[deliverable/linux.git] / drivers / staging / rdma / hfi1 / mmu_rb.c

/*
 * Copyright(c) 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <linux/list.h>
#include <linux/mmu_notifier.h>
#include <linux/interval_tree_generic.h>

#include "mmu_rb.h"
#include "trace.h"

struct mmu_rb_handler {
	struct list_head list;
	struct mmu_notifier mn;
	struct rb_root *root;
	spinlock_t lock;        /* protect the RB tree */
	struct mmu_rb_ops *ops;
};

static LIST_HEAD(mmu_rb_handlers);
static DEFINE_SPINLOCK(mmu_rb_lock); /* protect mmu_rb_handlers list */

static unsigned long mmu_node_start(struct mmu_rb_node *);
static unsigned long mmu_node_last(struct mmu_rb_node *);
static struct mmu_rb_handler *find_mmu_handler(struct rb_root *);
static inline void mmu_notifier_page(struct mmu_notifier *, struct mm_struct *,
				     unsigned long);
static inline void mmu_notifier_range_start(struct mmu_notifier *,
					    struct mm_struct *,
					    unsigned long, unsigned long);
static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
					unsigned long, unsigned long);
static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *,
					   unsigned long, unsigned long);

static struct mmu_notifier_ops mn_opts = {
	.invalidate_page = mmu_notifier_page,
	.invalidate_range_start = mmu_notifier_range_start,
};

INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last,
		     mmu_node_start, mmu_node_last, static, __mmu_int_rb);

static unsigned long mmu_node_start(struct mmu_rb_node *node)
{
	return node->addr & PAGE_MASK;
}

static unsigned long mmu_node_last(struct mmu_rb_node *node)
{
	return ((node->addr & PAGE_MASK) + node->len);
}

int hfi1_mmu_rb_register(struct rb_root *root, struct mmu_rb_ops *ops)
{
	struct mmu_rb_handler *handlr;
	unsigned long flags;

	if (!ops->compare || !ops->invalidate)
		return -EINVAL;

	handlr = kmalloc(sizeof(*handlr), GFP_KERNEL);
	if (!handlr)
		return -ENOMEM;

	handlr->root = root;
	handlr->ops = ops;
	INIT_HLIST_NODE(&handlr->mn.hlist);
	spin_lock_init(&handlr->lock);
	handlr->mn.ops = &mn_opts;
	spin_lock_irqsave(&mmu_rb_lock, flags);
	list_add_tail(&handlr->list, &mmu_rb_handlers);
	spin_unlock_irqrestore(&mmu_rb_lock, flags);

	return mmu_notifier_register(&handlr->mn, current->mm);
}

void hfi1_mmu_rb_unregister(struct rb_root *root)
{
	struct mmu_rb_handler *handler = find_mmu_handler(root);
	unsigned long flags;

	if (!handler)
		return;

	spin_lock_irqsave(&mmu_rb_lock, flags);
	list_del(&handler->list);
	spin_unlock_irqrestore(&mmu_rb_lock, flags);

	if (!RB_EMPTY_ROOT(root)) {
		struct rb_node *node;
		struct mmu_rb_node *rbnode;

		while ((node = rb_first(root))) {
			rbnode = rb_entry(node, struct mmu_rb_node, node);
			rb_erase(node, root);
			if (handler->ops->remove)
				handler->ops->remove(root, rbnode, false);
		}
	}

	if (current->mm)
		mmu_notifier_unregister(&handler->mn, current->mm);
	kfree(handler);
}

int hfi1_mmu_rb_insert(struct rb_root *root, struct mmu_rb_node *mnode)
{
	struct mmu_rb_handler *handler = find_mmu_handler(root);
	struct mmu_rb_node *node;
	unsigned long flags;
	int ret = 0;

	if (!handler)
		return -EINVAL;

	spin_lock_irqsave(&handler->lock, flags);
	hfi1_cdbg(MMU, "Inserting node addr 0x%llx, len %u", mnode->addr,
		  mnode->len);
	node = __mmu_rb_search(handler, mnode->addr, mnode->len);
	if (node) {
		ret = -EINVAL;
		goto unlock;
	}
	__mmu_int_rb_insert(mnode, root);

	if (handler->ops->insert) {
		ret = handler->ops->insert(root, mnode);
		if (ret)
			__mmu_int_rb_remove(mnode, root);
	}
unlock:
	spin_unlock_irqrestore(&handler->lock, flags);
	return ret;
}

/* Caller must host handler lock */
static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler,
					   unsigned long addr,
					   unsigned long len)
{
	struct mmu_rb_node *node;

	hfi1_cdbg(MMU, "Searching for addr 0x%llx, len %u", addr, len);
	node = __mmu_int_rb_iter_first(handler->root, addr, len);
	if (node)
		hfi1_cdbg(MMU, "Found node addr 0x%llx, len %u", node->addr,
			  node->len);
	return node;
}

static void __mmu_rb_remove(struct mmu_rb_handler *handler,
			    struct mmu_rb_node *node, bool arg)
{
	/* Validity of handler and node pointers has been checked by caller. */
	hfi1_cdbg(MMU, "Removing node addr 0x%llx, len %u", node->addr,
		  node->len);
	__mmu_int_rb_remove(node, handler->root);
	if (handler->ops->remove)
		handler->ops->remove(handler->root, node, arg);
}

struct mmu_rb_node *hfi1_mmu_rb_search(struct rb_root *root, unsigned long addr,
				       unsigned long len)
{
	struct mmu_rb_handler *handler = find_mmu_handler(root);
	struct mmu_rb_node *node;
	unsigned long flags;

	if (!handler)
		return ERR_PTR(-EINVAL);

	spin_lock_irqsave(&handler->lock, flags);
	node = __mmu_rb_search(handler, addr, len);
	spin_unlock_irqrestore(&handler->lock, flags);

	return node;
}

void hfi1_mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node)
{
	struct mmu_rb_handler *handler = find_mmu_handler(root);
	unsigned long flags;

	if (!handler || !node)
		return;

	spin_lock_irqsave(&handler->lock, flags);
	__mmu_rb_remove(handler, node, false);
	spin_unlock_irqrestore(&handler->lock, flags);
}

static struct mmu_rb_handler *find_mmu_handler(struct rb_root *root)
{
	struct mmu_rb_handler *handler;
	unsigned long flags;

	spin_lock_irqsave(&mmu_rb_lock, flags);
	list_for_each_entry(handler, &mmu_rb_handlers, list) {
		if (handler->root == root)
			goto unlock;
	}
	handler = NULL;
unlock:
	spin_unlock_irqrestore(&mmu_rb_lock, flags);
	return handler;
}

static inline void mmu_notifier_page(struct mmu_notifier *mn,
				     struct mm_struct *mm, unsigned long addr)
{
	mmu_notifier_mem_invalidate(mn, addr, addr + PAGE_SIZE);
}

static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
					    struct mm_struct *mm,
					    unsigned long start,
					    unsigned long end)
{
	mmu_notifier_mem_invalidate(mn, start, end);
}

static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
					unsigned long start, unsigned long end)
{
	struct mmu_rb_handler *handler =
		container_of(mn, struct mmu_rb_handler, mn);
	struct rb_root *root = handler->root;
	struct mmu_rb_node *node;
	unsigned long flags;

	spin_lock_irqsave(&handler->lock, flags);
	for (node = __mmu_int_rb_iter_first(root, start, end); node;
	     node = __mmu_int_rb_iter_next(node, start, end)) {
		hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
			  node->addr, node->len);
		if (handler->ops->invalidate(root, node))
			__mmu_rb_remove(handler, node, true);
	}
	spin_unlock_irqrestore(&handler->lock, flags);
}
Commit	Line	Data
06e0ffa6 MH	1	/*
	2	* Copyright(c) 2016 Intel Corporation.
	3	*
	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.
	6	*
	7	* GPL LICENSE SUMMARY
	8	*
	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.
	12	*
	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.
	17	*
	18	* BSD LICENSE
	19	*
	20	* Redistribution and use in source and binary forms, with or without
	21	* modification, are permitted provided that the following conditions
	22	* are met:
	23	*
	24	* - Redistributions of source code must retain the above copyright
	25	* notice, this list of conditions and the following disclaimer.
	26	* - Redistributions in binary form must reproduce the above copyright
	27	* notice, this list of conditions and the following disclaimer in
	28	* the documentation and/or other materials provided with the
	29	* distribution.
	30	* - Neither the name of Intel Corporation nor the names of its
	31	* contributors may be used to endorse or promote products derived
	32	* from this software without specific prior written permission.
	33	*
	34	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	35	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	36	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	37	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	38	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	39	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	40	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	41	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	42	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	43	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	44	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	45	*
	46	*/
	47	#include <linux/list.h>
	48	#include <linux/mmu_notifier.h>
df5a00f8	49	#include <linux/interval_tree_generic.h>
06e0ffa6 MH	50
	51	#include "mmu_rb.h"
	52	#include "trace.h"
	53
	54	struct mmu_rb_handler {
	55	struct list_head list;
	56	struct mmu_notifier mn;
	57	struct rb_root *root;
	58	spinlock_t lock; /* protect the RB tree */
	59	struct mmu_rb_ops *ops;
	60	};
	61
	62	static LIST_HEAD(mmu_rb_handlers);
	63	static DEFINE_SPINLOCK(mmu_rb_lock); /* protect mmu_rb_handlers list */
	64
df5a00f8 MH	65	static unsigned long mmu_node_start(struct mmu_rb_node *);
df5a00f8 MH	66	static unsigned long mmu_node_last(struct mmu_rb_node *);
06e0ffa6 MH	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 ,
	69	unsigned long);
	70	static inline void mmu_notifier_range_start(struct mmu_notifier *,
	71	struct mm_struct *,
	72	unsigned long, unsigned long);
	73	static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
	74	unsigned long, unsigned long);
	75	static struct mmu_rb_node __mmu_rb_search(struct mmu_rb_handler ,
	76	unsigned long, unsigned long);
	77
	78	static struct mmu_notifier_ops mn_opts = {
	79	.invalidate_page = mmu_notifier_page,
	80	.invalidate_range_start = mmu_notifier_range_start,
	81	};
	82
df5a00f8 MH	83	INTERVAL_TREE_DEFINE(struct mmu_rb_node, node, unsigned long, __last,
	84	mmu_node_start, mmu_node_last, static, __mmu_int_rb);
	85
	86	static unsigned long mmu_node_start(struct mmu_rb_node *node)
	87	{
	88	return node->addr & PAGE_MASK;
	89	}
	90
	91	static unsigned long mmu_node_last(struct mmu_rb_node *node)
	92	{
	93	return ((node->addr & PAGE_MASK) + node->len);
	94	}
	95
06e0ffa6 MH	96	int hfi1_mmu_rb_register(struct rb_root root, struct mmu_rb_ops ops)
	97	{
	98	struct mmu_rb_handler *handlr;
c81e1f64	99	unsigned long flags;
06e0ffa6 MH	100
	101	if (!ops->compare \|\| !ops->invalidate)
	102	return -EINVAL;
	103
	104	handlr = kmalloc(sizeof(*handlr), GFP_KERNEL);
	105	if (!handlr)
	106	return -ENOMEM;
	107
	108	handlr->root = root;
	109	handlr->ops = ops;
	110	INIT_HLIST_NODE(&handlr->mn.hlist);
	111	spin_lock_init(&handlr->lock);
	112	handlr->mn.ops = &mn_opts;
c81e1f64	113	spin_lock_irqsave(&mmu_rb_lock, flags);
06e0ffa6	114	list_add_tail(&handlr->list, &mmu_rb_handlers);
c81e1f64	115	spin_unlock_irqrestore(&mmu_rb_lock, flags);
06e0ffa6 MH	116
	117	return mmu_notifier_register(&handlr->mn, current->mm);
	118	}
	119
	120	void hfi1_mmu_rb_unregister(struct rb_root *root)
	121	{
	122	struct mmu_rb_handler *handler = find_mmu_handler(root);
c81e1f64	123	unsigned long flags;
06e0ffa6	124
4b00d949 MH	125	if (!handler)
	126	return;
	127
c81e1f64	128	spin_lock_irqsave(&mmu_rb_lock, flags);
06e0ffa6	129	list_del(&handler->list);
c81e1f64	130	spin_unlock_irqrestore(&mmu_rb_lock, flags);
06e0ffa6 MH	131
	132	if (!RB_EMPTY_ROOT(root)) {
	133	struct rb_node *node;
	134	struct mmu_rb_node *rbnode;
	135
	136	while ((node = rb_first(root))) {
	137	rbnode = rb_entry(node, struct mmu_rb_node, node);
eef9c896	138	rb_erase(node, root);
06e0ffa6	139	if (handler->ops->remove)
909e2cd0	140	handler->ops->remove(root, rbnode, false);
06e0ffa6 MH	141	}
	142	}
	143
	144	if (current->mm)
	145	mmu_notifier_unregister(&handler->mn, current->mm);
	146	kfree(handler);
	147	}
	148
	149	int hfi1_mmu_rb_insert(struct rb_root root, struct mmu_rb_node mnode)
	150	{
06e0ffa6	151	struct mmu_rb_handler *handler = find_mmu_handler(root);
df5a00f8	152	struct mmu_rb_node *node;
c81e1f64	153	unsigned long flags;
df5a00f8	154	int ret = 0;
06e0ffa6 MH	155
	156	if (!handler)
	157	return -EINVAL;
	158
c81e1f64	159	spin_lock_irqsave(&handler->lock, flags);
353b71c7 MH	160	hfi1_cdbg(MMU, "Inserting node addr 0x%llx, len %u", mnode->addr,
353b71c7 MH	161	mnode->len);
df5a00f8 MH	162	node = __mmu_rb_search(handler, mnode->addr, mnode->len);
	163	if (node) {
	164	ret = -EINVAL;
	165	goto unlock;
06e0ffa6	166	}
df5a00f8	167	__mmu_int_rb_insert(mnode, root);
06e0ffa6 MH	168
	169	if (handler->ops->insert) {
	170	ret = handler->ops->insert(root, mnode);
	171	if (ret)
df5a00f8	172	__mmu_int_rb_remove(mnode, root);
06e0ffa6	173	}
06e0ffa6	174	unlock:
c81e1f64	175	spin_unlock_irqrestore(&handler->lock, flags);
06e0ffa6 MH	176	return ret;
	177	}
	178
	179	/* Caller must host handler lock */
	180	static struct mmu_rb_node __mmu_rb_search(struct mmu_rb_handler handler,
	181	unsigned long addr,
	182	unsigned long len)
	183	{
df5a00f8 MH	184	struct mmu_rb_node *node;
df5a00f8 MH	185
353b71c7	186	hfi1_cdbg(MMU, "Searching for addr 0x%llx, len %u", addr, len);
df5a00f8	187	node = __mmu_int_rb_iter_first(handler->root, addr, len);
353b71c7 MH	188	if (node)
	189	hfi1_cdbg(MMU, "Found node addr 0x%llx, len %u", node->addr,
	190	node->len);
df5a00f8	191	return node;
06e0ffa6 MH	192	}
	193
	194	static void __mmu_rb_remove(struct mmu_rb_handler *handler,
909e2cd0	195	struct mmu_rb_node *node, bool arg)
06e0ffa6 MH	196	{
06e0ffa6 MH	197	/* Validity of handler and node pointers has been checked by caller. */
353b71c7 MH	198	hfi1_cdbg(MMU, "Removing node addr 0x%llx, len %u", node->addr,
353b71c7 MH	199	node->len);
df5a00f8	200	__mmu_int_rb_remove(node, handler->root);
06e0ffa6	201	if (handler->ops->remove)
909e2cd0	202	handler->ops->remove(handler->root, node, arg);
06e0ffa6 MH	203	}
	204
	205	struct mmu_rb_node hfi1_mmu_rb_search(struct rb_root root, unsigned long addr,
	206	unsigned long len)
	207	{
	208	struct mmu_rb_handler *handler = find_mmu_handler(root);
	209	struct mmu_rb_node *node;
c81e1f64	210	unsigned long flags;
06e0ffa6 MH	211
	212	if (!handler)
	213	return ERR_PTR(-EINVAL);
	214
c81e1f64	215	spin_lock_irqsave(&handler->lock, flags);
06e0ffa6	216	node = __mmu_rb_search(handler, addr, len);
c81e1f64	217	spin_unlock_irqrestore(&handler->lock, flags);
06e0ffa6 MH	218
	219	return node;
	220	}
	221
	222	void hfi1_mmu_rb_remove(struct rb_root root, struct mmu_rb_node node)
	223	{
	224	struct mmu_rb_handler *handler = find_mmu_handler(root);
c81e1f64	225	unsigned long flags;
06e0ffa6 MH	226
	227	if (!handler \|\| !node)
	228	return;
	229
c81e1f64	230	spin_lock_irqsave(&handler->lock, flags);
909e2cd0	231	__mmu_rb_remove(handler, node, false);
c81e1f64	232	spin_unlock_irqrestore(&handler->lock, flags);
06e0ffa6 MH	233	}
	234
	235	static struct mmu_rb_handler find_mmu_handler(struct rb_root root)
	236	{
	237	struct mmu_rb_handler *handler;
c81e1f64	238	unsigned long flags;
06e0ffa6	239
c81e1f64	240	spin_lock_irqsave(&mmu_rb_lock, flags);
06e0ffa6 MH	241	list_for_each_entry(handler, &mmu_rb_handlers, list) {
	242	if (handler->root == root)
	243	goto unlock;
	244	}
	245	handler = NULL;
	246	unlock:
c81e1f64	247	spin_unlock_irqrestore(&mmu_rb_lock, flags);
06e0ffa6 MH	248	return handler;
	249	}
	250
	251	static inline void mmu_notifier_page(struct mmu_notifier *mn,
	252	struct mm_struct *mm, unsigned long addr)
	253	{
	254	mmu_notifier_mem_invalidate(mn, addr, addr + PAGE_SIZE);
	255	}
	256
	257	static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
	258	struct mm_struct *mm,
	259	unsigned long start,
	260	unsigned long end)
	261	{
	262	mmu_notifier_mem_invalidate(mn, start, end);
	263	}
	264
	265	static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
	266	unsigned long start, unsigned long end)
	267	{
	268	struct mmu_rb_handler *handler =
	269	container_of(mn, struct mmu_rb_handler, mn);
	270	struct rb_root *root = handler->root;
	271	struct mmu_rb_node *node;
df5a00f8	272	unsigned long flags;
06e0ffa6	273
c81e1f64	274	spin_lock_irqsave(&handler->lock, flags);
df5a00f8 MH	275	for (node = __mmu_int_rb_iter_first(root, start, end); node;
df5a00f8 MH	276	node = __mmu_int_rb_iter_next(node, start, end)) {
353b71c7 MH	277	hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
353b71c7 MH	278	node->addr, node->len);
06e0ffa6	279	if (handler->ops->invalidate(root, node))
909e2cd0	280	__mmu_rb_remove(handler, node, true);
06e0ffa6	281	}
c81e1f64	282	spin_unlock_irqrestore(&handler->lock, flags);
06e0ffa6	283	}