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/[e-mail]
Signed-off-by: Max Gurtovoy <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

net/rds/Makefile

···
 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

···
 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,
···
 	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) &&
···
 		!!(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;
···
 		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

···
 	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

···
 		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

···
-/*
- * Copyright (c) 2016 Oracle.  All rights reserved.
- *
- * This software is available to you under a choice of one of two
- * licenses.  You may choose to be licensed under the terms of the GNU
- * General Public License (GPL) Version 2, available from the file
- * COPYING in the main directory of this source tree, or the
- * OpenIB.org BSD license below:
- *
- *     Redistribution and use in source and binary forms, with or
- *     without modification, are permitted provided that the following
- *     conditions are met:
- *
- *      - Redistributions of source code must retain the above
- *        copyright notice, this list of conditions and the following
- *        disclaimer.
- *
- *      - Redistributions in binary form must reproduce the above
- *        copyright notice, this list of conditions and the following
- *        disclaimer in the documentation and/or other materials
- *        provided with the distribution.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
- * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-#include "ib_mr.h"
-
-struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev, int npages)
-{
-	struct rds_ib_mr_pool *pool;
-	struct rds_ib_mr *ibmr = NULL;
-	struct rds_ib_fmr *fmr;
-	int err = 0;
-
-	if (npages <= RDS_MR_8K_MSG_SIZE)
-		pool = rds_ibdev->mr_8k_pool;
-	else
-		pool = rds_ibdev->mr_1m_pool;
-
-	if (atomic_read(&pool->dirty_count) >= pool->max_items / 10)
-		queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
-
-	/* Switch pools if one of the pool is reaching upper limit */
-	if (atomic_read(&pool->dirty_count) >=  pool->max_items * 9 / 10) {
-		if (pool->pool_type == RDS_IB_MR_8K_POOL)
-			pool = rds_ibdev->mr_1m_pool;
-		else
-			pool = rds_ibdev->mr_8k_pool;
-	}
-
-	ibmr = rds_ib_try_reuse_ibmr(pool);
-	if (ibmr)
-		return ibmr;
-
-	ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
-			    rdsibdev_to_node(rds_ibdev));
-	if (!ibmr) {
-		err = -ENOMEM;
-		goto out_no_cigar;
-	}
-
-	fmr = &ibmr->u.fmr;
-	fmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
-			(IB_ACCESS_LOCAL_WRITE |
-			 IB_ACCESS_REMOTE_READ |
-			 IB_ACCESS_REMOTE_WRITE |
-			 IB_ACCESS_REMOTE_ATOMIC),
-			&pool->fmr_attr);
-	if (IS_ERR(fmr->fmr)) {
-		err = PTR_ERR(fmr->fmr);
-		fmr->fmr = NULL;
-		pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, err);
-		goto out_no_cigar;
-	}
-
-	ibmr->pool = pool;
-	if (pool->pool_type == RDS_IB_MR_8K_POOL)
-		rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
-	else
-		rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
-
-	return ibmr;
-
-out_no_cigar:
-	kfree(ibmr);
-	atomic_dec(&pool->item_count);
-
-	return ERR_PTR(err);
-}
-
-static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev,
-			  struct rds_ib_mr *ibmr, struct scatterlist *sg,
-			  unsigned int nents)
-{
-	struct ib_device *dev = rds_ibdev->dev;
-	struct rds_ib_fmr *fmr = &ibmr->u.fmr;
-	struct scatterlist *scat = sg;
-	u64 io_addr = 0;
-	u64 *dma_pages;
-	u32 len;
-	int page_cnt, sg_dma_len;
-	int i, j;
-	int ret;
-
-	sg_dma_len = ib_dma_map_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
-	if (unlikely(!sg_dma_len)) {
-		pr_warn("RDS/IB: %s failed!\n", __func__);
-		return -EBUSY;
-	}
-
-	len = 0;
-	page_cnt = 0;
-
-	for (i = 0; i < sg_dma_len; ++i) {
-		unsigned int dma_len = sg_dma_len(&scat[i]);
-		u64 dma_addr = sg_dma_address(&scat[i]);
-
-		if (dma_addr & ~PAGE_MASK) {
-			if (i > 0) {
-				ib_dma_unmap_sg(dev, sg, nents,
-						DMA_BIDIRECTIONAL);
-				return -EINVAL;
-			} else {
-				++page_cnt;
-			}
-		}
-		if ((dma_addr + dma_len) & ~PAGE_MASK) {
-			if (i < sg_dma_len - 1) {
-				ib_dma_unmap_sg(dev, sg, nents,
-						DMA_BIDIRECTIONAL);
-				return -EINVAL;
-			} else {
-				++page_cnt;
-			}
-		}
-
-		len += dma_len;
-	}
-
-	page_cnt += len >> PAGE_SHIFT;
-	if (page_cnt > ibmr->pool->fmr_attr.max_pages) {
-		ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
-		return -EINVAL;
-	}
-
-	dma_pages = kmalloc_array_node(sizeof(u64), page_cnt, GFP_ATOMIC,
-				       rdsibdev_to_node(rds_ibdev));
-	if (!dma_pages) {
-		ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
-		return -ENOMEM;
-	}
-
-	page_cnt = 0;
-	for (i = 0; i < sg_dma_len; ++i) {
-		unsigned int dma_len = sg_dma_len(&scat[i]);
-		u64 dma_addr = sg_dma_address(&scat[i]);
-
-		for (j = 0; j < dma_len; j += PAGE_SIZE)
-			dma_pages[page_cnt++] =
-				(dma_addr & PAGE_MASK) + j;
-	}
-
-	ret = ib_map_phys_fmr(fmr->fmr, dma_pages, page_cnt, io_addr);
-	if (ret) {
-		ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
-		goto out;
-	}
-
-	/* Success - we successfully remapped the MR, so we can
-	 * safely tear down the old mapping.
-	 */
-	rds_ib_teardown_mr(ibmr);
-
-	ibmr->sg = scat;
-	ibmr->sg_len = nents;
-	ibmr->sg_dma_len = sg_dma_len;
-	ibmr->remap_count++;
-
-	if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
-		rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
-	else
-		rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
-	ret = 0;
-
-out:
-	kfree(dma_pages);
-
-	return ret;
-}
-
-struct rds_ib_mr *rds_ib_reg_fmr(struct rds_ib_device *rds_ibdev,
-				 struct scatterlist *sg,
-				 unsigned long nents,
-				 u32 *key)
-{
-	struct rds_ib_mr *ibmr = NULL;
-	struct rds_ib_fmr *fmr;
-	int ret;
-
-	ibmr = rds_ib_alloc_fmr(rds_ibdev, nents);
-	if (IS_ERR(ibmr))
-		return ibmr;
-
-	ibmr->device = rds_ibdev;
-	fmr = &ibmr->u.fmr;
-	ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
-	if (ret == 0)
-		*key = fmr->fmr->rkey;
-	else
-		rds_ib_free_mr(ibmr, 0);
-
-	return ibmr;
-}
-
-void rds_ib_unreg_fmr(struct list_head *list, unsigned int *nfreed,
-		      unsigned long *unpinned, unsigned int goal)
-{
-	struct rds_ib_mr *ibmr, *next;
-	struct rds_ib_fmr *fmr;
-	LIST_HEAD(fmr_list);
-	int ret = 0;
-	unsigned int freed = *nfreed;
-
-	/* String all ib_mr's onto one list and hand them to  ib_unmap_fmr */
-	list_for_each_entry(ibmr, list, unmap_list) {
-		fmr = &ibmr->u.fmr;
-		list_add(&fmr->fmr->list, &fmr_list);
-	}
-
-	ret = ib_unmap_fmr(&fmr_list);
-	if (ret)
-		pr_warn("RDS/IB: FMR invalidation failed (err=%d)\n", ret);
-
-	/* Now we can destroy the DMA mapping and unpin any pages */
-	list_for_each_entry_safe(ibmr, next, list, unmap_list) {
-		fmr = &ibmr->u.fmr;
-		*unpinned += ibmr->sg_len;
-		__rds_ib_teardown_mr(ibmr);
-		if (freed < goal ||
-		    ibmr->remap_count >= ibmr->pool->fmr_attr.max_maps) {
-			if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
-				rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
-			else
-				rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
-			list_del(&ibmr->unmap_list);
-			ib_dealloc_fmr(fmr->fmr);
-			kfree(ibmr);
-			freed++;
-		}
-	}
-	*nfreed = freed;
-}
-
-void rds_ib_free_fmr_list(struct rds_ib_mr *ibmr)
-{
-	struct rds_ib_mr_pool *pool = ibmr->pool;
-
-	if (ibmr->remap_count >= pool->fmr_attr.max_maps)
-		llist_add(&ibmr->llnode, &pool->drop_list);
-	else
-		llist_add(&ibmr->llnode, &pool->free_list);
-}

net/rds/ib_frmr.c

···
 
 	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);
···
 	}
 	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;
 	}

net/rds/ib_mr.h

···
 #define RDS_MR_8K_SCALE			(256 / (RDS_MR_8K_MSG_SIZE + 1))
 #define RDS_MR_8K_POOL_SIZE		(RDS_MR_8K_SCALE * (8192 / 2))
 
-struct rds_ib_fmr {
-	struct ib_fmr		*fmr;
-};
-
 enum rds_ib_fr_state {
 	FRMR_IS_FREE,	/* mr invalidated & ready for use */
 	FRMR_IS_INUSE,	/* mr is in use or used & can be invalidated */
···
 
 	u8				odp:1;
 	union {
-		struct rds_ib_fmr	fmr;
 		struct rds_ib_frmr	frmr;
 		struct ib_mr		*mr;
 	} u;
···
 	unsigned long		max_items;
 	unsigned long		max_items_soft;
 	unsigned long		max_free_pinned;
-	struct ib_fmr_attr	fmr_attr;
-	bool			use_fastreg;
+	unsigned int		max_pages;
 };
 
 extern struct workqueue_struct *rds_ib_mr_wq;
···
 
 void __rds_ib_teardown_mr(struct rds_ib_mr *);
 void rds_ib_teardown_mr(struct rds_ib_mr *);
-struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *, int);
 struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *);
 int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *, int, struct rds_ib_mr **);
-struct rds_ib_mr *rds_ib_reg_fmr(struct rds_ib_device *, struct scatterlist *,
-				 unsigned long, u32 *);
 struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *);
-void rds_ib_unreg_fmr(struct list_head *, unsigned int *,
-		      unsigned long *, unsigned int);
-void rds_ib_free_fmr_list(struct rds_ib_mr *);
 struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
 				  struct rds_ib_connection *ic,
 				  struct scatterlist *sg,

net/rds/ib_rdma.c

···
 	struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
 
 	iinfo->rdma_mr_max = pool_1m->max_items;
-	iinfo->rdma_mr_size = pool_1m->fmr_attr.max_pages;
+	iinfo->rdma_mr_size = pool_1m->max_pages;
 }
 
 #if IS_ENABLED(CONFIG_IPV6)
···
 	struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
 
 	iinfo6->rdma_mr_max = pool_1m->max_items;
-	iinfo6->rdma_mr_size = pool_1m->fmr_attr.max_pages;
+	iinfo6->rdma_mr_size = pool_1m->max_pages;
 }
 #endif
 
···
 	if (list_empty(&unmap_list))
 		goto out;
 
-	if (pool->use_fastreg)
-		rds_ib_unreg_frmr(&unmap_list, &nfreed, &unpinned, free_goal);
-	else
-		rds_ib_unreg_fmr(&unmap_list, &nfreed, &unpinned, free_goal);
+	rds_ib_unreg_frmr(&unmap_list, &nfreed, &unpinned, free_goal);
 
 	if (!list_empty(&unmap_list)) {
 		unsigned long flags;
···
 	}
 
 	/* Return it to the pool's free list */
-	if (rds_ibdev->use_fastreg)
-		rds_ib_free_frmr_list(ibmr);
-	else
-		rds_ib_free_fmr_list(ibmr);
+	rds_ib_free_frmr_list(ibmr);
 
 	atomic_add(ibmr->sg_len, &pool->free_pinned);
 	atomic_inc(&pool->dirty_count);
···
 		goto out;
 	}
 
-	if (rds_ibdev->use_fastreg)
-		ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
-	else
-		ibmr = rds_ib_reg_fmr(rds_ibdev, sg, nents, key_ret);
+	ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
 	if (IS_ERR(ibmr)) {
 		ret = PTR_ERR(ibmr);
 		pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret);
···
 
 	if (pool_type == RDS_IB_MR_1M_POOL) {
 		/* +1 allows for unaligned MRs */
-		pool->fmr_attr.max_pages = RDS_MR_1M_MSG_SIZE + 1;
+		pool->max_pages = RDS_MR_1M_MSG_SIZE + 1;
 		pool->max_items = rds_ibdev->max_1m_mrs;
 	} else {
 		/* pool_type == RDS_IB_MR_8K_POOL */
-		pool->fmr_attr.max_pages = RDS_MR_8K_MSG_SIZE + 1;
+		pool->max_pages = RDS_MR_8K_MSG_SIZE + 1;
 		pool->max_items = rds_ibdev->max_8k_mrs;
 	}
 
-	pool->max_free_pinned = pool->max_items * pool->fmr_attr.max_pages / 4;
-	pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
-	pool->fmr_attr.page_shift = PAGE_SHIFT;
+	pool->max_free_pinned = pool->max_items * pool->max_pages / 4;
 	pool->max_items_soft = rds_ibdev->max_mrs * 3 / 4;
-	pool->use_fastreg = rds_ibdev->use_fastreg;
 
 	return pool;
 }