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-rw-r--r--fs/smb/client/smbdirect.h319
1 files changed, 319 insertions, 0 deletions
diff --git a/fs/smb/client/smbdirect.h b/fs/smb/client/smbdirect.h
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+++ b/fs/smb/client/smbdirect.h
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2017, Microsoft Corporation.
+ *
+ * Author(s): Long Li <longli@microsoft.com>
+ */
+#ifndef _SMBDIRECT_H
+#define _SMBDIRECT_H
+
+#ifdef CONFIG_CIFS_SMB_DIRECT
+#define cifs_rdma_enabled(server) ((server)->rdma)
+
+#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 {
+ KEEP_ALIVE_NONE,
+ KEEP_ALIVE_PENDING,
+ KEEP_ALIVE_SENT,
+};
+
+enum smbd_connection_status {
+ SMBD_CREATED,
+ SMBD_CONNECTING,
+ SMBD_CONNECTED,
+ SMBD_NEGOTIATE_FAILED,
+ SMBD_DISCONNECTING,
+ SMBD_DISCONNECTED,
+ SMBD_DESTROYED
+};
+
+/*
+ * 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_connection_status transport_status;
+
+ /* RDMA related */
+ struct rdma_cm_id *id;
+ struct ib_qp_init_attr qp_attr;
+ struct ib_pd *pd;
+ struct ib_cq *send_cq, *recv_cq;
+ struct ib_device_attr dev_attr;
+ int ri_rc;
+ struct completion ri_done;
+ wait_queue_head_t conn_wait;
+ wait_queue_head_t disconn_wait;
+
+ struct completion negotiate_completion;
+ bool negotiate_done;
+
+ struct work_struct disconnect_work;
+ struct work_struct post_send_credits_work;
+
+ spinlock_t lock_new_credits_offered;
+ int new_credits_offered;
+
+ /* Connection parameters defined in [MS-SMBD] 3.1.1.1 */
+ int receive_credit_max;
+ int send_credit_target;
+ int max_send_size;
+ int max_fragmented_recv_size;
+ int max_fragmented_send_size;
+ int max_receive_size;
+ int keep_alive_interval;
+ int max_readwrite_size;
+ enum keep_alive_status keep_alive_requested;
+ int protocol;
+ atomic_t send_credits;
+ atomic_t receive_credits;
+ int receive_credit_target;
+ int fragment_reassembly_remaining;
+
+ /* Memory registrations */
+ /* Maximum number of RDMA read/write outstanding on this connection */
+ int responder_resources;
+ /* Maximum number of pages in a single RDMA write/read on this connection */
+ int max_frmr_depth;
+ /*
+ * If payload is less than or equal to the threshold,
+ * use RDMA send/recv to send upper layer I/O.
+ * If payload is more than the threshold,
+ * use RDMA read/write through memory registration for I/O.
+ */
+ int rdma_readwrite_threshold;
+ enum ib_mr_type mr_type;
+ struct list_head mr_list;
+ spinlock_t mr_list_lock;
+ /* The number of available MRs ready for memory registration */
+ atomic_t mr_ready_count;
+ atomic_t mr_used_count;
+ wait_queue_head_t wait_mr;
+ struct work_struct mr_recovery_work;
+ /* Used by transport to wait until all MRs are returned */
+ wait_queue_head_t wait_for_mr_cleanup;
+
+ /* Activity accoutning */
+ atomic_t send_pending;
+ wait_queue_head_t wait_send_pending;
+ wait_queue_head_t wait_post_send;
+
+ /* Receive queue */
+ struct list_head receive_queue;
+ int count_receive_queue;
+ spinlock_t receive_queue_lock;
+
+ struct list_head empty_packet_queue;
+ int count_empty_packet_queue;
+ spinlock_t empty_packet_queue_lock;
+
+ wait_queue_head_t wait_receive_queues;
+
+ /* Reassembly queue */
+ struct list_head reassembly_queue;
+ spinlock_t reassembly_queue_lock;
+ wait_queue_head_t wait_reassembly_queue;
+
+ /* total data length of reassembly queue */
+ int reassembly_data_length;
+ int reassembly_queue_length;
+ /* the offset to first buffer in reassembly queue */
+ int first_entry_offset;
+
+ bool send_immediate;
+
+ wait_queue_head_t wait_send_queue;
+
+ /*
+ * Indicate if we have received a full packet on the connection
+ * This is used to identify the first SMBD packet of a assembled
+ * payload (SMB packet) in reassembly queue so we can return a
+ * RFC1002 length to upper layer to indicate the length of the SMB
+ * packet received
+ */
+ bool full_packet_received;
+
+ struct workqueue_struct *workqueue;
+ struct delayed_work idle_timer_work;
+
+ /* Memory pool for preallocating buffers */
+ /* request pool for RDMA send */
+ struct kmem_cache *request_cache;
+ mempool_t *request_mempool;
+
+ /* response pool for RDMA receive */
+ struct kmem_cache *response_cache;
+ mempool_t *response_mempool;
+
+ /* for debug purposes */
+ unsigned int count_get_receive_buffer;
+ unsigned int count_put_receive_buffer;
+ unsigned int count_reassembly_queue;
+ unsigned int count_enqueue_reassembly_queue;
+ unsigned int count_dequeue_reassembly_queue;
+ unsigned int count_send_empty;
+};
+
+enum smbd_message_type {
+ SMBD_NEGOTIATE_RESP,
+ SMBD_TRANSFER_DATA,
+};
+
+#define SMB_DIRECT_RESPONSE_REQUESTED 0x0001
+
+/* SMBD negotiation request packet [MS-SMBD] 2.2.1 */
+struct smbd_negotiate_req {
+ __le16 min_version;
+ __le16 max_version;
+ __le16 reserved;
+ __le16 credits_requested;
+ __le32 preferred_send_size;
+ __le32 max_receive_size;
+ __le32 max_fragmented_size;
+} __packed;
+
+/* SMBD negotiation response packet [MS-SMBD] 2.2.2 */
+struct smbd_negotiate_resp {
+ __le16 min_version;
+ __le16 max_version;
+ __le16 negotiated_version;
+ __le16 reserved;
+ __le16 credits_requested;
+ __le16 credits_granted;
+ __le32 status;
+ __le32 max_readwrite_size;
+ __le32 preferred_send_size;
+ __le32 max_receive_size;
+ __le32 max_fragmented_size;
+} __packed;
+
+/* SMBD data transfer packet with payload [MS-SMBD] 2.2.3 */
+struct smbd_data_transfer {
+ __le16 credits_requested;
+ __le16 credits_granted;
+ __le16 flags;
+ __le16 reserved;
+ __le32 remaining_data_length;
+ __le32 data_offset;
+ __le32 data_length;
+ __le32 padding;
+ __u8 buffer[];
+} __packed;
+
+/* The packet fields for a registered RDMA buffer */
+struct smbd_buffer_descriptor_v1 {
+ __le64 offset;
+ __le32 token;
+ __le32 length;
+} __packed;
+
+/* Maximum number of SGEs used by smbdirect.c in any send work request */
+#define SMBDIRECT_MAX_SEND_SGE 6
+
+/* The context for a SMBD request */
+struct smbd_request {
+ struct smbd_connection *info;
+ struct ib_cqe cqe;
+
+ /* the SGE entries for this work request */
+ struct ib_sge sge[SMBDIRECT_MAX_SEND_SGE];
+ int num_sge;
+
+ /* SMBD packet header follows this structure */
+ u8 packet[];
+};
+
+/* Maximum number of SGEs used by smbdirect.c in any receive work request */
+#define SMBDIRECT_MAX_RECV_SGE 1
+
+/* The context for a SMBD response */
+struct smbd_response {
+ struct smbd_connection *info;
+ struct ib_cqe cqe;
+ struct ib_sge sge;
+
+ enum smbd_message_type type;
+
+ /* Link to receive queue or reassembly queue */
+ struct list_head list;
+
+ /* Indicate if this is the 1st packet of a payload */
+ bool first_segment;
+
+ /* SMBD packet header and payload follows this structure */
+ u8 packet[];
+};
+
+/* 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 {
+ MR_READY,
+ MR_REGISTERED,
+ MR_INVALIDATED,
+ MR_ERROR
+};
+
+struct smbd_mr {
+ struct smbd_connection *conn;
+ struct list_head list;
+ enum mr_state state;
+ struct ib_mr *mr;
+ struct sg_table sgt;
+ enum dma_data_direction dir;
+ union {
+ struct ib_reg_wr wr;
+ struct ib_send_wr inv_wr;
+ };
+ struct ib_cqe cqe;
+ bool need_invalidate;
+ struct completion invalidate_done;
+};
+
+/* 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(server) 0
+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