xref: /linux/drivers/infiniband/sw/rdmavt/mmap.c (revision d19e470b6605c900db21fc7b34c66b6891a79983)
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 
48 #include <linux/slab.h>
49 #include <linux/vmalloc.h>
50 #include <linux/mm.h>
51 #include <asm/pgtable.h>
52 #include <rdma/uverbs_ioctl.h>
53 #include "mmap.h"
54 
55 /**
56  * rvt_mmap_init - init link list and lock for mem map
57  * @rdi: rvt dev struct
58  */
59 void rvt_mmap_init(struct rvt_dev_info *rdi)
60 {
61 	INIT_LIST_HEAD(&rdi->pending_mmaps);
62 	spin_lock_init(&rdi->pending_lock);
63 	rdi->mmap_offset = PAGE_SIZE;
64 	spin_lock_init(&rdi->mmap_offset_lock);
65 }
66 
67 /**
68  * rvt_release_mmap_info - free mmap info structure
69  * @ref: a pointer to the kref within struct rvt_mmap_info
70  */
71 void rvt_release_mmap_info(struct kref *ref)
72 {
73 	struct rvt_mmap_info *ip =
74 		container_of(ref, struct rvt_mmap_info, ref);
75 	struct rvt_dev_info *rdi = ib_to_rvt(ip->context->device);
76 
77 	spin_lock_irq(&rdi->pending_lock);
78 	list_del(&ip->pending_mmaps);
79 	spin_unlock_irq(&rdi->pending_lock);
80 
81 	vfree(ip->obj);
82 	kfree(ip);
83 }
84 
85 static void rvt_vma_open(struct vm_area_struct *vma)
86 {
87 	struct rvt_mmap_info *ip = vma->vm_private_data;
88 
89 	kref_get(&ip->ref);
90 }
91 
92 static void rvt_vma_close(struct vm_area_struct *vma)
93 {
94 	struct rvt_mmap_info *ip = vma->vm_private_data;
95 
96 	kref_put(&ip->ref, rvt_release_mmap_info);
97 }
98 
99 static const struct vm_operations_struct rvt_vm_ops = {
100 	.open = rvt_vma_open,
101 	.close = rvt_vma_close,
102 };
103 
104 /**
105  * rvt_mmap - create a new mmap region
106  * @context: the IB user context of the process making the mmap() call
107  * @vma: the VMA to be initialized
108  *
109  * Return: zero if the mmap is OK. Otherwise, return an errno.
110  */
111 int rvt_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
112 {
113 	struct rvt_dev_info *rdi = ib_to_rvt(context->device);
114 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
115 	unsigned long size = vma->vm_end - vma->vm_start;
116 	struct rvt_mmap_info *ip, *pp;
117 	int ret = -EINVAL;
118 
119 	/*
120 	 * Search the device's list of objects waiting for a mmap call.
121 	 * Normally, this list is very short since a call to create a
122 	 * CQ, QP, or SRQ is soon followed by a call to mmap().
123 	 */
124 	spin_lock_irq(&rdi->pending_lock);
125 	list_for_each_entry_safe(ip, pp, &rdi->pending_mmaps,
126 				 pending_mmaps) {
127 		/* Only the creator is allowed to mmap the object */
128 		if (context != ip->context || (__u64)offset != ip->offset)
129 			continue;
130 		/* Don't allow a mmap larger than the object. */
131 		if (size > ip->size)
132 			break;
133 
134 		list_del_init(&ip->pending_mmaps);
135 		spin_unlock_irq(&rdi->pending_lock);
136 
137 		ret = remap_vmalloc_range(vma, ip->obj, 0);
138 		if (ret)
139 			goto done;
140 		vma->vm_ops = &rvt_vm_ops;
141 		vma->vm_private_data = ip;
142 		rvt_vma_open(vma);
143 		goto done;
144 	}
145 	spin_unlock_irq(&rdi->pending_lock);
146 done:
147 	return ret;
148 }
149 
150 /**
151  * rvt_create_mmap_info - allocate information for hfi1_mmap
152  * @rdi: rvt dev struct
153  * @size: size in bytes to map
154  * @udata: user data (must be valid!)
155  * @obj: opaque pointer to a cq, wq etc
156  *
157  * Return: rvt_mmap struct on success
158  */
159 struct rvt_mmap_info *rvt_create_mmap_info(struct rvt_dev_info *rdi, u32 size,
160 					   struct ib_udata *udata, void *obj)
161 {
162 	struct rvt_mmap_info *ip;
163 
164 	if (!udata)
165 		return ERR_PTR(-EINVAL);
166 
167 	ip = kmalloc_node(sizeof(*ip), GFP_KERNEL, rdi->dparms.node);
168 	if (!ip)
169 		return ip;
170 
171 	size = PAGE_ALIGN(size);
172 
173 	spin_lock_irq(&rdi->mmap_offset_lock);
174 	if (rdi->mmap_offset == 0)
175 		rdi->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
176 	ip->offset = rdi->mmap_offset;
177 	rdi->mmap_offset += ALIGN(size, SHMLBA);
178 	spin_unlock_irq(&rdi->mmap_offset_lock);
179 
180 	INIT_LIST_HEAD(&ip->pending_mmaps);
181 	ip->size = size;
182 	ip->context =
183 		container_of(udata, struct uverbs_attr_bundle, driver_udata)
184 			->context;
185 	ip->obj = obj;
186 	kref_init(&ip->ref);
187 
188 	return ip;
189 }
190 
191 /**
192  * rvt_update_mmap_info - update a mem map
193  * @rdi: rvt dev struct
194  * @ip: mmap info pointer
195  * @size: size to grow by
196  * @obj: opaque pointer to cq, wq, etc.
197  */
198 void rvt_update_mmap_info(struct rvt_dev_info *rdi, struct rvt_mmap_info *ip,
199 			  u32 size, void *obj)
200 {
201 	size = PAGE_ALIGN(size);
202 
203 	spin_lock_irq(&rdi->mmap_offset_lock);
204 	if (rdi->mmap_offset == 0)
205 		rdi->mmap_offset = PAGE_SIZE;
206 	ip->offset = rdi->mmap_offset;
207 	rdi->mmap_offset += size;
208 	spin_unlock_irq(&rdi->mmap_offset_lock);
209 
210 	ip->size = size;
211 	ip->obj = obj;
212 }
213