/* * 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/rculist.h> #include <linux/llist.h> #include "rds_single_path.h" #include "ib_mr.h" struct workqueue_struct *rds_ib_mr_wq; static DEFINE_PER_CPU(unsigned long, clean_list_grace); #define CLEAN_LIST_BUSY_BIT 0 static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr) { struct rds_ib_device *rds_ibdev; struct rds_ib_ipaddr *i_ipaddr; rcu_read_lock(); list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) { list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) { if (i_ipaddr->ipaddr == ipaddr) { atomic_inc(&rds_ibdev->refcount); rcu_read_unlock(); return rds_ibdev; } } } rcu_read_unlock(); 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_rcu(&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; struct rds_ib_ipaddr *to_free = NULL; spin_lock_irq(&rds_ibdev->spinlock); list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) { if (i_ipaddr->ipaddr == ipaddr) { list_del_rcu(&i_ipaddr->list); to_free = i_ipaddr; break; } } spin_unlock_irq(&rds_ibdev->spinlock); if (to_free) kfree_rcu(to_free, rcu); } 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) return rds_ib_add_ipaddr(rds_ibdev, ipaddr); if (rds_ibdev_old != rds_ibdev) { rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr); rds_ib_dev_put(rds_ibdev_old); return rds_ib_add_ipaddr(rds_ibdev, ipaddr); } rds_ib_dev_put(rds_ibdev_old); return 0; } void 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_lock(&rds_ibdev->spinlock); list_add_tail(&ic->ib_node, &rds_ibdev->conn_list); spin_unlock(&rds_ibdev->spinlock); spin_unlock_irq(&ib_nodev_conns_lock); ic->rds_ibdev = rds_ibdev; atomic_inc(&rds_ibdev->refcount); } void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn) { struct rds_ib_connection *ic = conn->c_transport_data; /* place conn on nodev_conns_list */ spin_lock(&ib_nodev_conns_lock); spin_lock_irq(&rds_ibdev->spinlock); BUG_ON(list_empty(&ic->ib_node)); list_del(&ic->ib_node); spin_unlock_irq(&rds_ibdev->spinlock); list_add_tail(&ic->ib_node, &ib_nodev_conns); spin_unlock(&ib_nodev_conns_lock); ic->rds_ibdev = NULL; rds_ib_dev_put(rds_ibdev); } void rds_ib_destroy_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); spin_unlock_irq(&ib_nodev_conns_lock); list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) rds_conn_destroy(ic->conn); } void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo) { 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; } struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *pool) { struct rds_ib_mr *ibmr = NULL; struct llist_node *ret; unsigned long *flag; preempt_disable(); flag = this_cpu_ptr(&clean_list_grace); set_bit(CLEAN_LIST_BUSY_BIT, flag); ret = llist_del_first(&pool->clean_list); if (ret) { ibmr = llist_entry(ret, struct rds_ib_mr, llnode); if (pool->pool_type == RDS_IB_MR_8K_POOL) rds_ib_stats_inc(s_ib_rdma_mr_8k_reused); else rds_ib_stats_inc(s_ib_rdma_mr_1m_reused); } clear_bit(CLEAN_LIST_BUSY_BIT, flag); preempt_enable(); return ibmr; } static inline void wait_clean_list_grace(void) { int cpu; unsigned long *flag; for_each_online_cpu(cpu) { flag = &per_cpu(clean_list_grace, cpu); while (test_bit(CLEAN_LIST_BUSY_BIT, flag)) cpu_relax(); } } 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; } } 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 */ WARN_ON(!page->mapping && irqs_disabled()); set_page_dirty(page); put_page(page); } kfree(ibmr->sg); ibmr->sg = NULL; ibmr->sg_len = 0; } } 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_mr_pool *pool = ibmr->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; } /* * given an llist of mrs, put them all into the list_head for more processing */ static unsigned int llist_append_to_list(struct llist_head *llist, struct list_head *list) { struct rds_ib_mr *ibmr; struct llist_node *node; struct llist_node *next; unsigned int count = 0; node = llist_del_all(llist); while (node) { next = node->next; ibmr = llist_entry(node, struct rds_ib_mr, llnode); list_add_tail(&ibmr->unmap_list, list); node = next; count++; } return count; } /* * this takes a list head of mrs and turns it into linked llist nodes * of clusters. Each cluster has linked llist nodes of * MR_CLUSTER_SIZE mrs that are ready for reuse. */ static void list_to_llist_nodes(struct rds_ib_mr_pool *pool, struct list_head *list, struct llist_node **nodes_head, struct llist_node **nodes_tail) { struct rds_ib_mr *ibmr; struct llist_node *cur = NULL; struct llist_node **next = nodes_head; list_for_each_entry(ibmr, list, unmap_list) { cur = &ibmr->llnode; *next = cur; next = &cur->next; } *next = NULL; *nodes_tail = cur; } /* * 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. */ int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all, struct rds_ib_mr **ibmr_ret) { struct rds_ib_mr *ibmr; struct llist_node *clean_nodes; struct llist_node *clean_tail; LIST_HEAD(unmap_list); unsigned long unpinned = 0; unsigned int nfreed = 0, dirty_to_clean = 0, free_goal; if (pool->pool_type == RDS_IB_MR_8K_POOL) rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_flush); else rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_flush); if (ibmr_ret) { DEFINE_WAIT(wait); while (!mutex_trylock(&pool->flush_lock)) { ibmr = rds_ib_reuse_mr(pool); if (ibmr) { *ibmr_ret = ibmr; finish_wait(&pool->flush_wait, &wait); goto out_nolock; } prepare_to_wait(&pool->flush_wait, &wait, TASK_UNINTERRUPTIBLE); if (llist_empty(&pool->clean_list)) schedule(); ibmr = rds_ib_reuse_mr(pool); if (ibmr) { *ibmr_ret = ibmr; finish_wait(&pool->flush_wait, &wait); goto out_nolock; } } finish_wait(&pool->flush_wait, &wait); } else mutex_lock(&pool->flush_lock); if (ibmr_ret) { ibmr = rds_ib_reuse_mr(pool); if (ibmr) { *ibmr_ret = ibmr; goto out; } } /* Get the list of all MRs to be dropped. Ordering matters - * we want to put drop_list ahead of free_list. */ dirty_to_clean = llist_append_to_list(&pool->drop_list, &unmap_list); dirty_to_clean += llist_append_to_list(&pool->free_list, &unmap_list); if (free_all) llist_append_to_list(&pool->clean_list, &unmap_list); free_goal = rds_ib_flush_goal(pool, free_all); 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); if (!list_empty(&unmap_list)) { /* we have to make sure that none of the things we're about * to put on the clean list would race with other cpus trying * to pull items off. The llist would explode if we managed to * remove something from the clean list and then add it back again * while another CPU was spinning on that same item in llist_del_first. * * This is pretty unlikely, but just in case wait for an llist grace period * here before adding anything back into the clean list. */ wait_clean_list_grace(); list_to_llist_nodes(pool, &unmap_list, &clean_nodes, &clean_tail); if (ibmr_ret) *ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode); /* more than one entry in llist nodes */ if (clean_nodes->next) llist_add_batch(clean_nodes->next, clean_tail, &pool->clean_list); } atomic_sub(unpinned, &pool->free_pinned); atomic_sub(dirty_to_clean, &pool->dirty_count); atomic_sub(nfreed, &pool->item_count); out: mutex_unlock(&pool->flush_lock); if (waitqueue_active(&pool->flush_wait)) wake_up(&pool->flush_wait); out_nolock: return 0; } struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *pool) { struct rds_ib_mr *ibmr = NULL; int iter = 0; if (atomic_read(&pool->dirty_count) >= pool->max_items_soft / 10) queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10); while (1) { ibmr = rds_ib_reuse_mr(pool); if (ibmr) return ibmr; if (atomic_inc_return(&pool->item_count) <= pool->max_items) break; atomic_dec(&pool->item_count); if (++iter > 2) { if (pool->pool_type == RDS_IB_MR_8K_POOL) rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_depleted); else rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_depleted); return ERR_PTR(-EAGAIN); } /* We do have some empty MRs. Flush them out. */ if (pool->pool_type == RDS_IB_MR_8K_POOL) rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_wait); else rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_wait); rds_ib_flush_mr_pool(pool, 0, &ibmr); if (ibmr) return ibmr; } return ibmr; } 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.work); rds_ib_flush_mr_pool(pool, 0, NULL); } void rds_ib_free_mr(void *trans_private, int invalidate) { struct rds_ib_mr *ibmr = trans_private; struct rds_ib_mr_pool *pool = ibmr->pool; struct rds_ib_device *rds_ibdev = ibmr->device; rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len); /* 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); 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); if (invalidate) { if (likely(!in_interrupt())) { rds_ib_flush_mr_pool(pool, 0, NULL); } else { /* We get here if the user created a MR marked * as use_once and invalidate at the same time. */ queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10); } } rds_ib_dev_put(rds_ibdev); } void rds_ib_flush_mrs(void) { struct rds_ib_device *rds_ibdev; down_read(&rds_ib_devices_lock); list_for_each_entry(rds_ibdev, &rds_ib_devices, list) { if (rds_ibdev->mr_8k_pool) rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 0, NULL); if (rds_ibdev->mr_1m_pool) rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 0, NULL); } up_read(&rds_ib_devices_lock); } 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; struct rds_ib_connection *ic = rs->rs_conn->c_transport_data; int ret; rds_ibdev = rds_ib_get_device(rs->rs_bound_addr); if (!rds_ibdev) { ret = -ENODEV; goto out; } if (!rds_ibdev->mr_8k_pool || !rds_ibdev->mr_1m_pool) { ret = -ENODEV; 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); if (ibmr) rds_ibdev = NULL; out: if (!ibmr) pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret); if (rds_ibdev) rds_ib_dev_put(rds_ibdev); return ibmr; } void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool) { cancel_delayed_work_sync(&pool->flush_worker); rds_ib_flush_mr_pool(pool, 1, NULL); WARN_ON(atomic_read(&pool->item_count)); WARN_ON(atomic_read(&pool->free_pinned)); kfree(pool); } struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev, int pool_type) { struct rds_ib_mr_pool *pool; pool = kzalloc(sizeof(*pool), GFP_KERNEL); if (!pool) return ERR_PTR(-ENOMEM); pool->pool_type = pool_type; init_llist_head(&pool->free_list); init_llist_head(&pool->drop_list); init_llist_head(&pool->clean_list); mutex_init(&pool->flush_lock); init_waitqueue_head(&pool->flush_wait); INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker); 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_items = RDS_MR_1M_POOL_SIZE; } else { /* pool_type == RDS_IB_MR_8K_POOL */ pool->fmr_attr.max_pages = RDS_MR_8K_MSG_SIZE + 1; pool->max_items = RDS_MR_8K_POOL_SIZE; } 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_items_soft = rds_ibdev->max_mrs * 3 / 4; pool->use_fastreg = rds_ibdev->use_fastreg; return pool; } int rds_ib_mr_init(void) { rds_ib_mr_wq = alloc_workqueue("rds_mr_flushd", WQ_MEM_RECLAIM, 0); if (!rds_ib_mr_wq) return -ENOMEM; return 0; } /* By the time this is called all the IB devices should have been torn down and * had their pools freed. As each pool is freed its work struct is waited on, * so the pool flushing work queue should be idle by the time we get here. */ void rds_ib_mr_exit(void) { destroy_workqueue(rds_ib_mr_wq); }