1/*
2 * Copyright (c) 2006 QLogic, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
18 *      - Redistributions in binary form must reproduce the above
19 *        copyright notice, this list of conditions and the following
20 *        disclaimer in the documentation and/or other materials
21 *        provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33#include <linux/module.h>
34#include <linux/vmalloc.h>
35#include <linux/mm.h>
36#include <linux/errno.h>
37#include <asm/pgtable.h>
38
39#include "ipath_verbs.h"
40
41/**
42 * ipath_release_mmap_info - free mmap info structure
43 * @ref: a pointer to the kref within struct ipath_mmap_info
44 */
45void ipath_release_mmap_info(struct kref *ref)
46{
47	struct ipath_mmap_info *ip =
48		container_of(ref, struct ipath_mmap_info, ref);
49	struct ipath_ibdev *dev = to_idev(ip->context->device);
50
51	spin_lock_irq(&dev->pending_lock);
52	list_del(&ip->pending_mmaps);
53	spin_unlock_irq(&dev->pending_lock);
54
55	vfree(ip->obj);
56	kfree(ip);
57}
58
59/*
60 * open and close keep track of how many times the CQ is mapped,
61 * to avoid releasing it.
62 */
63static void ipath_vma_open(struct vm_area_struct *vma)
64{
65	struct ipath_mmap_info *ip = vma->vm_private_data;
66
67	kref_get(&ip->ref);
68}
69
70static void ipath_vma_close(struct vm_area_struct *vma)
71{
72	struct ipath_mmap_info *ip = vma->vm_private_data;
73
74	kref_put(&ip->ref, ipath_release_mmap_info);
75}
76
77static struct vm_operations_struct ipath_vm_ops = {
78	.open =     ipath_vma_open,
79	.close =    ipath_vma_close,
80};
81
82/**
83 * ipath_mmap - create a new mmap region
84 * @context: the IB user context of the process making the mmap() call
85 * @vma: the VMA to be initialized
86 * Return zero if the mmap is OK. Otherwise, return an errno.
87 */
88int ipath_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
89{
90	struct ipath_ibdev *dev = to_idev(context->device);
91	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
92	unsigned long size = vma->vm_end - vma->vm_start;
93	struct ipath_mmap_info *ip, *pp;
94	int ret = -EINVAL;
95
96	/*
97	 * Search the device's list of objects waiting for a mmap call.
98	 * Normally, this list is very short since a call to create a
99	 * CQ, QP, or SRQ is soon followed by a call to mmap().
100	 */
101	spin_lock_irq(&dev->pending_lock);
102	list_for_each_entry_safe(ip, pp, &dev->pending_mmaps,
103				 pending_mmaps) {
104		/* Only the creator is allowed to mmap the object */
105		if (context != ip->context || (__u64) offset != ip->offset)
106			continue;
107		/* Don't allow a mmap larger than the object. */
108		if (size > ip->size)
109			break;
110
111		list_del_init(&ip->pending_mmaps);
112		spin_unlock_irq(&dev->pending_lock);
113
114		ret = remap_vmalloc_range(vma, ip->obj, 0);
115		if (ret)
116			goto done;
117		vma->vm_ops = &ipath_vm_ops;
118		vma->vm_private_data = ip;
119		ipath_vma_open(vma);
120		goto done;
121	}
122	spin_unlock_irq(&dev->pending_lock);
123done:
124	return ret;
125}
126
127/*
128 * Allocate information for ipath_mmap
129 */
130struct ipath_mmap_info *ipath_create_mmap_info(struct ipath_ibdev *dev,
131					       u32 size,
132					       struct ib_ucontext *context,
133					       void *obj) {
134	struct ipath_mmap_info *ip;
135
136	ip = kmalloc(sizeof *ip, GFP_KERNEL);
137	if (!ip)
138		goto bail;
139
140	size = PAGE_ALIGN(size);
141
142	spin_lock_irq(&dev->mmap_offset_lock);
143	if (dev->mmap_offset == 0)
144		dev->mmap_offset = PAGE_SIZE;
145	ip->offset = dev->mmap_offset;
146	dev->mmap_offset += size;
147	spin_unlock_irq(&dev->mmap_offset_lock);
148
149	INIT_LIST_HEAD(&ip->pending_mmaps);
150	ip->size = size;
151	ip->context = context;
152	ip->obj = obj;
153	kref_init(&ip->ref);
154
155bail:
156	return ip;
157}
158
159void ipath_update_mmap_info(struct ipath_ibdev *dev,
160			    struct ipath_mmap_info *ip,
161			    u32 size, void *obj) {
162	size = PAGE_ALIGN(size);
163
164	spin_lock_irq(&dev->mmap_offset_lock);
165	if (dev->mmap_offset == 0)
166		dev->mmap_offset = PAGE_SIZE;
167	ip->offset = dev->mmap_offset;
168	dev->mmap_offset += size;
169	spin_unlock_irq(&dev->mmap_offset_lock);
170
171	ip->size = size;
172	ip->obj = obj;
173}
174