1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
// SPDX-License-Identifier: GPL-2.0
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/shmem_fs.h>
#include "vkms_drv.h"
static struct vkms_gem_object *__vkms_gem_create(struct drm_device *dev,
u64 size)
{
struct vkms_gem_object *obj;
int ret;
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
if (!obj)
return ERR_PTR(-ENOMEM);
size = roundup(size, PAGE_SIZE);
ret = drm_gem_object_init(dev, &obj->gem, size);
if (ret) {
kfree(obj);
return ERR_PTR(ret);
}
mutex_init(&obj->pages_lock);
return obj;
}
void vkms_gem_free_object(struct drm_gem_object *obj)
{
struct vkms_gem_object *gem = container_of(obj, struct vkms_gem_object,
gem);
WARN_ON(gem->pages);
WARN_ON(gem->vaddr);
mutex_destroy(&gem->pages_lock);
drm_gem_object_release(obj);
kfree(gem);
}
vm_fault_t vkms_gem_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct vkms_gem_object *obj = vma->vm_private_data;
unsigned long vaddr = vmf->address;
pgoff_t page_offset;
loff_t num_pages;
vm_fault_t ret = VM_FAULT_SIGBUS;
page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
num_pages = DIV_ROUND_UP(obj->gem.size, PAGE_SIZE);
if (page_offset > num_pages)
return VM_FAULT_SIGBUS;
mutex_lock(&obj->pages_lock);
if (obj->pages) {
get_page(obj->pages[page_offset]);
vmf->page = obj->pages[page_offset];
ret = 0;
}
mutex_unlock(&obj->pages_lock);
if (ret) {
struct page *page;
struct address_space *mapping;
mapping = file_inode(obj->gem.filp)->i_mapping;
page = shmem_read_mapping_page(mapping, page_offset);
if (!IS_ERR(page)) {
vmf->page = page;
ret = 0;
} else {
switch (PTR_ERR(page)) {
case -ENOSPC:
case -ENOMEM:
ret = VM_FAULT_OOM;
break;
case -EBUSY:
ret = VM_FAULT_RETRY;
break;
case -EFAULT:
case -EINVAL:
ret = VM_FAULT_SIGBUS;
break;
default:
WARN_ON(PTR_ERR(page));
ret = VM_FAULT_SIGBUS;
break;
}
}
}
return ret;
}
struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
struct drm_file *file,
u32 *handle,
u64 size)
{
struct vkms_gem_object *obj;
int ret;
if (!file || !dev || !handle)
return ERR_PTR(-EINVAL);
obj = __vkms_gem_create(dev, size);
if (IS_ERR(obj))
return ERR_CAST(obj);
ret = drm_gem_handle_create(file, &obj->gem, handle);
drm_gem_object_put_unlocked(&obj->gem);
if (ret) {
drm_gem_object_release(&obj->gem);
kfree(obj);
return ERR_PTR(ret);
}
return &obj->gem;
}
int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args)
{
struct drm_gem_object *gem_obj;
u64 pitch, size;
if (!args || !dev || !file)
return -EINVAL;
pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
size = pitch * args->height;
if (!size)
return -EINVAL;
gem_obj = vkms_gem_create(dev, file, &args->handle, size);
if (IS_ERR(gem_obj))
return PTR_ERR(gem_obj);
args->size = gem_obj->size;
args->pitch = pitch;
DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
return 0;
}
int vkms_dumb_map(struct drm_file *file, struct drm_device *dev,
u32 handle, u64 *offset)
{
struct drm_gem_object *obj;
int ret;
obj = drm_gem_object_lookup(file, handle);
if (!obj)
return -ENOENT;
if (!obj->filp) {
ret = -EINVAL;
goto unref;
}
ret = drm_gem_create_mmap_offset(obj);
if (ret)
goto unref;
*offset = drm_vma_node_offset_addr(&obj->vma_node);
unref:
drm_gem_object_put_unlocked(obj);
return ret;
}
static struct page **_get_pages(struct vkms_gem_object *vkms_obj)
{
struct drm_gem_object *gem_obj = &vkms_obj->gem;
if (!vkms_obj->pages) {
struct page **pages = drm_gem_get_pages(gem_obj);
if (IS_ERR(pages))
return pages;
if (cmpxchg(&vkms_obj->pages, NULL, pages))
drm_gem_put_pages(gem_obj, pages, false, true);
}
return vkms_obj->pages;
}
void vkms_gem_vunmap(struct drm_gem_object *obj)
{
struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
mutex_lock(&vkms_obj->pages_lock);
if (vkms_obj->vmap_count < 1) {
WARN_ON(vkms_obj->vaddr);
WARN_ON(vkms_obj->pages);
mutex_unlock(&vkms_obj->pages_lock);
return;
}
vkms_obj->vmap_count--;
if (vkms_obj->vmap_count == 0) {
vunmap(vkms_obj->vaddr);
vkms_obj->vaddr = NULL;
drm_gem_put_pages(obj, vkms_obj->pages, false, true);
vkms_obj->pages = NULL;
}
mutex_unlock(&vkms_obj->pages_lock);
}
int vkms_gem_vmap(struct drm_gem_object *obj)
{
struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
int ret = 0;
mutex_lock(&vkms_obj->pages_lock);
if (!vkms_obj->vaddr) {
unsigned int n_pages = obj->size >> PAGE_SHIFT;
struct page **pages = _get_pages(vkms_obj);
if (IS_ERR(pages)) {
ret = PTR_ERR(pages);
goto out;
}
vkms_obj->vaddr = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
if (!vkms_obj->vaddr)
goto err_vmap;
vkms_obj->vmap_count++;
}
goto out;
err_vmap:
ret = -ENOMEM;
drm_gem_put_pages(obj, vkms_obj->pages, false, true);
vkms_obj->pages = NULL;
out:
mutex_unlock(&vkms_obj->pages_lock);
return ret;
}
|
