1 /* $NetBSD: drm_vm.c,v 1.13 2022/07/06 01:12:45 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 1.13 2022/07/06 01:12:45 riastradh Exp $"); 34 35 #include <sys/types.h> 36 #include <sys/conf.h> 37 38 #include <uvm/uvm.h> 39 #include <uvm/uvm_extern.h> 40 #include <uvm/uvm_device.h> 41 42 #include <linux/capability.h> 43 44 #include <drm/drm_device.h> 45 #include <drm/drm_file.h> 46 #include <drm/drm_legacy.h> 47 48 static paddr_t drm_legacy_mmap_paddr_locked(struct drm_device *, off_t, int); 49 static paddr_t drm_legacy_mmap_dma_paddr(struct drm_device *, off_t, int); 50 static paddr_t drm_legacy_mmap_map_paddr(struct drm_device *, 51 struct drm_local_map *, off_t, int); 52 53 int 54 drm_legacy_mmap_object(struct drm_device *dev, off_t offset, size_t size, 55 int prot, struct uvm_object **uobjp, voff_t *uoffsetp, 56 struct file *file __unused) 57 { 58 devmajor_t maj = cdevsw_lookup_major(&drm_cdevsw); 59 dev_t devno = makedev(maj, dev->primary->index); 60 struct uvm_object *uobj; 61 62 KASSERT(offset == (offset & ~(PAGE_SIZE-1))); 63 KASSERT(size > 0); 64 65 /* 66 * Attach the device. The size and offset are used only for 67 * access checks; offset does not become a base address for the 68 * subsequent uvm_map, hence we set *uoffsetp to offset, not 0. 69 */ 70 uobj = udv_attach(devno, prot, offset, size); 71 if (uobj == NULL) 72 return -EINVAL; 73 74 *uobjp = uobj; 75 *uoffsetp = offset; 76 return 0; 77 } 78 79 paddr_t 80 drm_legacy_mmap_paddr(struct drm_device *dev, off_t byte_offset, int prot) 81 { 82 paddr_t paddr; 83 84 if (byte_offset != (byte_offset & ~(PAGE_SIZE-1))) 85 return -1; 86 87 mutex_lock(&dev->struct_mutex); 88 paddr = drm_legacy_mmap_paddr_locked(dev, byte_offset, prot); 89 mutex_unlock(&dev->struct_mutex); 90 91 return paddr; 92 } 93 94 static paddr_t 95 drm_legacy_mmap_paddr_locked(struct drm_device *dev, off_t byte_offset, 96 int prot) 97 { 98 const off_t page_offset = (byte_offset >> PAGE_SHIFT); 99 struct drm_hash_item *hash; 100 101 KASSERT(mutex_is_locked(&dev->struct_mutex)); 102 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); 103 104 if ((dev->dma != NULL) && 105 (0 <= byte_offset) && 106 (page_offset <= dev->dma->page_count)) 107 return drm_legacy_mmap_dma_paddr(dev, byte_offset, prot); 108 109 if (drm_ht_find_item(&dev->map_hash, page_offset, &hash)) 110 return -1; 111 112 struct drm_local_map *const map = drm_hash_entry(hash, 113 struct drm_map_list, hash)->map; 114 if (map == NULL) 115 return -1; 116 117 /* 118 * XXX FreeBSD drops the mutex at this point, which would be 119 * nice, to allow sleeping in bus_dma cruft, but I don't know 120 * what guarantees the map will continue to exist. 121 */ 122 123 if (ISSET(map->flags, _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)) 124 return -1; 125 126 if (!(map->offset <= byte_offset)) 127 return -1; 128 if (map->size < (map->offset - byte_offset)) 129 return -1; 130 131 return drm_legacy_mmap_map_paddr(dev, map, (byte_offset - map->offset), 132 prot); 133 } 134 135 static paddr_t 136 drm_legacy_mmap_dma_paddr(struct drm_device *dev, off_t byte_offset, int prot) 137 { 138 const off_t page_offset = (byte_offset >> PAGE_SHIFT); 139 140 KASSERT(mutex_is_locked(&dev->struct_mutex)); 141 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); 142 KASSERT(page_offset <= dev->dma->page_count); 143 144 if (dev->dma->pagelist == NULL) 145 return (paddr_t)-1; 146 147 return dev->dma->pagelist[page_offset]; 148 } 149 150 static paddr_t 151 drm_legacy_mmap_map_paddr(struct drm_device *dev, struct drm_local_map *map, 152 off_t byte_offset, int prot) 153 { 154 int flags = 0; 155 156 KASSERT(byte_offset <= map->size); 157 158 switch (map->type) { 159 case _DRM_FRAME_BUFFER: 160 case _DRM_AGP: 161 flags |= BUS_SPACE_MAP_PREFETCHABLE; 162 /* Fall through. */ 163 164 case _DRM_REGISTERS: 165 flags |= BUS_SPACE_MAP_LINEAR; /* XXX Why? */ 166 167 return bus_space_mmap(map->lm_data.bus_space.bst, map->offset, 168 byte_offset, prot, flags); 169 170 case _DRM_CONSISTENT: { 171 struct drm_dma_handle *const dmah = map->lm_data.dmah; 172 173 return bus_dmamem_mmap(dev->dmat, &dmah->dmah_seg, 1, 174 byte_offset, prot, 175 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */ 176 /* XXX What else? BUS_DMA_COHERENT? */ 177 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE)); 178 } 179 180 case _DRM_SCATTER_GATHER: { 181 struct drm_sg_mem *const sg = dev->sg; 182 183 #if 0 /* XXX */ 184 KASSERT(sg == map->lm_data.sg); 185 #endif 186 187 return bus_dmamem_mmap(dev->dmat, sg->sg_segs, sg->sg_nsegs, 188 byte_offset, prot, 189 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */ 190 /* XXX What else? BUS_DMA_COHERENT? */ 191 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE)); 192 } 193 194 case _DRM_SHM: 195 default: 196 return (paddr_t)-1; 197 } 198 } 199
Indexes created Wed Sep 24 22:09:59 GMT 2025