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