1 /* $NetBSD: drm_gem_vm.c,v 1.3 2014/05/01 15:19:16 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 1.3 2014/05/01 15:19:16 riastradh Exp $"); 34 35 #include <sys/types.h> 36 37 #include <uvm/uvm_extern.h> 38 39 #include <drm/drmP.h> 40 41 static int drm_gem_mmap_object_locked(struct drm_device *, off_t, size_t, 42 int, struct uvm_object **, voff_t *); 43 44 void 45 drm_gem_pager_reference(struct uvm_object *uobj) 46 { 47 struct drm_gem_object *const obj = container_of(uobj, 48 struct drm_gem_object, gemo_uvmobj); 49 50 drm_gem_object_reference(obj); 51 } 52 53 void 54 drm_gem_pager_detach(struct uvm_object *uobj) 55 { 56 struct drm_gem_object *const obj = container_of(uobj, 57 struct drm_gem_object, gemo_uvmobj); 58 59 drm_gem_object_unreference_unlocked(obj); 60 } 61 62 int 63 drm_gem_mmap_object(struct drm_device *dev, off_t byte_offset, size_t nbytes, 64 int prot, struct uvm_object **uobjp, voff_t *uoffsetp) 65 { 66 int ret; 67 68 mutex_lock(&dev->struct_mutex); 69 ret = drm_gem_mmap_object_locked(dev, byte_offset, nbytes, prot, 70 uobjp, uoffsetp); 71 mutex_unlock(&dev->struct_mutex); 72 73 return ret; 74 } 75 76 static int 77 drm_gem_mmap_object_locked(struct drm_device *dev, off_t byte_offset, 78 size_t nbytes, int prot __unused, struct uvm_object **uobjp, 79 voff_t *uoffsetp) 80 { 81 struct drm_gem_mm *const mm = dev->mm_private; 82 const off_t page_offset = (byte_offset >> PAGE_SHIFT); 83 struct drm_hash_item *hash; 84 85 KASSERT(mutex_is_locked(&dev->struct_mutex)); 86 KASSERT(drm_core_check_feature(dev, DRIVER_GEM)); 87 KASSERT(dev->driver->gem_uvm_ops != NULL); 88 KASSERT(prot == (prot & (PROT_READ | PROT_WRITE))); 89 KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); 90 91 if (drm_ht_find_item(&mm->offset_hash, page_offset, &hash) != 0) { 92 /* Fall back to vanilla device mappings. */ 93 *uobjp = NULL; 94 *uoffsetp = (voff_t)-1; 95 return 0; 96 } 97 98 struct drm_local_map *const map = drm_hash_entry(hash, 99 struct drm_map_list, hash)->map; 100 101 if (map == NULL) /* XXX How can this happen? */ 102 return -EINVAL; 103 if (map->size < nbytes) 104 return -EOVERFLOW; 105 106 struct drm_gem_object *const obj = map->handle; 107 KASSERT(obj->dev == dev); 108 109 /* Success! */ 110 drm_gem_object_reference(obj); 111 *uobjp = &obj->gemo_uvmobj; 112 *uoffsetp = 0; 113 return 0; 114 } 115