1 | /* $NetBSD: drm_gem_vm.c,v 1.6 2015/03/09 01:29:40 riastradh Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2013 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Taylor R. Campbell. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | #include <sys/cdefs.h> |
33 | __KERNEL_RCSID(0, "$NetBSD: drm_gem_vm.c,v 1.6 2015/03/09 01:29:40 riastradh Exp $" ); |
34 | |
35 | #include <sys/types.h> |
36 | |
37 | #include <uvm/uvm_extern.h> |
38 | |
39 | #include <drm/drmP.h> |
40 | #include <drm/drm_vma_manager.h> |
41 | |
42 | static int drm_gem_mmap_object_locked(struct drm_device *, off_t, size_t, |
43 | int, struct uvm_object **, voff_t *, struct file *); |
44 | |
45 | void |
46 | (struct uvm_object *uobj) |
47 | { |
48 | struct drm_gem_object *const obj = container_of(uobj, |
49 | struct drm_gem_object, gemo_uvmobj); |
50 | |
51 | drm_gem_object_reference(obj); |
52 | } |
53 | |
54 | void |
55 | (struct uvm_object *uobj) |
56 | { |
57 | struct drm_gem_object *const obj = container_of(uobj, |
58 | struct drm_gem_object, gemo_uvmobj); |
59 | |
60 | drm_gem_object_unreference_unlocked(obj); |
61 | } |
62 | |
63 | int |
64 | drm_gem_or_legacy_mmap_object(struct drm_device *dev, off_t byte_offset, |
65 | size_t nbytes, int prot, struct uvm_object **uobjp, voff_t *uoffsetp, |
66 | struct file *file) |
67 | { |
68 | int ret; |
69 | |
70 | ret = drm_gem_mmap_object(dev, byte_offset, nbytes, prot, uobjp, |
71 | uoffsetp, file); |
72 | if (ret) |
73 | return ret; |
74 | if (*uobjp != NULL) |
75 | return 0; |
76 | |
77 | return drm_mmap_object(dev, byte_offset, nbytes, prot, uobjp, |
78 | uoffsetp, file); |
79 | } |
80 | |
81 | int |
82 | drm_gem_mmap_object(struct drm_device *dev, off_t byte_offset, size_t nbytes, |
83 | int prot, struct uvm_object **uobjp, voff_t *uoffsetp, struct file *file) |
84 | { |
85 | int ret; |
86 | |
87 | mutex_lock(&dev->struct_mutex); |
88 | ret = drm_gem_mmap_object_locked(dev, byte_offset, nbytes, prot, |
89 | uobjp, uoffsetp, file); |
90 | mutex_unlock(&dev->struct_mutex); |
91 | |
92 | return ret; |
93 | } |
94 | |
95 | static int |
96 | drm_gem_mmap_object_locked(struct drm_device *dev, off_t byte_offset, |
97 | size_t nbytes, int prot __unused, struct uvm_object **uobjp, |
98 | voff_t *uoffsetp, struct file *file) |
99 | { |
100 | const unsigned long startpage = (byte_offset >> PAGE_SHIFT); |
101 | const unsigned long npages = (nbytes >> PAGE_SHIFT); |
102 | |
103 | KASSERT(mutex_is_locked(&dev->struct_mutex)); |
104 | KASSERT(drm_core_check_feature(dev, DRIVER_GEM)); |
105 | KASSERT(dev->driver->gem_uvm_ops != NULL); |
106 | KASSERT(prot == (prot & (PROT_READ | PROT_WRITE))); |
107 | KASSERT(0 <= byte_offset); |
108 | KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); |
109 | KASSERT(nbytes == (npages << PAGE_SHIFT)); |
110 | |
111 | struct drm_vma_offset_node *const node = |
112 | drm_vma_offset_exact_lookup(dev->vma_offset_manager, startpage, |
113 | npages); |
114 | if (node == NULL) { |
115 | /* Fall back to vanilla device mappings. */ |
116 | *uobjp = NULL; |
117 | *uoffsetp = (voff_t)-1; |
118 | return 0; |
119 | } |
120 | |
121 | if (!drm_vma_node_is_allowed(node, file)) |
122 | return -EACCES; |
123 | |
124 | struct drm_gem_object *const obj = container_of(node, |
125 | struct drm_gem_object, vma_node); |
126 | KASSERT(obj->dev == dev); |
127 | |
128 | /* Success! */ |
129 | drm_gem_object_reference(obj); |
130 | *uobjp = &obj->gemo_uvmobj; |
131 | *uoffsetp = 0; |
132 | return 0; |
133 | } |
134 | |