summaryrefslogtreecommitdiff
path: root/drivers/infiniband/hw/qib/qib_mmap.c
blob: 34927b700b0e67f5ebbe605aceefd205c9651660 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <asm/pgtable.h>

#include "qib_verbs.h"

/**
 * qib_release_mmap_info - free mmap info structure
 * @ref: a pointer to the kref within struct qib_mmap_info
 */
void qib_release_mmap_info(struct kref *ref)
{
	struct qib_mmap_info *ip =
		container_of(ref, struct qib_mmap_info, ref);
	struct qib_ibdev *dev = to_idev(ip->context->device);

	spin_lock_irq(&dev->pending_lock);
	list_del(&ip->pending_mmaps);
	spin_unlock_irq(&dev->pending_lock);

	vfree(ip->obj);
	kfree(ip);
}

/*
 * open and close keep track of how many times the CQ is mapped,
 * to avoid releasing it.
 */
static void qib_vma_open(struct vm_area_struct *vma)
{
	struct qib_mmap_info *ip = vma->vm_private_data;

	kref_get(&ip->ref);
}

static void qib_vma_close(struct vm_area_struct *vma)
{
	struct qib_mmap_info *ip = vma->vm_private_data;

	kref_put(&ip->ref, qib_release_mmap_info);
}

static const struct vm_operations_struct qib_vm_ops = {
	.open =     qib_vma_open,
	.close =    qib_vma_close,
};

/**
 * qib_mmap - create a new mmap region
 * @context: the IB user context of the process making the mmap() call
 * @vma: the VMA to be initialized
 * Return zero if the mmap is OK. Otherwise, return an errno.
 */
int qib_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
{
	struct qib_ibdev *dev = to_idev(context->device);
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
	unsigned long size = vma->vm_end - vma->vm_start;
	struct qib_mmap_info *ip, *pp;
	int ret = -EINVAL;

	/*
	 * Search the device's list of objects waiting for a mmap call.
	 * Normally, this list is very short since a call to create a
	 * CQ, QP, or SRQ is soon followed by a call to mmap().
	 */
	spin_lock_irq(&dev->pending_lock);
	list_for_each_entry_safe(ip, pp, &dev->pending_mmaps,
				 pending_mmaps) {
		/* Only the creator is allowed to mmap the object */
		if (context != ip->context || (__u64) offset != ip->offset)
			continue;
		/* Don't allow a mmap larger than the object. */
		if (size > ip->size)
			break;

		list_del_init(&ip->pending_mmaps);
		spin_unlock_irq(&dev->pending_lock);

		ret = remap_vmalloc_range(vma, ip->obj, 0);
		if (ret)
			goto done;
		vma->vm_ops = &qib_vm_ops;
		vma->vm_private_data = ip;
		qib_vma_open(vma);
		goto done;
	}
	spin_unlock_irq(&dev->pending_lock);
done:
	return ret;
}

/*
 * Allocate information for qib_mmap
 */
struct qib_mmap_info *qib_create_mmap_info(struct qib_ibdev *dev,
					   u32 size,
					   struct ib_ucontext *context,
					   void *obj) {
	struct qib_mmap_info *ip;

	ip = kmalloc(sizeof(*ip), GFP_KERNEL);
	if (!ip)
		goto bail;

	size = PAGE_ALIGN(size);

	spin_lock_irq(&dev->mmap_offset_lock);
	if (dev->mmap_offset == 0)
		dev->mmap_offset = PAGE_SIZE;
	ip->offset = dev->mmap_offset;
	dev->mmap_offset += size;
	spin_unlock_irq(&dev->mmap_offset_lock);

	INIT_LIST_HEAD(&ip->pending_mmaps);
	ip->size = size;
	ip->context = context;
	ip->obj = obj;
	kref_init(&ip->ref);

bail:
	return ip;
}

void qib_update_mmap_info(struct qib_ibdev *dev, struct qib_mmap_info *ip,
			  u32 size, void *obj)
{
	size = PAGE_ALIGN(size);

	spin_lock_irq(&dev->mmap_offset_lock);
	if (dev->mmap_offset == 0)
		dev->mmap_offset = PAGE_SIZE;
	ip->offset = dev->mmap_offset;
	dev->mmap_offset += size;
	spin_unlock_irq(&dev->mmap_offset_lock);

	ip->size = size;
	ip->obj = obj;
}