xprtrdma: Remove REGISTER memory registration mode

All kernel RDMA providers except amso1100 support either MTHCAFMR
or FRMR, both of which are faster than REGISTER.  amso1100 can
continue to use ALLPHYSICAL.

The only other ULP consumer in the kernel that uses the reg_phys_mr
verb is Lustre.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -476,8 +476,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 			 * on receive. Therefore, we request a reply chunk
 			 * for non-writes wherever feasible and efficient.
 			 */
-			if (wtype == rpcrdma_noch &&
-			    r_xprt->rx_ia.ri_memreg_strategy > RPCRDMA_REGISTER)
+			if (wtype == rpcrdma_noch)
 				wtype = rpcrdma_replych;
 		}
 	}

net/sunrpc/xprtrdma/verbs.c

@@ -494,19 +494,11 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	switch (memreg) {
 	case RPCRDMA_MTHCAFMR:
 		if (!ia->ri_id->device->alloc_fmr) {
-#if RPCRDMA_PERSISTENT_REGISTRATION
 			dprintk("RPC:       %s: MTHCAFMR registration "
 				"specified but not supported by adapter, "
 				"using riskier RPCRDMA_ALLPHYSICAL\n",
 				__func__);
 			memreg = RPCRDMA_ALLPHYSICAL;
-#else
-			dprintk("RPC:       %s: MTHCAFMR registration "
-				"specified but not supported by adapter, "
-				"using slower RPCRDMA_REGISTER\n",
-				__func__);
-			memreg = RPCRDMA_REGISTER;
-#endif
 		}
 		break;
 	case RPCRDMA_FRMR:
@@ -514,19 +506,11 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		if ((devattr.device_cap_flags &
 		     (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) !=
 		    (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) {
-#if RPCRDMA_PERSISTENT_REGISTRATION
 			dprintk("RPC:       %s: FRMR registration "
 				"specified but not supported by adapter, "
 				"using riskier RPCRDMA_ALLPHYSICAL\n",
 				__func__);
 			memreg = RPCRDMA_ALLPHYSICAL;
-#else
-			dprintk("RPC:       %s: FRMR registration "
-				"specified but not supported by adapter, "
-				"using slower RPCRDMA_REGISTER\n",
-				__func__);
-			memreg = RPCRDMA_REGISTER;
-#endif
 		} else {
 			/* Mind the ia limit on FRMR page list depth */
 			ia->ri_max_frmr_depth = min_t(unsigned int,
@@ -545,7 +529,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	 * adapter.
 	 */
 	switch (memreg) {
-	case RPCRDMA_REGISTER:
 	case RPCRDMA_FRMR:
 		break;
 #if RPCRDMA_PERSISTENT_REGISTRATION
@@ -565,11 +548,10 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		ia->ri_bind_mem = ib_get_dma_mr(ia->ri_pd, mem_priv);
 		if (IS_ERR(ia->ri_bind_mem)) {
 			printk(KERN_ALERT "%s: ib_get_dma_mr for "
-				"phys register failed with %lX\n\t"
-				"Will continue with degraded performance\n",
+				"phys register failed with %lX\n",
 				__func__, PTR_ERR(ia->ri_bind_mem));
-			memreg = RPCRDMA_REGISTER;
-			ia->ri_bind_mem = NULL;
+			rc = -ENOMEM;
+			goto out2;
 		}
 		break;
 	default:
@@ -1611,67 +1593,6 @@ rpcrdma_deregister_fmr_external(struct rpcrdma_mr_seg *seg,
 	return rc;
 }
 
-static int
-rpcrdma_register_default_external(struct rpcrdma_mr_seg *seg,
-			int *nsegs, int writing, struct rpcrdma_ia *ia)
-{
-	int mem_priv = (writing ? IB_ACCESS_REMOTE_WRITE :
-				  IB_ACCESS_REMOTE_READ);
-	struct rpcrdma_mr_seg *seg1 = seg;
-	struct ib_phys_buf ipb[RPCRDMA_MAX_DATA_SEGS];
-	int len, i, rc = 0;
-
-	if (*nsegs > RPCRDMA_MAX_DATA_SEGS)
-		*nsegs = RPCRDMA_MAX_DATA_SEGS;
-	for (len = 0, i = 0; i < *nsegs;) {
-		rpcrdma_map_one(ia, seg, writing);
-		ipb[i].addr = seg->mr_dma;
-		ipb[i].size = seg->mr_len;
-		len += seg->mr_len;
-		++seg;
-		++i;
-		/* Check for holes */
-		if ((i < *nsegs && offset_in_page(seg->mr_offset)) ||
-		    offset_in_page((seg-1)->mr_offset+(seg-1)->mr_len))
-			break;
-	}
-	seg1->mr_base = seg1->mr_dma;
-	seg1->mr_chunk.rl_mr = ib_reg_phys_mr(ia->ri_pd,
-				ipb, i, mem_priv, &seg1->mr_base);
-	if (IS_ERR(seg1->mr_chunk.rl_mr)) {
-		rc = PTR_ERR(seg1->mr_chunk.rl_mr);
-		dprintk("RPC:       %s: failed ib_reg_phys_mr "
-			"%u@0x%llx (%d)... status %i\n",
-			__func__, len,
-			(unsigned long long)seg1->mr_dma, i, rc);
-		while (i--)
-			rpcrdma_unmap_one(ia, --seg);
-	} else {
-		seg1->mr_rkey = seg1->mr_chunk.rl_mr->rkey;
-		seg1->mr_nsegs = i;
-		seg1->mr_len = len;
-	}
-	*nsegs = i;
-	return rc;
-}
-
-static int
-rpcrdma_deregister_default_external(struct rpcrdma_mr_seg *seg,
-			struct rpcrdma_ia *ia)
-{
-	struct rpcrdma_mr_seg *seg1 = seg;
-	int rc;
-
-	rc = ib_dereg_mr(seg1->mr_chunk.rl_mr);
-	seg1->mr_chunk.rl_mr = NULL;
-	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(ia, seg++);
-	if (rc)
-		dprintk("RPC:       %s: failed ib_dereg_mr,"
-			" status %i\n", __func__, rc);
-	return rc;
-}
-
 int
 rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
 			int nsegs, int writing, struct rpcrdma_xprt *r_xprt)
@@ -1701,10 +1622,8 @@ rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
 		rc = rpcrdma_register_fmr_external(seg, &nsegs, writing, ia);
 		break;
 
-	/* Default registration each time */
 	default:
-		rc = rpcrdma_register_default_external(seg, &nsegs, writing, ia);
-		break;
+		return -1;
 	}
 	if (rc)
 		return -1;
@@ -1738,7 +1657,6 @@ rpcrdma_deregister_external(struct rpcrdma_mr_seg *seg,
 		break;
 
 	default:
-		rc = rpcrdma_deregister_default_external(seg, ia);
 		break;
 	}
 	if (r) {