1 /*
2 * Copyright (c) 2017-2019 François Tigeot <ftigeot@wolfpond.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/queue.h>
28 #include <vm/vm_extern.h>
29
30 #include <linux/vmalloc.h>
31 #include <linux/slab.h>
32 #include <linux/mm.h>
33
34 struct vmap {
35 void *addr;
36 int npages;
37 SLIST_ENTRY(vmap) vm_vmaps;
38 };
39
40 struct lock vmap_lock = LOCK_INITIALIZER("dlvml", 0, LK_CANRECURSE);
41
42 SLIST_HEAD(vmap_list_head, vmap) vmap_list = SLIST_HEAD_INITIALIZER(vmap_list);
43
44 /* vmap: map an array of pages into virtually contiguous space */
45 void *
vmap(struct page ** pages,unsigned int count,unsigned long flags,pgprot_t prot)46 vmap(struct page **pages, unsigned int count,
47 unsigned long flags, pgprot_t prot)
48 {
49 struct vmap *vmp;
50 vm_offset_t off;
51 size_t size;
52
53 vmp = kmalloc(sizeof(struct vmap), M_DRM, M_WAITOK | M_ZERO);
54
55 size = count * PAGE_SIZE;
56 off = kmem_alloc_nofault(kernel_map, size,
57 VM_SUBSYS_DRM_VMAP, PAGE_SIZE);
58 if (off == 0)
59 return (NULL);
60
61 vmp->addr = (void *)off;
62 vmp->npages = count;
63 pmap_qenter(off, (struct vm_page **)pages, count);
64 lockmgr(&vmap_lock, LK_EXCLUSIVE);
65 SLIST_INSERT_HEAD(&vmap_list, vmp, vm_vmaps);
66 lockmgr(&vmap_lock, LK_RELEASE);
67
68 return (void *)off;
69 }
70
71 void
vunmap(const void * addr)72 vunmap(const void *addr)
73 {
74 struct vmap *vmp, *tmp_vmp;
75 size_t size;
76
77 SLIST_FOREACH_MUTABLE(vmp, &vmap_list, vm_vmaps, tmp_vmp) {
78 if (vmp->addr == addr) {
79 size = vmp->npages * PAGE_SIZE;
80
81 pmap_qremove((vm_offset_t)addr, vmp->npages);
82 kmem_free(kernel_map, (vm_offset_t)addr, size);
83 goto found;
84 }
85 }
86
87 found:
88 lockmgr(&vmap_lock, LK_EXCLUSIVE);
89 SLIST_REMOVE(&vmap_list, vmp, vmap, vm_vmaps);
90 lockmgr(&vmap_lock, LK_RELEASE);
91 kfree(vmp);
92 }
93
94 int
is_vmalloc_addr(const void * x)95 is_vmalloc_addr(const void *x)
96 {
97 struct vmap *vmp, *tmp_vmp;
98
99 SLIST_FOREACH_MUTABLE(vmp, &vmap_list, vm_vmaps, tmp_vmp) {
100 if (vmp->addr == x)
101 return 1;
102 }
103
104 return false;
105 }
106
107 void *
vmalloc(unsigned long size)108 vmalloc(unsigned long size)
109 {
110 return kmalloc(size, M_DRM, M_WAITOK);
111 }
112
113 void *
vzalloc(unsigned long size)114 vzalloc(unsigned long size)
115 {
116 return kmalloc(size, M_DRM, M_WAITOK | M_ZERO);
117 }
118
119 /* allocate zeroed virtually contiguous memory for userspace */
120 void *
vmalloc_user(unsigned long size)121 vmalloc_user(unsigned long size)
122 {
123 return kmalloc(size, M_DRM, M_WAITOK | M_ZERO);
124 }
125
126 void
vfree(const void * addr)127 vfree(const void *addr)
128 {
129 void *nc_addr;
130
131 memcpy(&nc_addr, &addr, sizeof(void *));
132 kfree(nc_addr);
133 }
134
135 void *
kvmalloc_array(size_t n,size_t size,gfp_t flags)136 kvmalloc_array(size_t n, size_t size, gfp_t flags)
137 {
138 if (n == 0)
139 return NULL;
140
141 if (n > SIZE_MAX / size)
142 return NULL;
143
144 return kmalloc(n * size, M_DRM, flags);
145 }
146