1 files changed, 325 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c
new file mode 100644
index 000000000000..b7a80aa1ae30
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/mmu_rb.c
@@ -0,0 +1,325 @@
+/*
+ * 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/rculist.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 *,
+					struct mm_struct *,
+					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 PAGE_ALIGN(node->addr + node->len) - 1;
+}
+
+int hfi1_mmu_rb_register(struct rb_root *root, struct mmu_rb_ops *ops)
+{
+	struct mmu_rb_handler *handlr;
+
+	if (!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(&mmu_rb_lock);
+	list_add_tail_rcu(&handlr->list, &mmu_rb_handlers);
+	spin_unlock(&mmu_rb_lock);
+
+	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;
+
+	/* Unregister first so we don't get any more notifications. */
+	if (current->mm)
+		mmu_notifier_unregister(&handler->mn, current->mm);
+
+	spin_lock(&mmu_rb_lock);
+	list_del_rcu(&handler->list);
+	spin_unlock(&mmu_rb_lock);
+	synchronize_rcu();
+
+	spin_lock_irqsave(&handler->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, NULL);
+		}
+	}
+	spin_unlock_irqrestore(&handler->lock, flags);
+
+	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 hold 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 = NULL;
+
+	hfi1_cdbg(MMU, "Searching for addr 0x%llx, len %u", addr, len);
+	if (!handler->ops->filter) {
+		node = __mmu_int_rb_iter_first(handler->root, addr,
+					       (addr + len) - 1);
+	} else {
+		for (node = __mmu_int_rb_iter_first(handler->root, addr,
+						    (addr + len) - 1);
+		     node;
+		     node = __mmu_int_rb_iter_next(node, addr,
+						   (addr + len) - 1)) {
+			if (handler->ops->filter(node, addr, len))
+				return node;
+		}
+	}
+	return node;
+}
+
+/* Caller must *not* hold handler lock. */
+static void __mmu_rb_remove(struct mmu_rb_handler *handler,
+			    struct mmu_rb_node *node, struct mm_struct *mm)
+{
+	unsigned long flags;
+
+	/* 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);
+	spin_lock_irqsave(&handler->lock, flags);
+	__mmu_int_rb_remove(node, handler->root);
+	spin_unlock_irqrestore(&handler->lock, flags);
+
+	if (handler->ops->remove)
+		handler->ops->remove(handler->root, node, mm);
+}
+
+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;
+}
+
+struct mmu_rb_node *hfi1_mmu_rb_extract(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);
+	if (node)
+		__mmu_int_rb_remove(node, handler->root);
+	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);
+
+	if (!handler || !node)
+		return;
+
+	__mmu_rb_remove(handler, node, NULL);
+}
+
+static struct mmu_rb_handler *find_mmu_handler(struct rb_root *root)
+{
+	struct mmu_rb_handler *handler;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(handler, &mmu_rb_handlers, list) {
+		if (handler->root == root)
+			goto unlock;
+	}
+	handler = NULL;
+unlock:
+	rcu_read_unlock();
+	return handler;
+}
+
+static inline void mmu_notifier_page(struct mmu_notifier *mn,
+				     struct mm_struct *mm, unsigned long addr)
+{
+	mmu_notifier_mem_invalidate(mn, mm, 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, mm, start, end);
+}
+
+static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
+					struct mm_struct *mm,
+					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, *ptr = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&handler->lock, flags);
+	for (node = __mmu_int_rb_iter_first(root, start, end - 1);
+	     node; node = ptr) {
+		/* Guard against node removal. */
+		ptr = __mmu_int_rb_iter_next(node, start, end - 1);
+		hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
+			  node->addr, node->len);
+		if (handler->ops->invalidate(root, node)) {
+			__mmu_int_rb_remove(node, root);
+			if (handler->ops->remove)
+				handler->ops->remove(root, node, mm);
+		}
+	}
+	spin_unlock_irqrestore(&handler->lock, flags);
+}