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