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/mmu_notifier.h>
49 #include <linux/interval_tree_generic.h>
54 struct mmu_rb_handler {
55 struct list_head list;
56 struct mmu_notifier mn;
58 spinlock_t lock; /* protect the RB tree */
59 struct mmu_rb_ops *ops;
62 static LIST_HEAD(mmu_rb_handlers);
63 static DEFINE_SPINLOCK(mmu_rb_lock); /* protect mmu_rb_handlers list */
65 static unsigned long mmu_node_start(struct mmu_rb_node *);
66 static unsigned long mmu_node_last(struct mmu_rb_node *);
67 static struct mmu_rb_handler *find_mmu_handler(struct rb_root *);
68 static inline void mmu_notifier_page(struct mmu_notifier *, struct mm_struct *,
70 static inline void mmu_notifier_range_start(struct mmu_notifier *,
72 unsigned long, unsigned long);
73 static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
75 unsigned long, unsigned long);
76 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *,
77 unsigned long, unsigned long);
79 static struct mmu_notifier_ops mn_opts = {
80 .invalidate_page = mmu_notifier_page,
81 .invalidate_range_start = mmu_notifier_range_start,
84 INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last,
85 mmu_node_start, mmu_node_last, static, __mmu_int_rb);
87 static unsigned long mmu_node_start(struct mmu_rb_node *node)
89 return node->addr & PAGE_MASK;
92 static unsigned long mmu_node_last(struct mmu_rb_node *node)
94 return PAGE_ALIGN((node->addr & PAGE_MASK) + node->len) - 1;
97 int hfi1_mmu_rb_register(struct rb_root *root, struct mmu_rb_ops *ops)
99 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_irqsave(&mmu_rb_lock, flags);
115 list_add_tail(&handlr->list, &mmu_rb_handlers);
116 spin_unlock_irqrestore(&mmu_rb_lock, flags);
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 spin_lock_irqsave(&mmu_rb_lock, flags);
130 list_del(&handler->list);
131 spin_unlock_irqrestore(&mmu_rb_lock, flags);
133 if (!RB_EMPTY_ROOT(root)) {
134 struct rb_node *node;
135 struct mmu_rb_node *rbnode;
137 while ((node = rb_first(root))) {
138 rbnode = rb_entry(node, struct mmu_rb_node, node);
139 rb_erase(node, root);
140 if (handler->ops->remove)
141 handler->ops->remove(root, rbnode, NULL);
146 mmu_notifier_unregister(&handler->mn, current->mm);
150 int hfi1_mmu_rb_insert(struct rb_root *root, struct mmu_rb_node *mnode)
152 struct mmu_rb_handler *handler = find_mmu_handler(root);
153 struct mmu_rb_node *node;
160 spin_lock_irqsave(&handler->lock, flags);
161 hfi1_cdbg(MMU, "Inserting node addr 0x%llx, len %u", mnode->addr,
163 node = __mmu_rb_search(handler, mnode->addr, mnode->len);
168 __mmu_int_rb_insert(mnode, root);
170 if (handler->ops->insert) {
171 ret = handler->ops->insert(root, mnode);
173 __mmu_int_rb_remove(mnode, root);
176 spin_unlock_irqrestore(&handler->lock, flags);
180 /* Caller must hold handler lock */
181 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler,
185 struct mmu_rb_node *node = NULL;
187 hfi1_cdbg(MMU, "Searching for addr 0x%llx, len %u", addr, len);
188 if (!handler->ops->filter) {
189 node = __mmu_int_rb_iter_first(handler->root, addr,
192 for (node = __mmu_int_rb_iter_first(handler->root, addr,
195 node = __mmu_int_rb_iter_next(node, addr,
197 if (handler->ops->filter(node, addr, len))
204 /* Caller must *not* hold handler lock. */
205 static void __mmu_rb_remove(struct mmu_rb_handler *handler,
206 struct mmu_rb_node *node, struct mm_struct *mm)
210 /* Validity of handler and node pointers has been checked by caller. */
211 hfi1_cdbg(MMU, "Removing node addr 0x%llx, len %u", node->addr,
213 spin_lock_irqsave(&handler->lock, flags);
214 __mmu_int_rb_remove(node, handler->root);
215 spin_unlock_irqrestore(&handler->lock, flags);
217 if (handler->ops->remove)
218 handler->ops->remove(handler->root, node, mm);
221 struct mmu_rb_node *hfi1_mmu_rb_search(struct rb_root *root, unsigned long addr,
224 struct mmu_rb_handler *handler = find_mmu_handler(root);
225 struct mmu_rb_node *node;
229 return ERR_PTR(-EINVAL);
231 spin_lock_irqsave(&handler->lock, flags);
232 node = __mmu_rb_search(handler, addr, len);
233 spin_unlock_irqrestore(&handler->lock, flags);
238 void hfi1_mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node)
240 struct mmu_rb_handler *handler = find_mmu_handler(root);
242 if (!handler || !node)
245 __mmu_rb_remove(handler, node, NULL);
248 static struct mmu_rb_handler *find_mmu_handler(struct rb_root *root)
250 struct mmu_rb_handler *handler;
253 spin_lock_irqsave(&mmu_rb_lock, flags);
254 list_for_each_entry(handler, &mmu_rb_handlers, list) {
255 if (handler->root == root)
260 spin_unlock_irqrestore(&mmu_rb_lock, flags);
264 static inline void mmu_notifier_page(struct mmu_notifier *mn,
265 struct mm_struct *mm, unsigned long addr)
267 mmu_notifier_mem_invalidate(mn, mm, addr, addr + PAGE_SIZE);
270 static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
271 struct mm_struct *mm,
275 mmu_notifier_mem_invalidate(mn, mm, start, end);
278 static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
279 struct mm_struct *mm,
280 unsigned long start, unsigned long end)
282 struct mmu_rb_handler *handler =
283 container_of(mn, struct mmu_rb_handler, mn);
284 struct rb_root *root = handler->root;
285 struct mmu_rb_node *node, *ptr = NULL;
288 spin_lock_irqsave(&handler->lock, flags);
289 for (node = __mmu_int_rb_iter_first(root, start, end - 1);
291 /* Guard against node removal. */
292 ptr = __mmu_int_rb_iter_next(node, start, end - 1);
293 hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
294 node->addr, node->len);
295 if (handler->ops->invalidate(root, node)) {
296 spin_unlock_irqrestore(&handler->lock, flags);
297 __mmu_rb_remove(handler, node, mm);
298 spin_lock_irqsave(&handler->lock, flags);
301 spin_unlock_irqrestore(&handler->lock, flags);