| 1 | /* $NetBSD: drm_gem_vm.c,v 1.6 2015/03/09 01:29:40 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 1.6 2015/03/09 01:29:40 riastradh Exp $" ); |
| 34 | |
| 35 | #include <sys/types.h> |
| 36 | |
| 37 | #include <uvm/uvm_extern.h> |
| 38 | |
| 39 | #include <drm/drmP.h> |
| 40 | #include <drm/drm_vma_manager.h> |
| 41 | |
| 42 | static int drm_gem_mmap_object_locked(struct drm_device *, off_t, size_t, |
| 43 | int, struct uvm_object **, voff_t *, struct file *); |
| 44 | |
| 45 | void |
| 46 | (struct uvm_object *uobj) |
| 47 | { |
| 48 | struct drm_gem_object *const obj = container_of(uobj, |
| 49 | struct drm_gem_object, gemo_uvmobj); |
| 50 | |
| 51 | drm_gem_object_reference(obj); |
| 52 | } |
| 53 | |
| 54 | void |
| 55 | (struct uvm_object *uobj) |
| 56 | { |
| 57 | struct drm_gem_object *const obj = container_of(uobj, |
| 58 | struct drm_gem_object, gemo_uvmobj); |
| 59 | |
| 60 | drm_gem_object_unreference_unlocked(obj); |
| 61 | } |
| 62 | |
| 63 | int |
| 64 | drm_gem_or_legacy_mmap_object(struct drm_device *dev, off_t byte_offset, |
| 65 | size_t nbytes, int prot, struct uvm_object **uobjp, voff_t *uoffsetp, |
| 66 | struct file *file) |
| 67 | { |
| 68 | int ret; |
| 69 | |
| 70 | ret = drm_gem_mmap_object(dev, byte_offset, nbytes, prot, uobjp, |
| 71 | uoffsetp, file); |
| 72 | if (ret) |
| 73 | return ret; |
| 74 | if (*uobjp != NULL) |
| 75 | return 0; |
| 76 | |
| 77 | return drm_mmap_object(dev, byte_offset, nbytes, prot, uobjp, |
| 78 | uoffsetp, file); |
| 79 | } |
| 80 | |
| 81 | int |
| 82 | drm_gem_mmap_object(struct drm_device *dev, off_t byte_offset, size_t nbytes, |
| 83 | int prot, struct uvm_object **uobjp, voff_t *uoffsetp, struct file *file) |
| 84 | { |
| 85 | int ret; |
| 86 | |
| 87 | mutex_lock(&dev->struct_mutex); |
| 88 | ret = drm_gem_mmap_object_locked(dev, byte_offset, nbytes, prot, |
| 89 | uobjp, uoffsetp, file); |
| 90 | mutex_unlock(&dev->struct_mutex); |
| 91 | |
| 92 | return ret; |
| 93 | } |
| 94 | |
| 95 | static int |
| 96 | drm_gem_mmap_object_locked(struct drm_device *dev, off_t byte_offset, |
| 97 | size_t nbytes, int prot __unused, struct uvm_object **uobjp, |
| 98 | voff_t *uoffsetp, struct file *file) |
| 99 | { |
| 100 | const unsigned long startpage = (byte_offset >> PAGE_SHIFT); |
| 101 | const unsigned long npages = (nbytes >> PAGE_SHIFT); |
| 102 | |
| 103 | KASSERT(mutex_is_locked(&dev->struct_mutex)); |
| 104 | KASSERT(drm_core_check_feature(dev, DRIVER_GEM)); |
| 105 | KASSERT(dev->driver->gem_uvm_ops != NULL); |
| 106 | KASSERT(prot == (prot & (PROT_READ | PROT_WRITE))); |
| 107 | KASSERT(0 <= byte_offset); |
| 108 | KASSERT(byte_offset == (byte_offset & ~(PAGE_SIZE-1))); |
| 109 | KASSERT(nbytes == (npages << PAGE_SHIFT)); |
| 110 | |
| 111 | struct drm_vma_offset_node *const node = |
| 112 | drm_vma_offset_exact_lookup(dev->vma_offset_manager, startpage, |
| 113 | npages); |
| 114 | if (node == NULL) { |
| 115 | /* Fall back to vanilla device mappings. */ |
| 116 | *uobjp = NULL; |
| 117 | *uoffsetp = (voff_t)-1; |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | if (!drm_vma_node_is_allowed(node, file)) |
| 122 | return -EACCES; |
| 123 | |
| 124 | struct drm_gem_object *const obj = container_of(node, |
| 125 | struct drm_gem_object, vma_node); |
| 126 | KASSERT(obj->dev == dev); |
| 127 | |
| 128 | /* Success! */ |
| 129 | drm_gem_object_reference(obj); |
| 130 | *uobjp = &obj->gemo_uvmobj; |
| 131 | *uoffsetp = 0; |
| 132 | return 0; |
| 133 | } |
| 134 | |