fs/cifs/smbdirect.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  *   Copyright (C) 2017, Microsoft Corporation.
0004  *
0005  *   Author(s): Long Li <longli@microsoft.com>
0006  */
0007 #ifndef _SMBDIRECT_H
0008 #define _SMBDIRECT_H
0009
0010 #ifdef CONFIG_CIFS_SMB_DIRECT
0011 #define cifs_rdma_enabled(server)   ((server)->rdma)
0012
0013 #include "cifsglob.h"
0014 #include <rdma/ib_verbs.h>
0015 #include <rdma/rdma_cm.h>
0016 #include <linux/mempool.h>
0017
0018 extern int rdma_readwrite_threshold;
0019 extern int smbd_max_frmr_depth;
0020 extern int smbd_keep_alive_interval;
0021 extern int smbd_max_receive_size;
0022 extern int smbd_max_fragmented_recv_size;
0023 extern int smbd_max_send_size;
0024 extern int smbd_send_credit_target;
0025 extern int smbd_receive_credit_max;
0026
0027 enum keep_alive_status {
0028     KEEP_ALIVE_NONE,
0029     KEEP_ALIVE_PENDING,
0030     KEEP_ALIVE_SENT,
0031 };
0032
0033 enum smbd_connection_status {
0034     SMBD_CREATED,
0035     SMBD_CONNECTING,
0036     SMBD_CONNECTED,
0037     SMBD_NEGOTIATE_FAILED,
0038     SMBD_DISCONNECTING,
0039     SMBD_DISCONNECTED,
0040     SMBD_DESTROYED
0041 };
0042
0043 /*
0044  * The context for the SMBDirect transport
0045  * Everything related to the transport is here. It has several logical parts
0046  * 1. RDMA related structures
0047  * 2. SMBDirect connection parameters
0048  * 3. Memory registrations
0049  * 4. Receive and reassembly queues for data receive path
0050  * 5. mempools for allocating packets
0051  */
0052 struct smbd_connection {
0053     enum smbd_connection_status transport_status;
0054
0055     /* RDMA related */
0056     struct rdma_cm_id *id;
0057     struct ib_qp_init_attr qp_attr;
0058     struct ib_pd *pd;
0059     struct ib_cq *send_cq, *recv_cq;
0060     struct ib_device_attr dev_attr;
0061     int ri_rc;
0062     struct completion ri_done;
0063     wait_queue_head_t conn_wait;
0064     wait_queue_head_t disconn_wait;
0065
0066     struct completion negotiate_completion;
0067     bool negotiate_done;
0068
0069     struct work_struct disconnect_work;
0070     struct work_struct post_send_credits_work;
0071
0072     spinlock_t lock_new_credits_offered;
0073     int new_credits_offered;
0074
0075     /* Connection parameters defined in [MS-SMBD] 3.1.1.1 */
0076     int receive_credit_max;
0077     int send_credit_target;
0078     int max_send_size;
0079     int max_fragmented_recv_size;
0080     int max_fragmented_send_size;
0081     int max_receive_size;
0082     int keep_alive_interval;
0083     int max_readwrite_size;
0084     enum keep_alive_status keep_alive_requested;
0085     int protocol;
0086     atomic_t send_credits;
0087     atomic_t receive_credits;
0088     int receive_credit_target;
0089     int fragment_reassembly_remaining;
0090
0091     /* Memory registrations */
0092     /* Maximum number of RDMA read/write outstanding on this connection */
0093     int responder_resources;
0094     /* Maximum number of SGEs in a RDMA write/read */
0095     int max_frmr_depth;
0096     /*
0097      * If payload is less than or equal to the threshold,
0098      * use RDMA send/recv to send upper layer I/O.
0099      * If payload is more than the threshold,
0100      * use RDMA read/write through memory registration for I/O.
0101      */
0102     int rdma_readwrite_threshold;
0103     enum ib_mr_type mr_type;
0104     struct list_head mr_list;
0105     spinlock_t mr_list_lock;
0106     /* The number of available MRs ready for memory registration */
0107     atomic_t mr_ready_count;
0108     atomic_t mr_used_count;
0109     wait_queue_head_t wait_mr;
0110     struct work_struct mr_recovery_work;
0111     /* Used by transport to wait until all MRs are returned */
0112     wait_queue_head_t wait_for_mr_cleanup;
0113
0114     /* Activity accoutning */
0115     atomic_t send_pending;
0116     wait_queue_head_t wait_send_pending;
0117     wait_queue_head_t wait_post_send;
0118
0119     /* Receive queue */
0120     struct list_head receive_queue;
0121     int count_receive_queue;
0122     spinlock_t receive_queue_lock;
0123
0124     struct list_head empty_packet_queue;
0125     int count_empty_packet_queue;
0126     spinlock_t empty_packet_queue_lock;
0127
0128     wait_queue_head_t wait_receive_queues;
0129
0130     /* Reassembly queue */
0131     struct list_head reassembly_queue;
0132     spinlock_t reassembly_queue_lock;
0133     wait_queue_head_t wait_reassembly_queue;
0134
0135     /* total data length of reassembly queue */
0136     int reassembly_data_length;
0137     int reassembly_queue_length;
0138     /* the offset to first buffer in reassembly queue */
0139     int first_entry_offset;
0140
0141     bool send_immediate;
0142
0143     wait_queue_head_t wait_send_queue;
0144
0145     /*
0146      * Indicate if we have received a full packet on the connection
0147      * This is used to identify the first SMBD packet of a assembled
0148      * payload (SMB packet) in reassembly queue so we can return a
0149      * RFC1002 length to upper layer to indicate the length of the SMB
0150      * packet received
0151      */
0152     bool full_packet_received;
0153
0154     struct workqueue_struct *workqueue;
0155     struct delayed_work idle_timer_work;
0156
0157     /* Memory pool for preallocating buffers */
0158     /* request pool for RDMA send */
0159     struct kmem_cache *request_cache;
0160     mempool_t *request_mempool;
0161
0162     /* response pool for RDMA receive */
0163     struct kmem_cache *response_cache;
0164     mempool_t *response_mempool;
0165
0166     /* for debug purposes */
0167     unsigned int count_get_receive_buffer;
0168     unsigned int count_put_receive_buffer;
0169     unsigned int count_reassembly_queue;
0170     unsigned int count_enqueue_reassembly_queue;
0171     unsigned int count_dequeue_reassembly_queue;
0172     unsigned int count_send_empty;
0173 };
0174
0175 enum smbd_message_type {
0176     SMBD_NEGOTIATE_RESP,
0177     SMBD_TRANSFER_DATA,
0178 };
0179
0180 #define SMB_DIRECT_RESPONSE_REQUESTED 0x0001
0181
0182 /* SMBD negotiation request packet [MS-SMBD] 2.2.1 */
0183 struct smbd_negotiate_req {
0184     __le16 min_version;
0185     __le16 max_version;
0186     __le16 reserved;
0187     __le16 credits_requested;
0188     __le32 preferred_send_size;
0189     __le32 max_receive_size;
0190     __le32 max_fragmented_size;
0191 } __packed;
0192
0193 /* SMBD negotiation response packet [MS-SMBD] 2.2.2 */
0194 struct smbd_negotiate_resp {
0195     __le16 min_version;
0196     __le16 max_version;
0197     __le16 negotiated_version;
0198     __le16 reserved;
0199     __le16 credits_requested;
0200     __le16 credits_granted;
0201     __le32 status;
0202     __le32 max_readwrite_size;
0203     __le32 preferred_send_size;
0204     __le32 max_receive_size;
0205     __le32 max_fragmented_size;
0206 } __packed;
0207
0208 /* SMBD data transfer packet with payload [MS-SMBD] 2.2.3 */
0209 struct smbd_data_transfer {
0210     __le16 credits_requested;
0211     __le16 credits_granted;
0212     __le16 flags;
0213     __le16 reserved;
0214     __le32 remaining_data_length;
0215     __le32 data_offset;
0216     __le32 data_length;
0217     __le32 padding;
0218     __u8 buffer[];
0219 } __packed;
0220
0221 /* The packet fields for a registered RDMA buffer */
0222 struct smbd_buffer_descriptor_v1 {
0223     __le64 offset;
0224     __le32 token;
0225     __le32 length;
0226 } __packed;
0227
0228 /* Default maximum number of SGEs in a RDMA send/recv */
0229 #define SMBDIRECT_MAX_SGE   16
0230 /* The context for a SMBD request */
0231 struct smbd_request {
0232     struct smbd_connection *info;
0233     struct ib_cqe cqe;
0234
0235     /* the SGE entries for this packet */
0236     struct ib_sge sge[SMBDIRECT_MAX_SGE];
0237     int num_sge;
0238
0239     /* SMBD packet header follows this structure */
0240     u8 packet[];
0241 };
0242
0243 /* The context for a SMBD response */
0244 struct smbd_response {
0245     struct smbd_connection *info;
0246     struct ib_cqe cqe;
0247     struct ib_sge sge;
0248
0249     enum smbd_message_type type;
0250
0251     /* Link to receive queue or reassembly queue */
0252     struct list_head list;
0253
0254     /* Indicate if this is the 1st packet of a payload */
0255     bool first_segment;
0256
0257     /* SMBD packet header and payload follows this structure */
0258     u8 packet[];
0259 };
0260
0261 /* Create a SMBDirect session */
0262 struct smbd_connection *smbd_get_connection(
0263     struct TCP_Server_Info *server, struct sockaddr *dstaddr);
0264
0265 /* Reconnect SMBDirect session */
0266 int smbd_reconnect(struct TCP_Server_Info *server);
0267 /* Destroy SMBDirect session */
0268 void smbd_destroy(struct TCP_Server_Info *server);
0269
0270 /* Interface for carrying upper layer I/O through send/recv */
0271 int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
0272 int smbd_send(struct TCP_Server_Info *server,
0273     int num_rqst, struct smb_rqst *rqst);
0274
0275 enum mr_state {
0276     MR_READY,
0277     MR_REGISTERED,
0278     MR_INVALIDATED,
0279     MR_ERROR
0280 };
0281
0282 struct smbd_mr {
0283     struct smbd_connection  *conn;
0284     struct list_head    list;
0285     enum mr_state       state;
0286     struct ib_mr        *mr;
0287     struct scatterlist  *sgl;
0288     int         sgl_count;
0289     enum dma_data_direction dir;
0290     union {
0291         struct ib_reg_wr    wr;
0292         struct ib_send_wr   inv_wr;
0293     };
0294     struct ib_cqe       cqe;
0295     bool            need_invalidate;
0296     struct completion   invalidate_done;
0297 };
0298
0299 /* Interfaces to register and deregister MR for RDMA read/write */
0300 struct smbd_mr *smbd_register_mr(
0301     struct smbd_connection *info, struct page *pages[], int num_pages,
0302     int offset, int tailsz, bool writing, bool need_invalidate);
0303 int smbd_deregister_mr(struct smbd_mr *mr);
0304
0305 #else
0306 #define cifs_rdma_enabled(server)   0
0307 struct smbd_connection {};
0308 static inline void *smbd_get_connection(
0309     struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
0310 static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
0311 static inline void smbd_destroy(struct TCP_Server_Info *server) {}
0312 static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
0313 static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; }
0314 #endif
0315
0316 #endif