summaryrefslogtreecommitdiff
path: root/net/rds/iw_rdma.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/rds/iw_rdma.c
Initial import
Diffstat (limited to 'net/rds/iw_rdma.c')
-rw-r--r--net/rds/iw_rdma.c875
1 files changed, 875 insertions, 0 deletions
diff --git a/net/rds/iw_rdma.c b/net/rds/iw_rdma.c
new file mode 100644
index 000000000..dba8d0864
--- /dev/null
+++ b/net/rds/iw_rdma.c
@@ -0,0 +1,875 @@
+/*
+ * Copyright (c) 2006 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 <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/ratelimit.h>
+
+#include "rds.h"
+#include "iw.h"
+
+
+/*
+ * This is stored as mr->r_trans_private.
+ */
+struct rds_iw_mr {
+ struct rds_iw_device *device;
+ struct rds_iw_mr_pool *pool;
+ struct rdma_cm_id *cm_id;
+
+ struct ib_mr *mr;
+ struct ib_fast_reg_page_list *page_list;
+
+ struct rds_iw_mapping mapping;
+ unsigned char remap_count;
+};
+
+/*
+ * Our own little MR pool
+ */
+struct rds_iw_mr_pool {
+ struct rds_iw_device *device; /* back ptr to the device that owns us */
+
+ struct mutex flush_lock; /* serialize fmr invalidate */
+ struct work_struct flush_worker; /* flush worker */
+
+ spinlock_t list_lock; /* protect variables below */
+ atomic_t item_count; /* total # of MRs */
+ atomic_t dirty_count; /* # dirty of MRs */
+ struct list_head dirty_list; /* dirty mappings */
+ struct list_head clean_list; /* unused & unamapped MRs */
+ atomic_t free_pinned; /* memory pinned by free MRs */
+ unsigned long max_message_size; /* in pages */
+ unsigned long max_items;
+ unsigned long max_items_soft;
+ unsigned long max_free_pinned;
+ int max_pages;
+};
+
+static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all);
+static void rds_iw_mr_pool_flush_worker(struct work_struct *work);
+static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
+static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
+ struct rds_iw_mr *ibmr,
+ struct scatterlist *sg, unsigned int nents);
+static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
+static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
+ struct list_head *unmap_list,
+ struct list_head *kill_list,
+ int *unpinned);
+static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
+
+static int rds_iw_get_device(struct sockaddr_in *src, struct sockaddr_in *dst,
+ struct rds_iw_device **rds_iwdev,
+ struct rdma_cm_id **cm_id)
+{
+ struct rds_iw_device *iwdev;
+ struct rds_iw_cm_id *i_cm_id;
+
+ *rds_iwdev = NULL;
+ *cm_id = NULL;
+
+ list_for_each_entry(iwdev, &rds_iw_devices, list) {
+ spin_lock_irq(&iwdev->spinlock);
+ list_for_each_entry(i_cm_id, &iwdev->cm_id_list, list) {
+ struct sockaddr_in *src_addr, *dst_addr;
+
+ src_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.src_addr;
+ dst_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.dst_addr;
+
+ rdsdebug("local ipaddr = %x port %d, "
+ "remote ipaddr = %x port %d"
+ "..looking for %x port %d, "
+ "remote ipaddr = %x port %d\n",
+ src_addr->sin_addr.s_addr,
+ src_addr->sin_port,
+ dst_addr->sin_addr.s_addr,
+ dst_addr->sin_port,
+ src->sin_addr.s_addr,
+ src->sin_port,
+ dst->sin_addr.s_addr,
+ dst->sin_port);
+#ifdef WORKING_TUPLE_DETECTION
+ if (src_addr->sin_addr.s_addr == src->sin_addr.s_addr &&
+ src_addr->sin_port == src->sin_port &&
+ dst_addr->sin_addr.s_addr == dst->sin_addr.s_addr &&
+ dst_addr->sin_port == dst->sin_port) {
+#else
+ /* FIXME - needs to compare the local and remote
+ * ipaddr/port tuple, but the ipaddr is the only
+ * available information in the rds_sock (as the rest are
+ * zero'ed. It doesn't appear to be properly populated
+ * during connection setup...
+ */
+ if (src_addr->sin_addr.s_addr == src->sin_addr.s_addr) {
+#endif
+ spin_unlock_irq(&iwdev->spinlock);
+ *rds_iwdev = iwdev;
+ *cm_id = i_cm_id->cm_id;
+ return 0;
+ }
+ }
+ spin_unlock_irq(&iwdev->spinlock);
+ }
+
+ return 1;
+}
+
+static int rds_iw_add_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
+{
+ struct rds_iw_cm_id *i_cm_id;
+
+ i_cm_id = kmalloc(sizeof *i_cm_id, GFP_KERNEL);
+ if (!i_cm_id)
+ return -ENOMEM;
+
+ i_cm_id->cm_id = cm_id;
+
+ spin_lock_irq(&rds_iwdev->spinlock);
+ list_add_tail(&i_cm_id->list, &rds_iwdev->cm_id_list);
+ spin_unlock_irq(&rds_iwdev->spinlock);
+
+ return 0;
+}
+
+static void rds_iw_remove_cm_id(struct rds_iw_device *rds_iwdev,
+ struct rdma_cm_id *cm_id)
+{
+ struct rds_iw_cm_id *i_cm_id;
+
+ spin_lock_irq(&rds_iwdev->spinlock);
+ list_for_each_entry(i_cm_id, &rds_iwdev->cm_id_list, list) {
+ if (i_cm_id->cm_id == cm_id) {
+ list_del(&i_cm_id->list);
+ kfree(i_cm_id);
+ break;
+ }
+ }
+ spin_unlock_irq(&rds_iwdev->spinlock);
+}
+
+
+int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
+{
+ struct sockaddr_in *src_addr, *dst_addr;
+ struct rds_iw_device *rds_iwdev_old;
+ struct rdma_cm_id *pcm_id;
+ int rc;
+
+ src_addr = (struct sockaddr_in *)&cm_id->route.addr.src_addr;
+ dst_addr = (struct sockaddr_in *)&cm_id->route.addr.dst_addr;
+
+ rc = rds_iw_get_device(src_addr, dst_addr, &rds_iwdev_old, &pcm_id);
+ if (rc)
+ rds_iw_remove_cm_id(rds_iwdev, cm_id);
+
+ return rds_iw_add_cm_id(rds_iwdev, cm_id);
+}
+
+void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
+{
+ struct rds_iw_connection *ic = conn->c_transport_data;
+
+ /* conn was previously on the nodev_conns_list */
+ spin_lock_irq(&iw_nodev_conns_lock);
+ BUG_ON(list_empty(&iw_nodev_conns));
+ BUG_ON(list_empty(&ic->iw_node));
+ list_del(&ic->iw_node);
+
+ spin_lock(&rds_iwdev->spinlock);
+ list_add_tail(&ic->iw_node, &rds_iwdev->conn_list);
+ spin_unlock(&rds_iwdev->spinlock);
+ spin_unlock_irq(&iw_nodev_conns_lock);
+
+ ic->rds_iwdev = rds_iwdev;
+}
+
+void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
+{
+ struct rds_iw_connection *ic = conn->c_transport_data;
+
+ /* place conn on nodev_conns_list */
+ spin_lock(&iw_nodev_conns_lock);
+
+ spin_lock_irq(&rds_iwdev->spinlock);
+ BUG_ON(list_empty(&ic->iw_node));
+ list_del(&ic->iw_node);
+ spin_unlock_irq(&rds_iwdev->spinlock);
+
+ list_add_tail(&ic->iw_node, &iw_nodev_conns);
+
+ spin_unlock(&iw_nodev_conns_lock);
+
+ rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
+ ic->rds_iwdev = NULL;
+}
+
+void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock)
+{
+ struct rds_iw_connection *ic, *_ic;
+ LIST_HEAD(tmp_list);
+
+ /* avoid calling conn_destroy with irqs off */
+ spin_lock_irq(list_lock);
+ list_splice(list, &tmp_list);
+ INIT_LIST_HEAD(list);
+ spin_unlock_irq(list_lock);
+
+ list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node)
+ rds_conn_destroy(ic->conn);
+}
+
+static void rds_iw_set_scatterlist(struct rds_iw_scatterlist *sg,
+ struct scatterlist *list, unsigned int sg_len)
+{
+ sg->list = list;
+ sg->len = sg_len;
+ sg->dma_len = 0;
+ sg->dma_npages = 0;
+ sg->bytes = 0;
+}
+
+static u64 *rds_iw_map_scatterlist(struct rds_iw_device *rds_iwdev,
+ struct rds_iw_scatterlist *sg)
+{
+ struct ib_device *dev = rds_iwdev->dev;
+ u64 *dma_pages = NULL;
+ int i, j, ret;
+
+ WARN_ON(sg->dma_len);
+
+ sg->dma_len = ib_dma_map_sg(dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
+ if (unlikely(!sg->dma_len)) {
+ printk(KERN_WARNING "RDS/IW: dma_map_sg failed!\n");
+ return ERR_PTR(-EBUSY);
+ }
+
+ sg->bytes = 0;
+ sg->dma_npages = 0;
+
+ ret = -EINVAL;
+ for (i = 0; i < sg->dma_len; ++i) {
+ unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
+ u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
+ u64 end_addr;
+
+ sg->bytes += dma_len;
+
+ end_addr = dma_addr + dma_len;
+ if (dma_addr & PAGE_MASK) {
+ if (i > 0)
+ goto out_unmap;
+ dma_addr &= ~PAGE_MASK;
+ }
+ if (end_addr & PAGE_MASK) {
+ if (i < sg->dma_len - 1)
+ goto out_unmap;
+ end_addr = (end_addr + PAGE_MASK) & ~PAGE_MASK;
+ }
+
+ sg->dma_npages += (end_addr - dma_addr) >> PAGE_SHIFT;
+ }
+
+ /* Now gather the dma addrs into one list */
+ if (sg->dma_npages > fastreg_message_size)
+ goto out_unmap;
+
+ dma_pages = kmalloc(sizeof(u64) * sg->dma_npages, GFP_ATOMIC);
+ if (!dma_pages) {
+ ret = -ENOMEM;
+ goto out_unmap;
+ }
+
+ for (i = j = 0; i < sg->dma_len; ++i) {
+ unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
+ u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
+ u64 end_addr;
+
+ end_addr = dma_addr + dma_len;
+ dma_addr &= ~PAGE_MASK;
+ for (; dma_addr < end_addr; dma_addr += PAGE_SIZE)
+ dma_pages[j++] = dma_addr;
+ BUG_ON(j > sg->dma_npages);
+ }
+
+ return dma_pages;
+
+out_unmap:
+ ib_dma_unmap_sg(rds_iwdev->dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
+ sg->dma_len = 0;
+ kfree(dma_pages);
+ return ERR_PTR(ret);
+}
+
+
+struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *rds_iwdev)
+{
+ struct rds_iw_mr_pool *pool;
+
+ pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+ if (!pool) {
+ printk(KERN_WARNING "RDS/IW: rds_iw_create_mr_pool alloc error\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ pool->device = rds_iwdev;
+ INIT_LIST_HEAD(&pool->dirty_list);
+ INIT_LIST_HEAD(&pool->clean_list);
+ mutex_init(&pool->flush_lock);
+ spin_lock_init(&pool->list_lock);
+ INIT_WORK(&pool->flush_worker, rds_iw_mr_pool_flush_worker);
+
+ pool->max_message_size = fastreg_message_size;
+ pool->max_items = fastreg_pool_size;
+ pool->max_free_pinned = pool->max_items * pool->max_message_size / 4;
+ pool->max_pages = fastreg_message_size;
+
+ /* We never allow more than max_items MRs to be allocated.
+ * When we exceed more than max_items_soft, we start freeing
+ * items more aggressively.
+ * Make sure that max_items > max_items_soft > max_items / 2
+ */
+ pool->max_items_soft = pool->max_items * 3 / 4;
+
+ return pool;
+}
+
+void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo)
+{
+ struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
+
+ iinfo->rdma_mr_max = pool->max_items;
+ iinfo->rdma_mr_size = pool->max_pages;
+}
+
+void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *pool)
+{
+ flush_workqueue(rds_wq);
+ rds_iw_flush_mr_pool(pool, 1);
+ BUG_ON(atomic_read(&pool->item_count));
+ BUG_ON(atomic_read(&pool->free_pinned));
+ kfree(pool);
+}
+
+static inline struct rds_iw_mr *rds_iw_reuse_fmr(struct rds_iw_mr_pool *pool)
+{
+ struct rds_iw_mr *ibmr = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pool->list_lock, flags);
+ if (!list_empty(&pool->clean_list)) {
+ ibmr = list_entry(pool->clean_list.next, struct rds_iw_mr, mapping.m_list);
+ list_del_init(&ibmr->mapping.m_list);
+ }
+ spin_unlock_irqrestore(&pool->list_lock, flags);
+
+ return ibmr;
+}
+
+static struct rds_iw_mr *rds_iw_alloc_mr(struct rds_iw_device *rds_iwdev)
+{
+ struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
+ struct rds_iw_mr *ibmr = NULL;
+ int err = 0, iter = 0;
+
+ while (1) {
+ ibmr = rds_iw_reuse_fmr(pool);
+ if (ibmr)
+ return ibmr;
+
+ /* No clean MRs - now we have the choice of either
+ * allocating a fresh MR up to the limit imposed by the
+ * driver, or flush any dirty unused MRs.
+ * We try to avoid stalling in the send path if possible,
+ * so we allocate as long as we're allowed to.
+ *
+ * We're fussy with enforcing the FMR limit, though. If the driver
+ * tells us we can't use more than N fmrs, we shouldn't start
+ * arguing with it */
+ if (atomic_inc_return(&pool->item_count) <= pool->max_items)
+ break;
+
+ atomic_dec(&pool->item_count);
+
+ if (++iter > 2) {
+ rds_iw_stats_inc(s_iw_rdma_mr_pool_depleted);
+ return ERR_PTR(-EAGAIN);
+ }
+
+ /* We do have some empty MRs. Flush them out. */
+ rds_iw_stats_inc(s_iw_rdma_mr_pool_wait);
+ rds_iw_flush_mr_pool(pool, 0);
+ }
+
+ ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
+ if (!ibmr) {
+ err = -ENOMEM;
+ goto out_no_cigar;
+ }
+
+ spin_lock_init(&ibmr->mapping.m_lock);
+ INIT_LIST_HEAD(&ibmr->mapping.m_list);
+ ibmr->mapping.m_mr = ibmr;
+
+ err = rds_iw_init_fastreg(pool, ibmr);
+ if (err)
+ goto out_no_cigar;
+
+ rds_iw_stats_inc(s_iw_rdma_mr_alloc);
+ return ibmr;
+
+out_no_cigar:
+ if (ibmr) {
+ rds_iw_destroy_fastreg(pool, ibmr);
+ kfree(ibmr);
+ }
+ atomic_dec(&pool->item_count);
+ return ERR_PTR(err);
+}
+
+void rds_iw_sync_mr(void *trans_private, int direction)
+{
+ struct rds_iw_mr *ibmr = trans_private;
+ struct rds_iw_device *rds_iwdev = ibmr->device;
+
+ switch (direction) {
+ case DMA_FROM_DEVICE:
+ ib_dma_sync_sg_for_cpu(rds_iwdev->dev, ibmr->mapping.m_sg.list,
+ ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
+ break;
+ case DMA_TO_DEVICE:
+ ib_dma_sync_sg_for_device(rds_iwdev->dev, ibmr->mapping.m_sg.list,
+ ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
+ break;
+ }
+}
+
+/*
+ * Flush our pool of MRs.
+ * At a minimum, all currently unused MRs are unmapped.
+ * If the number of MRs allocated exceeds the limit, we also try
+ * to free as many MRs as needed to get back to this limit.
+ */
+static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all)
+{
+ struct rds_iw_mr *ibmr, *next;
+ LIST_HEAD(unmap_list);
+ LIST_HEAD(kill_list);
+ unsigned long flags;
+ unsigned int nfreed = 0, ncleaned = 0, unpinned = 0;
+ int ret = 0;
+
+ rds_iw_stats_inc(s_iw_rdma_mr_pool_flush);
+
+ mutex_lock(&pool->flush_lock);
+
+ spin_lock_irqsave(&pool->list_lock, flags);
+ /* Get the list of all mappings to be destroyed */
+ list_splice_init(&pool->dirty_list, &unmap_list);
+ if (free_all)
+ list_splice_init(&pool->clean_list, &kill_list);
+ spin_unlock_irqrestore(&pool->list_lock, flags);
+
+ /* Batched invalidate of dirty MRs.
+ * For FMR based MRs, the mappings on the unmap list are
+ * actually members of an ibmr (ibmr->mapping). They either
+ * migrate to the kill_list, or have been cleaned and should be
+ * moved to the clean_list.
+ * For fastregs, they will be dynamically allocated, and
+ * will be destroyed by the unmap function.
+ */
+ if (!list_empty(&unmap_list)) {
+ ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list,
+ &kill_list, &unpinned);
+ /* If we've been asked to destroy all MRs, move those
+ * that were simply cleaned to the kill list */
+ if (free_all)
+ list_splice_init(&unmap_list, &kill_list);
+ }
+
+ /* Destroy any MRs that are past their best before date */
+ list_for_each_entry_safe(ibmr, next, &kill_list, mapping.m_list) {
+ rds_iw_stats_inc(s_iw_rdma_mr_free);
+ list_del(&ibmr->mapping.m_list);
+ rds_iw_destroy_fastreg(pool, ibmr);
+ kfree(ibmr);
+ nfreed++;
+ }
+
+ /* Anything that remains are laundered ibmrs, which we can add
+ * back to the clean list. */
+ if (!list_empty(&unmap_list)) {
+ spin_lock_irqsave(&pool->list_lock, flags);
+ list_splice(&unmap_list, &pool->clean_list);
+ spin_unlock_irqrestore(&pool->list_lock, flags);
+ }
+
+ atomic_sub(unpinned, &pool->free_pinned);
+ atomic_sub(ncleaned, &pool->dirty_count);
+ atomic_sub(nfreed, &pool->item_count);
+
+ mutex_unlock(&pool->flush_lock);
+ return ret;
+}
+
+static void rds_iw_mr_pool_flush_worker(struct work_struct *work)
+{
+ struct rds_iw_mr_pool *pool = container_of(work, struct rds_iw_mr_pool, flush_worker);
+
+ rds_iw_flush_mr_pool(pool, 0);
+}
+
+void rds_iw_free_mr(void *trans_private, int invalidate)
+{
+ struct rds_iw_mr *ibmr = trans_private;
+ struct rds_iw_mr_pool *pool = ibmr->device->mr_pool;
+
+ rdsdebug("RDS/IW: free_mr nents %u\n", ibmr->mapping.m_sg.len);
+ if (!pool)
+ return;
+
+ /* Return it to the pool's free list */
+ rds_iw_free_fastreg(pool, ibmr);
+
+ /* 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 / 10)
+ queue_work(rds_wq, &pool->flush_worker);
+
+ if (invalidate) {
+ if (likely(!in_interrupt())) {
+ rds_iw_flush_mr_pool(pool, 0);
+ } else {
+ /* We get here if the user created a MR marked
+ * as use_once and invalidate at the same time. */
+ queue_work(rds_wq, &pool->flush_worker);
+ }
+ }
+}
+
+void rds_iw_flush_mrs(void)
+{
+ struct rds_iw_device *rds_iwdev;
+
+ list_for_each_entry(rds_iwdev, &rds_iw_devices, list) {
+ struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
+
+ if (pool)
+ rds_iw_flush_mr_pool(pool, 0);
+ }
+}
+
+void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents,
+ struct rds_sock *rs, u32 *key_ret)
+{
+ struct rds_iw_device *rds_iwdev;
+ struct rds_iw_mr *ibmr = NULL;
+ struct rdma_cm_id *cm_id;
+ struct sockaddr_in src = {
+ .sin_addr.s_addr = rs->rs_bound_addr,
+ .sin_port = rs->rs_bound_port,
+ };
+ struct sockaddr_in dst = {
+ .sin_addr.s_addr = rs->rs_conn_addr,
+ .sin_port = rs->rs_conn_port,
+ };
+ int ret;
+
+ ret = rds_iw_get_device(&src, &dst, &rds_iwdev, &cm_id);
+ if (ret || !cm_id) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (!rds_iwdev->mr_pool) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ ibmr = rds_iw_alloc_mr(rds_iwdev);
+ if (IS_ERR(ibmr))
+ return ibmr;
+
+ ibmr->cm_id = cm_id;
+ ibmr->device = rds_iwdev;
+
+ ret = rds_iw_map_fastreg(rds_iwdev->mr_pool, ibmr, sg, nents);
+ if (ret == 0)
+ *key_ret = ibmr->mr->rkey;
+ else
+ printk(KERN_WARNING "RDS/IW: failed to map mr (errno=%d)\n", ret);
+
+out:
+ if (ret) {
+ if (ibmr)
+ rds_iw_free_mr(ibmr, 0);
+ ibmr = ERR_PTR(ret);
+ }
+ return ibmr;
+}
+
+/*
+ * iWARP fastreg handling
+ *
+ * The life cycle of a fastreg registration is a bit different from
+ * FMRs.
+ * The idea behind fastreg is to have one MR, to which we bind different
+ * mappings over time. To avoid stalling on the expensive map and invalidate
+ * operations, these operations are pipelined on the same send queue on
+ * which we want to send the message containing the r_key.
+ *
+ * This creates a bit of a problem for us, as we do not have the destination
+ * IP in GET_MR, so the connection must be setup prior to the GET_MR call for
+ * RDMA to be correctly setup. If a fastreg request is present, rds_iw_xmit
+ * will try to queue a LOCAL_INV (if needed) and a FAST_REG_MR work request
+ * before queuing the SEND. When completions for these arrive, they are
+ * dispatched to the MR has a bit set showing that RDMa can be performed.
+ *
+ * There is another interesting aspect that's related to invalidation.
+ * The application can request that a mapping is invalidated in FREE_MR.
+ * The expectation there is that this invalidation step includes ALL
+ * PREVIOUSLY FREED MRs.
+ */
+static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool,
+ struct rds_iw_mr *ibmr)
+{
+ struct rds_iw_device *rds_iwdev = pool->device;
+ struct ib_fast_reg_page_list *page_list = NULL;
+ struct ib_mr *mr;
+ int err;
+
+ mr = ib_alloc_fast_reg_mr(rds_iwdev->pd, pool->max_message_size);
+ if (IS_ERR(mr)) {
+ err = PTR_ERR(mr);
+
+ printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_mr failed (err=%d)\n", err);
+ return err;
+ }
+
+ /* FIXME - this is overkill, but mapping->m_sg.dma_len/mapping->m_sg.dma_npages
+ * is not filled in.
+ */
+ page_list = ib_alloc_fast_reg_page_list(rds_iwdev->dev, pool->max_message_size);
+ if (IS_ERR(page_list)) {
+ err = PTR_ERR(page_list);
+
+ printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_page_list failed (err=%d)\n", err);
+ ib_dereg_mr(mr);
+ return err;
+ }
+
+ ibmr->page_list = page_list;
+ ibmr->mr = mr;
+ return 0;
+}
+
+static int rds_iw_rdma_build_fastreg(struct rds_iw_mapping *mapping)
+{
+ struct rds_iw_mr *ibmr = mapping->m_mr;
+ struct ib_send_wr f_wr, *failed_wr;
+ int ret;
+
+ /*
+ * 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(ibmr->mr, ibmr->remap_count++);
+ mapping->m_rkey = ibmr->mr->rkey;
+
+ memset(&f_wr, 0, sizeof(f_wr));
+ f_wr.wr_id = RDS_IW_FAST_REG_WR_ID;
+ f_wr.opcode = IB_WR_FAST_REG_MR;
+ f_wr.wr.fast_reg.length = mapping->m_sg.bytes;
+ f_wr.wr.fast_reg.rkey = mapping->m_rkey;
+ f_wr.wr.fast_reg.page_list = ibmr->page_list;
+ f_wr.wr.fast_reg.page_list_len = mapping->m_sg.dma_len;
+ f_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
+ f_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE |
+ IB_ACCESS_REMOTE_READ |
+ IB_ACCESS_REMOTE_WRITE;
+ f_wr.wr.fast_reg.iova_start = 0;
+ f_wr.send_flags = IB_SEND_SIGNALED;
+
+ failed_wr = &f_wr;
+ ret = ib_post_send(ibmr->cm_id->qp, &f_wr, &failed_wr);
+ BUG_ON(failed_wr != &f_wr);
+ if (ret)
+ printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
+ __func__, __LINE__, ret);
+ return ret;
+}
+
+static int rds_iw_rdma_fastreg_inv(struct rds_iw_mr *ibmr)
+{
+ struct ib_send_wr s_wr, *failed_wr;
+ int ret = 0;
+
+ if (!ibmr->cm_id->qp || !ibmr->mr)
+ goto out;
+
+ memset(&s_wr, 0, sizeof(s_wr));
+ s_wr.wr_id = RDS_IW_LOCAL_INV_WR_ID;
+ s_wr.opcode = IB_WR_LOCAL_INV;
+ s_wr.ex.invalidate_rkey = ibmr->mr->rkey;
+ s_wr.send_flags = IB_SEND_SIGNALED;
+
+ failed_wr = &s_wr;
+ ret = ib_post_send(ibmr->cm_id->qp, &s_wr, &failed_wr);
+ if (ret) {
+ printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
+ __func__, __LINE__, ret);
+ goto out;
+ }
+out:
+ return ret;
+}
+
+static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
+ struct rds_iw_mr *ibmr,
+ struct scatterlist *sg,
+ unsigned int sg_len)
+{
+ struct rds_iw_device *rds_iwdev = pool->device;
+ struct rds_iw_mapping *mapping = &ibmr->mapping;
+ u64 *dma_pages;
+ int i, ret = 0;
+
+ rds_iw_set_scatterlist(&mapping->m_sg, sg, sg_len);
+
+ dma_pages = rds_iw_map_scatterlist(rds_iwdev, &mapping->m_sg);
+ if (IS_ERR(dma_pages)) {
+ ret = PTR_ERR(dma_pages);
+ dma_pages = NULL;
+ goto out;
+ }
+
+ if (mapping->m_sg.dma_len > pool->max_message_size) {
+ ret = -EMSGSIZE;
+ goto out;
+ }
+
+ for (i = 0; i < mapping->m_sg.dma_npages; ++i)
+ ibmr->page_list->page_list[i] = dma_pages[i];
+
+ ret = rds_iw_rdma_build_fastreg(mapping);
+ if (ret)
+ goto out;
+
+ rds_iw_stats_inc(s_iw_rdma_mr_used);
+
+out:
+ kfree(dma_pages);
+
+ return ret;
+}
+
+/*
+ * "Free" a fastreg MR.
+ */
+static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool,
+ struct rds_iw_mr *ibmr)
+{
+ unsigned long flags;
+ int ret;
+
+ if (!ibmr->mapping.m_sg.dma_len)
+ return;
+
+ ret = rds_iw_rdma_fastreg_inv(ibmr);
+ if (ret)
+ return;
+
+ /* Try to post the LOCAL_INV WR to the queue. */
+ spin_lock_irqsave(&pool->list_lock, flags);
+
+ list_add_tail(&ibmr->mapping.m_list, &pool->dirty_list);
+ atomic_add(ibmr->mapping.m_sg.len, &pool->free_pinned);
+ atomic_inc(&pool->dirty_count);
+
+ spin_unlock_irqrestore(&pool->list_lock, flags);
+}
+
+static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
+ struct list_head *unmap_list,
+ struct list_head *kill_list,
+ int *unpinned)
+{
+ struct rds_iw_mapping *mapping, *next;
+ unsigned int ncleaned = 0;
+ LIST_HEAD(laundered);
+
+ /* Batched invalidation of fastreg MRs.
+ * Why do we do it this way, even though we could pipeline unmap
+ * and remap? The reason is the application semantics - when the
+ * application requests an invalidation of MRs, it expects all
+ * previously released R_Keys to become invalid.
+ *
+ * If we implement MR reuse naively, we risk memory corruption
+ * (this has actually been observed). So the default behavior
+ * requires that a MR goes through an explicit unmap operation before
+ * we can reuse it again.
+ *
+ * We could probably improve on this a little, by allowing immediate
+ * reuse of a MR on the same socket (eg you could add small
+ * cache of unused MRs to strct rds_socket - GET_MR could grab one
+ * of these without requiring an explicit invalidate).
+ */
+ while (!list_empty(unmap_list)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&pool->list_lock, flags);
+ list_for_each_entry_safe(mapping, next, unmap_list, m_list) {
+ *unpinned += mapping->m_sg.len;
+ list_move(&mapping->m_list, &laundered);
+ ncleaned++;
+ }
+ spin_unlock_irqrestore(&pool->list_lock, flags);
+ }
+
+ /* Move all laundered mappings back to the unmap list.
+ * We do not kill any WRs right now - it doesn't seem the
+ * fastreg API has a max_remap limit. */
+ list_splice_init(&laundered, unmap_list);
+
+ return ncleaned;
+}
+
+static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool,
+ struct rds_iw_mr *ibmr)
+{
+ if (ibmr->page_list)
+ ib_free_fast_reg_page_list(ibmr->page_list);
+ if (ibmr->mr)
+ ib_dereg_mr(ibmr->mr);
+}