/* 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 <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.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)
/*
* Interface Adapter -- one per transport instance
*/
struct rpcrdma_ia {
struct rdma_cm_id *ri_id;
struct ib_pd *ri_pd;
int ri_async_rc;
unsigned int ri_max_segs;
unsigned int ri_max_frwr_depth;
unsigned int ri_max_send_sges;
bool ri_implicit_roundup;
enum ib_mr_type ri_mrtype;
unsigned long ri_flags;
struct completion ri_done;
struct completion ri_remove_done;
};
enum {
RPCRDMA_IAF_REMOVING = 0,
};
/*
* RDMA Endpoint -- one per transport instance
*/
struct rpcrdma_ep {
unsigned int rep_send_count;
unsigned int rep_send_batch;
unsigned int rep_max_inline_send;
unsigned int rep_max_inline_recv;
int rep_connected;
struct ib_qp_init_attr rep_attr;
wait_queue_head_t rep_connect_wait;
struct rpcrdma_connect_private rep_cm_private;
struct rdma_conn_param rep_remote_cma;
unsigned int rep_max_requests; /* set by /proc */
unsigned int rep_inline_send; /* negotiated */
unsigned int rep_inline_recv; /* negotiated */
int rep_receive_count;
};
/* Pre-allocate extra Work Requests for handling backward 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
*
* The below structure appears at the front of a large region of kmalloc'd
* memory, which always starts on a good alignment boundary.
*/
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;
}
#define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
/* To ensure a transport can always make forward progress,
* the number of RDMA segments allowed in header chunk lists
* is capped at 8. This prevents less-capable devices and
* memory registrations 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. 8 read segments means the Read
* list (or Write list or Reply chunk) cannot consume more
* than
*
* ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
*
* And the fixed part of the header is another 24 bytes.
*
* The smallest inline threshold is 1024 bytes, ensuring that
* at least 750 bytes are available for RPC messages.
*/
enum {
RPCRDMA_MAX_HDR_SEGS = 8,
RPCRDMA_HDRBUF_SIZE = 256,
};
/*
* 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;
__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 list_head rr_list;
struct ib_recv_wr rr_recv_wr;
};
/* 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_xprt;
struct rpcrdma_sendctx {
struct ib_send_wr sc_wr;
struct ib_cqe sc_cqe;
struct ib_device *sc_device;
struct rpcrdma_xprt *sc_xprt;
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_frwr {
struct ib_mr *fr_mr;
struct ib_cqe fr_cqe;
struct completion fr_linv_done;
struct rpcrdma_req *fr_req;
union {
struct ib_reg_wr fr_regwr;
struct ib_send_wr fr_invwr;
};
};
struct rpcrdma_mr {
struct list_head mr_list;
struct scatterlist *mr_sg;
int mr_nents;
enum dma_data_direction mr_dir;
struct rpcrdma_frwr frwr;
struct rpcrdma_xprt *mr_xprt;
u32 mr_handle;
u32 mr_length;
u64 mr_offset;
struct work_struct mr_recycle;
struct list_head mr_all;
};
/*
* 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,
};
struct rpcrdma_mr_seg { /* chunk descriptors */
u32 mr_len; /* length of chunk or segment */
struct page *mr_page; /* owning page, if any */
char *mr_offset; /* kva if no page, else offset */
};
/* 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 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_registered; /* registered segments */
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_tail(&mr->mr_list, list);
}
static inline struct rpcrdma_mr *
rpcrdma_mr_pop(struct list_head *list)
{
struct rpcrdma_mr *mr;
mr = list_first_entry(list, struct rpcrdma_mr, mr_list);
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_mrlock; /* protect rb_mrs list */
struct list_head rb_mrs;
struct list_head rb_all;
unsigned long rb_sc_head;
unsigned long rb_sc_tail;
unsigned long rb_sc_last;
struct rpcrdma_sendctx **rb_sc_ctxs;
spinlock_t rb_lock; /* protect buf lists */
struct list_head rb_send_bufs;
struct list_head rb_recv_bufs;
struct list_head rb_allreqs;
u32 rb_max_requests;
u32 rb_credits; /* most recent credit grant */
u32 rb_bc_srv_max_requests;
u32 rb_bc_max_requests;
struct delayed_work 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_ia rx_ia;
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;
/*
* Interface Adapter calls - xprtrdma/verbs.c
*/
int rpcrdma_ia_open(struct rpcrdma_xprt *xprt);
void rpcrdma_ia_remove(struct rpcrdma_ia *ia);
void rpcrdma_ia_close(struct rpcrdma_ia *);
/*
* Endpoint calls - xprtrdma/verbs.c
*/
int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt);
void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt);
int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
struct rpcrdma_req *);
/*
* Buffer calls - xprtrdma/verbs.c
*/
struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
gfp_t flags);
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_mr_put(struct rpcrdma_mr *mr);
void rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr);
static inline void
rpcrdma_mr_recycle(struct rpcrdma_mr *mr)
{
schedule_work(&mr->mr_recycle);
}
struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
struct rpcrdma_req *req);
void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
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
*/
bool frwr_is_supported(struct ib_device *device);
void frwr_reset(struct rpcrdma_req *req);
int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep);
int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr);
void frwr_release_mr(struct rpcrdma_mr *mr);
size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt);
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_ia *ia, 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);
/*
* RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
*/
enum rpcrdma_chunktype {
rpcrdma_noch = 0,
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_xprt *);
void rpcrdma_complete_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_slot_table_entries;
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 */
