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kernel/linux-rt-4.4.41/net/sunrpc/xprtrdma/physical_ops.c 2.39 KB
5113f6f70   김현기   kernel add
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  /*
   * 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
  ",
  		       __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",
  };