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 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
 178 enum 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 */
 186 struct 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 */
 197 struct 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 */
 212 struct 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 */
 225 struct 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 */
 234 struct 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 */
 250 struct 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 */
 268 struct smbd_connection *smbd_get_connection(
 269         struct TCP_Server_Info *server, struct sockaddr *dstaddr);
 270
 271 /* Reconnect SMBDirect session */
 272 int smbd_reconnect(struct TCP_Server_Info *server);
 273 /* Destroy SMBDirect session */
 274 void smbd_destroy(struct TCP_Server_Info *server);
 275
 276 /* Interface for carrying upper layer I/O through send/recv */
 277 int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
 278 int smbd_send(struct TCP_Server_Info *server,
 279         int num_rqst, struct smb_rqst *rqst);
 280
 281 enum mr_state {
 282         MR_READY,
 283         MR_REGISTERED,
 284         MR_INVALIDATED,
 285         MR_ERROR
 286 };
 287
 288 struct 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 */
 306 struct 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);
 309 int smbd_deregister_mr(struct smbd_mr *mr);
 310
 311 #else
 312 #define cifs_rdma_enabled(server)       0
 313 struct smbd_connection {};
 314 static inline void *smbd_get_connection(
 315         struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
 316 static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
 317 static inline void smbd_destroy(struct TCP_Server_Info *server) {}
 318 static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
 319 static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; }
 320 #endif
 321
 322 #endif