diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 24ea6dd184e4..cdd6aacc9168 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1828,6 +1828,61 @@ rpcrdma_deregister_internal(struct rpcrdma_ia *ia, return rc; } +/** + * rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers + * @ia: controlling rpcrdma_ia + * @size: size of buffer to be allocated, in bytes + * @flags: GFP flags + * + * Returns pointer to private header of an area of internally + * registered memory, or an ERR_PTR. The registered buffer follows + * the end of the private header. + * + * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for + * receiving the payload of RDMA RECV operations. regbufs are not + * used for RDMA READ/WRITE operations, thus are registered only for + * LOCAL access. + */ +struct rpcrdma_regbuf * +rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags) +{ + struct rpcrdma_regbuf *rb; + int rc; + + rc = -ENOMEM; + rb = kmalloc(sizeof(*rb) + size, flags); + if (rb == NULL) + goto out; + + rb->rg_size = size; + rb->rg_owner = NULL; + rc = rpcrdma_register_internal(ia, rb->rg_base, size, + &rb->rg_mr, &rb->rg_iov); + if (rc) + goto out_free; + + return rb; + +out_free: + kfree(rb); +out: + return ERR_PTR(rc); +} + +/** + * rpcrdma_free_regbuf - deregister and free registered buffer + * @ia: controlling rpcrdma_ia + * @rb: regbuf to be deregistered and freed + */ +void +rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb) +{ + if (rb) { + rpcrdma_deregister_internal(ia, rb->rg_mr, &rb->rg_iov); + kfree(rb); + } +} + /* * Wrappers for chunk registration, shared by read/write chunk code. */ diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 5c2fac3f30b6..36c37c60f1fe 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -106,6 +106,44 @@ struct rpcrdma_ep { #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit) #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount) +/* 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; +} + enum rpcrdma_chunktype { rpcrdma_noch = 0, rpcrdma_readch, @@ -372,6 +410,11 @@ int rpcrdma_register_external(struct rpcrdma_mr_seg *, int rpcrdma_deregister_external(struct rpcrdma_mr_seg *, struct rpcrdma_xprt *); +struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *, + size_t, gfp_t); +void rpcrdma_free_regbuf(struct rpcrdma_ia *, + struct rpcrdma_regbuf *); + /* * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c */