diff options
Diffstat (limited to 'drivers/infiniband/hw/hfi1/mmu_rb.c')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/mmu_rb.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c new file mode 100644 index 000000000..e1c7996c0 --- /dev/null +++ b/drivers/infiniband/hw/hfi1/mmu_rb.c @@ -0,0 +1,357 @@ +/* + * Copyright(c) 2016 - 2017 Intel Corporation. + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * BSD LICENSE + * + * 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. + * - Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ +#include <linux/list.h> +#include <linux/rculist.h> +#include <linux/mmu_notifier.h> +#include <linux/interval_tree_generic.h> + +#include "mmu_rb.h" +#include "trace.h" + +struct mmu_rb_handler { + struct mmu_notifier mn; + struct rb_root_cached root; + void *ops_arg; + spinlock_t lock; /* protect the RB tree */ + struct mmu_rb_ops *ops; + struct mm_struct *mm; + struct list_head lru_list; + struct work_struct del_work; + struct list_head del_list; + struct workqueue_struct *wq; +}; + +static unsigned long mmu_node_start(struct mmu_rb_node *); +static unsigned long mmu_node_last(struct mmu_rb_node *); +static int mmu_notifier_range_start(struct mmu_notifier *, + struct mm_struct *, + unsigned long, unsigned long, bool); +static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *, + unsigned long, unsigned long); +static void do_remove(struct mmu_rb_handler *handler, + struct list_head *del_list); +static void handle_remove(struct work_struct *work); + +static const struct mmu_notifier_ops mn_opts = { + .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, + .invalidate_range_start = mmu_notifier_range_start, +}; + +INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last, + mmu_node_start, mmu_node_last, static, __mmu_int_rb); + +static unsigned long mmu_node_start(struct mmu_rb_node *node) +{ + return node->addr & PAGE_MASK; +} + +static unsigned long mmu_node_last(struct mmu_rb_node *node) +{ + return PAGE_ALIGN(node->addr + node->len) - 1; +} + +int hfi1_mmu_rb_register(void *ops_arg, struct mm_struct *mm, + struct mmu_rb_ops *ops, + struct workqueue_struct *wq, + struct mmu_rb_handler **handler) +{ + struct mmu_rb_handler *handlr; + int ret; + + handlr = kmalloc(sizeof(*handlr), GFP_KERNEL); + if (!handlr) + return -ENOMEM; + + handlr->root = RB_ROOT_CACHED; + handlr->ops = ops; + handlr->ops_arg = ops_arg; + INIT_HLIST_NODE(&handlr->mn.hlist); + spin_lock_init(&handlr->lock); + handlr->mn.ops = &mn_opts; + handlr->mm = mm; + INIT_WORK(&handlr->del_work, handle_remove); + INIT_LIST_HEAD(&handlr->del_list); + INIT_LIST_HEAD(&handlr->lru_list); + handlr->wq = wq; + + ret = mmu_notifier_register(&handlr->mn, handlr->mm); + if (ret) { + kfree(handlr); + return ret; + } + + *handler = handlr; + return 0; +} + +void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler) +{ + struct mmu_rb_node *rbnode; + struct rb_node *node; + unsigned long flags; + struct list_head del_list; + + /* Unregister first so we don't get any more notifications. */ + mmu_notifier_unregister(&handler->mn, handler->mm); + + /* + * Make sure the wq delete handler is finished running. It will not + * be triggered once the mmu notifiers are unregistered above. + */ + flush_work(&handler->del_work); + + INIT_LIST_HEAD(&del_list); + + spin_lock_irqsave(&handler->lock, flags); + while ((node = rb_first_cached(&handler->root))) { + rbnode = rb_entry(node, struct mmu_rb_node, node); + rb_erase_cached(node, &handler->root); + /* move from LRU list to delete list */ + list_move(&rbnode->list, &del_list); + } + spin_unlock_irqrestore(&handler->lock, flags); + + do_remove(handler, &del_list); + + kfree(handler); +} + +int hfi1_mmu_rb_insert(struct mmu_rb_handler *handler, + struct mmu_rb_node *mnode) +{ + struct mmu_rb_node *node; + unsigned long flags; + int ret = 0; + + trace_hfi1_mmu_rb_insert(mnode->addr, mnode->len); + spin_lock_irqsave(&handler->lock, flags); + node = __mmu_rb_search(handler, mnode->addr, mnode->len); + if (node) { + ret = -EINVAL; + goto unlock; + } + __mmu_int_rb_insert(mnode, &handler->root); + list_add(&mnode->list, &handler->lru_list); + + ret = handler->ops->insert(handler->ops_arg, mnode); + if (ret) { + __mmu_int_rb_remove(mnode, &handler->root); + list_del(&mnode->list); /* remove from LRU list */ + } +unlock: + spin_unlock_irqrestore(&handler->lock, flags); + return ret; +} + +/* Caller must hold handler lock */ +static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler, + unsigned long addr, + unsigned long len) +{ + struct mmu_rb_node *node = NULL; + + trace_hfi1_mmu_rb_search(addr, len); + if (!handler->ops->filter) { + node = __mmu_int_rb_iter_first(&handler->root, addr, + (addr + len) - 1); + } else { + for (node = __mmu_int_rb_iter_first(&handler->root, addr, + (addr + len) - 1); + node; + node = __mmu_int_rb_iter_next(node, addr, + (addr + len) - 1)) { + if (handler->ops->filter(node, addr, len)) + return node; + } + } + return node; +} + +bool hfi1_mmu_rb_remove_unless_exact(struct mmu_rb_handler *handler, + unsigned long addr, unsigned long len, + struct mmu_rb_node **rb_node) +{ + struct mmu_rb_node *node; + unsigned long flags; + bool ret = false; + + spin_lock_irqsave(&handler->lock, flags); + node = __mmu_rb_search(handler, addr, len); + if (node) { + if (node->addr == addr && node->len == len) + goto unlock; + __mmu_int_rb_remove(node, &handler->root); + list_del(&node->list); /* remove from LRU list */ + ret = true; + } +unlock: + spin_unlock_irqrestore(&handler->lock, flags); + *rb_node = node; + return ret; +} + +void hfi1_mmu_rb_evict(struct mmu_rb_handler *handler, void *evict_arg) +{ + struct mmu_rb_node *rbnode, *ptr; + struct list_head del_list; + unsigned long flags; + bool stop = false; + + INIT_LIST_HEAD(&del_list); + + spin_lock_irqsave(&handler->lock, flags); + list_for_each_entry_safe_reverse(rbnode, ptr, &handler->lru_list, + list) { + if (handler->ops->evict(handler->ops_arg, rbnode, evict_arg, + &stop)) { + __mmu_int_rb_remove(rbnode, &handler->root); + /* move from LRU list to delete list */ + list_move(&rbnode->list, &del_list); + } + if (stop) + break; + } + spin_unlock_irqrestore(&handler->lock, flags); + + while (!list_empty(&del_list)) { + rbnode = list_first_entry(&del_list, struct mmu_rb_node, list); + list_del(&rbnode->list); + handler->ops->remove(handler->ops_arg, rbnode); + } +} + +/* + * It is up to the caller to ensure that this function does not race with the + * mmu invalidate notifier which may be calling the users remove callback on + * 'node'. + */ +void hfi1_mmu_rb_remove(struct mmu_rb_handler *handler, + struct mmu_rb_node *node) +{ + unsigned long flags; + + /* Validity of handler and node pointers has been checked by caller. */ + trace_hfi1_mmu_rb_remove(node->addr, node->len); + spin_lock_irqsave(&handler->lock, flags); + __mmu_int_rb_remove(node, &handler->root); + list_del(&node->list); /* remove from LRU list */ + spin_unlock_irqrestore(&handler->lock, flags); + + handler->ops->remove(handler->ops_arg, node); +} + +static int mmu_notifier_range_start(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, + unsigned long end, + bool blockable) +{ + struct mmu_rb_handler *handler = + container_of(mn, struct mmu_rb_handler, mn); + struct rb_root_cached *root = &handler->root; + struct mmu_rb_node *node, *ptr = NULL; + unsigned long flags; + bool added = false; + + spin_lock_irqsave(&handler->lock, flags); + for (node = __mmu_int_rb_iter_first(root, start, end - 1); + node; node = ptr) { + /* Guard against node removal. */ + ptr = __mmu_int_rb_iter_next(node, start, end - 1); + trace_hfi1_mmu_mem_invalidate(node->addr, node->len); + if (handler->ops->invalidate(handler->ops_arg, node)) { + __mmu_int_rb_remove(node, root); + /* move from LRU list to delete list */ + list_move(&node->list, &handler->del_list); + added = true; + } + } + spin_unlock_irqrestore(&handler->lock, flags); + + if (added) + queue_work(handler->wq, &handler->del_work); + + return 0; +} + +/* + * Call the remove function for the given handler and the list. This + * is expected to be called with a delete list extracted from handler. + * The caller should not be holding the handler lock. + */ +static void do_remove(struct mmu_rb_handler *handler, + struct list_head *del_list) +{ + struct mmu_rb_node *node; + + while (!list_empty(del_list)) { + node = list_first_entry(del_list, struct mmu_rb_node, list); + list_del(&node->list); + handler->ops->remove(handler->ops_arg, node); + } +} + +/* + * Work queue function to remove all nodes that have been queued up to + * be removed. The key feature is that mm->mmap_sem is not being held + * and the remove callback can sleep while taking it, if needed. + */ +static void handle_remove(struct work_struct *work) +{ + struct mmu_rb_handler *handler = container_of(work, + struct mmu_rb_handler, + del_work); + struct list_head del_list; + unsigned long flags; + + /* remove anything that is queued to get removed */ + spin_lock_irqsave(&handler->lock, flags); + list_replace_init(&handler->del_list, &del_list); + spin_unlock_irqrestore(&handler->lock, flags); + + do_remove(handler, &del_list); +} |