linux/fs/smb/client/smbdirect.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *   Copyright (C) 2017, Microsoft Corporation.
 *
 *   Author(s): Long Li <[email protected]>
 */
#ifndef _SMBDIRECT_H
#define _SMBDIRECT_H

#ifdef CONFIG_CIFS_SMB_DIRECT
#define cifs_rdma_enabled(server) …

#include "cifsglob.h"
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <linux/mempool.h>

extern int rdma_readwrite_threshold;
extern int smbd_max_frmr_depth;
extern int smbd_keep_alive_interval;
extern int smbd_max_receive_size;
extern int smbd_max_fragmented_recv_size;
extern int smbd_max_send_size;
extern int smbd_send_credit_target;
extern int smbd_receive_credit_max;

enum keep_alive_status { … };

enum smbd_connection_status { … };

/*
 * The context for the SMBDirect transport
 * Everything related to the transport is here. It has several logical parts
 * 1. RDMA related structures
 * 2. SMBDirect connection parameters
 * 3. Memory registrations
 * 4. Receive and reassembly queues for data receive path
 * 5. mempools for allocating packets
 */
struct smbd_connection { … };

enum smbd_message_type { … };

#define SMB_DIRECT_RESPONSE_REQUESTED …

/* SMBD negotiation request packet [MS-SMBD] 2.2.1 */
struct smbd_negotiate_req { … } __packed;

/* SMBD negotiation response packet [MS-SMBD] 2.2.2 */
struct smbd_negotiate_resp { … } __packed;

/* SMBD data transfer packet with payload [MS-SMBD] 2.2.3 */
struct smbd_data_transfer { … } __packed;

/* The packet fields for a registered RDMA buffer */
struct smbd_buffer_descriptor_v1 { … } __packed;

/* Maximum number of SGEs used by smbdirect.c in any send work request */
#define SMBDIRECT_MAX_SEND_SGE …

/* The context for a SMBD request */
struct smbd_request { … };

/* Maximum number of SGEs used by smbdirect.c in any receive work request */
#define SMBDIRECT_MAX_RECV_SGE …

/* The context for a SMBD response */
struct smbd_response { … };

/* Create a SMBDirect session */
struct smbd_connection *smbd_get_connection(
	struct TCP_Server_Info *server, struct sockaddr *dstaddr);

/* Reconnect SMBDirect session */
int smbd_reconnect(struct TCP_Server_Info *server);
/* Destroy SMBDirect session */
void smbd_destroy(struct TCP_Server_Info *server);

/* Interface for carrying upper layer I/O through send/recv */
int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
int smbd_send(struct TCP_Server_Info *server,
	int num_rqst, struct smb_rqst *rqst);

enum mr_state { … };

struct smbd_mr { … };

/* Interfaces to register and deregister MR for RDMA read/write */
struct smbd_mr *smbd_register_mr(
	struct smbd_connection *info, struct iov_iter *iter,
	bool writing, bool need_invalidate);
int smbd_deregister_mr(struct smbd_mr *mr);

#else
#define cifs_rdma_enabled …
struct smbd_connection {};
static inline void *smbd_get_connection(
	struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; }
static inline void smbd_destroy(struct TCP_Server_Info *server) {}
static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; }
static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; }
#endif

#endif