282 lines
7.4 KiB
C
282 lines
7.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
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/*
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* Copyright(c) 2020 Cornelis Networks, Inc.
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* Copyright(c) 2016 - 2017 Intel Corporation.
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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 <linux/sched/mm.h>
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#include "mmu_rb.h"
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#include "trace.h"
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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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const struct mmu_notifier_range *);
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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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.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,
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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 *h;
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int ret;
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h = kzalloc(sizeof(*h), GFP_KERNEL);
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if (!h)
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return -ENOMEM;
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h->root = RB_ROOT_CACHED;
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h->ops = ops;
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h->ops_arg = ops_arg;
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INIT_HLIST_NODE(&h->mn.hlist);
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spin_lock_init(&h->lock);
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h->mn.ops = &mn_opts;
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INIT_WORK(&h->del_work, handle_remove);
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INIT_LIST_HEAD(&h->del_list);
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INIT_LIST_HEAD(&h->lru_list);
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h->wq = wq;
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ret = mmu_notifier_register(&h->mn, current->mm);
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if (ret) {
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kfree(h);
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return ret;
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}
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*handler = h;
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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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/* Prevent freeing of mm until we are completely finished. */
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mmgrab(handler->mn.mm);
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/* Unregister first so we don't get any more notifications. */
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mmu_notifier_unregister(&handler->mn, handler->mn.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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/* Now the mm may be freed. */
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mmdrop(handler->mn.mm);
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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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if (current->mm != handler->mn.mm)
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return -EPERM;
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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 = -EEXIST;
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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_tail(&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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mnode->handler = handler;
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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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struct mmu_rb_node *hfi1_mmu_rb_get_first(struct mmu_rb_handler *handler,
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unsigned long addr, unsigned long len)
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{
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struct mmu_rb_node *node;
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trace_hfi1_mmu_rb_search(addr, len);
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node = __mmu_int_rb_iter_first(&handler->root, addr, (addr + len) - 1);
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if (node)
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list_move_tail(&node->list, &handler->lru_list);
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return node;
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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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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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if (current->mm != handler->mn.mm)
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return;
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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(rbnode, ptr, &handler->lru_list, 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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list_for_each_entry_safe(rbnode, ptr, &del_list, list) {
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handler->ops->remove(handler->ops_arg, rbnode);
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}
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}
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static int mmu_notifier_range_start(struct mmu_notifier *mn,
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const struct mmu_notifier_range *range)
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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, range->start, range->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, range->start,
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range->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_lock 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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