2 * Copyright(c) 2016 Intel Corporation.
4 * This file is provided under a dual BSD/GPLv2 license. When using or
5 * redistributing this file, you may do so under either license.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of version 2 of the GNU General Public License as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
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47 #include <linux/list.h>
48 #include <linux/rculist.h>
49 #include <linux/mmu_notifier.h>
50 #include <linux/interval_tree_generic.h>
55 struct mmu_rb_handler {
56 struct list_head list;
57 struct mmu_notifier mn;
59 spinlock_t lock; /* protect the RB tree */
60 struct mmu_rb_ops *ops;
63 static LIST_HEAD(mmu_rb_handlers);
64 static DEFINE_SPINLOCK(mmu_rb_lock); /* protect mmu_rb_handlers list */
66 static unsigned long mmu_node_start(struct mmu_rb_node *);
67 static unsigned long mmu_node_last(struct mmu_rb_node *);
68 static struct mmu_rb_handler *find_mmu_handler(struct rb_root *);
69 static inline void mmu_notifier_page(struct mmu_notifier *, struct mm_struct *,
71 static inline void mmu_notifier_range_start(struct mmu_notifier *,
73 unsigned long, unsigned long);
74 static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
76 unsigned long, unsigned long);
77 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *,
78 unsigned long, unsigned long);
80 static struct mmu_notifier_ops mn_opts = {
81 .invalidate_page = mmu_notifier_page,
82 .invalidate_range_start = mmu_notifier_range_start,
85 INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last,
86 mmu_node_start, mmu_node_last, static, __mmu_int_rb);
88 static unsigned long mmu_node_start(struct mmu_rb_node *node)
90 return node->addr & PAGE_MASK;
93 static unsigned long mmu_node_last(struct mmu_rb_node *node)
95 return PAGE_ALIGN(node->addr + node->len) - 1;
98 int hfi1_mmu_rb_register(struct rb_root *root, struct mmu_rb_ops *ops)
100 struct mmu_rb_handler *handlr;
102 if (!ops->invalidate)
105 handlr = kmalloc(sizeof(*handlr), GFP_KERNEL);
111 INIT_HLIST_NODE(&handlr->mn.hlist);
112 spin_lock_init(&handlr->lock);
113 handlr->mn.ops = &mn_opts;
114 spin_lock(&mmu_rb_lock);
115 list_add_tail_rcu(&handlr->list, &mmu_rb_handlers);
116 spin_unlock(&mmu_rb_lock);
118 return mmu_notifier_register(&handlr->mn, current->mm);
121 void hfi1_mmu_rb_unregister(struct rb_root *root)
123 struct mmu_rb_handler *handler = find_mmu_handler(root);
129 /* Unregister first so we don't get any more notifications. */
131 mmu_notifier_unregister(&handler->mn, current->mm);
133 spin_lock(&mmu_rb_lock);
134 list_del_rcu(&handler->list);
135 spin_unlock(&mmu_rb_lock);
138 spin_lock_irqsave(&handler->lock, flags);
139 if (!RB_EMPTY_ROOT(root)) {
140 struct rb_node *node;
141 struct mmu_rb_node *rbnode;
143 while ((node = rb_first(root))) {
144 rbnode = rb_entry(node, struct mmu_rb_node, node);
145 rb_erase(node, root);
146 if (handler->ops->remove)
147 handler->ops->remove(root, rbnode, NULL);
150 spin_unlock_irqrestore(&handler->lock, flags);
155 int hfi1_mmu_rb_insert(struct rb_root *root, struct mmu_rb_node *mnode)
157 struct mmu_rb_handler *handler = find_mmu_handler(root);
158 struct mmu_rb_node *node;
165 spin_lock_irqsave(&handler->lock, flags);
166 hfi1_cdbg(MMU, "Inserting node addr 0x%llx, len %u", mnode->addr,
168 node = __mmu_rb_search(handler, mnode->addr, mnode->len);
173 __mmu_int_rb_insert(mnode, root);
175 if (handler->ops->insert) {
176 ret = handler->ops->insert(root, mnode);
178 __mmu_int_rb_remove(mnode, root);
181 spin_unlock_irqrestore(&handler->lock, flags);
185 /* Caller must hold handler lock */
186 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler,
190 struct mmu_rb_node *node = NULL;
192 hfi1_cdbg(MMU, "Searching for addr 0x%llx, len %u", addr, len);
193 if (!handler->ops->filter) {
194 node = __mmu_int_rb_iter_first(handler->root, addr,
197 for (node = __mmu_int_rb_iter_first(handler->root, addr,
200 node = __mmu_int_rb_iter_next(node, addr,
202 if (handler->ops->filter(node, addr, len))
209 /* Caller must *not* hold handler lock. */
210 static void __mmu_rb_remove(struct mmu_rb_handler *handler,
211 struct mmu_rb_node *node, struct mm_struct *mm)
215 /* Validity of handler and node pointers has been checked by caller. */
216 hfi1_cdbg(MMU, "Removing node addr 0x%llx, len %u", node->addr,
218 spin_lock_irqsave(&handler->lock, flags);
219 __mmu_int_rb_remove(node, handler->root);
220 spin_unlock_irqrestore(&handler->lock, flags);
222 if (handler->ops->remove)
223 handler->ops->remove(handler->root, node, mm);
226 struct mmu_rb_node *hfi1_mmu_rb_search(struct rb_root *root, unsigned long addr,
229 struct mmu_rb_handler *handler = find_mmu_handler(root);
230 struct mmu_rb_node *node;
234 return ERR_PTR(-EINVAL);
236 spin_lock_irqsave(&handler->lock, flags);
237 node = __mmu_rb_search(handler, addr, len);
238 spin_unlock_irqrestore(&handler->lock, flags);
243 struct mmu_rb_node *hfi1_mmu_rb_extract(struct rb_root *root,
244 unsigned long addr, unsigned long len)
246 struct mmu_rb_handler *handler = find_mmu_handler(root);
247 struct mmu_rb_node *node;
251 return ERR_PTR(-EINVAL);
253 spin_lock_irqsave(&handler->lock, flags);
254 node = __mmu_rb_search(handler, addr, len);
256 __mmu_int_rb_remove(node, handler->root);
257 spin_unlock_irqrestore(&handler->lock, flags);
262 void hfi1_mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node)
264 struct mmu_rb_handler *handler = find_mmu_handler(root);
266 if (!handler || !node)
269 __mmu_rb_remove(handler, node, NULL);
272 static struct mmu_rb_handler *find_mmu_handler(struct rb_root *root)
274 struct mmu_rb_handler *handler;
277 list_for_each_entry_rcu(handler, &mmu_rb_handlers, list) {
278 if (handler->root == root)
287 static inline void mmu_notifier_page(struct mmu_notifier *mn,
288 struct mm_struct *mm, unsigned long addr)
290 mmu_notifier_mem_invalidate(mn, mm, addr, addr + PAGE_SIZE);
293 static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
294 struct mm_struct *mm,
298 mmu_notifier_mem_invalidate(mn, mm, start, end);
301 static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
302 struct mm_struct *mm,
303 unsigned long start, unsigned long end)
305 struct mmu_rb_handler *handler =
306 container_of(mn, struct mmu_rb_handler, mn);
307 struct rb_root *root = handler->root;
308 struct mmu_rb_node *node, *ptr = NULL;
311 spin_lock_irqsave(&handler->lock, flags);
312 for (node = __mmu_int_rb_iter_first(root, start, end - 1);
314 /* Guard against node removal. */
315 ptr = __mmu_int_rb_iter_next(node, start, end - 1);
316 hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
317 node->addr, node->len);
318 if (handler->ops->invalidate(root, node)) {
319 __mmu_int_rb_remove(node, root);
320 if (handler->ops->remove)
321 handler->ops->remove(root, node, mm);
324 spin_unlock_irqrestore(&handler->lock, flags);