1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * RDMA Transport Layer
4  *
5  * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6  * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7  * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8  */
9 
10 #ifndef RTRS_PRI_H
11 #define RTRS_PRI_H
12 
13 #include <linux/uuid.h>
14 #include <rdma/rdma_cm.h>
15 #include <rdma/ib_verbs.h>
16 #include <rdma/ib.h>
17 
18 #include "rtrs.h"
19 
20 #define RTRS_PROTO_VER_MAJOR 2
21 #define RTRS_PROTO_VER_MINOR 0
22 
23 #define RTRS_PROTO_VER_STRING __stringify(RTRS_PROTO_VER_MAJOR) "." \
24 			       __stringify(RTRS_PROTO_VER_MINOR)
25 
26 enum rtrs_imm_const {
27 	MAX_IMM_TYPE_BITS = 4,
28 	MAX_IMM_TYPE_MASK = ((1 << MAX_IMM_TYPE_BITS) - 1),
29 	MAX_IMM_PAYL_BITS = 28,
30 	MAX_IMM_PAYL_MASK = ((1 << MAX_IMM_PAYL_BITS) - 1),
31 };
32 
33 enum rtrs_imm_type {
34 	RTRS_IO_REQ_IMM       = 0, /* client to server */
35 	RTRS_IO_RSP_IMM       = 1, /* server to client */
36 	RTRS_IO_RSP_W_INV_IMM = 2, /* server to client */
37 
38 	RTRS_HB_MSG_IMM = 8, /* HB: HeartBeat */
39 	RTRS_HB_ACK_IMM = 9,
40 
41 	RTRS_LAST_IMM,
42 };
43 
44 enum {
45 	SERVICE_CON_QUEUE_DEPTH = 512,
46 
47 	MAX_PATHS_NUM = 128,
48 
49 	/*
50 	 * With the size of struct rtrs_permit allocated on the client, 4K
51 	 * is the maximum number of rtrs_permits we can allocate. This number is
52 	 * also used on the client to allocate the IU for the user connection
53 	 * to receive the RDMA addresses from the server.
54 	 */
55 	MAX_SESS_QUEUE_DEPTH = 4096,
56 
57 	RTRS_HB_INTERVAL_MS = 5000,
58 	RTRS_HB_MISSED_MAX = 5,
59 
60 	RTRS_MAGIC = 0x1BBD,
61 	RTRS_PROTO_VER = (RTRS_PROTO_VER_MAJOR << 8) | RTRS_PROTO_VER_MINOR,
62 };
63 
64 struct rtrs_ib_dev;
65 
66 struct rtrs_rdma_dev_pd_ops {
67 	struct rtrs_ib_dev *(*alloc)(void);
68 	void (*free)(struct rtrs_ib_dev *dev);
69 	int (*init)(struct rtrs_ib_dev *dev);
70 	void (*deinit)(struct rtrs_ib_dev *dev);
71 };
72 
73 struct rtrs_rdma_dev_pd {
74 	struct mutex		mutex;
75 	struct list_head	list;
76 	enum ib_pd_flags	pd_flags;
77 	const struct rtrs_rdma_dev_pd_ops *ops;
78 };
79 
80 struct rtrs_ib_dev {
81 	struct ib_device	 *ib_dev;
82 	struct ib_pd		 *ib_pd;
83 	struct kref		 ref;
84 	struct list_head	 entry;
85 	struct rtrs_rdma_dev_pd *pool;
86 };
87 
88 struct rtrs_con {
89 	struct rtrs_sess	*sess;
90 	struct ib_qp		*qp;
91 	struct ib_cq		*cq;
92 	struct rdma_cm_id	*cm_id;
93 	unsigned int		cid;
94 };
95 
96 struct rtrs_sess {
97 	struct list_head	entry;
98 	struct sockaddr_storage dst_addr;
99 	struct sockaddr_storage src_addr;
100 	char			sessname[NAME_MAX];
101 	uuid_t			uuid;
102 	struct rtrs_con	**con;
103 	unsigned int		con_num;
104 	unsigned int		recon_cnt;
105 	struct rtrs_ib_dev	*dev;
106 	int			dev_ref;
107 	struct ib_cqe		*hb_cqe;
108 	void			(*hb_err_handler)(struct rtrs_con *con);
109 	struct workqueue_struct *hb_wq;
110 	struct delayed_work	hb_dwork;
111 	unsigned int		hb_interval_ms;
112 	unsigned int		hb_missed_cnt;
113 	unsigned int		hb_missed_max;
114 };
115 
116 /* rtrs information unit */
117 struct rtrs_iu {
118 	struct ib_cqe           cqe;
119 	dma_addr_t              dma_addr;
120 	void                    *buf;
121 	size_t                  size;
122 	enum dma_data_direction direction;
123 };
124 
125 /**
126  * enum rtrs_msg_types - RTRS message types, see also rtrs/README
127  * @RTRS_MSG_INFO_REQ:		Client additional info request to the server
128  * @RTRS_MSG_INFO_RSP:		Server additional info response to the client
129  * @RTRS_MSG_WRITE:		Client writes data per RDMA to server
130  * @RTRS_MSG_READ:		Client requests data transfer from server
131  * @RTRS_MSG_RKEY_RSP:		Server refreshed rkey for rbuf
132  */
133 enum rtrs_msg_types {
134 	RTRS_MSG_INFO_REQ,
135 	RTRS_MSG_INFO_RSP,
136 	RTRS_MSG_WRITE,
137 	RTRS_MSG_READ,
138 	RTRS_MSG_RKEY_RSP,
139 };
140 
141 /**
142  * enum rtrs_msg_flags - RTRS message flags.
143  * @RTRS_NEED_INVAL:	Send invalidation in response.
144  * @RTRS_MSG_NEW_RKEY_F: Send refreshed rkey in response.
145  */
146 enum rtrs_msg_flags {
147 	RTRS_MSG_NEED_INVAL_F = 1 << 0,
148 	RTRS_MSG_NEW_RKEY_F = 1 << 1,
149 };
150 
151 /**
152  * struct rtrs_sg_desc - RDMA-Buffer entry description
153  * @addr:	Address of RDMA destination buffer
154  * @key:	Authorization rkey to write to the buffer
155  * @len:	Size of the buffer
156  */
157 struct rtrs_sg_desc {
158 	__le64			addr;
159 	__le32			key;
160 	__le32			len;
161 };
162 
163 /**
164  * struct rtrs_msg_conn_req - Client connection request to the server
165  * @magic:	   RTRS magic
166  * @version:	   RTRS protocol version
167  * @cid:	   Current connection id
168  * @cid_num:	   Number of connections per session
169  * @recon_cnt:	   Reconnections counter
170  * @sess_uuid:	   UUID of a session (path)
171  * @paths_uuid:	   UUID of a group of sessions (paths)
172  *
173  * NOTE: max size 56 bytes, see man rdma_connect().
174  */
175 struct rtrs_msg_conn_req {
176 	/* Is set to 0 by cma.c in case of AF_IB, do not touch that.
177 	 * see https://www.spinics.net/lists/linux-rdma/msg22397.html
178 	 */
179 	u8		__cma_version;
180 	/* On sender side that should be set to 0, or cma_save_ip_info()
181 	 * extract garbage and will fail.
182 	 */
183 	u8		__ip_version;
184 	__le16		magic;
185 	__le16		version;
186 	__le16		cid;
187 	__le16		cid_num;
188 	__le16		recon_cnt;
189 	uuid_t		sess_uuid;
190 	uuid_t		paths_uuid;
191 	u8		first_conn : 1;
192 	u8		reserved_bits : 7;
193 	u8		reserved[11];
194 };
195 
196 /**
197  * struct rtrs_msg_conn_rsp - Server connection response to the client
198  * @magic:	   RTRS magic
199  * @version:	   RTRS protocol version
200  * @errno:	   If rdma_accept() then 0, if rdma_reject() indicates error
201  * @queue_depth:   max inflight messages (queue-depth) in this session
202  * @max_io_size:   max io size server supports
203  * @max_hdr_size:  max msg header size server supports
204  *
205  * NOTE: size is 56 bytes, max possible is 136 bytes, see man rdma_accept().
206  */
207 struct rtrs_msg_conn_rsp {
208 	__le16		magic;
209 	__le16		version;
210 	__le16		errno;
211 	__le16		queue_depth;
212 	__le32		max_io_size;
213 	__le32		max_hdr_size;
214 	__le32		flags;
215 	u8		reserved[36];
216 };
217 
218 /**
219  * struct rtrs_msg_info_req
220  * @type:		@RTRS_MSG_INFO_REQ
221  * @sessname:		Session name chosen by client
222  */
223 struct rtrs_msg_info_req {
224 	__le16		type;
225 	u8		sessname[NAME_MAX];
226 	u8		reserved[15];
227 };
228 
229 /**
230  * struct rtrs_msg_info_rsp
231  * @type:		@RTRS_MSG_INFO_RSP
232  * @sg_cnt:		Number of @desc entries
233  * @desc:		RDMA buffers where the client can write to server
234  */
235 struct rtrs_msg_info_rsp {
236 	__le16		type;
237 	__le16          sg_cnt;
238 	u8              reserved[4];
239 	struct rtrs_sg_desc desc[];
240 };
241 
242 /**
243  * struct rtrs_msg_rkey_rsp
244  * @type:		@RTRS_MSG_RKEY_RSP
245  * @buf_id:		RDMA buf_id of the new rkey
246  * @rkey:		new remote key for RDMA buffers id from server
247  */
248 struct rtrs_msg_rkey_rsp {
249 	__le16		type;
250 	__le16          buf_id;
251 	__le32		rkey;
252 };
253 
254 /**
255  * struct rtrs_msg_rdma_read - RDMA data transfer request from client
256  * @type:		always @RTRS_MSG_READ
257  * @usr_len:		length of user payload
258  * @sg_cnt:		number of @desc entries
259  * @desc:		RDMA buffers where the server can write the result to
260  */
261 struct rtrs_msg_rdma_read {
262 	__le16			type;
263 	__le16			usr_len;
264 	__le16			flags;
265 	__le16			sg_cnt;
266 	struct rtrs_sg_desc    desc[];
267 };
268 
269 /**
270  * struct_msg_rdma_write - Message transferred to server with RDMA-Write
271  * @type:		always @RTRS_MSG_WRITE
272  * @usr_len:		length of user payload
273  */
274 struct rtrs_msg_rdma_write {
275 	__le16			type;
276 	__le16			usr_len;
277 };
278 
279 /**
280  * struct_msg_rdma_hdr - header for read or write request
281  * @type:		@RTRS_MSG_WRITE | @RTRS_MSG_READ
282  */
283 struct rtrs_msg_rdma_hdr {
284 	__le16			type;
285 };
286 
287 /* rtrs.c */
288 
289 struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t t,
290 			      struct ib_device *dev, enum dma_data_direction,
291 			      void (*done)(struct ib_cq *cq, struct ib_wc *wc));
292 void rtrs_iu_free(struct rtrs_iu *iu, struct ib_device *dev, u32 queue_size);
293 int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu);
294 int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
295 		      struct ib_send_wr *head);
296 int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
297 				struct ib_sge *sge, unsigned int num_sge,
298 				u32 rkey, u64 rdma_addr, u32 imm_data,
299 				enum ib_send_flags flags,
300 				struct ib_send_wr *head);
301 
302 int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe);
303 int rtrs_post_rdma_write_imm_empty(struct rtrs_con *con, struct ib_cqe *cqe,
304 				   u32 imm_data, enum ib_send_flags flags,
305 				   struct ib_send_wr *head);
306 
307 int rtrs_cq_qp_create(struct rtrs_sess *rtrs_sess, struct rtrs_con *con,
308 		      u32 max_send_sge, int cq_vector, int cq_size,
309 		      u32 max_send_wr, u32 max_recv_wr,
310 		      enum ib_poll_context poll_ctx);
311 void rtrs_cq_qp_destroy(struct rtrs_con *con);
312 
313 void rtrs_init_hb(struct rtrs_sess *sess, struct ib_cqe *cqe,
314 		  unsigned int interval_ms, unsigned int missed_max,
315 		  void (*err_handler)(struct rtrs_con *con),
316 		  struct workqueue_struct *wq);
317 void rtrs_start_hb(struct rtrs_sess *sess);
318 void rtrs_stop_hb(struct rtrs_sess *sess);
319 void rtrs_send_hb_ack(struct rtrs_sess *sess);
320 
321 void rtrs_rdma_dev_pd_init(enum ib_pd_flags pd_flags,
322 			   struct rtrs_rdma_dev_pd *pool);
323 void rtrs_rdma_dev_pd_deinit(struct rtrs_rdma_dev_pd *pool);
324 
325 struct rtrs_ib_dev *rtrs_ib_dev_find_or_add(struct ib_device *ib_dev,
326 					    struct rtrs_rdma_dev_pd *pool);
327 int rtrs_ib_dev_put(struct rtrs_ib_dev *dev);
328 
329 static inline u32 rtrs_to_imm(u32 type, u32 payload)
330 {
331 	BUILD_BUG_ON(MAX_IMM_PAYL_BITS + MAX_IMM_TYPE_BITS != 32);
332 	BUILD_BUG_ON(RTRS_LAST_IMM > (1<<MAX_IMM_TYPE_BITS));
333 	return ((type & MAX_IMM_TYPE_MASK) << MAX_IMM_PAYL_BITS) |
334 		(payload & MAX_IMM_PAYL_MASK);
335 }
336 
337 static inline void rtrs_from_imm(u32 imm, u32 *type, u32 *payload)
338 {
339 	*payload = imm & MAX_IMM_PAYL_MASK;
340 	*type = imm >> MAX_IMM_PAYL_BITS;
341 }
342 
343 static inline u32 rtrs_to_io_req_imm(u32 addr)
344 {
345 	return rtrs_to_imm(RTRS_IO_REQ_IMM, addr);
346 }
347 
348 static inline u32 rtrs_to_io_rsp_imm(u32 msg_id, int errno, bool w_inval)
349 {
350 	enum rtrs_imm_type type;
351 	u32 payload;
352 
353 	/* 9 bits for errno, 19 bits for msg_id */
354 	payload = (abs(errno) & 0x1ff) << 19 | (msg_id & 0x7ffff);
355 	type = w_inval ? RTRS_IO_RSP_W_INV_IMM : RTRS_IO_RSP_IMM;
356 
357 	return rtrs_to_imm(type, payload);
358 }
359 
360 static inline void rtrs_from_io_rsp_imm(u32 payload, u32 *msg_id, int *errno)
361 {
362 	/* 9 bits for errno, 19 bits for msg_id */
363 	*msg_id = payload & 0x7ffff;
364 	*errno = -(int)((payload >> 19) & 0x1ff);
365 }
366 
367 #define STAT_STORE_FUNC(type, set_value, reset)				\
368 static ssize_t set_value##_store(struct kobject *kobj,			\
369 			     struct kobj_attribute *attr,		\
370 			     const char *buf, size_t count)		\
371 {									\
372 	int ret = -EINVAL;						\
373 	type *stats = container_of(kobj, type, kobj_stats);		\
374 									\
375 	if (sysfs_streq(buf, "1"))					\
376 		ret = reset(stats, true);			\
377 	else if (sysfs_streq(buf, "0"))					\
378 		ret = reset(stats, false);			\
379 	if (ret)							\
380 		return ret;						\
381 									\
382 	return count;							\
383 }
384 
385 #define STAT_SHOW_FUNC(type, get_value, print)				\
386 static ssize_t get_value##_show(struct kobject *kobj,			\
387 			   struct kobj_attribute *attr,			\
388 			   char *page)					\
389 {									\
390 	type *stats = container_of(kobj, type, kobj_stats);		\
391 									\
392 	return print(stats, page, PAGE_SIZE);			\
393 }
394 
395 #define STAT_ATTR(type, stat, print, reset)				\
396 STAT_STORE_FUNC(type, stat, reset)					\
397 STAT_SHOW_FUNC(type, stat, print)					\
398 static struct kobj_attribute stat##_attr = __ATTR_RW(stat)
399 
400 #endif /* RTRS_PRI_H */
401