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Diffstat (limited to 'net/sunrpc/xprtrdma/xprt_rdma.h')
| -rw-r--r-- | net/sunrpc/xprtrdma/xprt_rdma.h | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h new file mode 100644 index 000000000..5e5ff6784 --- /dev/null +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -0,0 +1,605 @@ +/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */ +/* + * Copyright (c) 2014-2017 Oracle. All rights reserved. + * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the BSD-type + * license below: + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * Neither the name of the Network Appliance, Inc. nor the names of + * its contributors may be used to endorse or promote products + * derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _LINUX_SUNRPC_XPRT_RDMA_H +#define _LINUX_SUNRPC_XPRT_RDMA_H + +#include <linux/wait.h> /* wait_queue_head_t, etc */ +#include <linux/spinlock.h> /* spinlock_t, etc */ +#include <linux/atomic.h> /* atomic_t, etc */ +#include <linux/kref.h> /* struct kref */ +#include <linux/workqueue.h> /* struct work_struct */ +#include <linux/llist.h> + +#include <rdma/rdma_cm.h> /* RDMA connection api */ +#include <rdma/ib_verbs.h> /* RDMA verbs api */ + +#include <linux/sunrpc/clnt.h> /* rpc_xprt */ +#include <linux/sunrpc/rpc_rdma_cid.h> /* completion IDs */ +#include <linux/sunrpc/rpc_rdma.h> /* RPC/RDMA protocol */ +#include <linux/sunrpc/xprtrdma.h> /* xprt parameters */ + +#define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */ +#define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */ + +#define RPCRDMA_BIND_TO (60U * HZ) +#define RPCRDMA_INIT_REEST_TO (5U * HZ) +#define RPCRDMA_MAX_REEST_TO (30U * HZ) +#define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ) + +/* + * RDMA Endpoint -- connection endpoint details + */ +struct rpcrdma_mr; +struct rpcrdma_ep { + struct kref re_kref; + struct rdma_cm_id *re_id; + struct ib_pd *re_pd; + unsigned int re_max_rdma_segs; + unsigned int re_max_fr_depth; + struct rpcrdma_mr *re_write_pad_mr; + enum ib_mr_type re_mrtype; + struct completion re_done; + unsigned int re_send_count; + unsigned int re_send_batch; + unsigned int re_max_inline_send; + unsigned int re_max_inline_recv; + int re_async_rc; + int re_connect_status; + atomic_t re_receiving; + atomic_t re_force_disconnect; + struct ib_qp_init_attr re_attr; + wait_queue_head_t re_connect_wait; + struct rpc_xprt *re_xprt; + struct rpcrdma_connect_private + re_cm_private; + struct rdma_conn_param re_remote_cma; + int re_receive_count; + unsigned int re_max_requests; /* depends on device */ + unsigned int re_inline_send; /* negotiated */ + unsigned int re_inline_recv; /* negotiated */ + + atomic_t re_completion_ids; + + char re_write_pad[XDR_UNIT]; +}; + +/* Pre-allocate extra Work Requests for handling reverse-direction + * Receives and Sends. This is a fixed value because the Work Queues + * are allocated when the forward channel is set up, long before the + * backchannel is provisioned. This value is two times + * NFS4_DEF_CB_SLOT_TABLE_SIZE. + */ +#if defined(CONFIG_SUNRPC_BACKCHANNEL) +#define RPCRDMA_BACKWARD_WRS (32) +#else +#define RPCRDMA_BACKWARD_WRS (0) +#endif + +/* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV + */ + +struct rpcrdma_regbuf { + struct ib_sge rg_iov; + struct ib_device *rg_device; + enum dma_data_direction rg_direction; + void *rg_data; +}; + +static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb) +{ + return rb->rg_iov.addr; +} + +static inline u32 rdmab_length(struct rpcrdma_regbuf *rb) +{ + return rb->rg_iov.length; +} + +static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb) +{ + return rb->rg_iov.lkey; +} + +static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb) +{ + return rb->rg_device; +} + +static inline void *rdmab_data(const struct rpcrdma_regbuf *rb) +{ + return rb->rg_data; +} + +/* Do not use emergency memory reserves, and fail quickly if memory + * cannot be allocated easily. These flags may be used wherever there + * is robust logic to handle a failure to allocate. + */ +#define XPRTRDMA_GFP_FLAGS (__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN) + +/* To ensure a transport can always make forward progress, + * the number of RDMA segments allowed in header chunk lists + * is capped at 16. This prevents less-capable devices from + * overrunning the Send buffer while building chunk lists. + * + * Elements of the Read list take up more room than the + * Write list or Reply chunk. 16 read segments means the + * chunk lists cannot consume more than + * + * ((16 + 2) * read segment size) + 1 XDR words, + * + * or about 400 bytes. The fixed part of the header is + * another 24 bytes. Thus when the inline threshold is + * 1024 bytes, at least 600 bytes are available for RPC + * message bodies. + */ +enum { + RPCRDMA_MAX_HDR_SEGS = 16, +}; + +/* + * struct rpcrdma_rep -- this structure encapsulates state required + * to receive and complete an RPC Reply, asychronously. It needs + * several pieces of state: + * + * o receive buffer and ib_sge (donated to provider) + * o status of receive (success or not, length, inv rkey) + * o bookkeeping state to get run by reply handler (XDR stream) + * + * These structures are allocated during transport initialization. + * N of these are associated with a transport instance, managed by + * struct rpcrdma_buffer. N is the max number of outstanding RPCs. + */ + +struct rpcrdma_rep { + struct ib_cqe rr_cqe; + struct rpc_rdma_cid rr_cid; + + __be32 rr_xid; + __be32 rr_vers; + __be32 rr_proc; + int rr_wc_flags; + u32 rr_inv_rkey; + bool rr_temp; + struct rpcrdma_regbuf *rr_rdmabuf; + struct rpcrdma_xprt *rr_rxprt; + struct rpc_rqst *rr_rqst; + struct xdr_buf rr_hdrbuf; + struct xdr_stream rr_stream; + struct llist_node rr_node; + struct ib_recv_wr rr_recv_wr; + struct list_head rr_all; +}; + +/* To reduce the rate at which a transport invokes ib_post_recv + * (and thus the hardware doorbell rate), xprtrdma posts Receive + * WRs in batches. + * + * Setting this to zero disables Receive post batching. + */ +enum { + RPCRDMA_MAX_RECV_BATCH = 7, +}; + +/* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes + */ +struct rpcrdma_req; +struct rpcrdma_sendctx { + struct ib_cqe sc_cqe; + struct rpc_rdma_cid sc_cid; + struct rpcrdma_req *sc_req; + unsigned int sc_unmap_count; + struct ib_sge sc_sges[]; +}; + +/* + * struct rpcrdma_mr - external memory region metadata + * + * An external memory region is any buffer or page that is registered + * on the fly (ie, not pre-registered). + */ +struct rpcrdma_req; +struct rpcrdma_mr { + struct list_head mr_list; + struct rpcrdma_req *mr_req; + + struct ib_mr *mr_ibmr; + struct ib_device *mr_device; + struct scatterlist *mr_sg; + int mr_nents; + enum dma_data_direction mr_dir; + struct ib_cqe mr_cqe; + struct completion mr_linv_done; + union { + struct ib_reg_wr mr_regwr; + struct ib_send_wr mr_invwr; + }; + struct rpcrdma_xprt *mr_xprt; + u32 mr_handle; + u32 mr_length; + u64 mr_offset; + struct list_head mr_all; + struct rpc_rdma_cid mr_cid; +}; + +/* + * struct rpcrdma_req -- structure central to the request/reply sequence. + * + * N of these are associated with a transport instance, and stored in + * struct rpcrdma_buffer. N is the max number of outstanding requests. + * + * It includes pre-registered buffer memory for send AND recv. + * The recv buffer, however, is not owned by this structure, and + * is "donated" to the hardware when a recv is posted. When a + * reply is handled, the recv buffer used is given back to the + * struct rpcrdma_req associated with the request. + * + * In addition to the basic memory, this structure includes an array + * of iovs for send operations. The reason is that the iovs passed to + * ib_post_{send,recv} must not be modified until the work request + * completes. + */ + +/* Maximum number of page-sized "segments" per chunk list to be + * registered or invalidated. Must handle a Reply chunk: + */ +enum { + RPCRDMA_MAX_IOV_SEGS = 3, + RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1, + RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS + + RPCRDMA_MAX_IOV_SEGS, +}; + +/* Arguments for DMA mapping and registration */ +struct rpcrdma_mr_seg { + u32 mr_len; /* length of segment */ + struct page *mr_page; /* underlying struct page */ + u64 mr_offset; /* IN: page offset, OUT: iova */ +}; + +/* The Send SGE array is provisioned to send a maximum size + * inline request: + * - RPC-over-RDMA header + * - xdr_buf head iovec + * - RPCRDMA_MAX_INLINE bytes, in pages + * - xdr_buf tail iovec + * + * The actual number of array elements consumed by each RPC + * depends on the device's max_sge limit. + */ +enum { + RPCRDMA_MIN_SEND_SGES = 3, + RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT, + RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1, +}; + +struct rpcrdma_buffer; +struct rpcrdma_req { + struct list_head rl_list; + struct rpc_rqst rl_slot; + struct rpcrdma_rep *rl_reply; + struct xdr_stream rl_stream; + struct xdr_buf rl_hdrbuf; + struct ib_send_wr rl_wr; + struct rpcrdma_sendctx *rl_sendctx; + struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */ + struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */ + struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */ + + struct list_head rl_all; + struct kref rl_kref; + + struct list_head rl_free_mrs; + struct list_head rl_registered; + struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; +}; + +static inline struct rpcrdma_req * +rpcr_to_rdmar(const struct rpc_rqst *rqst) +{ + return container_of(rqst, struct rpcrdma_req, rl_slot); +} + +static inline void +rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list) +{ + list_add(&mr->mr_list, list); +} + +static inline struct rpcrdma_mr * +rpcrdma_mr_pop(struct list_head *list) +{ + struct rpcrdma_mr *mr; + + mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list); + if (mr) + list_del_init(&mr->mr_list); + return mr; +} + +/* + * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for + * inline requests/replies, and client/server credits. + * + * One of these is associated with a transport instance + */ +struct rpcrdma_buffer { + spinlock_t rb_lock; + struct list_head rb_send_bufs; + struct list_head rb_mrs; + + unsigned long rb_sc_head; + unsigned long rb_sc_tail; + unsigned long rb_sc_last; + struct rpcrdma_sendctx **rb_sc_ctxs; + + struct list_head rb_allreqs; + struct list_head rb_all_mrs; + struct list_head rb_all_reps; + + struct llist_head rb_free_reps; + + __be32 rb_max_requests; + u32 rb_credits; /* most recent credit grant */ + + u32 rb_bc_srv_max_requests; + u32 rb_bc_max_requests; + + struct work_struct rb_refresh_worker; +}; + +/* + * Statistics for RPCRDMA + */ +struct rpcrdma_stats { + /* accessed when sending a call */ + unsigned long read_chunk_count; + unsigned long write_chunk_count; + unsigned long reply_chunk_count; + unsigned long long total_rdma_request; + + /* rarely accessed error counters */ + unsigned long long pullup_copy_count; + unsigned long hardway_register_count; + unsigned long failed_marshal_count; + unsigned long bad_reply_count; + unsigned long mrs_recycled; + unsigned long mrs_orphaned; + unsigned long mrs_allocated; + unsigned long empty_sendctx_q; + + /* accessed when receiving a reply */ + unsigned long long total_rdma_reply; + unsigned long long fixup_copy_count; + unsigned long reply_waits_for_send; + unsigned long local_inv_needed; + unsigned long nomsg_call_count; + unsigned long bcall_count; +}; + +/* + * RPCRDMA transport -- encapsulates the structures above for + * integration with RPC. + * + * The contained structures are embedded, not pointers, + * for convenience. This structure need not be visible externally. + * + * It is allocated and initialized during mount, and released + * during unmount. + */ +struct rpcrdma_xprt { + struct rpc_xprt rx_xprt; + struct rpcrdma_ep *rx_ep; + struct rpcrdma_buffer rx_buf; + struct delayed_work rx_connect_worker; + struct rpc_timeout rx_timeout; + struct rpcrdma_stats rx_stats; +}; + +#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt) + +static inline const char * +rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt) +{ + return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR]; +} + +static inline const char * +rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt) +{ + return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT]; +} + +/* Setting this to 0 ensures interoperability with early servers. + * Setting this to 1 enhances certain unaligned read/write performance. + * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */ +extern int xprt_rdma_pad_optimize; + +/* This setting controls the hunt for a supported memory + * registration strategy. + */ +extern unsigned int xprt_rdma_memreg_strategy; + +/* + * Endpoint calls - xprtrdma/verbs.c + */ +void rpcrdma_force_disconnect(struct rpcrdma_ep *ep); +void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc); +int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt); +void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt); + +void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp); + +/* + * Buffer calls - xprtrdma/verbs.c + */ +struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, + size_t size); +int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); +void rpcrdma_req_destroy(struct rpcrdma_req *req); +int rpcrdma_buffer_create(struct rpcrdma_xprt *); +void rpcrdma_buffer_destroy(struct rpcrdma_buffer *); +struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt); + +struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt); +void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt); + +struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); +void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, + struct rpcrdma_req *req); +void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep); +void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req); + +bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, + gfp_t flags); +bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, + struct rpcrdma_regbuf *rb); + +/** + * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped + * + * Returns true if the buffer is now mapped to rb->rg_device. + */ +static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb) +{ + return rb->rg_device != NULL; +} + +/** + * rpcrdma_regbuf_dma_map - DMA-map a regbuf + * @r_xprt: controlling transport instance + * @rb: regbuf to be mapped + * + * Returns true if the buffer is currently DMA mapped. + */ +static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, + struct rpcrdma_regbuf *rb) +{ + if (likely(rpcrdma_regbuf_is_mapped(rb))) + return true; + return __rpcrdma_regbuf_dma_map(r_xprt, rb); +} + +/* + * Wrappers for chunk registration, shared by read/write chunk code. + */ + +static inline enum dma_data_direction +rpcrdma_data_dir(bool writing) +{ + return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; +} + +/* Memory registration calls xprtrdma/frwr_ops.c + */ +void frwr_reset(struct rpcrdma_req *req); +int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device); +int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr); +void frwr_mr_release(struct rpcrdma_mr *mr); +struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, + struct rpcrdma_mr_seg *seg, + int nsegs, bool writing, __be32 xid, + struct rpcrdma_mr *mr); +int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); +void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs); +void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); +void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); +int frwr_wp_create(struct rpcrdma_xprt *r_xprt); + +/* + * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c + */ + +enum rpcrdma_chunktype { + rpcrdma_noch = 0, + rpcrdma_noch_pullup, + rpcrdma_noch_mapped, + rpcrdma_readch, + rpcrdma_areadch, + rpcrdma_writech, + rpcrdma_replych +}; + +int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt, + struct rpcrdma_req *req, u32 hdrlen, + struct xdr_buf *xdr, + enum rpcrdma_chunktype rtype); +void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc); +int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst); +void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep); +void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt); +void rpcrdma_complete_rqst(struct rpcrdma_rep *rep); +void rpcrdma_unpin_rqst(struct rpcrdma_rep *rep); +void rpcrdma_reply_handler(struct rpcrdma_rep *rep); + +static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len) +{ + xdr->head[0].iov_len = len; + xdr->len = len; +} + +/* RPC/RDMA module init - xprtrdma/transport.c + */ +extern unsigned int xprt_rdma_max_inline_read; +extern unsigned int xprt_rdma_max_inline_write; +void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap); +void xprt_rdma_free_addresses(struct rpc_xprt *xprt); +void xprt_rdma_close(struct rpc_xprt *xprt); +void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq); +int xprt_rdma_init(void); +void xprt_rdma_cleanup(void); + +/* Backchannel calls - xprtrdma/backchannel.c + */ +#if defined(CONFIG_SUNRPC_BACKCHANNEL) +int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int); +size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *); +unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *); +int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); +void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *); +int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst); +void xprt_rdma_bc_free_rqst(struct rpc_rqst *); +void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); +#endif /* CONFIG_SUNRPC_BACKCHANNEL */ + +extern struct xprt_class xprt_rdma_bc; + +#endif /* _LINUX_SUNRPC_XPRT_RDMA_H */ |