fs/cifs/smbdirect.h

   1 /*
   2  *   Copyright (C) 2017, Microsoft Corporation.
   3  *
   4  *   Author(s): Long Li <longli@microsoft.com>
   5  *
   6  *   This program is free software;  you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  14  *   the GNU General Public License for more details.
  15  */
  16 #ifndef _SMBDIRECT_H
  17 #define _SMBDIRECT_H
  18
  19 #ifdef CONFIG_CIFS_SMB_DIRECT
  20 #define cifs_rdma_enabled(server)       ((server)->rdma)
  21
  22 #include "cifsglob.h"
  23 #include <rdma/ib_verbs.h>
  24 #include <rdma/rdma_cm.h>
  25 #include <linux/mempool.h>
  26
  27 extern int rdma_readwrite_threshold;
  28 extern int smbd_max_frmr_depth;
  29 extern int smbd_keep_alive_interval;
  30 extern int smbd_max_receive_size;
  31 extern int smbd_max_fragmented_recv_size;
  32 extern int smbd_max_send_size;
  33 extern int smbd_send_credit_target;
  34 extern int smbd_receive_credit_max;
  35
  36 enum keep_alive_status {
  37         KEEP_ALIVE_NONE,
  38         KEEP_ALIVE_PENDING,
  39         KEEP_ALIVE_SENT,
  40 };
  41
  42 enum smbd_connection_status {
  43         SMBD_CREATED,
  44         SMBD_CONNECTING,
  45         SMBD_CONNECTED,
  46         SMBD_NEGOTIATE_FAILED,
  47         SMBD_DISCONNECTING,
  48         SMBD_DISCONNECTED,
  49         SMBD_DESTROYED
  50 };
  51
  52 /*
  53  * The context for the SMBDirect transport
  54  * Everything related to the transport is here. It has several logical parts
  55  * 1. RDMA related structures
  56  * 2. SMBDirect connection parameters
  57  * 3. Memory registrations
  58  * 4. Receive and reassembly queues for data receive path
  59  * 5. mempools for allocating packets
  60  */
  61 struct smbd_connection {
  62         enum smbd_connection_status transport_status;
  63
  64         /* RDMA related */
  65         struct rdma_cm_id *id;
  66         struct ib_qp_init_attr qp_attr;
  67         struct ib_pd *pd;
  68         struct ib_cq *send_cq, *recv_cq;
  69         struct ib_device_attr dev_attr;
  70         int ri_rc;
  71         struct completion ri_done;
  72         wait_queue_head_t conn_wait;
  73         wait_queue_head_t wait_destroy;
  74
  75         struct completion negotiate_completion;
  76         bool negotiate_done;
  77
  78         struct work_struct destroy_work;
  79         struct work_struct disconnect_work;
  80         struct work_struct recv_done_work;
  81         struct work_struct post_send_credits_work;
  82
  83         spinlock_t lock_new_credits_offered;
  84         int new_credits_offered;
  85
  86         /* Connection parameters defined in [MS-SMBD] 3.1.1.1 */
  87         int receive_credit_max;
  88         int send_credit_target;
  89         int max_send_size;
  90         int max_fragmented_recv_size;
  91         int max_fragmented_send_size;
  92         int max_receive_size;
  93         int keep_alive_interval;
  94         int max_readwrite_size;
  95         enum keep_alive_status keep_alive_requested;
  96         int protocol;
  97         atomic_t send_credits;
  98         atomic_t receive_credits;
  99         int receive_credit_target;
 100         int fragment_reassembly_remaining;
 101
 102         /* Memory registrations */
 103         /* Maximum number of RDMA read/write outstanding on this connection */
 104         int responder_resources;
 105         /* Maximum number of SGEs in a RDMA write/read */
 106         int max_frmr_depth;
 107         /*
 108          * If payload is less than or equal to the threshold,
 109          * use RDMA send/recv to send upper layer I/O.
 110          * If payload is more than the threshold,
 111          * use RDMA read/write through memory registration for I/O.
 112          */
 113         int rdma_readwrite_threshold;
 114         enum ib_mr_type mr_type;
 115         struct list_head mr_list;
 116         spinlock_t mr_list_lock;
 117         /* The number of available MRs ready for memory registration */
 118         atomic_t mr_ready_count;
 119         atomic_t mr_used_count;
 120         wait_queue_head_t wait_mr;
 121         struct work_struct mr_recovery_work;
 122         /* Used by transport to wait until all MRs are returned */
 123         wait_queue_head_t wait_for_mr_cleanup;
 124
 125         /* Activity accoutning */
 126         /* Pending reqeusts issued from upper layer */
 127         int smbd_send_pending;
 128         wait_queue_head_t wait_smbd_send_pending;
 129
 130         int smbd_recv_pending;
 131         wait_queue_head_t wait_smbd_recv_pending;
 132
 133         atomic_t send_pending;
 134         wait_queue_head_t wait_send_pending;
 135         atomic_t send_payload_pending;
 136         wait_queue_head_t wait_send_payload_pending;
 137
 138         /* Receive queue */
 139         struct list_head receive_queue;
 140         int count_receive_queue;
 141         spinlock_t receive_queue_lock;
 142
 143         struct list_head empty_packet_queue;
 144         int count_empty_packet_queue;
 145         spinlock_t empty_packet_queue_lock;
 146
 147         wait_queue_head_t wait_receive_queues;
 148
 149         /* Reassembly queue */
 150         struct list_head reassembly_queue;
 151         spinlock_t reassembly_queue_lock;
 152         wait_queue_head_t wait_reassembly_queue;
 153
 154         /* total data length of reassembly queue */
 155         int reassembly_data_length;
 156         int reassembly_queue_length;
 157         /* the offset to first buffer in reassembly queue */
 158         int first_entry_offset;
 159
 160         bool send_immediate;
 161
 162         wait_queue_head_t wait_send_queue;
 163
 164         /*
 165          * Indicate if we have received a full packet on the connection
 166          * This is used to identify the first SMBD packet of a assembled
 167          * payload (SMB packet) in reassembly queue so we can return a
 168          * RFC1002 length to upper layer to indicate the length of the SMB
 169          * packet received
 170          */
 171         bool full_packet_received;
 172
 173         struct workqueue_struct *workqueue;
 174         struct delayed_work idle_timer_work;
 175         struct delayed_work send_immediate_work;
 176
 177         /* Memory pool for preallocating buffers */
 178         /* request pool for RDMA send */
 179         struct kmem_cache *request_cache;
 180         mempool_t *request_mempool;
 181
 182         /* response pool for RDMA receive */
 183         struct kmem_cache *response_cache;
 184         mempool_t *response_mempool;
 185
 186         /* for debug purposes */
 187         unsigned int count_get_receive_buffer;
 188         unsigned int count_put_receive_buffer;
 189         unsigned int count_reassembly_queue;
 190         unsigned int count_enqueue_reassembly_queue;
 191         unsigned int count_dequeue_reassembly_queue;
 192         unsigned int count_send_empty;
 193 };
 194
 195 enum smbd_message_type {
 196         SMBD_NEGOTIATE_RESP,
 197         SMBD_TRANSFER_DATA,
 198 };
 199
 200 #define SMB_DIRECT_RESPONSE_REQUESTED 0x0001
 201
 202 /* SMBD negotiation request packet [MS-SMBD] 2.2.1 */
 203 struct smbd_negotiate_req {
 204         __le16 min_version;
 205         __le16 max_version;
 206         __le16 reserved;
 207         __le16 credits_requested;
 208         __le32 preferred_send_size;
 209         __le32 max_receive_size;
 210         __le32 max_fragmented_size;
 211 } __packed;
 212
 213 /* SMBD negotiation response packet [MS-SMBD] 2.2.2 */
 214 struct smbd_negotiate_resp {
 215         __le16 min_version;
 216         __le16 max_version;
 217         __le16 negotiated_version;
 218         __le16 reserved;
 219         __le16 credits_requested;
 220         __le16 credits_granted;
 221         __le32 status;
 222         __le32 max_readwrite_size;
 223         __le32 preferred_send_size;
 224         __le32 max_receive_size;
 225         __le32 max_fragmented_size;
 226 } __packed;
 227
 228 /* SMBD data transfer packet with payload [MS-SMBD] 2.2.3 */
 229 struct smbd_data_transfer {
 230         __le16 credits_requested;
 231         __le16 credits_granted;
 232         __le16 flags;
 233         __le16 reserved;
 234         __le32 remaining_data_length;
 235         __le32 data_offset;
 236         __le32 data_length;
 237         __le32 padding;
 238         __u8 buffer[];
 239 } __packed;
 240
 241 /* The packet fields for a registered RDMA buffer */
 242 struct smbd_buffer_descriptor_v1 {
 243         __le64 offset;
 244         __le32 token;
 245         __le32 length;
 246 } __packed;
 247
 248 /* Default maximum number of SGEs in a RDMA send/recv */
 249 #define SMBDIRECT_MAX_SGE       16
 250 /* The context for a SMBD request */
 251 struct smbd_request {
 252         struct smbd_connection *info;
 253         struct ib_cqe cqe;
 254
 255         /* true if this request carries upper layer payload */
 256         bool has_payload;
 257
 258         /* the SGE entries for this packet */
 259         struct ib_sge sge[SMBDIRECT_MAX_SGE];
 260         int num_sge;
 261
 262         /* SMBD packet header follows this structure */
 263         u8 packet[];
 264 };
 265
 266 /* The context for a SMBD response */
 267 struct smbd_response {
 268         struct smbd_connection *info;
 269         struct ib_cqe cqe;
 270         struct ib_sge sge;
 271
 272         enum smbd_message_type type;
 273
 274         /* Link to receive queue or reassembly queue */
 275         struct list_head list;
 276
 277         /* Indicate if this is the 1st packet of a payload */
 278         bool first_segment;
 279
 280         /* SMBD packet header and payload follows this structure */
 281         u8 packet[];
 282 };
 283
 284 /* Create a SMBDirect session */
 285 struct smbd_connection *smbd_get_connection(
 286         struct TCP_Server_Info *server, struct sockaddr *dstaddr);
 287
 288 /* Reconnect SMBDirect session */
 289 int smbd_reconnect(struct TCP_Server_Info *server);
 290 /* Destroy SMBDirect session */
 291 void smbd_destroy(struct smbd_connection *info);
 292
 293 /* Interface for carrying upper layer I/O through send/recv */
 294 int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
 295 int smbd_send(struct TCP_Server_Info *server, struct smb_rqst *rqst);
 296
 297 enum mr_state {
 298         MR_READY,
 299         MR_REGISTERED,
 300         MR_INVALIDATED,
 301         MR_ERROR
 302 };
 303
 304 struct smbd_mr {
 305         struct smbd_connection  *conn;
 306         struct list_head        list;
 307         enum mr_state           state;
 308         struct ib_mr            *mr;
 309         struct scatterlist      *sgl;
 310         int                     sgl_count;
 311         enum dma_data_direction dir;
 312         union {
 313                 struct ib_reg_wr        wr;
 314                 struct ib_send_wr       inv_wr;
 315         };
 316         struct ib_cqe           cqe;
 317         bool                    need_invalidate;
 318         struct completion       invalidate_done;
 319 };
 320
 321 /* Interfaces to register and deregister MR for RDMA read/write */
 322 struct smbd_mr *smbd_register_mr(
 323         struct smbd_connection *info, struct page *pages[], int num_pages,
 324         int offset, int tailsz, bool writing, bool need_invalidate);
 325 int smbd_deregister_mr(struct smbd_mr *mr);
 326
 327 #else
 328 #define cifs_rdma_enabled(server)       0
 329 struct smbd_connection {};
 330 static inline void *smbd_get_connection(
 331         struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
 332 static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
 333 static inline void smbd_destroy(struct smbd_connection *info) {}
 334 static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
 335 static inline int smbd_send(struct TCP_Server_Info *server, struct smb_rqst *rqst) {return -1; }
 336 #endif
 337
 338 #endif