tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
18extern int rdma_readwrite_threshold;
19extern int smbd_max_frmr_depth;
20extern int smbd_keep_alive_interval;
21extern int smbd_max_receive_size;
22extern int smbd_max_fragmented_recv_size;
23extern int smbd_max_send_size;
24extern int smbd_send_credit_target;
25extern int smbd_receive_credit_max;
26
27enum keep_alive_status {
28 KEEP_ALIVE_NONE,
29 KEEP_ALIVE_PENDING,
30 KEEP_ALIVE_SENT,
31};
32
33enum 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 */
52struct 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 recv_done_work;
71 struct work_struct post_send_credits_work;
72
73 spinlock_t lock_new_credits_offered;
74 int new_credits_offered;
75
76 /* Connection parameters defined in [MS-SMBD] 3.1.1.1 */
77 int receive_credit_max;
78 int send_credit_target;
79 int max_send_size;
80 int max_fragmented_recv_size;
81 int max_fragmented_send_size;
82 int max_receive_size;
83 int keep_alive_interval;
84 int max_readwrite_size;
85 enum keep_alive_status keep_alive_requested;
86 int protocol;
87 atomic_t send_credits;
88 atomic_t receive_credits;
89 int receive_credit_target;
90 int fragment_reassembly_remaining;
91
92 /* Memory registrations */
93 /* Maximum number of RDMA read/write outstanding on this connection */
94 int responder_resources;
95 /* Maximum number of SGEs in a RDMA write/read */
96 int max_frmr_depth;
97 /*
98 * If payload is less than or equal to the threshold,
99 * use RDMA send/recv to send upper layer I/O.
100 * If payload is more than the threshold,
101 * use RDMA read/write through memory registration for I/O.
102 */
103 int rdma_readwrite_threshold;
104 enum ib_mr_type mr_type;
105 struct list_head mr_list;
106 spinlock_t mr_list_lock;
107 /* The number of available MRs ready for memory registration */
108 atomic_t mr_ready_count;
109 atomic_t mr_used_count;
110 wait_queue_head_t wait_mr;
111 struct work_struct mr_recovery_work;
112 /* Used by transport to wait until all MRs are returned */
113 wait_queue_head_t wait_for_mr_cleanup;
114
115 /* Activity accoutning */
116 atomic_t send_pending;
117 wait_queue_head_t wait_send_pending;
118 atomic_t send_payload_pending;
119 wait_queue_head_t wait_send_payload_pending;
120
121 /* Receive queue */
122 struct list_head receive_queue;
123 int count_receive_queue;
124 spinlock_t receive_queue_lock;
125
126 struct list_head empty_packet_queue;
127 int count_empty_packet_queue;
128 spinlock_t empty_packet_queue_lock;
129
130 wait_queue_head_t wait_receive_queues;
131
132 /* Reassembly queue */
133 struct list_head reassembly_queue;
134 spinlock_t reassembly_queue_lock;
135 wait_queue_head_t wait_reassembly_queue;
136
137 /* total data length of reassembly queue */
138 int reassembly_data_length;
139 int reassembly_queue_length;
140 /* the offset to first buffer in reassembly queue */
141 int first_entry_offset;
142
143 bool send_immediate;
144
145 wait_queue_head_t wait_send_queue;
146
147 /*
148 * Indicate if we have received a full packet on the connection
149 * This is used to identify the first SMBD packet of a assembled
150 * payload (SMB packet) in reassembly queue so we can return a
151 * RFC1002 length to upper layer to indicate the length of the SMB
152 * packet received
153 */
154 bool full_packet_received;
155
156 struct workqueue_struct *workqueue;
157 struct delayed_work idle_timer_work;
158 struct delayed_work send_immediate_work;
159
160 /* Memory pool for preallocating buffers */
161 /* request pool for RDMA send */
162 struct kmem_cache *request_cache;
163 mempool_t *request_mempool;
164
165 /* response pool for RDMA receive */
166 struct kmem_cache *response_cache;
167 mempool_t *response_mempool;
168
169 /* for debug purposes */
170 unsigned int count_get_receive_buffer;
171 unsigned int count_put_receive_buffer;
172 unsigned int count_reassembly_queue;
173 unsigned int count_enqueue_reassembly_queue;
174 unsigned int count_dequeue_reassembly_queue;
175 unsigned int count_send_empty;
176};
177
178enum smbd_message_type {
179 SMBD_NEGOTIATE_RESP,
180 SMBD_TRANSFER_DATA,
181};
182
183#define SMB_DIRECT_RESPONSE_REQUESTED 0x0001
184
185/* SMBD negotiation request packet [MS-SMBD] 2.2.1 */
186struct smbd_negotiate_req {
187 __le16 min_version;
188 __le16 max_version;
189 __le16 reserved;
190 __le16 credits_requested;
191 __le32 preferred_send_size;
192 __le32 max_receive_size;
193 __le32 max_fragmented_size;
194} __packed;
195
196/* SMBD negotiation response packet [MS-SMBD] 2.2.2 */
197struct smbd_negotiate_resp {
198 __le16 min_version;
199 __le16 max_version;
200 __le16 negotiated_version;
201 __le16 reserved;
202 __le16 credits_requested;
203 __le16 credits_granted;
204 __le32 status;
205 __le32 max_readwrite_size;
206 __le32 preferred_send_size;
207 __le32 max_receive_size;
208 __le32 max_fragmented_size;
209} __packed;
210
211/* SMBD data transfer packet with payload [MS-SMBD] 2.2.3 */
212struct smbd_data_transfer {
213 __le16 credits_requested;
214 __le16 credits_granted;
215 __le16 flags;
216 __le16 reserved;
217 __le32 remaining_data_length;
218 __le32 data_offset;
219 __le32 data_length;
220 __le32 padding;
221 __u8 buffer[];
222} __packed;
223
224/* The packet fields for a registered RDMA buffer */
225struct smbd_buffer_descriptor_v1 {
226 __le64 offset;
227 __le32 token;
228 __le32 length;
229} __packed;
230
231/* Default maximum number of SGEs in a RDMA send/recv */
232#define SMBDIRECT_MAX_SGE 16
233/* The context for a SMBD request */
234struct smbd_request {
235 struct smbd_connection *info;
236 struct ib_cqe cqe;
237
238 /* true if this request carries upper layer payload */
239 bool has_payload;
240
241 /* the SGE entries for this packet */
242 struct ib_sge sge[SMBDIRECT_MAX_SGE];
243 int num_sge;
244
245 /* SMBD packet header follows this structure */
246 u8 packet[];
247};
248
249/* The context for a SMBD response */
250struct smbd_response {
251 struct smbd_connection *info;
252 struct ib_cqe cqe;
253 struct ib_sge sge;
254
255 enum smbd_message_type type;
256
257 /* Link to receive queue or reassembly queue */
258 struct list_head list;
259
260 /* Indicate if this is the 1st packet of a payload */
261 bool first_segment;
262
263 /* SMBD packet header and payload follows this structure */
264 u8 packet[];
265};
266
267/* Create a SMBDirect session */
268struct smbd_connection *smbd_get_connection(
269 struct TCP_Server_Info *server, struct sockaddr *dstaddr);
270
271/* Reconnect SMBDirect session */
272int smbd_reconnect(struct TCP_Server_Info *server);
273/* Destroy SMBDirect session */
274void smbd_destroy(struct TCP_Server_Info *server);
275
276/* Interface for carrying upper layer I/O through send/recv */
277int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
278int smbd_send(struct TCP_Server_Info *server,
279 int num_rqst, struct smb_rqst *rqst);
280
281enum mr_state {
282 MR_READY,
283 MR_REGISTERED,
284 MR_INVALIDATED,
285 MR_ERROR
286};
287
288struct smbd_mr {
289 struct smbd_connection *conn;
290 struct list_head list;
291 enum mr_state state;
292 struct ib_mr *mr;
293 struct scatterlist *sgl;
294 int sgl_count;
295 enum dma_data_direction dir;
296 union {
297 struct ib_reg_wr wr;
298 struct ib_send_wr inv_wr;
299 };
300 struct ib_cqe cqe;
301 bool need_invalidate;
302 struct completion invalidate_done;
303};
304
305/* Interfaces to register and deregister MR for RDMA read/write */
306struct smbd_mr *smbd_register_mr(
307 struct smbd_connection *info, struct page *pages[], int num_pages,
308 int offset, int tailsz, bool writing, bool need_invalidate);
309int smbd_deregister_mr(struct smbd_mr *mr);
310
311#else
312#define cifs_rdma_enabled(server) 0
313struct smbd_connection {};
314static inline void *smbd_get_connection(
315 struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
316static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
317static inline void smbd_destroy(struct TCP_Server_Info *server) {}
318static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
319static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; }
320#endif
321
322#endif