/* 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 */
#include <linux/sunrpc/rdma_rn.h> /* removal notifications */
#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;
struct rpcrdma_notification re_rn;
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;
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);
/*
* 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 *);
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 */
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