diff options
Diffstat (limited to 'net/rds/iw_rdma.c')
| -rw-r--r-- | net/rds/iw_rdma.c | 888 |
1 files changed, 888 insertions, 0 deletions
diff --git a/net/rds/iw_rdma.c b/net/rds/iw_rdma.c new file mode 100644 index 000000000000..dcdb37da80f2 --- /dev/null +++ b/net/rds/iw_rdma.c @@ -0,0 +1,888 @@ +/* + * 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 "rds.h" +#include "rdma.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); +static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr); + +static int rds_iw_get_device(struct rds_sock *rs, 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, + rs->rs_bound_addr, + rs->rs_bound_port, + rs->rs_conn_addr, + rs->rs_conn_port); +#ifdef WORKING_TUPLE_DETECTION + if (src_addr->sin_addr.s_addr == rs->rs_bound_addr && + src_addr->sin_port == rs->rs_bound_port && + dst_addr->sin_addr.s_addr == rs->rs_conn_addr && + dst_addr->sin_port == rs->rs_conn_port) { +#else + /* FIXME - needs to compare the local and remote + * ipaddr/port tuple, but the ipaddr is the only + * available infomation 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 == rs->rs_bound_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; +} + +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 rds_sock rs; + 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; + + rs.rs_bound_addr = src_addr->sin_addr.s_addr; + rs.rs_bound_port = src_addr->sin_port; + rs.rs_conn_addr = dst_addr->sin_addr.s_addr; + rs.rs_conn_port = dst_addr->sin_port; + + rc = rds_iw_get_device(&rs, &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_irq(&rds_iwdev->spinlock); + list_add_tail(&ic->iw_node, &rds_iwdev->conn_list); + spin_unlock_irq(&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) { + if (ic->conn->c_passive) + rds_conn_destroy(ic->conn->c_passive); + 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, + unsigned int dma_page_shift) +{ + struct ib_device *dev = rds_iwdev->dev; + u64 *dma_pages = NULL; + u64 dma_mask; + unsigned int dma_page_size; + int i, j, ret; + + dma_page_size = 1 << dma_page_shift; + dma_mask = dma_page_size - 1; + + 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 & dma_mask) { + if (i > 0) + goto out_unmap; + dma_addr &= ~dma_mask; + } + if (end_addr & dma_mask) { + if (i < sg->dma_len - 1) + goto out_unmap; + end_addr = (end_addr + dma_mask) & ~dma_mask; + } + + sg->dma_npages += (end_addr - dma_addr) >> dma_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 &= ~dma_mask; + for (; dma_addr < end_addr; dma_addr += dma_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; + } +} + +static inline unsigned int rds_iw_flush_goal(struct rds_iw_mr_pool *pool, int free_all) +{ + unsigned int item_count; + + item_count = atomic_read(&pool->item_count); + if (free_all) + return item_count; + + return 0; +} + +/* + * 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, free_goal; + 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); + + free_goal = rds_iw_flush_goal(pool, free_all); + + /* 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); + /* 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(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; + int ret; + + ret = rds_iw_get_device(rs, &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 = ibmr->device->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_ratelimit()) + printk(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_ratelimit()) { + printk(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, + rds_iwdev->page_shift); + 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) +{ + 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) { + 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); +} |