1/* $NetBSD: drm_vm.c,v 1.7 2014/12/31 08:55:18 mrg 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 1.7 2014/12/31 08:55:18 mrg 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
43static paddr_t drm_mmap_paddr_locked(struct drm_device *, off_t, int);
44static paddr_t drm_mmap_dma_paddr(struct drm_device *, off_t, int);
45static paddr_t drm_mmap_map_paddr(struct drm_device *, struct drm_local_map *,
46 off_t, int);
47
48int
49drm_mmap_object(struct drm_device *dev, off_t offset, size_t size, int prot,
50 struct uvm_object **uobjp, voff_t *uoffsetp, struct file *file __unused)
51{
52 devmajor_t maj = cdevsw_lookup_major(&drm_cdevsw);
53 dev_t devno = makedev(maj, dev->primary->index);
54 struct uvm_object *uobj;
55
56 KASSERT(offset == (offset & ~(PAGE_SIZE-1)));
57
58 /*
59 * Attach the device. The size and offset are used only for
60 * access checks; offset does not become a base address for the
61 * subsequent uvm_map, hence we set *uoffsetp to offset, not 0.
62 */
63 uobj = udv_attach(devno, prot, offset, size);
64 if (uobj == NULL)
65 return -EINVAL;
66
67 *uobjp = uobj;
68 *uoffsetp = offset;
69 return 0;
70}
71
72paddr_t
73drm_mmap_paddr(struct drm_device *dev, off_t byte_offset, int prot)
74{
75 paddr_t paddr;
76
77 if (byte_offset != (byte_offset & ~(PAGE_SIZE-1)))
78 return -1;
79
80 mutex_lock(&dev->struct_mutex);
81 paddr = drm_mmap_paddr_locked(dev, byte_offset, prot);
82 mutex_unlock(&dev->struct_mutex);
83
84 return paddr;
85}
86
87static paddr_t
88drm_mmap_paddr_locked(struct drm_device *dev, off_t byte_offset, int prot)
89{
90 const off_t page_offset = (byte_offset >> PAGE_SHIFT);
91 struct drm_hash_item *hash;
92
93 KASSERT(mutex_is_locked(&dev->struct_mutex));
94 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1)));
95
96 if ((dev->dma != NULL) &&
97 (0 <= byte_offset) &&
98 (page_offset <= dev->dma->page_count))
99 return drm_mmap_dma_paddr(dev, byte_offset, prot);
100
101 if (drm_ht_find_item(&dev->map_hash, page_offset, &hash))
102 return -1;
103
104 struct drm_local_map *const map = drm_hash_entry(hash,
105 struct drm_map_list, hash)->map;
106 if (map == NULL)
107 return -1;
108
109 /*
110 * XXX FreeBSD drops the mutex at this point, which would be
111 * nice, to allow sleeping in bus_dma cruft, but I don't know
112 * what guarantees the map will continue to exist.
113 */
114
115 if (ISSET(map->flags, _DRM_RESTRICTED) && !DRM_SUSER())
116 return -1;
117
118 if (!(map->offset <= byte_offset))
119 return -1;
120 if (map->size < (map->offset - byte_offset))
121 return -1;
122
123 return drm_mmap_map_paddr(dev, map, (byte_offset - map->offset), prot);
124}
125
126static paddr_t
127drm_mmap_dma_paddr(struct drm_device *dev, off_t byte_offset, int prot)
128{
129 const off_t page_offset = (byte_offset >> PAGE_SHIFT);
130
131 KASSERT(mutex_is_locked(&dev->struct_mutex));
132 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1)));
133 KASSERT(page_offset <= dev->dma->page_count);
134
135 if (dev->dma->pagelist == NULL)
136 return (paddr_t)-1;
137
138 return dev->dma->pagelist[page_offset];
139}
140
141static paddr_t
142drm_mmap_map_paddr(struct drm_device *dev, struct drm_local_map *map,
143 off_t byte_offset, int prot)
144{
145 int flags = 0;
146
147 KASSERT(byte_offset <= map->size);
148
149 switch (map->type) {
150 case _DRM_FRAME_BUFFER:
151 case _DRM_AGP:
152 flags |= BUS_SPACE_MAP_PREFETCHABLE;
153 /* Fall through. */
154
155 case _DRM_REGISTERS:
156 flags |= BUS_SPACE_MAP_LINEAR; /* XXX Why? */
157
158 return bus_space_mmap(map->lm_data.bus_space.bst, map->offset,
159 byte_offset, prot, flags);
160
161 case _DRM_CONSISTENT: {
162 struct drm_dma_handle *const dmah = map->lm_data.dmah;
163
164 return bus_dmamem_mmap(dev->dmat, &dmah->dmah_seg, 1,
165 byte_offset, prot,
166 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */
167 /* XXX What else? BUS_DMA_COHERENT? */
168 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
169 }
170
171 case _DRM_SCATTER_GATHER: {
172 struct drm_sg_mem *const sg = dev->sg;
173
174#if 0 /* XXX */
175 KASSERT(sg == map->lm_data.sg);
176#endif
177
178 return bus_dmamem_mmap(dev->dmat, sg->sg_segs, sg->sg_nsegs,
179 byte_offset, prot,
180 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */
181 /* XXX What else? BUS_DMA_COHERENT? */
182 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
183 }
184
185 case _DRM_SHM:
186 default:
187 return (paddr_t)-1;
188 }
189}
190