mirror of https://gitee.com/openkylin/linux.git
123 lines
3.3 KiB
C
123 lines
3.3 KiB
C
/*
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* Copyright (c) 2015 Oracle. All rights reserved.
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* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
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*/
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/* No-op chunk preparation. All client memory is pre-registered.
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* Sometimes referred to as ALLPHYSICAL mode.
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*
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* Physical registration is simple because all client memory is
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* pre-registered and never deregistered. This mode is good for
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* adapter bring up, but is considered not safe: the server is
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* trusted not to abuse its access to client memory not involved
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* in RDMA I/O.
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*/
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#include "xprt_rdma.h"
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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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# define RPCDBG_FACILITY RPCDBG_TRANS
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#endif
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static int
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physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
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struct rpcrdma_create_data_internal *cdata)
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{
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struct ib_mr *mr;
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/* Obtain an rkey to use for RPC data payloads.
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*/
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mr = ib_get_dma_mr(ia->ri_pd,
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IB_ACCESS_LOCAL_WRITE |
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IB_ACCESS_REMOTE_WRITE |
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IB_ACCESS_REMOTE_READ);
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if (IS_ERR(mr)) {
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pr_err("%s: ib_get_dma_mr for failed with %lX\n",
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__func__, PTR_ERR(mr));
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return -ENOMEM;
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}
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ia->ri_dma_mr = mr;
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rpcrdma_set_max_header_sizes(ia, cdata, min_t(unsigned int,
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RPCRDMA_MAX_DATA_SEGS,
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RPCRDMA_MAX_HDR_SEGS));
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return 0;
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}
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/* PHYSICAL memory registration conveys one page per chunk segment.
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*/
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static size_t
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physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
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{
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return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
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RPCRDMA_MAX_HDR_SEGS);
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}
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static int
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physical_op_init(struct rpcrdma_xprt *r_xprt)
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{
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return 0;
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}
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/* The client's physical memory is already exposed for
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* remote access via RDMA READ or RDMA WRITE.
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*/
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static int
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physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
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int nsegs, bool writing)
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{
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struct rpcrdma_ia *ia = &r_xprt->rx_ia;
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rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
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seg->mr_rkey = ia->ri_dma_mr->rkey;
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seg->mr_base = seg->mr_dma;
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return 1;
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}
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/* DMA unmap all memory regions that were mapped for "req".
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*/
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static void
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physical_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
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{
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struct ib_device *device = r_xprt->rx_ia.ri_device;
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unsigned int i;
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for (i = 0; req->rl_nchunks; --req->rl_nchunks)
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rpcrdma_unmap_one(device, &req->rl_segments[i++]);
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}
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/* Use a slow, safe mechanism to invalidate all memory regions
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* that were registered for "req".
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*
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* For physical memory registration, there is no good way to
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* fence a single MR that has been advertised to the server. The
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* client has already handed the server an R_key that cannot be
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* invalidated and is shared by all MRs on this connection.
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* Tearing down the PD might be the only safe choice, but it's
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* not clear that a freshly acquired DMA R_key would be different
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* than the one used by the PD that was just destroyed.
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* FIXME.
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*/
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static void
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physical_op_unmap_safe(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
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bool sync)
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{
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physical_op_unmap_sync(r_xprt, req);
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}
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static void
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physical_op_destroy(struct rpcrdma_buffer *buf)
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{
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}
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const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
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.ro_map = physical_op_map,
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.ro_unmap_sync = physical_op_unmap_sync,
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.ro_unmap_safe = physical_op_unmap_safe,
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.ro_open = physical_op_open,
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.ro_maxpages = physical_op_maxpages,
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.ro_init = physical_op_init,
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.ro_destroy = physical_op_destroy,
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.ro_displayname = "physical",
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};
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