drm_vm.c revision 1.4 1 /* $NetBSD: drm_vm.c,v 1.4 2014/07/16 20:56:25 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_vm.c,v 1.4 2014/07/16 20:56:25 riastradh Exp $");
34
35 #include <sys/types.h>
36 #include <sys/conf.h>
37
38 #include <uvm/uvm_extern.h>
39 #include <uvm/uvm_device.h>
40
41 #include <drm/drmP.h>
42
43 static paddr_t drm_mmap_paddr_locked(struct drm_device *, off_t, int);
44 static paddr_t drm_mmap_dma_paddr(struct drm_device *, off_t, int);
45 static paddr_t drm_mmap_map_paddr(struct drm_device *, struct drm_local_map *,
46 off_t, int);
47
48 int
49 drm_mmap_object(struct drm_device *dev, off_t offset, size_t size, int prot,
50 struct uvm_object **uobjp, voff_t *uoffsetp)
51 {
52 dev_t devno = cdevsw_lookup_major(&drm_cdevsw);
53 struct uvm_object *uobj;
54
55 KASSERT(offset == (offset & ~(PAGE_SIZE-1)));
56
57 /*
58 * Attach the device. The size and offset are used only for
59 * access checks; offset does not become a base address for the
60 * subsequent uvm_map, hence we set *uoffsetp to offset, not 0.
61 */
62 uobj = udv_attach(&devno, prot, offset, size);
63 if (uobj == NULL)
64 return -EINVAL;
65
66 *uobjp = uobj;
67 *uoffsetp = offset;
68 return 0;
69 }
70
71 paddr_t
72 drm_mmap_paddr(struct drm_device *dev, off_t byte_offset, int prot)
73 {
74 paddr_t paddr;
75
76 if (byte_offset != (byte_offset & ~(PAGE_SIZE-1)))
77 return -1;
78
79 mutex_lock(&dev->struct_mutex);
80 paddr = drm_mmap_paddr_locked(dev, byte_offset, prot);
81 mutex_unlock(&dev->struct_mutex);
82
83 return paddr;
84 }
85
86 static paddr_t
87 drm_mmap_paddr_locked(struct drm_device *dev, off_t byte_offset, int prot)
88 {
89 const off_t page_offset = (byte_offset >> PAGE_SHIFT);
90 struct drm_hash_item *hash;
91
92 KASSERT(mutex_is_locked(&dev->struct_mutex));
93 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1)));
94
95 if ((dev->dma != NULL) &&
96 (0 <= byte_offset) &&
97 (page_offset <= dev->dma->page_count))
98 return drm_mmap_dma_paddr(dev, byte_offset, prot);
99
100 if (drm_ht_find_item(&dev->map_hash, page_offset, &hash))
101 return -1;
102
103 struct drm_local_map *const map = drm_hash_entry(hash,
104 struct drm_map_list, hash)->map;
105 if (map == NULL)
106 return -1;
107
108 /*
109 * XXX FreeBSD drops the mutex at this point, which would be
110 * nice, to allow sleeping in bus_dma cruft, but I don't know
111 * what guarantees the map will continue to exist.
112 */
113
114 if (ISSET(map->flags, _DRM_RESTRICTED) && !DRM_SUSER())
115 return -1;
116
117 if (!(map->offset <= byte_offset))
118 return -1;
119 if (map->size < (map->offset - byte_offset))
120 return -1;
121
122 return drm_mmap_map_paddr(dev, map, (byte_offset - map->offset), prot);
123 }
124
125 static paddr_t
126 drm_mmap_dma_paddr(struct drm_device *dev, off_t byte_offset, int prot)
127 {
128 const off_t page_offset = (byte_offset >> PAGE_SHIFT);
129
130 KASSERT(mutex_is_locked(&dev->struct_mutex));
131 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1)));
132 KASSERT(page_offset <= dev->dma->page_count);
133
134 if (dev->dma->pagelist == NULL)
135 return (paddr_t)-1;
136
137 return dev->dma->pagelist[page_offset];
138 }
139
140 static paddr_t
141 drm_mmap_map_paddr(struct drm_device *dev, struct drm_local_map *map,
142 off_t byte_offset, int prot)
143 {
144 int flags = 0;
145
146 KASSERT(byte_offset <= map->size);
147
148 switch (map->type) {
149 case _DRM_FRAME_BUFFER:
150 case _DRM_AGP:
151 flags |= BUS_SPACE_MAP_PREFETCHABLE;
152 /* Fall through. */
153
154 case _DRM_REGISTERS:
155 flags |= BUS_SPACE_MAP_LINEAR; /* XXX Why? */
156
157 return bus_space_mmap(map->lm_data.bus_space.bst, map->offset,
158 byte_offset, prot, flags);
159
160 case _DRM_CONSISTENT: {
161 struct drm_dma_handle *const dmah = map->lm_data.dmah;
162
163 return bus_dmamem_mmap(dev->dmat, &dmah->dmah_seg, 1,
164 byte_offset, prot,
165 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */
166 /* XXX What else? BUS_DMA_COHERENT? */
167 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
168 }
169
170 case _DRM_SCATTER_GATHER: {
171 struct drm_sg_mem *const sg = dev->sg;
172
173 #if 0 /* XXX */
174 KASSERT(sg == map->lm_data.sg);
175 #endif
176
177 return bus_dmamem_mmap(dev->dmat, sg->sg_segs, sg->sg_nsegs,
178 byte_offset, prot,
179 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */
180 /* XXX What else? BUS_DMA_COHERENT? */
181 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
182 }
183
184 case _DRM_SHM:
185 default:
186 return (paddr_t)-1;
187 }
188 }
189