1 /* $NetBSD: drm_vm.c,v 1.11 2020/02/14 04:36:56 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 1.11 2020/02/14 04:36:56 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 <drm/drmP.h> 43 #include <drm/drm_legacy.h> 44 45 static paddr_t drm_legacy_mmap_paddr_locked(struct drm_device *, off_t, int); 46 static paddr_t drm_legacy_mmap_dma_paddr(struct drm_device *, off_t, int); 47 static paddr_t drm_legacy_mmap_map_paddr(struct drm_device *, 48 struct drm_local_map *, off_t, int); 49 50 int 51 drm_legacy_mmap_object(struct drm_device *dev, off_t offset, size_t size, 52 int prot, struct uvm_object **uobjp, voff_t *uoffsetp, 53 struct file *file __unused) 54 { 55 devmajor_t maj = cdevsw_lookup_major(&drm_cdevsw); 56 dev_t devno = makedev(maj, dev->primary->index); 57 struct uvm_object *uobj; 58 59 KASSERT(offset == (offset & ~(PAGE_SIZE-1))); 60 61 /* 62 * Attach the device. The size and offset are used only for 63 * access checks; offset does not become a base address for the 64 * subsequent uvm_map, hence we set *uoffsetp to offset, not 0. 65 */ 66 uobj = udv_attach(devno, prot, offset, size); 67 if (uobj == NULL) 68 return -EINVAL; 69 70 *uobjp = uobj; 71 *uoffsetp = offset; 72 return 0; 73 } 74 75 paddr_t 76 drm_legacy_mmap_paddr(struct drm_device *dev, off_t byte_offset, int prot) 77 { 78 paddr_t paddr; 79 80 if (byte_offset != (byte_offset & ~(PAGE_SIZE-1))) 81 return -1; 82 83 mutex_lock(&dev->struct_mutex); 84 paddr = drm_legacy_mmap_paddr_locked(dev, byte_offset, prot); 85 mutex_unlock(&dev->struct_mutex); 86 87 return paddr; 88 } 89 90 static paddr_t 91 drm_legacy_mmap_paddr_locked(struct drm_device *dev, off_t byte_offset, 92 int prot) 93 { 94 const off_t page_offset = (byte_offset >> PAGE_SHIFT); 95 struct drm_hash_item *hash; 96 97 KASSERT(mutex_is_locked(&dev->struct_mutex)); 98 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); 99 100 if ((dev->dma != NULL) && 101 (0 <= byte_offset) && 102 (page_offset <= dev->dma->page_count)) 103 return drm_legacy_mmap_dma_paddr(dev, byte_offset, prot); 104 105 if (drm_ht_find_item(&dev->map_hash, page_offset, &hash)) 106 return -1; 107 108 struct drm_local_map *const map = drm_hash_entry(hash, 109 struct drm_map_list, hash)->map; 110 if (map == NULL) 111 return -1; 112 113 /* 114 * XXX FreeBSD drops the mutex at this point, which would be 115 * nice, to allow sleeping in bus_dma cruft, but I don't know 116 * what guarantees the map will continue to exist. 117 */ 118 119 if (ISSET(map->flags, _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)) 120 return -1; 121 122 if (!(map->offset <= byte_offset)) 123 return -1; 124 if (map->size < (map->offset - byte_offset)) 125 return -1; 126 127 return drm_legacy_mmap_map_paddr(dev, map, (byte_offset - map->offset), 128 prot); 129 } 130 131 static paddr_t 132 drm_legacy_mmap_dma_paddr(struct drm_device *dev, off_t byte_offset, int prot) 133 { 134 const off_t page_offset = (byte_offset >> PAGE_SHIFT); 135 136 KASSERT(mutex_is_locked(&dev->struct_mutex)); 137 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); 138 KASSERT(page_offset <= dev->dma->page_count); 139 140 if (dev->dma->pagelist == NULL) 141 return (paddr_t)-1; 142 143 return dev->dma->pagelist[page_offset]; 144 } 145 146 static paddr_t 147 drm_legacy_mmap_map_paddr(struct drm_device *dev, struct drm_local_map *map, 148 off_t byte_offset, int prot) 149 { 150 int flags = 0; 151 152 KASSERT(byte_offset <= map->size); 153 154 switch (map->type) { 155 case _DRM_FRAME_BUFFER: 156 case _DRM_AGP: 157 flags |= BUS_SPACE_MAP_PREFETCHABLE; 158 /* Fall through. */ 159 160 case _DRM_REGISTERS: 161 flags |= BUS_SPACE_MAP_LINEAR; /* XXX Why? */ 162 163 return bus_space_mmap(map->lm_data.bus_space.bst, map->offset, 164 byte_offset, prot, flags); 165 166 case _DRM_CONSISTENT: { 167 struct drm_dma_handle *const dmah = map->lm_data.dmah; 168 169 return bus_dmamem_mmap(dev->dmat, &dmah->dmah_seg, 1, 170 byte_offset, prot, 171 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */ 172 /* XXX What else? BUS_DMA_COHERENT? */ 173 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE)); 174 } 175 176 case _DRM_SCATTER_GATHER: { 177 struct drm_sg_mem *const sg = dev->sg; 178 179 #if 0 /* XXX */ 180 KASSERT(sg == map->lm_data.sg); 181 #endif 182 183 return bus_dmamem_mmap(dev->dmat, sg->sg_segs, sg->sg_nsegs, 184 byte_offset, prot, 185 /* XXX BUS_DMA_WAITOK? We're holding a mutex... */ 186 /* XXX What else? BUS_DMA_COHERENT? */ 187 (BUS_DMA_WAITOK | BUS_DMA_NOCACHE)); 188 } 189 190 case _DRM_SHM: 191 default: 192 return (paddr_t)-1; 193 } 194 } 195