xprtrdma: Remove rpcrdma_memreg_ops

Clean up: Now that there is only FRWR, there is no need for a memory
registration switch. The indirect calls to the memreg operations can
be replaced with faster direct calls.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 84 insertions, 47 deletions

diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 16976b031865..fb0944d854c9 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -15,21 +15,21 @@
 /* Normal operation
  *
  * A Memory Region is prepared for RDMA READ or WRITE using a FAST_REG
- * Work Request (frwr_op_map). When the RDMA operation is finished, this
+ * Work Request (frwr_map). When the RDMA operation is finished, this
  * Memory Region is invalidated using a LOCAL_INV Work Request
- * (frwr_op_unmap_sync).
+ * (frwr_unmap_sync).
  *
  * Typically these Work Requests are not signaled, and neither are RDMA
  * SEND Work Requests (with the exception of signaling occasionally to
  * prevent provider work queue overflows). This greatly reduces HCA
  * interrupt workload.
  *
- * As an optimization, frwr_op_unmap marks MRs INVALID before the
+ * As an optimization, frwr_unmap marks MRs INVALID before the
  * LOCAL_INV WR is posted. If posting succeeds, the MR is placed on
  * rb_mrs immediately so that no work (like managing a linked list
  * under a spinlock) is needed in the completion upcall.
  *
- * But this means that frwr_op_map() can occasionally encounter an MR
+ * But this means that frwr_map() can occasionally encounter an MR
  * that is INVALID but the LOCAL_INV WR has not completed. Work Queue
  * ordering prevents a subsequent FAST_REG WR from executing against
  * that MR while it is still being invalidated.
@@ -57,14 +57,14 @@
  * FLUSHED_LI:	The MR was being invalidated when the QP entered ERROR
  *		state, and the pending WR was flushed.
  *
- * When frwr_op_map encounters FLUSHED and VALID MRs, they are recovered
+ * When frwr_map encounters FLUSHED and VALID MRs, they are recovered
  * with ib_dereg_mr and then are re-initialized. Because MR recovery
  * allocates fresh resources, it is deferred to a workqueue, and the
  * recovered MRs are placed back on the rb_mrs list when recovery is
- * complete. frwr_op_map allocates another MR for the current RPC while
+ * complete. frwr_map allocates another MR for the current RPC while
  * the broken MR is reset.
  *
- * To ensure that frwr_op_map doesn't encounter an MR that is marked
+ * To ensure that frwr_map doesn't encounter an MR that is marked
  * INVALID but that is about to be flushed due to a previous transport
  * disconnect, the transport connect worker attempts to drain all
  * pending send queue WRs before the transport is reconnected.
@@ -80,8 +80,13 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
-bool
-frwr_is_supported(struct rpcrdma_ia *ia)
+/**
+ * frwr_is_supported - Check if device supports FRWR
+ * @ia: interface adapter to check
+ *
+ * Returns true if device supports FRWR, otherwise false
+ */
+bool frwr_is_supported(struct rpcrdma_ia *ia)
 {
 	struct ib_device_attr *attrs = &ia->ri_device->attrs;
 
@@ -97,8 +102,12 @@ out_not_supported:
 	return false;
 }
 
-static void
-frwr_op_release_mr(struct rpcrdma_mr *mr)
+/**
+ * frwr_release_mr - Destroy one MR
+ * @mr: MR allocated by frwr_init_mr
+ *
+ */
+void frwr_release_mr(struct rpcrdma_mr *mr)
 {
 	int rc;
 
@@ -132,11 +141,19 @@ frwr_mr_recycle_worker(struct work_struct *work)
 	list_del(&mr->mr_all);
 	r_xprt->rx_stats.mrs_recycled++;
 	spin_unlock(&r_xprt->rx_buf.rb_mrlock);
-	frwr_op_release_mr(mr);
+
+	frwr_release_mr(mr);
 }
 
-static int
-frwr_op_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr)
+/**
+ * frwr_init_mr - Initialize one MR
+ * @ia: interface adapter
+ * @mr: generic MR to prepare for FRWR
+ *
+ * Returns zero if successful. Otherwise a negative errno
+ * is returned.
+ */
+int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr)
 {
 	unsigned int depth = ia->ri_max_frwr_depth;
 	struct rpcrdma_frwr *frwr = &mr->frwr;
@@ -172,7 +189,13 @@ out_list_err:
 	return rc;
 }
 
-/* On success, sets:
+/**
+ * frwr_open - Prepare an endpoint for use with FRWR
+ * @ia: interface adapter this endpoint will use
+ * @ep: endpoint to prepare
+ * @cdata: transport parameters
+ *
+ * On success, sets:
  *	ep->rep_attr.cap.max_send_wr
  *	ep->rep_attr.cap.max_recv_wr
  *	cdata->max_requests
@@ -181,10 +204,11 @@ out_list_err:
  * And these FRWR-related fields:
  *	ia->ri_max_frwr_depth
  *	ia->ri_mrtype
+ *
+ * On failure, a negative errno is returned.
  */
-static int
-frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
-	     struct rpcrdma_create_data_internal *cdata)
+int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
+	      struct rpcrdma_create_data_internal *cdata)
 {
 	struct ib_device_attr *attrs = &ia->ri_device->attrs;
 	int max_qp_wr, depth, delta;
@@ -258,11 +282,16 @@ frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 	return 0;
 }
 
-/* FRWR mode conveys a list of pages per chunk segment. The
+/**
+ * frwr_maxpages - Compute size of largest payload
+ * @r_xprt: transport
+ *
+ * Returns maximum size of an RPC message, in pages.
+ *
+ * FRWR mode conveys a list of pages per chunk segment. The
  * maximum length of that list is the FRWR page list depth.
  */
-static size_t
-frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
+size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 
@@ -344,12 +373,24 @@ frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc)
 	trace_xprtrdma_wc_li_wake(wc, frwr);
 }
 
-/* Post a REG_MR Work Request to register a memory region
+/**
+ * frwr_map - Register a memory region
+ * @r_xprt: controlling transport
+ * @seg: memory region co-ordinates
+ * @nsegs: number of segments remaining
+ * @writing: true when RDMA Write will be used
+ * @out: initialized MR
+ *
+ * Prepare a REG_MR Work Request to register a memory region
  * for remote access via RDMA READ or RDMA WRITE.
+ *
+ * Returns the next segment or a negative errno pointer.
+ * On success, the prepared MR is planted in @out.
  */
-static struct rpcrdma_mr_seg *
-frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
-	    int nsegs, bool writing, struct rpcrdma_mr **out)
+struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
+				struct rpcrdma_mr_seg *seg,
+				int nsegs, bool writing,
+				struct rpcrdma_mr **out)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	bool holes_ok = ia->ri_mrtype == IB_MR_TYPE_SG_GAPS;
@@ -434,14 +475,18 @@ out_mapmr_err:
 	return ERR_PTR(-EIO);
 }
 
-/* Post Send WR containing the RPC Call message.
+/**
+ * frwr_send - post Send WR containing the RPC Call message
+ * @ia: interface adapter
+ * @req: Prepared RPC Call
  *
  * For FRMR, chain any FastReg WRs to the Send WR. Only a
  * single ib_post_send call is needed to register memory
  * and then post the Send WR.
+ *
+ * Returns the result of ib_post_send.
  */
-static int
-frwr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
+int frwr_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
 {
 	struct ib_send_wr *post_wr;
 	struct rpcrdma_mr *mr;
@@ -468,10 +513,13 @@ frwr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
 	return ib_post_send(ia->ri_id->qp, post_wr, NULL);
 }
 
-/* Handle a remotely invalidated mr on the @mrs list
+/**
+ * frwr_reminv - handle a remotely invalidated mr on the @mrs list
+ * @rep: Received reply
+ * @mrs: list of MRs to check
+ *
  */
-static void
-frwr_op_reminv(struct rpcrdma_rep *rep, struct list_head *mrs)
+void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs)
 {
 	struct rpcrdma_mr *mr;
 
@@ -485,7 +533,10 @@ frwr_op_reminv(struct rpcrdma_rep *rep, struct list_head *mrs)
 		}
 }
 
-/* Invalidate all memory regions that were registered for "req".
+/**
+ * frwr_unmap_sync - invalidate memory regions that were registered for @req
+ * @r_xprt: controlling transport
+ * @mrs: list of MRs to process
  *
  * Sleeps until it is safe for the host CPU to access the
  * previously mapped memory regions.
@@ -493,8 +544,7 @@ frwr_op_reminv(struct rpcrdma_rep *rep, struct list_head *mrs)
  * Caller ensures that @mrs is not empty before the call. This
  * function empties the list.
  */
-static void
-frwr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct list_head *mrs)
+void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct list_head *mrs)
 {
 	struct ib_send_wr *first, **prev, *last;
 	const struct ib_send_wr *bad_wr;
@@ -577,16 +627,3 @@ out_release:
 		rpcrdma_mr_recycle(mr);
 	}
 }
-
-const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
-	.ro_map				= frwr_op_map,
-	.ro_send			= frwr_op_send,
-	.ro_reminv			= frwr_op_reminv,
-	.ro_unmap_sync			= frwr_op_unmap_sync,
-	.ro_open			= frwr_op_open,
-	.ro_maxpages			= frwr_op_maxpages,
-	.ro_init_mr			= frwr_op_init_mr,
-	.ro_release_mr			= frwr_op_release_mr,
-	.ro_displayname			= "frwr",
-	.ro_send_w_inv_ok		= RPCRDMA_CMP_F_SND_W_INV_OK,
-};