116 
117 struct srp_request {
118 	struct list_head	list;
119 	struct scsi_cmnd       *scmnd;
120 	struct srp_iu	       *cmd;
121 	union {
122 		struct ib_pool_fmr **fmr_list;
123 		struct srp_fr_desc **fr_list;
124 	};
125 	u64		       *map_page;
126 	struct srp_direct_buf  *indirect_desc;
127 	dma_addr_t		indirect_dma_addr;
128 	short			nmdesc;
129 	short			index;
130 };
131 
132 struct srp_target_port {
133 	/* These are RW in the hot path, and commonly used together */
134 	struct list_head	free_tx;
135 	struct list_head	free_reqs;
136 	spinlock_t		lock;
137 	s32			req_lim;
138 
139 	/* These are read-only in the hot path */
140 	struct ib_cq	       *send_cq ____cacheline_aligned_in_smp;
141 	struct ib_cq	       *recv_cq;
142 	struct ib_qp	       *qp;
143 	union {
144 		struct ib_fmr_pool     *fmr_pool;
145 		struct srp_fr_pool     *fr_pool;
146 	};
147 	u32			lkey;
148 	u32			rkey;
149 	enum srp_target_state	state;
150 	unsigned int		max_iu_len;
151 	unsigned int		cmd_sg_cnt;
152 	unsigned int		indirect_size;
153 	bool			allow_ext_sg;
154 
155 	/* Everything above this point is used in the hot path of
156 	 * command processing. Try to keep them packed into cachelines.
157 	 */
158 
159 	__be64			id_ext;
160 	__be64			ioc_guid;
161 	__be64			service_id;
162 	__be64			initiator_ext;
163 	u16			io_class;
164 	struct srp_host	       *srp_host;
165 	struct Scsi_Host       *scsi_host;
166 	struct srp_rport       *rport;
167 	char			target_name[32];
168 	unsigned int		scsi_id;
169 	unsigned int		sg_tablesize;
170 	int			queue_size;
171 	int			req_ring_size;
172 	int			comp_vector;
173 	int			tl_retry_count;
174 
175 	struct ib_sa_path_rec	path;
176 	__be16			orig_dgid[8];
177 	struct ib_sa_query     *path_query;
178 	int			path_query_id;
179 
180 	u32			rq_tmo_jiffies;
181 	bool			connected;
182 
183 	struct ib_cm_id	       *cm_id;
184 
185 	int			max_ti_iu_len;
186 
187 	int			zero_req_lim;
188 
189 	struct srp_iu	       **tx_ring;
190 	struct srp_iu	       **rx_ring;
191 	struct srp_request	*req_ring;
192 
193 	struct work_struct	tl_err_work;
194 	struct work_struct	remove_work;
195 
196 	struct list_head	list;
197 	struct completion	done;
198 	int			status;
199 	bool			qp_in_error;
200 
201 	struct completion	tsk_mgmt_done;
202 	u8			tsk_mgmt_status;
203 };
204 
205 struct srp_iu {
206 	struct list_head	list;
207 	u64			dma;
208 	void		       *buf;
209 	size_t			size;
210 	enum dma_data_direction	direction;
211 };
212 
213 /**
214  * struct srp_fr_desc - fast registration work request arguments
215  * @entry: Entry in srp_fr_pool.free_list.
216  * @mr:    Memory region.
217  * @frpl:  Fast registration page list.
218  */
219 struct srp_fr_desc {
220 	struct list_head		entry;
221 	struct ib_mr			*mr;
222 	struct ib_fast_reg_page_list	*frpl;
223 };
224 
225 /**
226  * struct srp_fr_pool - pool of fast registration descriptors
227  *
228  * An entry is available for allocation if and only if it occurs in @free_list.
229  *
230  * @size:      Number of descriptors in this pool.
231  * @max_page_list_len: Maximum fast registration work request page list length.
232  * @lock:      Protects free_list.
233  * @free_list: List of free descriptors.
234  * @desc:      Fast registration descriptor pool.
235  */
236 struct srp_fr_pool {
237 	int			size;
238 	int			max_page_list_len;
239 	spinlock_t		lock;
240 	struct list_head	free_list;
241 	struct srp_fr_desc	desc[0];
242 };
243 
244 /**
245  * struct srp_map_state - per-request DMA memory mapping state
246  * @desc:	    Pointer to the element of the SRP buffer descriptor array
247  *		    that is being filled in.
248  * @pages:	    Array with DMA addresses of pages being considered for
249  *		    memory registration.
250  * @base_dma_addr:  DMA address of the first page that has not yet been mapped.
251  * @dma_len:	    Number of bytes that will be registered with the next
252  *		    FMR or FR memory registration call.
253  * @total_len:	    Total number of bytes in the sg-list being mapped.
254  * @npages:	    Number of page addresses in the pages[] array.
255  * @nmdesc:	    Number of FMR or FR memory descriptors used for mapping.
256  * @ndesc:	    Number of SRP buffer descriptors that have been filled in.
257  * @unmapped_sg:    First element of the sg-list that is mapped via FMR or FR.
258  * @unmapped_index: Index of the first element mapped via FMR or FR.
259  * @unmapped_addr:  DMA address of the first element mapped via FMR or FR.
260  */
261 struct srp_map_state {
262 	union {
263 		struct ib_pool_fmr **next_fmr;
264 		struct srp_fr_desc **next_fr;
265 	};
266 	struct srp_direct_buf  *desc;
267 	u64		       *pages;
268 	dma_addr_t		base_dma_addr;
269 	u32			dma_len;
270 	u32			total_len;
271 	unsigned int		npages;
272 	unsigned int		nmdesc;
273 	unsigned int		ndesc;
274 	struct scatterlist     *unmapped_sg;
275 	int			unmapped_index;
276 	dma_addr_t		unmapped_addr;
277 };
278 
279 #endif /* IB_SRP_H */
280