fs/cifs/smbdirect.h

   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 SGEs in a RDMA write/read */
  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 /* Default maximum number of SGEs in a RDMA send/recv */
 229 #define SMBDIRECT_MAX_SGE       16
 230 /* The context for a SMBD request */
 231 struct smbd_request {
 232         struct smbd_connection *info;
 233         struct ib_cqe cqe;
 234
 235         /* the SGE entries for this packet */
 236         struct ib_sge sge[SMBDIRECT_MAX_SGE];
 237         int num_sge;
 238
 239         /* SMBD packet header follows this structure */
 240         u8 packet[];
 241 };
 242
 243 /* The context for a SMBD response */
 244 struct smbd_response {
 245         struct smbd_connection *info;
 246         struct ib_cqe cqe;
 247         struct ib_sge sge;
 248
 249         enum smbd_message_type type;
 250
 251         /* Link to receive queue or reassembly queue */
 252         struct list_head list;
 253
 254         /* Indicate if this is the 1st packet of a payload */
 255         bool first_segment;
 256
 257         /* SMBD packet header and payload follows this structure */
 258         u8 packet[];
 259 };
 260
 261 /* Create a SMBDirect session */
 262 struct smbd_connection *smbd_get_connection(
 263         struct TCP_Server_Info *server, struct sockaddr *dstaddr);
 264
 265 /* Reconnect SMBDirect session */
 266 int smbd_reconnect(struct TCP_Server_Info *server);
 267 /* Destroy SMBDirect session */
 268 void smbd_destroy(struct TCP_Server_Info *server);
 269
 270 /* Interface for carrying upper layer I/O through send/recv */
 271 int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
 272 int smbd_send(struct TCP_Server_Info *server,
 273         int num_rqst, struct smb_rqst *rqst);
 274
 275 enum mr_state {
 276         MR_READY,
 277         MR_REGISTERED,
 278         MR_INVALIDATED,
 279         MR_ERROR
 280 };
 281
 282 struct smbd_mr {
 283         struct smbd_connection  *conn;
 284         struct list_head        list;
 285         enum mr_state           state;
 286         struct ib_mr            *mr;
 287         struct scatterlist      *sgl;
 288         int                     sgl_count;
 289         enum dma_data_direction dir;
 290         union {
 291                 struct ib_reg_wr        wr;
 292                 struct ib_send_wr       inv_wr;
 293         };
 294         struct ib_cqe           cqe;
 295         bool                    need_invalidate;
 296         struct completion       invalidate_done;
 297 };
 298
 299 /* Interfaces to register and deregister MR for RDMA read/write */
 300 struct smbd_mr *smbd_register_mr(
 301         struct smbd_connection *info, struct page *pages[], int num_pages,
 302         int offset, int tailsz, bool writing, bool need_invalidate);
 303 int smbd_deregister_mr(struct smbd_mr *mr);
 304
 305 #else
 306 #define cifs_rdma_enabled(server)       0
 307 struct smbd_connection {};
 308 static inline void *smbd_get_connection(
 309         struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
 310 static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
 311 static inline void smbd_destroy(struct TCP_Server_Info *server) {}
 312 static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
 313 static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; }
 314 #endif
 315
 316 #endif