RDMA/rds: Remove FMR support for memory registration

Use FRWR method for memory registration by default and remove the ancient
and unsafe FMR method.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Max Gurtovoy <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

Author: Max Gurtovoy

net/rds/Makefile

@@ -7,7 +7,7 @@ rds-y :=	af_rds.o bind.o cong.o connection.o info.o message.o   \
 obj-$(CONFIG_RDS_RDMA) += rds_rdma.o
 rds_rdma-y :=	rdma_transport.o \
 			ib.o ib_cm.o ib_recv.o ib_ring.o ib_send.o ib_stats.o \
-			ib_sysctl.o ib_rdma.o ib_fmr.o ib_frmr.o
+			ib_sysctl.o ib_rdma.o ib_frmr.o
 
 
 obj-$(CONFIG_RDS_TCP) += rds_tcp.o

net/rds/ib.c

@@ -130,13 +130,16 @@ void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
 static int rds_ib_add_one(struct ib_device *device)
 {
 	struct rds_ib_device *rds_ibdev;
-	bool has_fr, has_fmr;
 	int ret;
 
 	/* Only handle IB (no iWARP) devices */
 	if (device->node_type != RDMA_NODE_IB_CA)
 		return -EOPNOTSUPP;
 
+	/* Device must support FRWR */
+	if (!(device->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
+		return -EOPNOTSUPP;
+
 	rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
 				 ibdev_to_node(device));
 	if (!rds_ibdev)
@@ -152,11 +155,6 @@ static int rds_ib_add_one(struct ib_device *device)
 	rds_ibdev->max_wrs = device->attrs.max_qp_wr;
 	rds_ibdev->max_sge = min(device->attrs.max_send_sge, RDS_IB_MAX_SGE);
 
-	has_fr = (device->attrs.device_cap_flags &
-		  IB_DEVICE_MEM_MGT_EXTENSIONS);
-	has_fmr = (device->ops.alloc_fmr && device->ops.dealloc_fmr &&
-		   device->ops.map_phys_fmr && device->ops.unmap_fmr);
-	rds_ibdev->use_fastreg = (has_fr && !has_fmr);
 	rds_ibdev->odp_capable =
 		!!(device->attrs.device_cap_flags &
 		   IB_DEVICE_ON_DEMAND_PAGING) &&
@@ -165,7 +163,6 @@ static int rds_ib_add_one(struct ib_device *device)
 		!!(device->attrs.odp_caps.per_transport_caps.rc_odp_caps &
 		   IB_ODP_SUPPORT_READ);
 
-	rds_ibdev->fmr_max_remaps = device->attrs.max_map_per_fmr?: 32;
 	rds_ibdev->max_1m_mrs = device->attrs.max_mr ?
 		min_t(unsigned int, (device->attrs.max_mr / 2),
 		      rds_ib_mr_1m_pool_size) : rds_ib_mr_1m_pool_size;
@@ -219,14 +216,11 @@ static int rds_ib_add_one(struct ib_device *device)
 		goto put_dev;
 	}
 
-	rdsdebug("RDS/IB: max_mr = %d, max_wrs = %d, max_sge = %d, fmr_max_remaps = %d, max_1m_mrs = %d, max_8k_mrs = %d\n",
+	rdsdebug("RDS/IB: max_mr = %d, max_wrs = %d, max_sge = %d, max_1m_mrs = %d, max_8k_mrs = %d\n",
 		 device->attrs.max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
-		 rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_mrs,
-		 rds_ibdev->max_8k_mrs);
+		 rds_ibdev->max_1m_mrs, rds_ibdev->max_8k_mrs);
 
-	pr_info("RDS/IB: %s: %s supported and preferred\n",
-		device->name,
-		rds_ibdev->use_fastreg ? "FRMR" : "FMR");
+	pr_info("RDS/IB: %s: added\n", device->name);
 
 	down_write(&rds_ib_devices_lock);
 	list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);

net/rds/ib.h

@@ -247,13 +247,11 @@ struct rds_ib_device {
 	struct ib_device	*dev;
 	struct ib_pd		*pd;
 	struct dma_pool		*rid_hdrs_pool; /* RDS headers DMA pool */
-	u8			use_fastreg:1;
 	u8			odp_capable:1;
 
 	unsigned int		max_mrs;
 	struct rds_ib_mr_pool	*mr_1m_pool;
 	struct rds_ib_mr_pool   *mr_8k_pool;
-	unsigned int		fmr_max_remaps;
 	unsigned int		max_8k_mrs;
 	unsigned int		max_1m_mrs;
 	int			max_sge;

net/rds/ib_cm.c

@@ -527,10 +527,10 @@ static int rds_ib_setup_qp(struct rds_connection *conn)
 		return -EOPNOTSUPP;
 
 	/* The fr_queue_space is currently set to 512, to add extra space on
-	 * completion queue and send queue. This extra space is used for FRMR
+	 * completion queue and send queue. This extra space is used for FRWR
 	 * registration and invalidation work requests
 	 */
-	fr_queue_space = (rds_ibdev->use_fastreg ? RDS_IB_DEFAULT_FR_WR : 0);
+	fr_queue_space = RDS_IB_DEFAULT_FR_WR;
 
 	/* add the conn now so that connection establishment has the dev */
 	rds_ib_add_conn(rds_ibdev, conn);

net/rds/ib_fmr.c

@@ -76,7 +76,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev,
 
 	frmr = &ibmr->u.frmr;
 	frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG,
-			 pool->fmr_attr.max_pages);
+			 pool->max_pages);
 	if (IS_ERR(frmr->mr)) {
 		pr_warn("RDS/IB: %s failed to allocate MR", __func__);
 		err = PTR_ERR(frmr->mr);
@@ -240,7 +240,7 @@ static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
 	}
 	frmr->dma_npages += len >> PAGE_SHIFT;
 
-	if (frmr->dma_npages > ibmr->pool->fmr_attr.max_pages) {
+	if (frmr->dma_npages > ibmr->pool->max_pages) {
 		ret = -EMSGSIZE;
 		goto out_unmap;
 	}