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 	 * Max IB immediate data size is 2^28 (MAX_IMM_PAYL_BITS)
51 	 * and the minimum chunk size is 4096 (2^12).
52 	 * So the maximum sess_queue_depth is 65536 (2^16) in theory.
53 	 * But mempool_create, create_qp and ib_post_send fail with
54 	 * "cannot allocate memory" error if sess_queue_depth is too big.
55 	 * Therefore the pratical max value of sess_queue_depth is
56 	 * somewhere between 1 and 65534 and it depends on the system.
57 	 */
58 	MAX_SESS_QUEUE_DEPTH = 65535,
59 	MIN_CHUNK_SIZE = 8192,
60 
61 	RTRS_HB_INTERVAL_MS = 5000,
62 	RTRS_HB_MISSED_MAX = 5,
63 
64 	RTRS_MAGIC = 0x1BBD,
65 	RTRS_PROTO_VER = (RTRS_PROTO_VER_MAJOR << 8) | RTRS_PROTO_VER_MINOR,
66 };
67 
68 struct rtrs_ib_dev;
69 
70 struct rtrs_rdma_dev_pd_ops {
71 	struct rtrs_ib_dev *(*alloc)(void);
72 	void (*free)(struct rtrs_ib_dev *dev);
73 	int (*init)(struct rtrs_ib_dev *dev);
74 	void (*deinit)(struct rtrs_ib_dev *dev);
75 };
76 
77 struct rtrs_rdma_dev_pd {
78 	struct mutex		mutex;
79 	struct list_head	list;
80 	enum ib_pd_flags	pd_flags;
81 	const struct rtrs_rdma_dev_pd_ops *ops;
82 };
83 
84 struct rtrs_ib_dev {
85 	struct ib_device	 *ib_dev;
86 	struct ib_pd		 *ib_pd;
87 	struct kref		 ref;
88 	struct list_head	 entry;
89 	struct rtrs_rdma_dev_pd *pool;
90 };
91 
92 struct rtrs_con {
93 	struct rtrs_sess	*sess;
94 	struct ib_qp		*qp;
95 	struct ib_cq		*cq;
96 	struct rdma_cm_id	*cm_id;
97 	unsigned int		cid;
98 	int                     nr_cqe;
99 	atomic_t		wr_cnt;
100 	atomic_t		sq_wr_avail;
101 };
102 
103 struct rtrs_sess {
104 	struct list_head	entry;
105 	struct sockaddr_storage dst_addr;
106 	struct sockaddr_storage src_addr;
107 	char			sessname[NAME_MAX];
108 	uuid_t			uuid;
109 	struct rtrs_con	**con;
110 	unsigned int		con_num;
111 	unsigned int		irq_con_num;
112 	unsigned int		recon_cnt;
113 	unsigned int		signal_interval;
114 	struct rtrs_ib_dev	*dev;
115 	int			dev_ref;
116 	struct ib_cqe		*hb_cqe;
117 	void			(*hb_err_handler)(struct rtrs_con *con);
118 	struct workqueue_struct *hb_wq;
119 	struct delayed_work	hb_dwork;
120 	unsigned int		hb_interval_ms;
121 	unsigned int		hb_missed_cnt;
122 	unsigned int		hb_missed_max;
123 	ktime_t			hb_last_sent;
124 	ktime_t			hb_cur_latency;
125 };
126 
127 /* rtrs information unit */
128 struct rtrs_iu {
129 	struct ib_cqe           cqe;
130 	dma_addr_t              dma_addr;
131 	void                    *buf;
132 	size_t                  size;
133 	enum dma_data_direction direction;
134 };
135 
136 /**
137  * enum rtrs_msg_types - RTRS message types, see also rtrs/README
138  * @RTRS_MSG_INFO_REQ:		Client additional info request to the server
139  * @RTRS_MSG_INFO_RSP:		Server additional info response to the client
140  * @RTRS_MSG_WRITE:		Client writes data per RDMA to server
141  * @RTRS_MSG_READ:		Client requests data transfer from server
142  * @RTRS_MSG_RKEY_RSP:		Server refreshed rkey for rbuf
143  */
144 enum rtrs_msg_types {
145 	RTRS_MSG_INFO_REQ,
146 	RTRS_MSG_INFO_RSP,
147 	RTRS_MSG_WRITE,
148 	RTRS_MSG_READ,
149 	RTRS_MSG_RKEY_RSP,
150 };
151 
152 /**
153  * enum rtrs_msg_flags - RTRS message flags.
154  * @RTRS_NEED_INVAL:	Send invalidation in response.
155  * @RTRS_MSG_NEW_RKEY_F: Send refreshed rkey in response.
156  */
157 enum rtrs_msg_flags {
158 	RTRS_MSG_NEED_INVAL_F = 1 << 0,
159 	RTRS_MSG_NEW_RKEY_F = 1 << 1,
160 };
161 
162 /**
163  * struct rtrs_sg_desc - RDMA-Buffer entry description
164  * @addr:	Address of RDMA destination buffer
165  * @key:	Authorization rkey to write to the buffer
166  * @len:	Size of the buffer
167  */
168 struct rtrs_sg_desc {
169 	__le64			addr;
170 	__le32			key;
171 	__le32			len;
172 };
173 
174 /**
175  * struct rtrs_msg_conn_req - Client connection request to the server
176  * @magic:	   RTRS magic
177  * @version:	   RTRS protocol version
178  * @cid:	   Current connection id
179  * @cid_num:	   Number of connections per session
180  * @recon_cnt:	   Reconnections counter
181  * @sess_uuid:	   UUID of a session (path)
182  * @paths_uuid:	   UUID of a group of sessions (paths)
183  *
184  * NOTE: max size 56 bytes, see man rdma_connect().
185  */
186 struct rtrs_msg_conn_req {
187 	/* Is set to 0 by cma.c in case of AF_IB, do not touch that.
188 	 * see https://www.spinics.net/lists/linux-rdma/msg22397.html
189 	 */
190 	u8		__cma_version;
191 	/* On sender side that should be set to 0, or cma_save_ip_info()
192 	 * extract garbage and will fail.
193 	 */
194 	u8		__ip_version;
195 	__le16		magic;
196 	__le16		version;
197 	__le16		cid;
198 	__le16		cid_num;
199 	__le16		recon_cnt;
200 	uuid_t		sess_uuid;
201 	uuid_t		paths_uuid;
202 	u8		first_conn : 1;
203 	u8		reserved_bits : 7;
204 	u8		reserved[11];
205 };
206 
207 /**
208  * struct rtrs_msg_conn_rsp - Server connection response to the client
209  * @magic:	   RTRS magic
210  * @version:	   RTRS protocol version
211  * @errno:	   If rdma_accept() then 0, if rdma_reject() indicates error
212  * @queue_depth:   max inflight messages (queue-depth) in this session
213  * @max_io_size:   max io size server supports
214  * @max_hdr_size:  max msg header size server supports
215  *
216  * NOTE: size is 56 bytes, max possible is 136 bytes, see man rdma_accept().
217  */
218 struct rtrs_msg_conn_rsp {
219 	__le16		magic;
220 	__le16		version;
221 	__le16		errno;
222 	__le16		queue_depth;
223 	__le32		max_io_size;
224 	__le32		max_hdr_size;
225 	__le32		flags;
226 	u8		reserved[36];
227 };
228 
229 /**
230  * struct rtrs_msg_info_req
231  * @type:		@RTRS_MSG_INFO_REQ
232  * @sessname:		Session name chosen by client
233  */
234 struct rtrs_msg_info_req {
235 	__le16		type;
236 	u8		sessname[NAME_MAX];
237 	u8		reserved[15];
238 };
239 
240 /**
241  * struct rtrs_msg_info_rsp
242  * @type:		@RTRS_MSG_INFO_RSP
243  * @sg_cnt:		Number of @desc entries
244  * @desc:		RDMA buffers where the client can write to server
245  */
246 struct rtrs_msg_info_rsp {
247 	__le16		type;
248 	__le16          sg_cnt;
249 	u8              reserved[4];
250 	struct rtrs_sg_desc desc[];
251 };
252 
253 /**
254  * struct rtrs_msg_rkey_rsp
255  * @type:		@RTRS_MSG_RKEY_RSP
256  * @buf_id:		RDMA buf_id of the new rkey
257  * @rkey:		new remote key for RDMA buffers id from server
258  */
259 struct rtrs_msg_rkey_rsp {
260 	__le16		type;
261 	__le16          buf_id;
262 	__le32		rkey;
263 };
264 
265 /**
266  * struct rtrs_msg_rdma_read - RDMA data transfer request from client
267  * @type:		always @RTRS_MSG_READ
268  * @usr_len:		length of user payload
269  * @sg_cnt:		number of @desc entries
270  * @desc:		RDMA buffers where the server can write the result to
271  */
272 struct rtrs_msg_rdma_read {
273 	__le16			type;
274 	__le16			usr_len;
275 	__le16			flags;
276 	__le16			sg_cnt;
277 	struct rtrs_sg_desc    desc[];
278 };
279 
280 /**
281  * struct_msg_rdma_write - Message transferred to server with RDMA-Write
282  * @type:		always @RTRS_MSG_WRITE
283  * @usr_len:		length of user payload
284  */
285 struct rtrs_msg_rdma_write {
286 	__le16			type;
287 	__le16			usr_len;
288 };
289 
290 /**
291  * struct_msg_rdma_hdr - header for read or write request
292  * @type:		@RTRS_MSG_WRITE | @RTRS_MSG_READ
293  */
294 struct rtrs_msg_rdma_hdr {
295 	__le16			type;
296 };
297 
298 /* rtrs.c */
299 
300 struct rtrs_iu *rtrs_iu_alloc(u32 queue_num, size_t size, gfp_t t,
301 			      struct ib_device *dev, enum dma_data_direction,
302 			      void (*done)(struct ib_cq *cq, struct ib_wc *wc));
303 void rtrs_iu_free(struct rtrs_iu *iu, struct ib_device *dev, u32 queue_num);
304 int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu);
305 int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
306 		      struct ib_send_wr *head);
307 int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
308 				struct ib_sge *sge, unsigned int num_sge,
309 				u32 rkey, u64 rdma_addr, u32 imm_data,
310 				enum ib_send_flags flags,
311 				struct ib_send_wr *head,
312 				struct ib_send_wr *tail);
313 
314 int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe);
315 
316 int rtrs_cq_qp_create(struct rtrs_sess *sess, struct rtrs_con *con,
317 		      u32 max_send_sge, int cq_vector, int nr_cqe,
318 		      u32 max_send_wr, u32 max_recv_wr,
319 		      enum ib_poll_context poll_ctx);
320 void rtrs_cq_qp_destroy(struct rtrs_con *con);
321 
322 void rtrs_init_hb(struct rtrs_sess *sess, struct ib_cqe *cqe,
323 		  unsigned int interval_ms, unsigned int missed_max,
324 		  void (*err_handler)(struct rtrs_con *con),
325 		  struct workqueue_struct *wq);
326 void rtrs_start_hb(struct rtrs_sess *sess);
327 void rtrs_stop_hb(struct rtrs_sess *sess);
328 void rtrs_send_hb_ack(struct rtrs_sess *sess);
329 
330 void rtrs_rdma_dev_pd_init(enum ib_pd_flags pd_flags,
331 			   struct rtrs_rdma_dev_pd *pool);
332 void rtrs_rdma_dev_pd_deinit(struct rtrs_rdma_dev_pd *pool);
333 
334 struct rtrs_ib_dev *rtrs_ib_dev_find_or_add(struct ib_device *ib_dev,
335 					    struct rtrs_rdma_dev_pd *pool);
336 int rtrs_ib_dev_put(struct rtrs_ib_dev *dev);
337 
338 static inline u32 rtrs_to_imm(u32 type, u32 payload)
339 {
340 	BUILD_BUG_ON(MAX_IMM_PAYL_BITS + MAX_IMM_TYPE_BITS != 32);
341 	BUILD_BUG_ON(RTRS_LAST_IMM > (1<<MAX_IMM_TYPE_BITS));
342 	return ((type & MAX_IMM_TYPE_MASK) << MAX_IMM_PAYL_BITS) |
343 		(payload & MAX_IMM_PAYL_MASK);
344 }
345 
346 static inline void rtrs_from_imm(u32 imm, u32 *type, u32 *payload)
347 {
348 	*payload = imm & MAX_IMM_PAYL_MASK;
349 	*type = imm >> MAX_IMM_PAYL_BITS;
350 }
351 
352 static inline u32 rtrs_to_io_req_imm(u32 addr)
353 {
354 	return rtrs_to_imm(RTRS_IO_REQ_IMM, addr);
355 }
356 
357 static inline u32 rtrs_to_io_rsp_imm(u32 msg_id, int errno, bool w_inval)
358 {
359 	enum rtrs_imm_type type;
360 	u32 payload;
361 
362 	/* 9 bits for errno, 19 bits for msg_id */
363 	payload = (abs(errno) & 0x1ff) << 19 | (msg_id & 0x7ffff);
364 	type = w_inval ? RTRS_IO_RSP_W_INV_IMM : RTRS_IO_RSP_IMM;
365 
366 	return rtrs_to_imm(type, payload);
367 }
368 
369 static inline void rtrs_from_io_rsp_imm(u32 payload, u32 *msg_id, int *errno)
370 {
371 	/* 9 bits for errno, 19 bits for msg_id */
372 	*msg_id = payload & 0x7ffff;
373 	*errno = -(int)((payload >> 19) & 0x1ff);
374 }
375 
376 #define STAT_STORE_FUNC(type, set_value, reset)				\
377 static ssize_t set_value##_store(struct kobject *kobj,			\
378 			     struct kobj_attribute *attr,		\
379 			     const char *buf, size_t count)		\
380 {									\
381 	int ret = -EINVAL;						\
382 	type *stats = container_of(kobj, type, kobj_stats);		\
383 									\
384 	if (sysfs_streq(buf, "1"))					\
385 		ret = reset(stats, true);			\
386 	else if (sysfs_streq(buf, "0"))					\
387 		ret = reset(stats, false);			\
388 	if (ret)							\
389 		return ret;						\
390 									\
391 	return count;							\
392 }
393 
394 #define STAT_SHOW_FUNC(type, get_value, print)				\
395 static ssize_t get_value##_show(struct kobject *kobj,			\
396 			   struct kobj_attribute *attr,			\
397 			   char *page)					\
398 {									\
399 	type *stats = container_of(kobj, type, kobj_stats);		\
400 									\
401 	return print(stats, page);			\
402 }
403 
404 #define STAT_ATTR(type, stat, print, reset)				\
405 STAT_STORE_FUNC(type, stat, reset)					\
406 STAT_SHOW_FUNC(type, stat, print)					\
407 static struct kobj_attribute stat##_attr = __ATTR_RW(stat)
408 
409 #endif /* RTRS_PRI_H */
410