2 * Copyright(c) 2016 - 2017 Intel Corporation.
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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
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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 mmu_notifier mn;
59 spinlock_t lock; /* protect the RB tree */
60 struct mmu_rb_ops *ops;
62 struct list_head lru_list;
63 struct work_struct del_work;
64 struct list_head del_list;
65 struct workqueue_struct *wq;
68 static unsigned long mmu_node_start(struct mmu_rb_node *);
69 static unsigned long mmu_node_last(struct mmu_rb_node *);
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);
78 static void do_remove(struct mmu_rb_handler *handler,
79 struct list_head *del_list);
80 static void handle_remove(struct work_struct *work);
82 static const struct mmu_notifier_ops mn_opts = {
83 .invalidate_range_start = mmu_notifier_range_start,
86 INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last,
87 mmu_node_start, mmu_node_last, static, __mmu_int_rb);
89 static unsigned long mmu_node_start(struct mmu_rb_node *node)
91 return node->addr & PAGE_MASK;
94 static unsigned long mmu_node_last(struct mmu_rb_node *node)
96 return PAGE_ALIGN(node->addr + node->len) - 1;
99 int hfi1_mmu_rb_register(void *ops_arg, struct mm_struct *mm,
100 struct mmu_rb_ops *ops,
101 struct workqueue_struct *wq,
102 struct mmu_rb_handler **handler)
104 struct mmu_rb_handler *handlr;
107 handlr = kmalloc(sizeof(*handlr), GFP_KERNEL);
111 handlr->root = RB_ROOT;
113 handlr->ops_arg = ops_arg;
114 INIT_HLIST_NODE(&handlr->mn.hlist);
115 spin_lock_init(&handlr->lock);
116 handlr->mn.ops = &mn_opts;
118 INIT_WORK(&handlr->del_work, handle_remove);
119 INIT_LIST_HEAD(&handlr->del_list);
120 INIT_LIST_HEAD(&handlr->lru_list);
123 ret = mmu_notifier_register(&handlr->mn, handlr->mm);
133 void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler)
135 struct mmu_rb_node *rbnode;
136 struct rb_node *node;
138 struct list_head del_list;
140 /* Unregister first so we don't get any more notifications. */
141 mmu_notifier_unregister(&handler->mn, handler->mm);
144 * Make sure the wq delete handler is finished running. It will not
145 * be triggered once the mmu notifiers are unregistered above.
147 flush_work(&handler->del_work);
149 INIT_LIST_HEAD(&del_list);
151 spin_lock_irqsave(&handler->lock, flags);
152 while ((node = rb_first(&handler->root))) {
153 rbnode = rb_entry(node, struct mmu_rb_node, node);
154 rb_erase(node, &handler->root);
155 /* move from LRU list to delete list */
156 list_move(&rbnode->list, &del_list);
158 spin_unlock_irqrestore(&handler->lock, flags);
160 do_remove(handler, &del_list);
165 int hfi1_mmu_rb_insert(struct mmu_rb_handler *handler,
166 struct mmu_rb_node *mnode)
168 struct mmu_rb_node *node;
172 trace_hfi1_mmu_rb_insert(mnode->addr, mnode->len);
173 spin_lock_irqsave(&handler->lock, flags);
174 node = __mmu_rb_search(handler, mnode->addr, mnode->len);
179 __mmu_int_rb_insert(mnode, &handler->root);
180 list_add(&mnode->list, &handler->lru_list);
182 ret = handler->ops->insert(handler->ops_arg, mnode);
184 __mmu_int_rb_remove(mnode, &handler->root);
185 list_del(&mnode->list); /* remove from LRU list */
188 spin_unlock_irqrestore(&handler->lock, flags);
192 /* Caller must hold handler lock */
193 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler,
197 struct mmu_rb_node *node = NULL;
199 trace_hfi1_mmu_rb_search(addr, len);
200 if (!handler->ops->filter) {
201 node = __mmu_int_rb_iter_first(&handler->root, addr,
204 for (node = __mmu_int_rb_iter_first(&handler->root, addr,
207 node = __mmu_int_rb_iter_next(node, addr,
209 if (handler->ops->filter(node, addr, len))
216 bool hfi1_mmu_rb_remove_unless_exact(struct mmu_rb_handler *handler,
217 unsigned long addr, unsigned long len,
218 struct mmu_rb_node **rb_node)
220 struct mmu_rb_node *node;
224 spin_lock_irqsave(&handler->lock, flags);
225 node = __mmu_rb_search(handler, addr, len);
227 if (node->addr == addr && node->len == len)
229 __mmu_int_rb_remove(node, &handler->root);
230 list_del(&node->list); /* remove from LRU list */
234 spin_unlock_irqrestore(&handler->lock, flags);
239 void hfi1_mmu_rb_evict(struct mmu_rb_handler *handler, void *evict_arg)
241 struct mmu_rb_node *rbnode, *ptr;
242 struct list_head del_list;
246 INIT_LIST_HEAD(&del_list);
248 spin_lock_irqsave(&handler->lock, flags);
249 list_for_each_entry_safe_reverse(rbnode, ptr, &handler->lru_list,
251 if (handler->ops->evict(handler->ops_arg, rbnode, evict_arg,
253 __mmu_int_rb_remove(rbnode, &handler->root);
254 /* move from LRU list to delete list */
255 list_move(&rbnode->list, &del_list);
260 spin_unlock_irqrestore(&handler->lock, flags);
262 while (!list_empty(&del_list)) {
263 rbnode = list_first_entry(&del_list, struct mmu_rb_node, list);
264 list_del(&rbnode->list);
265 handler->ops->remove(handler->ops_arg, rbnode);
270 * It is up to the caller to ensure that this function does not race with the
271 * mmu invalidate notifier which may be calling the users remove callback on
274 void hfi1_mmu_rb_remove(struct mmu_rb_handler *handler,
275 struct mmu_rb_node *node)
279 /* Validity of handler and node pointers has been checked by caller. */
280 trace_hfi1_mmu_rb_remove(node->addr, node->len);
281 spin_lock_irqsave(&handler->lock, flags);
282 __mmu_int_rb_remove(node, &handler->root);
283 list_del(&node->list); /* remove from LRU list */
284 spin_unlock_irqrestore(&handler->lock, flags);
286 handler->ops->remove(handler->ops_arg, node);
289 static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
290 struct mm_struct *mm,
294 mmu_notifier_mem_invalidate(mn, mm, start, end);
297 static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
298 struct mm_struct *mm,
299 unsigned long start, unsigned long end)
301 struct mmu_rb_handler *handler =
302 container_of(mn, struct mmu_rb_handler, mn);
303 struct rb_root *root = &handler->root;
304 struct mmu_rb_node *node, *ptr = NULL;
308 spin_lock_irqsave(&handler->lock, flags);
309 for (node = __mmu_int_rb_iter_first(root, start, end - 1);
311 /* Guard against node removal. */
312 ptr = __mmu_int_rb_iter_next(node, start, end - 1);
313 trace_hfi1_mmu_mem_invalidate(node->addr, node->len);
314 if (handler->ops->invalidate(handler->ops_arg, node)) {
315 __mmu_int_rb_remove(node, root);
316 /* move from LRU list to delete list */
317 list_move(&node->list, &handler->del_list);
321 spin_unlock_irqrestore(&handler->lock, flags);
324 queue_work(handler->wq, &handler->del_work);
328 * Call the remove function for the given handler and the list. This
329 * is expected to be called with a delete list extracted from handler.
330 * The caller should not be holding the handler lock.
332 static void do_remove(struct mmu_rb_handler *handler,
333 struct list_head *del_list)
335 struct mmu_rb_node *node;
337 while (!list_empty(del_list)) {
338 node = list_first_entry(del_list, struct mmu_rb_node, list);
339 list_del(&node->list);
340 handler->ops->remove(handler->ops_arg, node);
345 * Work queue function to remove all nodes that have been queued up to
346 * be removed. The key feature is that mm->mmap_sem is not being held
347 * and the remove callback can sleep while taking it, if needed.
349 static void handle_remove(struct work_struct *work)
351 struct mmu_rb_handler *handler = container_of(work,
352 struct mmu_rb_handler,
354 struct list_head del_list;
357 /* remove anything that is queued to get removed */
358 spin_lock_irqsave(&handler->lock, flags);
359 list_replace_init(&handler->del_list, &del_list);
360 spin_unlock_irqrestore(&handler->lock, flags);
362 do_remove(handler, &del_list);