xref: /openbmc/linux/fs/smb/client/smbdirect.h (revision cabce92d)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *   Copyright (C) 2017, Microsoft Corporation.
4  *
5  *   Author(s): Long Li <longli@microsoft.com>
6  */
7 #ifndef _SMBDIRECT_H
8 #define _SMBDIRECT_H
9 
10 #ifdef CONFIG_CIFS_SMB_DIRECT
11 #define cifs_rdma_enabled(server)	((server)->rdma)
12 
13 #include "cifsglob.h"
14 #include <rdma/ib_verbs.h>
15 #include <rdma/rdma_cm.h>
16 #include <linux/mempool.h>
17 
18 extern int rdma_readwrite_threshold;
19 extern int smbd_max_frmr_depth;
20 extern int smbd_keep_alive_interval;
21 extern int smbd_max_receive_size;
22 extern int smbd_max_fragmented_recv_size;
23 extern int smbd_max_send_size;
24 extern int smbd_send_credit_target;
25 extern int smbd_receive_credit_max;
26 
27 enum keep_alive_status {
28 	KEEP_ALIVE_NONE,
29 	KEEP_ALIVE_PENDING,
30 	KEEP_ALIVE_SENT,
31 };
32 
33 enum smbd_connection_status {
34 	SMBD_CREATED,
35 	SMBD_CONNECTING,
36 	SMBD_CONNECTED,
37 	SMBD_NEGOTIATE_FAILED,
38 	SMBD_DISCONNECTING,
39 	SMBD_DISCONNECTED,
40 	SMBD_DESTROYED
41 };
42 
43 /*
44  * The context for the SMBDirect transport
45  * Everything related to the transport is here. It has several logical parts
46  * 1. RDMA related structures
47  * 2. SMBDirect connection parameters
48  * 3. Memory registrations
49  * 4. Receive and reassembly queues for data receive path
50  * 5. mempools for allocating packets
51  */
52 struct smbd_connection {
53 	enum smbd_connection_status transport_status;
54 
55 	/* RDMA related */
56 	struct rdma_cm_id *id;
57 	struct ib_qp_init_attr qp_attr;
58 	struct ib_pd *pd;
59 	struct ib_cq *send_cq, *recv_cq;
60 	struct ib_device_attr dev_attr;
61 	int ri_rc;
62 	struct completion ri_done;
63 	wait_queue_head_t conn_wait;
64 	wait_queue_head_t disconn_wait;
65 
66 	struct completion negotiate_completion;
67 	bool negotiate_done;
68 
69 	struct work_struct disconnect_work;
70 	struct work_struct post_send_credits_work;
71 
72 	spinlock_t lock_new_credits_offered;
73 	int new_credits_offered;
74 
75 	/* Connection parameters defined in [MS-SMBD] 3.1.1.1 */
76 	int receive_credit_max;
77 	int send_credit_target;
78 	int max_send_size;
79 	int max_fragmented_recv_size;
80 	int max_fragmented_send_size;
81 	int max_receive_size;
82 	int keep_alive_interval;
83 	int max_readwrite_size;
84 	enum keep_alive_status keep_alive_requested;
85 	int protocol;
86 	atomic_t send_credits;
87 	atomic_t receive_credits;
88 	int receive_credit_target;
89 	int fragment_reassembly_remaining;
90 
91 	/* Memory registrations */
92 	/* Maximum number of RDMA read/write outstanding on this connection */
93 	int responder_resources;
94 	/* Maximum number of pages in a single RDMA write/read on this connection */
95 	int max_frmr_depth;
96 	/*
97 	 * If payload is less than or equal to the threshold,
98 	 * use RDMA send/recv to send upper layer I/O.
99 	 * If payload is more than the threshold,
100 	 * use RDMA read/write through memory registration for I/O.
101 	 */
102 	int rdma_readwrite_threshold;
103 	enum ib_mr_type mr_type;
104 	struct list_head mr_list;
105 	spinlock_t mr_list_lock;
106 	/* The number of available MRs ready for memory registration */
107 	atomic_t mr_ready_count;
108 	atomic_t mr_used_count;
109 	wait_queue_head_t wait_mr;
110 	struct work_struct mr_recovery_work;
111 	/* Used by transport to wait until all MRs are returned */
112 	wait_queue_head_t wait_for_mr_cleanup;
113 
114 	/* Activity accoutning */
115 	atomic_t send_pending;
116 	wait_queue_head_t wait_send_pending;
117 	wait_queue_head_t wait_post_send;
118 
119 	/* Receive queue */
120 	struct list_head receive_queue;
121 	int count_receive_queue;
122 	spinlock_t receive_queue_lock;
123 
124 	struct list_head empty_packet_queue;
125 	int count_empty_packet_queue;
126 	spinlock_t empty_packet_queue_lock;
127 
128 	wait_queue_head_t wait_receive_queues;
129 
130 	/* Reassembly queue */
131 	struct list_head reassembly_queue;
132 	spinlock_t reassembly_queue_lock;
133 	wait_queue_head_t wait_reassembly_queue;
134 
135 	/* total data length of reassembly queue */
136 	int reassembly_data_length;
137 	int reassembly_queue_length;
138 	/* the offset to first buffer in reassembly queue */
139 	int first_entry_offset;
140 
141 	bool send_immediate;
142 
143 	wait_queue_head_t wait_send_queue;
144 
145 	/*
146 	 * Indicate if we have received a full packet on the connection
147 	 * This is used to identify the first SMBD packet of a assembled
148 	 * payload (SMB packet) in reassembly queue so we can return a
149 	 * RFC1002 length to upper layer to indicate the length of the SMB
150 	 * packet received
151 	 */
152 	bool full_packet_received;
153 
154 	struct workqueue_struct *workqueue;
155 	struct delayed_work idle_timer_work;
156 
157 	/* Memory pool for preallocating buffers */
158 	/* request pool for RDMA send */
159 	struct kmem_cache *request_cache;
160 	mempool_t *request_mempool;
161 
162 	/* response pool for RDMA receive */
163 	struct kmem_cache *response_cache;
164 	mempool_t *response_mempool;
165 
166 	/* for debug purposes */
167 	unsigned int count_get_receive_buffer;
168 	unsigned int count_put_receive_buffer;
169 	unsigned int count_reassembly_queue;
170 	unsigned int count_enqueue_reassembly_queue;
171 	unsigned int count_dequeue_reassembly_queue;
172 	unsigned int count_send_empty;
173 };
174 
175 enum smbd_message_type {
176 	SMBD_NEGOTIATE_RESP,
177 	SMBD_TRANSFER_DATA,
178 };
179 
180 #define SMB_DIRECT_RESPONSE_REQUESTED 0x0001
181 
182 /* SMBD negotiation request packet [MS-SMBD] 2.2.1 */
183 struct smbd_negotiate_req {
184 	__le16 min_version;
185 	__le16 max_version;
186 	__le16 reserved;
187 	__le16 credits_requested;
188 	__le32 preferred_send_size;
189 	__le32 max_receive_size;
190 	__le32 max_fragmented_size;
191 } __packed;
192 
193 /* SMBD negotiation response packet [MS-SMBD] 2.2.2 */
194 struct smbd_negotiate_resp {
195 	__le16 min_version;
196 	__le16 max_version;
197 	__le16 negotiated_version;
198 	__le16 reserved;
199 	__le16 credits_requested;
200 	__le16 credits_granted;
201 	__le32 status;
202 	__le32 max_readwrite_size;
203 	__le32 preferred_send_size;
204 	__le32 max_receive_size;
205 	__le32 max_fragmented_size;
206 } __packed;
207 
208 /* SMBD data transfer packet with payload [MS-SMBD] 2.2.3 */
209 struct smbd_data_transfer {
210 	__le16 credits_requested;
211 	__le16 credits_granted;
212 	__le16 flags;
213 	__le16 reserved;
214 	__le32 remaining_data_length;
215 	__le32 data_offset;
216 	__le32 data_length;
217 	__le32 padding;
218 	__u8 buffer[];
219 } __packed;
220 
221 /* The packet fields for a registered RDMA buffer */
222 struct smbd_buffer_descriptor_v1 {
223 	__le64 offset;
224 	__le32 token;
225 	__le32 length;
226 } __packed;
227 
228 /* Maximum number of SGEs used by smbdirect.c in any send work request */
229 #define SMBDIRECT_MAX_SEND_SGE	6
230 
231 /* The context for a SMBD request */
232 struct smbd_request {
233 	struct smbd_connection *info;
234 	struct ib_cqe cqe;
235 
236 	/* the SGE entries for this work request */
237 	struct ib_sge sge[SMBDIRECT_MAX_SEND_SGE];
238 	int num_sge;
239 
240 	/* SMBD packet header follows this structure */
241 	u8 packet[];
242 };
243 
244 /* Maximum number of SGEs used by smbdirect.c in any receive work request */
245 #define SMBDIRECT_MAX_RECV_SGE	1
246 
247 /* The context for a SMBD response */
248 struct smbd_response {
249 	struct smbd_connection *info;
250 	struct ib_cqe cqe;
251 	struct ib_sge sge;
252 
253 	enum smbd_message_type type;
254 
255 	/* Link to receive queue or reassembly queue */
256 	struct list_head list;
257 
258 	/* Indicate if this is the 1st packet of a payload */
259 	bool first_segment;
260 
261 	/* SMBD packet header and payload follows this structure */
262 	u8 packet[];
263 };
264 
265 /* Create a SMBDirect session */
266 struct smbd_connection *smbd_get_connection(
267 	struct TCP_Server_Info *server, struct sockaddr *dstaddr);
268 
269 /* Reconnect SMBDirect session */
270 int smbd_reconnect(struct TCP_Server_Info *server);
271 /* Destroy SMBDirect session */
272 void smbd_destroy(struct TCP_Server_Info *server);
273 
274 /* Interface for carrying upper layer I/O through send/recv */
275 int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
276 int smbd_send(struct TCP_Server_Info *server,
277 	int num_rqst, struct smb_rqst *rqst);
278 
279 enum mr_state {
280 	MR_READY,
281 	MR_REGISTERED,
282 	MR_INVALIDATED,
283 	MR_ERROR
284 };
285 
286 struct smbd_mr {
287 	struct smbd_connection	*conn;
288 	struct list_head	list;
289 	enum mr_state		state;
290 	struct ib_mr		*mr;
291 	struct sg_table		sgt;
292 	enum dma_data_direction	dir;
293 	union {
294 		struct ib_reg_wr	wr;
295 		struct ib_send_wr	inv_wr;
296 	};
297 	struct ib_cqe		cqe;
298 	bool			need_invalidate;
299 	struct completion	invalidate_done;
300 };
301 
302 /* Interfaces to register and deregister MR for RDMA read/write */
303 struct smbd_mr *smbd_register_mr(
304 	struct smbd_connection *info, struct iov_iter *iter,
305 	bool writing, bool need_invalidate);
306 int smbd_deregister_mr(struct smbd_mr *mr);
307 
308 #else
309 #define cifs_rdma_enabled(server)	0
310 struct smbd_connection {};
311 static inline void *smbd_get_connection(
312 	struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
313 static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
314 static inline void smbd_destroy(struct TCP_Server_Info *server) {}
315 static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
316 static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; }
317 #endif
318 
319 #endif
320