diff options
Diffstat (limited to 'net/rds/ib_rdma.c')
| -rw-r--r-- | net/rds/ib_rdma.c | 641 |
1 files changed, 641 insertions, 0 deletions
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c new file mode 100644 index 0000000..69a6289 --- /dev/null +++ b/net/rds/ib_rdma.c @@ -0,0 +1,641 @@ +/* + * 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 "ib.h" + + +/* + * This is stored as mr->r_trans_private. + */ +struct rds_ib_mr { + struct rds_ib_device *device; + struct rds_ib_mr_pool *pool; + struct ib_fmr *fmr; + struct list_head list; + unsigned int remap_count; + + struct scatterlist *sg; + unsigned int sg_len; + u64 *dma; + int sg_dma_len; +}; + +/* + * Our own little FMR pool + */ +struct rds_ib_mr_pool { + 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 drop_list; /* MRs that have reached their max_maps limit */ + struct list_head free_list; /* unused MRs */ + struct list_head clean_list; /* unused & unamapped MRs */ + atomic_t free_pinned; /* memory pinned by free MRs */ + unsigned long max_items; + unsigned long max_items_soft; + unsigned long max_free_pinned; + struct ib_fmr_attr fmr_attr; +}; + +static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all); +static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr); +static void rds_ib_mr_pool_flush_worker(struct work_struct *work); + +static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr) +{ + struct rds_ib_device *rds_ibdev; + struct rds_ib_ipaddr *i_ipaddr; + + list_for_each_entry(rds_ibdev, &rds_ib_devices, list) { + spin_lock_irq(&rds_ibdev->spinlock); + list_for_each_entry(i_ipaddr, &rds_ibdev->ipaddr_list, list) { + if (i_ipaddr->ipaddr == ipaddr) { + spin_unlock_irq(&rds_ibdev->spinlock); + return rds_ibdev; + } + } + spin_unlock_irq(&rds_ibdev->spinlock); + } + + return NULL; +} + +static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) +{ + struct rds_ib_ipaddr *i_ipaddr; + + i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL); + if (!i_ipaddr) + return -ENOMEM; + + i_ipaddr->ipaddr = ipaddr; + + spin_lock_irq(&rds_ibdev->spinlock); + list_add_tail(&i_ipaddr->list, &rds_ibdev->ipaddr_list); + spin_unlock_irq(&rds_ibdev->spinlock); + + return 0; +} + +static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) +{ + struct rds_ib_ipaddr *i_ipaddr, *next; + + spin_lock_irq(&rds_ibdev->spinlock); + list_for_each_entry_safe(i_ipaddr, next, &rds_ibdev->ipaddr_list, list) { + if (i_ipaddr->ipaddr == ipaddr) { + list_del(&i_ipaddr->list); + kfree(i_ipaddr); + break; + } + } + spin_unlock_irq(&rds_ibdev->spinlock); +} + +int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) +{ + struct rds_ib_device *rds_ibdev_old; + + rds_ibdev_old = rds_ib_get_device(ipaddr); + if (rds_ibdev_old) + rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr); + + return rds_ib_add_ipaddr(rds_ibdev, ipaddr); +} + +int rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn) +{ + struct rds_ib_connection *ic = conn->c_transport_data; + + /* conn was previously on the nodev_conns_list */ + spin_lock_irq(&ib_nodev_conns_lock); + BUG_ON(list_empty(&ib_nodev_conns)); + BUG_ON(list_empty(&ic->ib_node)); + list_del(&ic->ib_node); + spin_unlock_irq(&ib_nodev_conns_lock); + + spin_lock_irq(&rds_ibdev->spinlock); + list_add_tail(&ic->ib_node, &rds_ibdev->conn_list); + spin_unlock_irq(&rds_ibdev->spinlock); + + ic->rds_ibdev = rds_ibdev; + + return 0; +} + +void rds_ib_remove_nodev_conns(void) +{ + struct rds_ib_connection *ic, *_ic; + LIST_HEAD(tmp_list); + + /* avoid calling conn_destroy with irqs off */ + spin_lock_irq(&ib_nodev_conns_lock); + list_splice(&ib_nodev_conns, &tmp_list); + INIT_LIST_HEAD(&ib_nodev_conns); + spin_unlock_irq(&ib_nodev_conns_lock); + + list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) { + if (ic->conn->c_passive) + rds_conn_destroy(ic->conn->c_passive); + rds_conn_destroy(ic->conn); + } +} + +void rds_ib_remove_conns(struct rds_ib_device *rds_ibdev) +{ + struct rds_ib_connection *ic, *_ic; + LIST_HEAD(tmp_list); + + /* avoid calling conn_destroy with irqs off */ + spin_lock_irq(&rds_ibdev->spinlock); + list_splice(&rds_ibdev->conn_list, &tmp_list); + INIT_LIST_HEAD(&rds_ibdev->conn_list); + spin_unlock_irq(&rds_ibdev->spinlock); + + list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) { + if (ic->conn->c_passive) + rds_conn_destroy(ic->conn->c_passive); + rds_conn_destroy(ic->conn); + } +} + +struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev) +{ + struct rds_ib_mr_pool *pool; + + pool = kzalloc(sizeof(*pool), GFP_KERNEL); + if (!pool) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&pool->free_list); + INIT_LIST_HEAD(&pool->drop_list); + INIT_LIST_HEAD(&pool->clean_list); + mutex_init(&pool->flush_lock); + spin_lock_init(&pool->list_lock); + INIT_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker); + + pool->fmr_attr.max_pages = fmr_message_size; + pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps; + pool->fmr_attr.page_shift = rds_ibdev->fmr_page_shift; + pool->max_free_pinned = rds_ibdev->max_fmrs * fmr_message_size / 4; + + /* 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 = rds_ibdev->max_fmrs * 3 / 4; + pool->max_items = rds_ibdev->max_fmrs; + + return pool; +} + +void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo) +{ + struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; + + iinfo->rdma_mr_max = pool->max_items; + iinfo->rdma_mr_size = pool->fmr_attr.max_pages; +} + +void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool) +{ + flush_workqueue(rds_wq); + rds_ib_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_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool) +{ + struct rds_ib_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_ib_mr, list); + list_del_init(&ibmr->list); + } + spin_unlock_irqrestore(&pool->list_lock, flags); + + return ibmr; +} + +static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev) +{ + struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; + struct rds_ib_mr *ibmr = NULL; + int err = 0, iter = 0; + + while (1) { + ibmr = rds_ib_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_ib_stats_inc(s_ib_rdma_mr_pool_depleted); + return ERR_PTR(-EAGAIN); + } + + /* We do have some empty MRs. Flush them out. */ + rds_ib_stats_inc(s_ib_rdma_mr_pool_wait); + rds_ib_flush_mr_pool(pool, 0); + } + + ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL); + if (!ibmr) { + err = -ENOMEM; + goto out_no_cigar; + } + + ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd, + (IB_ACCESS_LOCAL_WRITE | + IB_ACCESS_REMOTE_READ | + IB_ACCESS_REMOTE_WRITE), + &pool->fmr_attr); + if (IS_ERR(ibmr->fmr)) { + err = PTR_ERR(ibmr->fmr); + ibmr->fmr = NULL; + printk(KERN_WARNING "RDS/IB: ib_alloc_fmr failed (err=%d)\n", err); + goto out_no_cigar; + } + + rds_ib_stats_inc(s_ib_rdma_mr_alloc); + return ibmr; + +out_no_cigar: + if (ibmr) { + if (ibmr->fmr) + ib_dealloc_fmr(ibmr->fmr); + 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 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)) { + printk(KERN_WARNING "RDS/IB: dma_map_sg failed!\n"); + return -EBUSY; + } + + len = 0; + page_cnt = 0; + + for (i = 0; i < sg_dma_len; ++i) { + unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]); + u64 dma_addr = ib_sg_dma_address(dev, &scat[i]); + + if (dma_addr & ~rds_ibdev->fmr_page_mask) { + if (i > 0) + return -EINVAL; + else + ++page_cnt; + } + if ((dma_addr + dma_len) & ~rds_ibdev->fmr_page_mask) { + if (i < sg_dma_len - 1) + return -EINVAL; + else + ++page_cnt; + } + + len += dma_len; + } + + page_cnt += len >> rds_ibdev->fmr_page_shift; + if (page_cnt > fmr_message_size) + return -EINVAL; + + dma_pages = kmalloc(sizeof(u64) * page_cnt, GFP_ATOMIC); + if (!dma_pages) + return -ENOMEM; + + page_cnt = 0; + for (i = 0; i < sg_dma_len; ++i) { + unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]); + u64 dma_addr = ib_sg_dma_address(dev, &scat[i]); + + for (j = 0; j < dma_len; j += rds_ibdev->fmr_page_size) + dma_pages[page_cnt++] = + (dma_addr & rds_ibdev->fmr_page_mask) + j; + } + + ret = ib_map_phys_fmr(ibmr->fmr, + dma_pages, page_cnt, io_addr); + if (ret) + 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++; + + rds_ib_stats_inc(s_ib_rdma_mr_used); + ret = 0; + +out: + kfree(dma_pages); + + return ret; +} + +void rds_ib_sync_mr(void *trans_private, int direction) +{ + struct rds_ib_mr *ibmr = trans_private; + struct rds_ib_device *rds_ibdev = ibmr->device; + + switch (direction) { + case DMA_FROM_DEVICE: + ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg, + ibmr->sg_dma_len, DMA_BIDIRECTIONAL); + break; + case DMA_TO_DEVICE: + ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg, + ibmr->sg_dma_len, DMA_BIDIRECTIONAL); + break; + } +} + +static void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr) +{ + struct rds_ib_device *rds_ibdev = ibmr->device; + + if (ibmr->sg_dma_len) { + ib_dma_unmap_sg(rds_ibdev->dev, + ibmr->sg, ibmr->sg_len, + DMA_BIDIRECTIONAL); + ibmr->sg_dma_len = 0; + } + + /* Release the s/g list */ + if (ibmr->sg_len) { + unsigned int i; + + for (i = 0; i < ibmr->sg_len; ++i) { + struct page *page = sg_page(&ibmr->sg[i]); + + /* FIXME we need a way to tell a r/w MR + * from a r/o MR */ + set_page_dirty(page); + put_page(page); + } + kfree(ibmr->sg); + + ibmr->sg = NULL; + ibmr->sg_len = 0; + } +} + +static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr) +{ + unsigned int pinned = ibmr->sg_len; + + __rds_ib_teardown_mr(ibmr); + if (pinned) { + struct rds_ib_device *rds_ibdev = ibmr->device; + struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; + + atomic_sub(pinned, &pool->free_pinned); + } +} + +static inline unsigned int rds_ib_flush_goal(struct rds_ib_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_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all) +{ + struct rds_ib_mr *ibmr, *next; + LIST_HEAD(unmap_list); + LIST_HEAD(fmr_list); + unsigned long unpinned = 0; + unsigned long flags; + unsigned int nfreed = 0, ncleaned = 0, free_goal; + int ret = 0; + + rds_ib_stats_inc(s_ib_rdma_mr_pool_flush); + + mutex_lock(&pool->flush_lock); + + spin_lock_irqsave(&pool->list_lock, flags); + /* Get the list of all MRs to be dropped. Ordering matters - + * we want to put drop_list ahead of free_list. */ + list_splice_init(&pool->free_list, &unmap_list); + list_splice_init(&pool->drop_list, &unmap_list); + if (free_all) + list_splice_init(&pool->clean_list, &unmap_list); + spin_unlock_irqrestore(&pool->list_lock, flags); + + free_goal = rds_ib_flush_goal(pool, free_all); + + if (list_empty(&unmap_list)) + goto out; + + /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */ + list_for_each_entry(ibmr, &unmap_list, list) + list_add(&ibmr->fmr->list, &fmr_list); + ret = ib_unmap_fmr(&fmr_list); + if (ret) + printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret); + + /* Now we can destroy the DMA mapping and unpin any pages */ + list_for_each_entry_safe(ibmr, next, &unmap_list, list) { + unpinned += ibmr->sg_len; + __rds_ib_teardown_mr(ibmr); + if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) { + rds_ib_stats_inc(s_ib_rdma_mr_free); + list_del(&ibmr->list); + ib_dealloc_fmr(ibmr->fmr); + kfree(ibmr); + nfreed++; + } + ncleaned++; + } + + 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); + +out: + mutex_unlock(&pool->flush_lock); + return ret; +} + +static void rds_ib_mr_pool_flush_worker(struct work_struct *work) +{ + struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker); + + rds_ib_flush_mr_pool(pool, 0); +} + +void rds_ib_free_mr(void *trans_private, int invalidate) +{ + struct rds_ib_mr *ibmr = trans_private; + struct rds_ib_device *rds_ibdev = ibmr->device; + struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; + unsigned long flags; + + rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len); + + /* Return it to the pool's free list */ + spin_lock_irqsave(&pool->list_lock, flags); + if (ibmr->remap_count >= pool->fmr_attr.max_maps) + list_add(&ibmr->list, &pool->drop_list); + else + list_add(&ibmr->list, &pool->free_list); + + atomic_add(ibmr->sg_len, &pool->free_pinned); + atomic_inc(&pool->dirty_count); + spin_unlock_irqrestore(&pool->list_lock, flags); + + /* 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_ib_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_ib_flush_mrs(void) +{ + struct rds_ib_device *rds_ibdev; + + list_for_each_entry(rds_ibdev, &rds_ib_devices, list) { + struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool; + + if (pool) + rds_ib_flush_mr_pool(pool, 0); + } +} + +void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, + struct rds_sock *rs, u32 *key_ret) +{ + struct rds_ib_device *rds_ibdev; + struct rds_ib_mr *ibmr = NULL; + int ret; + + rds_ibdev = rds_ib_get_device(rs->rs_bound_addr); + if (!rds_ibdev) { + ret = -ENODEV; + goto out; + } + + if (!rds_ibdev->mr_pool) { + ret = -ENODEV; + goto out; + } + + ibmr = rds_ib_alloc_fmr(rds_ibdev); + if (IS_ERR(ibmr)) + return ibmr; + + ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents); + if (ret == 0) + *key_ret = ibmr->fmr->rkey; + else + printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret); + + ibmr->device = rds_ibdev; + + out: + if (ret) { + if (ibmr) + rds_ib_free_mr(ibmr, 0); + ibmr = ERR_PTR(ret); + } + return ibmr; +} |