--- /dev/null
+/*
+ * 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/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 */
+#include <linux/sunrpc/svc.h> /* RPCSVC_MAXPAYLOAD */
+
+#define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
+#define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
+
+/*
+ * Interface Adapter -- one per transport instance
+ */
+struct rpcrdma_ia {
+ const struct rpcrdma_memreg_ops *ri_ops;
+ rwlock_t ri_qplock;
+ struct rdma_cm_id *ri_id;
+ struct ib_pd *ri_pd;
+ struct ib_mr *ri_bind_mem;
+ u32 ri_dma_lkey;
+ int ri_have_dma_lkey;
+ struct completion ri_done;
+ int ri_async_rc;
+ enum rpcrdma_memreg ri_memreg_strategy;
+ unsigned int ri_max_frmr_depth;
+ struct ib_device_attr ri_devattr;
+ struct ib_qp_attr ri_qp_attr;
+ struct ib_qp_init_attr ri_qp_init_attr;
+};
+
+/*
+ * RDMA Endpoint -- one per transport instance
+ */
+
+#define RPCRDMA_WC_BUDGET (128)
+#define RPCRDMA_POLLSIZE (16)
+
+struct rpcrdma_ep {
+ atomic_t rep_cqcount;
+ int rep_cqinit;
+ int rep_connected;
+ struct ib_qp_init_attr rep_attr;
+ wait_queue_head_t rep_connect_wait;
+ struct rpcrdma_regbuf *rep_padbuf;
+ struct rdma_conn_param rep_remote_cma;
+ struct sockaddr_storage rep_remote_addr;
+ struct delayed_work rep_connect_worker;
+ struct ib_wc rep_send_wcs[RPCRDMA_POLLSIZE];
+ struct ib_wc rep_recv_wcs[RPCRDMA_POLLSIZE];
+};
+
+/*
+ * Force a signaled SEND Work Request every so often,
+ * in case the provider needs to do some housekeeping.
+ */
+#define RPCRDMA_MAX_UNSIGNALED_SENDS (32)
+
+#define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
+#define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
+
+/* Force completion handler to ignore the signal
+ */
+#define RPCRDMA_IGNORE_COMPLETION (0ULL)
+
+/* 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 {
+ size_t rg_size;
+ struct rpcrdma_req *rg_owner;
+ struct ib_mr *rg_mr;
+ struct ib_sge rg_iov;
+ __be32 rg_base[0] __attribute__ ((aligned(256)));
+};
+
+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 rpcrdma_msg *
+rdmab_to_msg(struct rpcrdma_regbuf *rb)
+{
+ return (struct rpcrdma_msg *)rb->rg_base;
+}
+
+/*
+ * struct rpcrdma_rep -- this structure encapsulates state required to recv
+ * and complete a reply, asychronously. It needs several pieces of
+ * state:
+ * o recv buffer (posted to provider)
+ * o ib_sge (also donated to provider)
+ * o status of reply (length, success or not)
+ * o bookkeeping state to get run by tasklet (list, etc)
+ *
+ * These are allocated during initialization, per-transport instance;
+ * however, the tasklet execution list itself is global, as it should
+ * always be pretty short.
+ *
+ * N of these are associated with a transport instance, and stored in
+ * struct rpcrdma_buffer. N is the max number of outstanding requests.
+ */
+
+/* temporary static scatter/gather max */
+#define RPCRDMA_MAX_DATA_SEGS (64) /* max scatter/gather */
+#define RPCRDMA_MAX_SEGS (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
+
+struct rpcrdma_buffer;
+
+struct rpcrdma_rep {
+ unsigned int rr_len;
+ struct rpcrdma_buffer *rr_buffer;
+ struct rpc_xprt *rr_xprt;
+ void (*rr_func)(struct rpcrdma_rep *);
+ struct list_head rr_list;
+ struct rpcrdma_regbuf *rr_rdmabuf;
+};
+
+/*
+ * struct rpcrdma_mw - external memory region metadata
+ *
+ * An external memory region is any buffer or page that is registered
+ * on the fly (ie, not pre-registered).
+ *
+ * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
+ * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
+ * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
+ * track of registration metadata while each RPC is pending.
+ * rpcrdma_deregister_external() uses this metadata to unmap and
+ * release these resources when an RPC is complete.
+ */
+enum rpcrdma_frmr_state {
+ FRMR_IS_INVALID, /* ready to be used */
+ FRMR_IS_VALID, /* in use */
+ FRMR_IS_STALE, /* failed completion */
+};
+
+struct rpcrdma_frmr {
+ struct ib_fast_reg_page_list *fr_pgl;
+ struct ib_mr *fr_mr;
+ enum rpcrdma_frmr_state fr_state;
+};
+
+struct rpcrdma_mw {
+ union {
+ struct ib_fmr *fmr;
+ struct rpcrdma_frmr frmr;
+ } r;
+ void (*mw_sendcompletion)(struct ib_wc *);
+ struct list_head mw_list;
+ struct list_head mw_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.
+ *
+ * NOTES:
+ * o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
+ * marshal. The number needed varies depending on the iov lists that
+ * are passed to us, the memory registration mode we are in, and if
+ * physical addressing is used, the layout.
+ */
+
+struct rpcrdma_mr_seg { /* chunk descriptors */
+ struct rpcrdma_mw *rl_mw; /* registered MR */
+ u64 mr_base; /* registration result */
+ u32 mr_rkey; /* registration result */
+ u32 mr_len; /* length of chunk or segment */
+ int mr_nsegs; /* number of segments in chunk or 0 */
+ enum dma_data_direction mr_dir; /* segment mapping direction */
+ dma_addr_t mr_dma; /* segment mapping address */
+ size_t mr_dmalen; /* segment mapping length */
+ struct page *mr_page; /* owning page, if any */
+ char *mr_offset; /* kva if no page, else offset */
+};
+
+struct rpcrdma_req {
+ unsigned int rl_niovs; /* 0, 2 or 4 */
+ unsigned int rl_nchunks; /* non-zero if chunks */
+ unsigned int rl_connect_cookie; /* retry detection */
+ struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
+ struct rpcrdma_rep *rl_reply;/* holder for reply buffer */
+ struct ib_sge rl_send_iov[4]; /* for active requests */
+ struct rpcrdma_regbuf *rl_rdmabuf;
+ struct rpcrdma_regbuf *rl_sendbuf;
+ struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
+};
+
+static inline struct rpcrdma_req *
+rpcr_to_rdmar(struct rpc_rqst *rqst)
+{
+ void *buffer = rqst->rq_buffer;
+ struct rpcrdma_regbuf *rb;
+
+ rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
+ return rb->rg_owner;
+}
+
+/*
+ * 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; /* protects indexes */
+ u32 rb_max_requests;/* client max requests */
+ struct list_head rb_mws; /* optional memory windows/fmrs/frmrs */
+ struct list_head rb_all;
+ int rb_send_index;
+ struct rpcrdma_req **rb_send_bufs;
+ int rb_recv_index;
+ struct rpcrdma_rep **rb_recv_bufs;
+ char *rb_pool;
+};
+#define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
+
+/*
+ * Internal structure for transport instance creation. This
+ * exists primarily for modularity.
+ *
+ * This data should be set with mount options
+ */
+struct rpcrdma_create_data_internal {
+ struct sockaddr_storage addr; /* RDMA server address */
+ unsigned int max_requests; /* max requests (slots) in flight */
+ unsigned int rsize; /* mount rsize - max read hdr+data */
+ unsigned int wsize; /* mount wsize - max write hdr+data */
+ unsigned int inline_rsize; /* max non-rdma read data payload */
+ unsigned int inline_wsize; /* max non-rdma write data payload */
+ unsigned int padding; /* non-rdma write header padding */
+};
+
+#define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
+ (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
+
+#define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
+ (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
+
+#define RPCRDMA_INLINE_PAD_VALUE(rq)\
+ rpcx_to_rdmad(rq->rq_xprt).padding
+
+/*
+ * Statistics for RPCRDMA
+ */
+struct rpcrdma_stats {
+ unsigned long read_chunk_count;
+ unsigned long write_chunk_count;
+ unsigned long reply_chunk_count;
+
+ unsigned long long total_rdma_request;
+ unsigned long long total_rdma_reply;
+
+ unsigned long long pullup_copy_count;
+ unsigned long long fixup_copy_count;
+ unsigned long hardway_register_count;
+ unsigned long failed_marshal_count;
+ unsigned long bad_reply_count;
+};
+
+/*
+ * Per-registration mode operations
+ */
+struct rpcrdma_xprt;
+struct rpcrdma_memreg_ops {
+ int (*ro_map)(struct rpcrdma_xprt *,
+ struct rpcrdma_mr_seg *, int, bool);
+ int (*ro_unmap)(struct rpcrdma_xprt *,
+ struct rpcrdma_mr_seg *);
+ int (*ro_open)(struct rpcrdma_ia *,
+ struct rpcrdma_ep *,
+ struct rpcrdma_create_data_internal *);
+ size_t (*ro_maxpages)(struct rpcrdma_xprt *);
+ int (*ro_init)(struct rpcrdma_xprt *);
+ void (*ro_reset)(struct rpcrdma_xprt *);
+ void (*ro_destroy)(struct rpcrdma_buffer *);
+ const char *ro_displayname;
+};
+
+extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
+extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
+extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
+
+/*
+ * 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 rpcrdma_create_data_internal rx_data;
+ struct delayed_work rx_connect_worker;
+ struct rpcrdma_stats rx_stats;
+};
+
+#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
+#define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
+
+/* 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;
+
+/*
+ * Interface Adapter calls - xprtrdma/verbs.c
+ */
+int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
+void rpcrdma_ia_close(struct rpcrdma_ia *);
+
+/*
+ * Endpoint calls - xprtrdma/verbs.c
+ */
+int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
+ struct rpcrdma_create_data_internal *);
+void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
+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 *);
+int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
+ struct rpcrdma_rep *);
+
+/*
+ * Buffer calls - xprtrdma/verbs.c
+ */
+int rpcrdma_buffer_create(struct rpcrdma_xprt *);
+void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
+
+struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
+void rpcrdma_buffer_put(struct rpcrdma_req *);
+void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
+void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
+
+struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
+ size_t, gfp_t);
+void rpcrdma_free_regbuf(struct rpcrdma_ia *,
+ struct rpcrdma_regbuf *);
+
+unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
+
+/*
+ * Wrappers for chunk registration, shared by read/write chunk code.
+ */
+
+void rpcrdma_mapping_error(struct rpcrdma_mr_seg *);
+
+static inline enum dma_data_direction
+rpcrdma_data_dir(bool writing)
+{
+ return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+}
+
+static inline void
+rpcrdma_map_one(struct ib_device *device, struct rpcrdma_mr_seg *seg,
+ enum dma_data_direction direction)
+{
+ seg->mr_dir = direction;
+ seg->mr_dmalen = seg->mr_len;
+
+ if (seg->mr_page)
+ seg->mr_dma = ib_dma_map_page(device,
+ seg->mr_page, offset_in_page(seg->mr_offset),
+ seg->mr_dmalen, seg->mr_dir);
+ else
+ seg->mr_dma = ib_dma_map_single(device,
+ seg->mr_offset,
+ seg->mr_dmalen, seg->mr_dir);
+
+ if (ib_dma_mapping_error(device, seg->mr_dma))
+ rpcrdma_mapping_error(seg);
+}
+
+static inline void
+rpcrdma_unmap_one(struct ib_device *device, struct rpcrdma_mr_seg *seg)
+{
+ if (seg->mr_page)
+ ib_dma_unmap_page(device,
+ seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
+ else
+ ib_dma_unmap_single(device,
+ seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
+}
+
+/*
+ * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
+ */
+void rpcrdma_connect_worker(struct work_struct *);
+void rpcrdma_conn_func(struct rpcrdma_ep *);
+void rpcrdma_reply_handler(struct rpcrdma_rep *);
+
+/*
+ * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
+ */
+int rpcrdma_marshal_req(struct rpc_rqst *);
+
+/* Temporary NFS request map cache. Created in svc_rdma.c */
+extern struct kmem_cache *svc_rdma_map_cachep;
+/* WR context cache. Created in svc_rdma.c */
+extern struct kmem_cache *svc_rdma_ctxt_cachep;
+/* Workqueue created in svc_rdma.c */
+extern struct workqueue_struct *svc_rdma_wq;
+
+#if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
+#define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD
+#else
+#define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
+#endif
+
+#endif /* _LINUX_SUNRPC_XPRT_RDMA_H */
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