1 files changed, 446 insertions, 0 deletions

diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c
new file mode 100644
index 000000000..28c1b0022
--- /dev/null
+++ b/net/rds/ib_frmr.c
@@ -0,0 +1,446 @@
+/*
+ * 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"
+
+static inline void
+rds_transition_frwr_state(struct rds_ib_mr *ibmr,
+			  enum rds_ib_fr_state old_state,
+			  enum rds_ib_fr_state new_state)
+{
+	if (cmpxchg(&ibmr->u.frmr.fr_state,
+		    old_state, new_state) == old_state &&
+	    old_state == FRMR_IS_INUSE) {
+		/* enforce order of ibmr->u.frmr.fr_state update
+		 * before decrementing i_fastreg_inuse_count
+		 */
+		smp_mb__before_atomic();
+		atomic_dec(&ibmr->ic->i_fastreg_inuse_count);
+		if (waitqueue_active(&rds_ib_ring_empty_wait))
+			wake_up(&rds_ib_ring_empty_wait);
+	}
+}
+
+static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev,
+					   int npages)
+{
+	struct rds_ib_mr_pool *pool;
+	struct rds_ib_mr *ibmr = NULL;
+	struct rds_ib_frmr *frmr;
+	int err = 0;
+
+	if (npages <= RDS_MR_8K_MSG_SIZE)
+		pool = rds_ibdev->mr_8k_pool;
+	else
+		pool = rds_ibdev->mr_1m_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;
+	}
+
+	frmr = &ibmr->u.frmr;
+	frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG,
+			 pool->max_pages);
+	if (IS_ERR(frmr->mr)) {
+		pr_warn("RDS/IB: %s failed to allocate MR", __func__);
+		err = PTR_ERR(frmr->mr);
+		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);
+
+	if (atomic_read(&pool->item_count) > pool->max_items_soft)
+		pool->max_items_soft = pool->max_items;
+
+	frmr->fr_state = FRMR_IS_FREE;
+	init_waitqueue_head(&frmr->fr_inv_done);
+	init_waitqueue_head(&frmr->fr_reg_done);
+	return ibmr;
+
+out_no_cigar:
+	kfree(ibmr);
+	atomic_dec(&pool->item_count);
+	return ERR_PTR(err);
+}
+
+static void rds_ib_free_frmr(struct rds_ib_mr *ibmr, bool drop)
+{
+	struct rds_ib_mr_pool *pool = ibmr->pool;
+
+	if (drop)
+		llist_add(&ibmr->llnode, &pool->drop_list);
+	else
+		llist_add(&ibmr->llnode, &pool->free_list);
+	atomic_add(ibmr->sg_len, &pool->free_pinned);
+	atomic_inc(&pool->dirty_count);
+
+	/* If we've pinned too many pages, request a flush */
+	if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
+	    atomic_read(&pool->dirty_count) >= pool->max_items / 5)
+		queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
+}
+
+static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
+{
+	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
+	struct ib_reg_wr reg_wr;
+	int ret, off = 0;
+
+	while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
+		atomic_inc(&ibmr->ic->i_fastreg_wrs);
+		cpu_relax();
+	}
+
+	ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len,
+				&off, PAGE_SIZE);
+	if (unlikely(ret != ibmr->sg_dma_len))
+		return ret < 0 ? ret : -EINVAL;
+
+	if (cmpxchg(&frmr->fr_state,
+		    FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE)
+		return -EBUSY;
+
+	atomic_inc(&ibmr->ic->i_fastreg_inuse_count);
+
+	/* Perform a WR for the fast_reg_mr. Each individual page
+	 * in the sg list is added to the fast reg page list and placed
+	 * inside the fast_reg_mr WR.  The key used is a rolling 8bit
+	 * counter, which should guarantee uniqueness.
+	 */
+	ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++);
+	frmr->fr_reg = true;
+
+	memset(&reg_wr, 0, sizeof(reg_wr));
+	reg_wr.wr.wr_id = (unsigned long)(void *)ibmr;
+	reg_wr.wr.opcode = IB_WR_REG_MR;
+	reg_wr.wr.num_sge = 0;
+	reg_wr.mr = frmr->mr;
+	reg_wr.key = frmr->mr->rkey;
+	reg_wr.access = IB_ACCESS_LOCAL_WRITE |
+			IB_ACCESS_REMOTE_READ |
+			IB_ACCESS_REMOTE_WRITE;
+	reg_wr.wr.send_flags = IB_SEND_SIGNALED;
+
+	ret = ib_post_send(ibmr->ic->i_cm_id->qp, &reg_wr.wr, NULL);
+	if (unlikely(ret)) {
+		/* Failure here can be because of -ENOMEM as well */
+		rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
+
+		atomic_inc(&ibmr->ic->i_fastreg_wrs);
+		if (printk_ratelimit())
+			pr_warn("RDS/IB: %s returned error(%d)\n",
+				__func__, ret);
+		goto out;
+	}
+
+	/* Wait for the registration to complete in order to prevent an invalid
+	 * access error resulting from a race between the memory region already
+	 * being accessed while registration is still pending.
+	 */
+	wait_event(frmr->fr_reg_done, !frmr->fr_reg);
+
+out:
+
+	return ret;
+}
+
+static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
+			   struct rds_ib_mr_pool *pool,
+			   struct rds_ib_mr *ibmr,
+			   struct scatterlist *sg, unsigned int sg_len)
+{
+	struct ib_device *dev = rds_ibdev->dev;
+	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
+	int i;
+	u32 len;
+	int ret = 0;
+
+	/* We want to teardown old ibmr values here and fill it up with
+	 * new sg values
+	 */
+	rds_ib_teardown_mr(ibmr);
+
+	ibmr->sg = sg;
+	ibmr->sg_len = sg_len;
+	ibmr->sg_dma_len = 0;
+	frmr->sg_byte_len = 0;
+	WARN_ON(ibmr->sg_dma_len);
+	ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len,
+					 DMA_BIDIRECTIONAL);
+	if (unlikely(!ibmr->sg_dma_len)) {
+		pr_warn("RDS/IB: %s failed!\n", __func__);
+		return -EBUSY;
+	}
+
+	frmr->sg_byte_len = 0;
+	frmr->dma_npages = 0;
+	len = 0;
+
+	ret = -EINVAL;
+	for (i = 0; i < ibmr->sg_dma_len; ++i) {
+		unsigned int dma_len = sg_dma_len(&ibmr->sg[i]);
+		u64 dma_addr = sg_dma_address(&ibmr->sg[i]);
+
+		frmr->sg_byte_len += dma_len;
+		if (dma_addr & ~PAGE_MASK) {
+			if (i > 0)
+				goto out_unmap;
+			else
+				++frmr->dma_npages;
+		}
+
+		if ((dma_addr + dma_len) & ~PAGE_MASK) {
+			if (i < ibmr->sg_dma_len - 1)
+				goto out_unmap;
+			else
+				++frmr->dma_npages;
+		}
+
+		len += dma_len;
+	}
+	frmr->dma_npages += len >> PAGE_SHIFT;
+
+	if (frmr->dma_npages > ibmr->pool->max_pages) {
+		ret = -EMSGSIZE;
+		goto out_unmap;
+	}
+
+	ret = rds_ib_post_reg_frmr(ibmr);
+	if (ret)
+		goto out_unmap;
+
+	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);
+
+	return ret;
+
+out_unmap:
+	ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
+			DMA_BIDIRECTIONAL);
+	ibmr->sg_dma_len = 0;
+	return ret;
+}
+
+static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
+{
+	struct ib_send_wr *s_wr;
+	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
+	struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
+	int ret = -EINVAL;
+
+	if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
+		goto out;
+
+	if (frmr->fr_state != FRMR_IS_INUSE)
+		goto out;
+
+	while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
+		atomic_inc(&ibmr->ic->i_fastreg_wrs);
+		cpu_relax();
+	}
+
+	frmr->fr_inv = true;
+	s_wr = &frmr->fr_wr;
+
+	memset(s_wr, 0, sizeof(*s_wr));
+	s_wr->wr_id = (unsigned long)(void *)ibmr;
+	s_wr->opcode = IB_WR_LOCAL_INV;
+	s_wr->ex.invalidate_rkey = frmr->mr->rkey;
+	s_wr->send_flags = IB_SEND_SIGNALED;
+
+	ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
+	if (unlikely(ret)) {
+		rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
+		frmr->fr_inv = false;
+		/* enforce order of frmr->fr_inv update
+		 * before incrementing i_fastreg_wrs
+		 */
+		smp_mb__before_atomic();
+		atomic_inc(&ibmr->ic->i_fastreg_wrs);
+		pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
+		goto out;
+	}
+
+	/* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to
+	 * 1) avoid a silly bouncing between "clean_list" and "drop_list"
+	 *    triggered by function "rds_ib_reg_frmr" as it is releases frmr
+	 *    regions whose state is not "FRMR_IS_FREE" right away.
+	 * 2) prevents an invalid access error in a race
+	 *    from a pending "IB_WR_LOCAL_INV" operation
+	 *    with a teardown ("dma_unmap_sg", "put_page")
+	 *    and de-registration ("ib_dereg_mr") of the corresponding
+	 *    memory region.
+	 */
+	wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE);
+
+out:
+	return ret;
+}
+
+void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
+{
+	struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
+	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
+
+	if (wc->status != IB_WC_SUCCESS) {
+		rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
+		if (rds_conn_up(ic->conn))
+			rds_ib_conn_error(ic->conn,
+					  "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
+					  &ic->conn->c_laddr,
+					  &ic->conn->c_faddr,
+					  wc->status,
+					  ib_wc_status_msg(wc->status),
+					  wc->vendor_err);
+	}
+
+	if (frmr->fr_inv) {
+		rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE);
+		frmr->fr_inv = false;
+		wake_up(&frmr->fr_inv_done);
+	}
+
+	if (frmr->fr_reg) {
+		frmr->fr_reg = false;
+		wake_up(&frmr->fr_reg_done);
+	}
+
+	/* enforce order of frmr->{fr_reg,fr_inv} update
+	 * before incrementing i_fastreg_wrs
+	 */
+	smp_mb__before_atomic();
+	atomic_inc(&ic->i_fastreg_wrs);
+}
+
+void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
+		       unsigned long *unpinned, unsigned int goal)
+{
+	struct rds_ib_mr *ibmr, *next;
+	struct rds_ib_frmr *frmr;
+	int ret = 0, ret2;
+	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) {
+		if (ibmr->sg_dma_len) {
+			ret2 = rds_ib_post_inv(ibmr);
+			if (ret2 && !ret)
+				ret = ret2;
+		}
+	}
+
+	if (ret)
+		pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
+
+	/* Now we can destroy the DMA mapping and unpin any pages */
+	list_for_each_entry_safe(ibmr, next, list, unmap_list) {
+		*unpinned += ibmr->sg_len;
+		frmr = &ibmr->u.frmr;
+		__rds_ib_teardown_mr(ibmr);
+		if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
+			/* Don't de-allocate if the MR is not free yet */
+			if (frmr->fr_state == FRMR_IS_INUSE)
+				continue;
+
+			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);
+			if (frmr->mr)
+				ib_dereg_mr(frmr->mr);
+			kfree(ibmr);
+			freed++;
+		}
+	}
+	*nfreed = freed;
+}
+
+struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
+				  struct rds_ib_connection *ic,
+				  struct scatterlist *sg,
+				  unsigned long nents, u32 *key)
+{
+	struct rds_ib_mr *ibmr = NULL;
+	struct rds_ib_frmr *frmr;
+	int ret;
+
+	if (!ic) {
+		/* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+
+	do {
+		if (ibmr)
+			rds_ib_free_frmr(ibmr, true);
+		ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
+		if (IS_ERR(ibmr))
+			return ibmr;
+		frmr = &ibmr->u.frmr;
+	} while (frmr->fr_state != FRMR_IS_FREE);
+
+	ibmr->ic = ic;
+	ibmr->device = rds_ibdev;
+	ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
+	if (ret == 0) {
+		*key = frmr->mr->rkey;
+	} else {
+		rds_ib_free_frmr(ibmr, false);
+		ibmr = ERR_PTR(ret);
+	}
+
+	return ibmr;
+}
+
+void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
+{
+	struct rds_ib_mr_pool *pool = ibmr->pool;
+	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
+
+	if (frmr->fr_state == FRMR_IS_STALE)
+		llist_add(&ibmr->llnode, &pool->drop_list);
+	else
+		llist_add(&ibmr->llnode, &pool->free_list);
+}