linux/net/sunrpc/xprtrdma/physical_ops.c

100 lines
2.4 KiB
C

/*
* Copyright (c) 2015 Oracle. All rights reserved.
* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
*/
/* No-op chunk preparation. All client memory is pre-registered.
* Sometimes referred to as ALLPHYSICAL mode.
*
* Physical registration is simple because all client memory is
* pre-registered and never deregistered. This mode is good for
* adapter bring up, but is considered not safe: the server is
* trusted not to abuse its access to client memory not involved
* in RDMA I/O.
*/
#include "xprt_rdma.h"
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
static int
physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
struct rpcrdma_create_data_internal *cdata)
{
struct ib_mr *mr;
/* Obtain an rkey to use for RPC data payloads.
*/
mr = ib_get_dma_mr(ia->ri_pd,
IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_READ);
if (IS_ERR(mr)) {
pr_err("%s: ib_get_dma_mr for failed with %lX\n",
__func__, PTR_ERR(mr));
return -ENOMEM;
}
ia->ri_dma_mr = mr;
return 0;
}
/* PHYSICAL memory registration conveys one page per chunk segment.
*/
static size_t
physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
{
return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
rpcrdma_max_segments(r_xprt));
}
static int
physical_op_init(struct rpcrdma_xprt *r_xprt)
{
return 0;
}
/* The client's physical memory is already exposed for
* remote access via RDMA READ or RDMA WRITE.
*/
static int
physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
int nsegs, bool writing)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
seg->mr_rkey = ia->ri_dma_mr->rkey;
seg->mr_base = seg->mr_dma;
seg->mr_nsegs = 1;
return 1;
}
/* Unmap a memory region, but leave it registered.
*/
static int
physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
rpcrdma_unmap_one(ia->ri_device, seg);
return 1;
}
static void
physical_op_destroy(struct rpcrdma_buffer *buf)
{
}
const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
.ro_map = physical_op_map,
.ro_unmap = physical_op_unmap,
.ro_open = physical_op_open,
.ro_maxpages = physical_op_maxpages,
.ro_init = physical_op_init,
.ro_destroy = physical_op_destroy,
.ro_displayname = "physical",
};