1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 */
8
9 #include <linux/shmem_fs.h>
10
11 #include "vkms_drv.h"
12
__vkms_gem_create(struct drm_device * dev,u64 size)13 static struct vkms_gem_object *__vkms_gem_create(struct drm_device *dev,
14 u64 size)
15 {
16 struct vkms_gem_object *obj;
17 int ret;
18
19 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
20 if (!obj)
21 return ERR_PTR(-ENOMEM);
22
23 size = roundup(size, PAGE_SIZE);
24 ret = drm_gem_object_init(dev, &obj->gem, size);
25 if (ret) {
26 kfree(obj);
27 return ERR_PTR(ret);
28 }
29
30 mutex_init(&obj->pages_lock);
31
32 return obj;
33 }
34
vkms_gem_free_object(struct drm_gem_object * obj)35 void vkms_gem_free_object(struct drm_gem_object *obj)
36 {
37 struct vkms_gem_object *gem = container_of(obj, struct vkms_gem_object,
38 gem);
39
40 kvfree(gem->pages);
41 mutex_destroy(&gem->pages_lock);
42 drm_gem_object_release(obj);
43 kfree(gem);
44 }
45
vkms_gem_fault(struct vm_fault * vmf)46 int vkms_gem_fault(struct vm_fault *vmf)
47 {
48 struct vm_area_struct *vma = vmf->vma;
49 struct vkms_gem_object *obj = vma->vm_private_data;
50 unsigned long vaddr = vmf->address;
51 pgoff_t page_offset;
52 loff_t num_pages;
53 int ret;
54
55 page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
56 num_pages = DIV_ROUND_UP(obj->gem.size, PAGE_SIZE);
57
58 if (page_offset > num_pages)
59 return VM_FAULT_SIGBUS;
60
61 ret = -ENOENT;
62 mutex_lock(&obj->pages_lock);
63 if (obj->pages) {
64 get_page(obj->pages[page_offset]);
65 vmf->page = obj->pages[page_offset];
66 ret = 0;
67 }
68 mutex_unlock(&obj->pages_lock);
69 if (ret) {
70 struct page *page;
71 struct address_space *mapping;
72
73 mapping = file_inode(obj->gem.filp)->i_mapping;
74 page = shmem_read_mapping_page(mapping, page_offset);
75
76 if (!IS_ERR(page)) {
77 vmf->page = page;
78 ret = 0;
79 } else {
80 switch (PTR_ERR(page)) {
81 case -ENOSPC:
82 case -ENOMEM:
83 ret = VM_FAULT_OOM;
84 break;
85 case -EBUSY:
86 ret = VM_FAULT_RETRY;
87 break;
88 case -EFAULT:
89 case -EINVAL:
90 ret = VM_FAULT_SIGBUS;
91 break;
92 default:
93 WARN_ON(PTR_ERR(page));
94 ret = VM_FAULT_SIGBUS;
95 break;
96 }
97 }
98 }
99 return ret;
100 }
101
vkms_gem_create(struct drm_device * dev,struct drm_file * file,u32 * handle,u64 size)102 struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
103 struct drm_file *file,
104 u32 *handle,
105 u64 size)
106 {
107 struct vkms_gem_object *obj;
108 int ret;
109
110 if (!file || !dev || !handle)
111 return ERR_PTR(-EINVAL);
112
113 obj = __vkms_gem_create(dev, size);
114 if (IS_ERR(obj))
115 return ERR_CAST(obj);
116
117 ret = drm_gem_handle_create(file, &obj->gem, handle);
118 drm_gem_object_put_unlocked(&obj->gem);
119 if (ret) {
120 drm_gem_object_release(&obj->gem);
121 kfree(obj);
122 return ERR_PTR(ret);
123 }
124
125 return &obj->gem;
126 }
127
vkms_dumb_create(struct drm_file * file,struct drm_device * dev,struct drm_mode_create_dumb * args)128 int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
129 struct drm_mode_create_dumb *args)
130 {
131 struct drm_gem_object *gem_obj;
132 u64 pitch, size;
133
134 if (!args || !dev || !file)
135 return -EINVAL;
136
137 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
138 size = pitch * args->height;
139
140 if (!size)
141 return -EINVAL;
142
143 gem_obj = vkms_gem_create(dev, file, &args->handle, size);
144 if (IS_ERR(gem_obj))
145 return PTR_ERR(gem_obj);
146
147 args->size = gem_obj->size;
148 args->pitch = pitch;
149
150 DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
151
152 return 0;
153 }
154
vkms_dumb_map(struct drm_file * file,struct drm_device * dev,u32 handle,u64 * offset)155 int vkms_dumb_map(struct drm_file *file, struct drm_device *dev,
156 u32 handle, u64 *offset)
157 {
158 struct drm_gem_object *obj;
159 int ret;
160
161 obj = drm_gem_object_lookup(file, handle);
162 if (!obj)
163 return -ENOENT;
164
165 if (!obj->filp) {
166 ret = -EINVAL;
167 goto unref;
168 }
169
170 ret = drm_gem_create_mmap_offset(obj);
171 if (ret)
172 goto unref;
173
174 *offset = drm_vma_node_offset_addr(&obj->vma_node);
175 unref:
176 drm_gem_object_put_unlocked(obj);
177
178 return ret;
179 }
180
