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authorChuck Lever <chuck.lever@oracle.com>2016-09-15 10:56:10 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2016-09-19 13:08:37 -0400
commit99ef4db329f1ee2413dad49346e72a6c902474d1 (patch)
treee1ba252d10de1bac6fe4ad83b4a6f5339a3d235d /net/sunrpc/xprtrdma/xprt_rdma.h
parent08cf2efd5423121985af5962d66e6db14dff4130 (diff)
downloadlinux-99ef4db329f1ee2413dad49346e72a6c902474d1.tar.bz2
xprtrdma: Replace DMA_BIDIRECTIONAL
The use of DMA_BIDIRECTIONAL is discouraged by DMA-API.txt. Fortunately, xprtrdma now knows which direction I/O is going as soon as it allocates each regbuf. The RPC Call and Reply buffers are no longer the same regbuf. They can each be labeled correctly now. The RPC Reply buffer is never part of either a Send or Receive WR, but it can be part of Reply chunk, which is mapped and registered via ->ro_map . So it is not DMA mapped when it is allocated (DMA_NONE), to avoid a double- mapping. Since Receive buffers are no longer DMA_BIDIRECTIONAL and their contents are never modified by the host CPU, DMA-API-HOWTO.txt suggests that a DMA sync before posting each buffer should be unnecessary. (See my_card_interrupt_handler). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xprtrdma/xprt_rdma.h')
-rw-r--r--net/sunrpc/xprtrdma/xprt_rdma.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index cc426b165c09..9569b212be54 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -113,6 +113,7 @@ struct rpcrdma_ep {
struct rpcrdma_regbuf {
struct ib_sge rg_iov;
+ enum dma_data_direction rg_direction;
__be32 rg_base[0] __attribute__ ((aligned(256)));
};
@@ -477,7 +478,8 @@ void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
void rpcrdma_defer_mr_recovery(struct rpcrdma_mw *);
struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
- size_t, gfp_t);
+ size_t, enum dma_data_direction,
+ gfp_t);
void rpcrdma_free_regbuf(struct rpcrdma_ia *,
struct rpcrdma_regbuf *);