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 /*
27  * Max IB immediate data size is 2^28 (MAX_IMM_PAYL_BITS)
28  * and the minimum chunk size is 4096 (2^12).
29  * So the maximum sess_queue_depth is 65536 (2^16) in theory.
30  * But mempool_create, create_qp and ib_post_send fail with
31  * "cannot allocate memory" error if sess_queue_depth is too big.
32  * Therefore the pratical max value of sess_queue_depth is
33  * somewhere between 1 and 65534 and it depends on the system.
34  */
35 #define MAX_SESS_QUEUE_DEPTH 65535
36 
37 enum rtrs_imm_const {
38 	MAX_IMM_TYPE_BITS = 4,
39 	MAX_IMM_TYPE_MASK = ((1 << MAX_IMM_TYPE_BITS) - 1),
40 	MAX_IMM_PAYL_BITS = 28,
41 	MAX_IMM_PAYL_MASK = ((1 << MAX_IMM_PAYL_BITS) - 1),
42 };
43 
44 enum rtrs_imm_type {
45 	RTRS_IO_REQ_IMM       = 0, /* client to server */
46 	RTRS_IO_RSP_IMM       = 1, /* server to client */
47 	RTRS_IO_RSP_W_INV_IMM = 2, /* server to client */
48 
49 	RTRS_HB_MSG_IMM = 8, /* HB: HeartBeat */
50 	RTRS_HB_ACK_IMM = 9,
51 
52 	RTRS_LAST_IMM,
53 };
54 
55 enum {
56 	SERVICE_CON_QUEUE_DEPTH = 512,
57 
58 	MAX_PATHS_NUM = 128,
59 
60 	MIN_CHUNK_SIZE = 8192,
61 
62 	RTRS_HB_INTERVAL_MS = 5000,
63 	RTRS_HB_MISSED_MAX = 5,
64 
65 	RTRS_MAGIC = 0x1BBD,
66 	RTRS_PROTO_VER = (RTRS_PROTO_VER_MAJOR << 8) | RTRS_PROTO_VER_MINOR,
67 };
68 
69 struct rtrs_ib_dev;
70 
71 struct rtrs_rdma_dev_pd_ops {
72 	struct rtrs_ib_dev *(*alloc)(void);
73 	void (*free)(struct rtrs_ib_dev *dev);
74 	int (*init)(struct rtrs_ib_dev *dev);
75 	void (*deinit)(struct rtrs_ib_dev *dev);
76 };
77 
78 struct rtrs_rdma_dev_pd {
79 	struct mutex		mutex;
80 	struct list_head	list;
81 	enum ib_pd_flags	pd_flags;
82 	const struct rtrs_rdma_dev_pd_ops *ops;
83 };
84 
85 struct rtrs_ib_dev {
86 	struct ib_device	 *ib_dev;
87 	struct ib_pd		 *ib_pd;
88 	struct kref		 ref;
89 	struct list_head	 entry;
90 	struct rtrs_rdma_dev_pd *pool;
91 };
92 
93 struct rtrs_con {
94 	struct rtrs_path	*path;
95 	struct ib_qp		*qp;
96 	struct ib_cq		*cq;
97 	struct rdma_cm_id	*cm_id;
98 	unsigned int		cid;
99 	int                     nr_cqe;
100 	atomic_t		wr_cnt;
101 	atomic_t		sq_wr_avail;
102 };
103 
104 struct rtrs_path {
105 	struct list_head	entry;
106 	struct sockaddr_storage dst_addr;
107 	struct sockaddr_storage src_addr;
108 	char			sessname[NAME_MAX];
109 	uuid_t			uuid;
110 	struct rtrs_con	**con;
111 	unsigned int		con_num;
112 	unsigned int		irq_con_num;
113 	unsigned int		recon_cnt;
114 	unsigned int		signal_interval;
115 	struct rtrs_ib_dev	*dev;
116 	int			dev_ref;
117 	struct ib_cqe		*hb_cqe;
118 	void			(*hb_err_handler)(struct rtrs_con *con);
119 	struct workqueue_struct *hb_wq;
120 	struct delayed_work	hb_dwork;
121 	unsigned int		hb_interval_ms;
122 	unsigned int		hb_missed_cnt;
123 	unsigned int		hb_missed_max;
124 	ktime_t			hb_last_sent;
125 	ktime_t			hb_cur_latency;
126 };
127 
128 /* rtrs information unit */
129 struct rtrs_iu {
130 	struct ib_cqe           cqe;
131 	dma_addr_t              dma_addr;
132 	void                    *buf;
133 	size_t                  size;
134 	enum dma_data_direction direction;
135 };
136 
137 /**
138  * enum rtrs_msg_types - RTRS message types, see also rtrs/README
139  * @RTRS_MSG_INFO_REQ:		Client additional info request to the server
140  * @RTRS_MSG_INFO_RSP:		Server additional info response to the client
141  * @RTRS_MSG_WRITE:		Client writes data per RDMA to server
142  * @RTRS_MSG_READ:		Client requests data transfer from server
143  * @RTRS_MSG_RKEY_RSP:		Server refreshed rkey for rbuf
144  */
145 enum rtrs_msg_types {
146 	RTRS_MSG_INFO_REQ,
147 	RTRS_MSG_INFO_RSP,
148 	RTRS_MSG_WRITE,
149 	RTRS_MSG_READ,
150 	RTRS_MSG_RKEY_RSP,
151 };
152 
153 /**
154  * enum rtrs_msg_flags - RTRS message flags.
155  * @RTRS_NEED_INVAL:	Send invalidation in response.
156  * @RTRS_MSG_NEW_RKEY_F: Send refreshed rkey in response.
157  */
158 enum rtrs_msg_flags {
159 	RTRS_MSG_NEED_INVAL_F = 1 << 0,
160 	RTRS_MSG_NEW_RKEY_F = 1 << 1,
161 };
162 
163 /**
164  * struct rtrs_sg_desc - RDMA-Buffer entry description
165  * @addr:	Address of RDMA destination buffer
166  * @key:	Authorization rkey to write to the buffer
167  * @len:	Size of the buffer
168  */
169 struct rtrs_sg_desc {
170 	__le64			addr;
171 	__le32			key;
172 	__le32			len;
173 };
174 
175 /**
176  * struct rtrs_msg_conn_req - Client connection request to the server
177  * @magic:	   RTRS magic
178  * @version:	   RTRS protocol version
179  * @cid:	   Current connection id
180  * @cid_num:	   Number of connections per session
181  * @recon_cnt:	   Reconnections counter
182  * @sess_uuid:	   UUID of a session (path)
183  * @paths_uuid:	   UUID of a group of sessions (paths)
184  *
185  * NOTE: max size 56 bytes, see man rdma_connect().
186  */
187 struct rtrs_msg_conn_req {
188 	/* Is set to 0 by cma.c in case of AF_IB, do not touch that.
189 	 * see https://www.spinics.net/lists/linux-rdma/msg22397.html
190 	 */
191 	u8		__cma_version;
192 	/* On sender side that should be set to 0, or cma_save_ip_info()
193 	 * extract garbage and will fail.
194 	 */
195 	u8		__ip_version;
196 	__le16		magic;
197 	__le16		version;
198 	__le16		cid;
199 	__le16		cid_num;
200 	__le16		recon_cnt;
201 	uuid_t		sess_uuid;
202 	uuid_t		paths_uuid;
203 	u8		first_conn : 1;
204 	u8		reserved_bits : 7;
205 	u8		reserved[11];
206 };
207 
208 /**
209  * struct rtrs_msg_conn_rsp - Server connection response to the client
210  * @magic:	   RTRS magic
211  * @version:	   RTRS protocol version
212  * @errno:	   If rdma_accept() then 0, if rdma_reject() indicates error
213  * @queue_depth:   max inflight messages (queue-depth) in this session
214  * @max_io_size:   max io size server supports
215  * @max_hdr_size:  max msg header size server supports
216  *
217  * NOTE: size is 56 bytes, max possible is 136 bytes, see man rdma_accept().
218  */
219 struct rtrs_msg_conn_rsp {
220 	__le16		magic;
221 	__le16		version;
222 	__le16		errno;
223 	__le16		queue_depth;
224 	__le32		max_io_size;
225 	__le32		max_hdr_size;
226 	__le32		flags;
227 	u8		reserved[36];
228 };
229 
230 /**
231  * struct rtrs_msg_info_req
232  * @type:		@RTRS_MSG_INFO_REQ
233  * @pathname:		Path name chosen by client
234  */
235 struct rtrs_msg_info_req {
236 	__le16		type;
237 	u8		pathname[NAME_MAX];
238 	u8		reserved[15];
239 };
240 
241 /**
242  * struct rtrs_msg_info_rsp
243  * @type:		@RTRS_MSG_INFO_RSP
244  * @sg_cnt:		Number of @desc entries
245  * @desc:		RDMA buffers where the client can write to server
246  */
247 struct rtrs_msg_info_rsp {
248 	__le16		type;
249 	__le16          sg_cnt;
250 	u8              reserved[4];
251 	struct rtrs_sg_desc desc[];
252 };
253 
254 /**
255  * struct rtrs_msg_rkey_rsp
256  * @type:		@RTRS_MSG_RKEY_RSP
257  * @buf_id:		RDMA buf_id of the new rkey
258  * @rkey:		new remote key for RDMA buffers id from server
259  */
260 struct rtrs_msg_rkey_rsp {
261 	__le16		type;
262 	__le16          buf_id;
263 	__le32		rkey;
264 };
265 
266 /**
267  * struct rtrs_msg_rdma_read - RDMA data transfer request from client
268  * @type:		always @RTRS_MSG_READ
269  * @usr_len:		length of user payload
270  * @sg_cnt:		number of @desc entries
271  * @desc:		RDMA buffers where the server can write the result to
272  */
273 struct rtrs_msg_rdma_read {
274 	__le16			type;
275 	__le16			usr_len;
276 	__le16			flags;
277 	__le16			sg_cnt;
278 	struct rtrs_sg_desc    desc[];
279 };
280 
281 /**
282  * struct_msg_rdma_write - Message transferred to server with RDMA-Write
283  * @type:		always @RTRS_MSG_WRITE
284  * @usr_len:		length of user payload
285  */
286 struct rtrs_msg_rdma_write {
287 	__le16			type;
288 	__le16			usr_len;
289 };
290 
291 /**
292  * struct_msg_rdma_hdr - header for read or write request
293  * @type:		@RTRS_MSG_WRITE | @RTRS_MSG_READ
294  */
295 struct rtrs_msg_rdma_hdr {
296 	__le16			type;
297 };
298 
299 /* rtrs.c */
300 
301 struct rtrs_iu *rtrs_iu_alloc(u32 queue_num, size_t size, gfp_t t,
302 			      struct ib_device *dev, enum dma_data_direction,
303 			      void (*done)(struct ib_cq *cq, struct ib_wc *wc));
304 void rtrs_iu_free(struct rtrs_iu *iu, struct ib_device *dev, u32 queue_num);
305 int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu);
306 int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
307 		      struct ib_send_wr *head);
308 int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
309 				struct ib_sge *sge, unsigned int num_sge,
310 				u32 rkey, u64 rdma_addr, u32 imm_data,
311 				enum ib_send_flags flags,
312 				struct ib_send_wr *head,
313 				struct ib_send_wr *tail);
314 
315 int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe);
316 
317 int rtrs_cq_qp_create(struct rtrs_path *path, struct rtrs_con *con,
318 		      u32 max_send_sge, int cq_vector, int nr_cqe,
319 		      u32 max_send_wr, u32 max_recv_wr,
320 		      enum ib_poll_context poll_ctx);
321 void rtrs_cq_qp_destroy(struct rtrs_con *con);
322 
323 void rtrs_init_hb(struct rtrs_path *path, struct ib_cqe *cqe,
324 		  unsigned int interval_ms, unsigned int missed_max,
325 		  void (*err_handler)(struct rtrs_con *con),
326 		  struct workqueue_struct *wq);
327 void rtrs_start_hb(struct rtrs_path *path);
328 void rtrs_stop_hb(struct rtrs_path *path);
329 void rtrs_send_hb_ack(struct rtrs_path *path);
330 
331 void rtrs_rdma_dev_pd_init(enum ib_pd_flags pd_flags,
332 			   struct rtrs_rdma_dev_pd *pool);
333 void rtrs_rdma_dev_pd_deinit(struct rtrs_rdma_dev_pd *pool);
334 
335 struct rtrs_ib_dev *rtrs_ib_dev_find_or_add(struct ib_device *ib_dev,
336 					    struct rtrs_rdma_dev_pd *pool);
337 int rtrs_ib_dev_put(struct rtrs_ib_dev *dev);
338 
339 static inline u32 rtrs_to_imm(u32 type, u32 payload)
340 {
341 	BUILD_BUG_ON(MAX_IMM_PAYL_BITS + MAX_IMM_TYPE_BITS != 32);
342 	BUILD_BUG_ON(RTRS_LAST_IMM > (1<<MAX_IMM_TYPE_BITS));
343 	return ((type & MAX_IMM_TYPE_MASK) << MAX_IMM_PAYL_BITS) |
344 		(payload & MAX_IMM_PAYL_MASK);
345 }
346 
347 static inline void rtrs_from_imm(u32 imm, u32 *type, u32 *payload)
348 {
349 	*payload = imm & MAX_IMM_PAYL_MASK;
350 	*type = imm >> MAX_IMM_PAYL_BITS;
351 }
352 
353 static inline u32 rtrs_to_io_req_imm(u32 addr)
354 {
355 	return rtrs_to_imm(RTRS_IO_REQ_IMM, addr);
356 }
357 
358 static inline u32 rtrs_to_io_rsp_imm(u32 msg_id, int errno, bool w_inval)
359 {
360 	enum rtrs_imm_type type;
361 	u32 payload;
362 
363 	/* 9 bits for errno, 19 bits for msg_id */
364 	payload = (abs(errno) & 0x1ff) << 19 | (msg_id & 0x7ffff);
365 	type = w_inval ? RTRS_IO_RSP_W_INV_IMM : RTRS_IO_RSP_IMM;
366 
367 	return rtrs_to_imm(type, payload);
368 }
369 
370 static inline void rtrs_from_io_rsp_imm(u32 payload, u32 *msg_id, int *errno)
371 {
372 	/* 9 bits for errno, 19 bits for msg_id */
373 	*msg_id = payload & 0x7ffff;
374 	*errno = -(int)((payload >> 19) & 0x1ff);
375 }
376 
377 #define STAT_STORE_FUNC(type, set_value, reset)				\
378 static ssize_t set_value##_store(struct kobject *kobj,			\
379 			     struct kobj_attribute *attr,		\
380 			     const char *buf, size_t count)		\
381 {									\
382 	int ret = -EINVAL;						\
383 	type *stats = container_of(kobj, type, kobj_stats);		\
384 									\
385 	if (sysfs_streq(buf, "1"))					\
386 		ret = reset(stats, true);			\
387 	else if (sysfs_streq(buf, "0"))					\
388 		ret = reset(stats, false);			\
389 	if (ret)							\
390 		return ret;						\
391 									\
392 	return count;							\
393 }
394 
395 #define STAT_SHOW_FUNC(type, get_value, print)				\
396 static ssize_t get_value##_show(struct kobject *kobj,			\
397 			   struct kobj_attribute *attr,			\
398 			   char *page)					\
399 {									\
400 	type *stats = container_of(kobj, type, kobj_stats);		\
401 									\
402 	return print(stats, page);			\
403 }
404 
405 #define STAT_ATTR(type, stat, print, reset)				\
406 STAT_STORE_FUNC(type, stat, reset)					\
407 STAT_SHOW_FUNC(type, stat, print)					\
408 static struct kobj_attribute stat##_attr = __ATTR_RW(stat)
409 
410 #endif /* RTRS_PRI_H */
411