Loading...
1// SPDX-License-Identifier: GPL-2.0 OR MIT
2/**************************************************************************
3 *
4 * Copyright 2009-2022 VMware, Inc., Palo Alto, CA., USA
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28#include "vmwgfx_drv.h"
29#include "vmwgfx_devcaps.h"
30#include "vmwgfx_kms.h"
31
32#include <drm/vmwgfx_drm.h>
33#include <linux/pci.h>
34#include <linux/vmalloc.h>
35
36int vmw_getparam_ioctl(struct drm_device *dev, void *data,
37 struct drm_file *file_priv)
38{
39 struct vmw_private *dev_priv = vmw_priv(dev);
40 struct drm_vmw_getparam_arg *param =
41 (struct drm_vmw_getparam_arg *)data;
42 struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
43
44 switch (param->param) {
45 case DRM_VMW_PARAM_NUM_STREAMS:
46 param->value = vmw_overlay_num_overlays(dev_priv);
47 break;
48 case DRM_VMW_PARAM_NUM_FREE_STREAMS:
49 param->value = vmw_overlay_num_free_overlays(dev_priv);
50 break;
51 case DRM_VMW_PARAM_3D:
52 param->value = vmw_supports_3d(dev_priv) ? 1 : 0;
53 break;
54 case DRM_VMW_PARAM_HW_CAPS:
55 param->value = dev_priv->capabilities;
56 break;
57 case DRM_VMW_PARAM_HW_CAPS2:
58 param->value = dev_priv->capabilities2;
59 break;
60 case DRM_VMW_PARAM_FIFO_CAPS:
61 param->value = vmw_fifo_caps(dev_priv);
62 break;
63 case DRM_VMW_PARAM_MAX_FB_SIZE:
64 param->value = dev_priv->max_primary_mem;
65 break;
66 case DRM_VMW_PARAM_FIFO_HW_VERSION:
67 {
68 if ((dev_priv->capabilities & SVGA_CAP_GBOBJECTS))
69 param->value = SVGA3D_HWVERSION_WS8_B1;
70 else
71 param->value = vmw_fifo_mem_read(
72 dev_priv,
73 ((vmw_fifo_caps(dev_priv) &
74 SVGA_FIFO_CAP_3D_HWVERSION_REVISED) ?
75 SVGA_FIFO_3D_HWVERSION_REVISED :
76 SVGA_FIFO_3D_HWVERSION));
77 break;
78 }
79 case DRM_VMW_PARAM_MAX_SURF_MEMORY:
80 if ((dev_priv->capabilities & SVGA_CAP_GBOBJECTS) &&
81 !vmw_fp->gb_aware)
82 param->value = dev_priv->max_mob_pages * PAGE_SIZE / 2;
83 else
84 param->value = dev_priv->memory_size;
85 break;
86 case DRM_VMW_PARAM_3D_CAPS_SIZE:
87 param->value = vmw_devcaps_size(dev_priv, vmw_fp->gb_aware);
88 break;
89 case DRM_VMW_PARAM_MAX_MOB_MEMORY:
90 vmw_fp->gb_aware = true;
91 param->value = dev_priv->max_mob_pages * PAGE_SIZE;
92 break;
93 case DRM_VMW_PARAM_MAX_MOB_SIZE:
94 param->value = dev_priv->max_mob_size;
95 break;
96 case DRM_VMW_PARAM_SCREEN_TARGET:
97 param->value =
98 (dev_priv->active_display_unit == vmw_du_screen_target);
99 break;
100 case DRM_VMW_PARAM_DX:
101 param->value = has_sm4_context(dev_priv);
102 break;
103 case DRM_VMW_PARAM_SM4_1:
104 param->value = has_sm4_1_context(dev_priv);
105 break;
106 case DRM_VMW_PARAM_SM5:
107 param->value = has_sm5_context(dev_priv);
108 break;
109 case DRM_VMW_PARAM_GL43:
110 param->value = has_gl43_context(dev_priv);
111 break;
112 case DRM_VMW_PARAM_DEVICE_ID:
113 param->value = to_pci_dev(dev_priv->drm.dev)->device;
114 break;
115 default:
116 return -EINVAL;
117 }
118
119 return 0;
120}
121
122
123int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data,
124 struct drm_file *file_priv)
125{
126 struct drm_vmw_get_3d_cap_arg *arg =
127 (struct drm_vmw_get_3d_cap_arg *) data;
128 struct vmw_private *dev_priv = vmw_priv(dev);
129 uint32_t size;
130 void __user *buffer = (void __user *)((unsigned long)(arg->buffer));
131 void *bounce = NULL;
132 int ret;
133 struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
134
135 if (unlikely(arg->pad64 != 0 || arg->max_size == 0)) {
136 VMW_DEBUG_USER("Illegal GET_3D_CAP argument.\n");
137 return -EINVAL;
138 }
139
140 size = vmw_devcaps_size(dev_priv, vmw_fp->gb_aware);
141 if (unlikely(size == 0)) {
142 DRM_ERROR("Failed to figure out the devcaps size (no 3D).\n");
143 return -ENOMEM;
144 }
145
146 if (arg->max_size < size)
147 size = arg->max_size;
148
149 bounce = vzalloc(size);
150 if (unlikely(bounce == NULL)) {
151 DRM_ERROR("Failed to allocate bounce buffer for 3D caps.\n");
152 return -ENOMEM;
153 }
154
155 ret = vmw_devcaps_copy(dev_priv, vmw_fp->gb_aware, bounce, size);
156 if (unlikely (ret != 0))
157 goto out_err;
158
159 ret = copy_to_user(buffer, bounce, size);
160 if (ret)
161 ret = -EFAULT;
162out_err:
163 vfree(bounce);
164
165 if (unlikely(ret != 0))
166 DRM_ERROR("Failed to report 3D caps info.\n");
167
168 return ret;
169}
170
171int vmw_present_ioctl(struct drm_device *dev, void *data,
172 struct drm_file *file_priv)
173{
174 struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
175 struct vmw_private *dev_priv = vmw_priv(dev);
176 struct drm_vmw_present_arg *arg =
177 (struct drm_vmw_present_arg *)data;
178 struct vmw_surface *surface;
179 struct drm_vmw_rect __user *clips_ptr;
180 struct drm_vmw_rect *clips = NULL;
181 struct drm_framebuffer *fb;
182 struct vmw_framebuffer *vfb;
183 struct vmw_resource *res;
184 uint32_t num_clips;
185 int ret;
186
187 num_clips = arg->num_clips;
188 clips_ptr = (struct drm_vmw_rect __user *)(unsigned long)arg->clips_ptr;
189
190 if (unlikely(num_clips == 0))
191 return 0;
192
193 if (clips_ptr == NULL) {
194 VMW_DEBUG_USER("Variable clips_ptr must be specified.\n");
195 ret = -EINVAL;
196 goto out_clips;
197 }
198
199 clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
200 if (clips == NULL) {
201 DRM_ERROR("Failed to allocate clip rect list.\n");
202 ret = -ENOMEM;
203 goto out_clips;
204 }
205
206 ret = copy_from_user(clips, clips_ptr, num_clips * sizeof(*clips));
207 if (ret) {
208 DRM_ERROR("Failed to copy clip rects from userspace.\n");
209 ret = -EFAULT;
210 goto out_no_copy;
211 }
212
213 drm_modeset_lock_all(dev);
214
215 fb = drm_framebuffer_lookup(dev, file_priv, arg->fb_id);
216 if (!fb) {
217 VMW_DEBUG_USER("Invalid framebuffer id.\n");
218 ret = -ENOENT;
219 goto out_no_fb;
220 }
221 vfb = vmw_framebuffer_to_vfb(fb);
222
223 ret = vmw_user_resource_lookup_handle(dev_priv, tfile, arg->sid,
224 user_surface_converter,
225 &res);
226 if (ret)
227 goto out_no_surface;
228
229 surface = vmw_res_to_srf(res);
230 ret = vmw_kms_present(dev_priv, file_priv,
231 vfb, surface, arg->sid,
232 arg->dest_x, arg->dest_y,
233 clips, num_clips);
234
235 /* vmw_user_surface_lookup takes one ref so does new_fb */
236 vmw_surface_unreference(&surface);
237
238out_no_surface:
239 drm_framebuffer_put(fb);
240out_no_fb:
241 drm_modeset_unlock_all(dev);
242out_no_copy:
243 kfree(clips);
244out_clips:
245 return ret;
246}
247
248int vmw_present_readback_ioctl(struct drm_device *dev, void *data,
249 struct drm_file *file_priv)
250{
251 struct vmw_private *dev_priv = vmw_priv(dev);
252 struct drm_vmw_present_readback_arg *arg =
253 (struct drm_vmw_present_readback_arg *)data;
254 struct drm_vmw_fence_rep __user *user_fence_rep =
255 (struct drm_vmw_fence_rep __user *)
256 (unsigned long)arg->fence_rep;
257 struct drm_vmw_rect __user *clips_ptr;
258 struct drm_vmw_rect *clips = NULL;
259 struct drm_framebuffer *fb;
260 struct vmw_framebuffer *vfb;
261 uint32_t num_clips;
262 int ret;
263
264 num_clips = arg->num_clips;
265 clips_ptr = (struct drm_vmw_rect __user *)(unsigned long)arg->clips_ptr;
266
267 if (unlikely(num_clips == 0))
268 return 0;
269
270 if (clips_ptr == NULL) {
271 VMW_DEBUG_USER("Argument clips_ptr must be specified.\n");
272 ret = -EINVAL;
273 goto out_clips;
274 }
275
276 clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
277 if (clips == NULL) {
278 DRM_ERROR("Failed to allocate clip rect list.\n");
279 ret = -ENOMEM;
280 goto out_clips;
281 }
282
283 ret = copy_from_user(clips, clips_ptr, num_clips * sizeof(*clips));
284 if (ret) {
285 DRM_ERROR("Failed to copy clip rects from userspace.\n");
286 ret = -EFAULT;
287 goto out_no_copy;
288 }
289
290 drm_modeset_lock_all(dev);
291
292 fb = drm_framebuffer_lookup(dev, file_priv, arg->fb_id);
293 if (!fb) {
294 VMW_DEBUG_USER("Invalid framebuffer id.\n");
295 ret = -ENOENT;
296 goto out_no_fb;
297 }
298
299 vfb = vmw_framebuffer_to_vfb(fb);
300 if (!vfb->bo) {
301 VMW_DEBUG_USER("Framebuffer not buffer backed.\n");
302 ret = -EINVAL;
303 goto out_no_ttm_lock;
304 }
305
306 ret = vmw_kms_readback(dev_priv, file_priv,
307 vfb, user_fence_rep,
308 clips, num_clips);
309
310out_no_ttm_lock:
311 drm_framebuffer_put(fb);
312out_no_fb:
313 drm_modeset_unlock_all(dev);
314out_no_copy:
315 kfree(clips);
316out_clips:
317 return ret;
318}
1/**************************************************************************
2 *
3 * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28#include "vmwgfx_drv.h"
29#include "vmwgfx_drm.h"
30#include "vmwgfx_kms.h"
31
32int vmw_getparam_ioctl(struct drm_device *dev, void *data,
33 struct drm_file *file_priv)
34{
35 struct vmw_private *dev_priv = vmw_priv(dev);
36 struct drm_vmw_getparam_arg *param =
37 (struct drm_vmw_getparam_arg *)data;
38
39 switch (param->param) {
40 case DRM_VMW_PARAM_NUM_STREAMS:
41 param->value = vmw_overlay_num_overlays(dev_priv);
42 break;
43 case DRM_VMW_PARAM_NUM_FREE_STREAMS:
44 param->value = vmw_overlay_num_free_overlays(dev_priv);
45 break;
46 case DRM_VMW_PARAM_3D:
47 param->value = vmw_fifo_have_3d(dev_priv) ? 1 : 0;
48 break;
49 case DRM_VMW_PARAM_HW_CAPS:
50 param->value = dev_priv->capabilities;
51 break;
52 case DRM_VMW_PARAM_FIFO_CAPS:
53 param->value = dev_priv->fifo.capabilities;
54 break;
55 case DRM_VMW_PARAM_MAX_FB_SIZE:
56 param->value = dev_priv->vram_size;
57 break;
58 case DRM_VMW_PARAM_FIFO_HW_VERSION:
59 {
60 __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
61 const struct vmw_fifo_state *fifo = &dev_priv->fifo;
62
63 param->value =
64 ioread32(fifo_mem +
65 ((fifo->capabilities &
66 SVGA_FIFO_CAP_3D_HWVERSION_REVISED) ?
67 SVGA_FIFO_3D_HWVERSION_REVISED :
68 SVGA_FIFO_3D_HWVERSION));
69 break;
70 }
71 default:
72 DRM_ERROR("Illegal vmwgfx get param request: %d\n",
73 param->param);
74 return -EINVAL;
75 }
76
77 return 0;
78}
79
80
81int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data,
82 struct drm_file *file_priv)
83{
84 struct drm_vmw_get_3d_cap_arg *arg =
85 (struct drm_vmw_get_3d_cap_arg *) data;
86 struct vmw_private *dev_priv = vmw_priv(dev);
87 uint32_t size;
88 __le32 __iomem *fifo_mem;
89 void __user *buffer = (void __user *)((unsigned long)(arg->buffer));
90 void *bounce;
91 int ret;
92
93 if (unlikely(arg->pad64 != 0)) {
94 DRM_ERROR("Illegal GET_3D_CAP argument.\n");
95 return -EINVAL;
96 }
97
98 size = (SVGA_FIFO_3D_CAPS_LAST - SVGA_FIFO_3D_CAPS + 1) << 2;
99
100 if (arg->max_size < size)
101 size = arg->max_size;
102
103 bounce = vmalloc(size);
104 if (unlikely(bounce == NULL)) {
105 DRM_ERROR("Failed to allocate bounce buffer for 3D caps.\n");
106 return -ENOMEM;
107 }
108
109 fifo_mem = dev_priv->mmio_virt;
110 memcpy_fromio(bounce, &fifo_mem[SVGA_FIFO_3D_CAPS], size);
111
112 ret = copy_to_user(buffer, bounce, size);
113 vfree(bounce);
114
115 if (unlikely(ret != 0))
116 DRM_ERROR("Failed to report 3D caps info.\n");
117
118 return ret;
119}
120
121int vmw_present_ioctl(struct drm_device *dev, void *data,
122 struct drm_file *file_priv)
123{
124 struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
125 struct vmw_private *dev_priv = vmw_priv(dev);
126 struct drm_vmw_present_arg *arg =
127 (struct drm_vmw_present_arg *)data;
128 struct vmw_surface *surface;
129 struct vmw_master *vmaster = vmw_master(file_priv->master);
130 struct drm_vmw_rect __user *clips_ptr;
131 struct drm_vmw_rect *clips = NULL;
132 struct drm_mode_object *obj;
133 struct vmw_framebuffer *vfb;
134 uint32_t num_clips;
135 int ret;
136
137 num_clips = arg->num_clips;
138 clips_ptr = (struct drm_vmw_rect *)(unsigned long)arg->clips_ptr;
139
140 if (unlikely(num_clips == 0))
141 return 0;
142
143 if (clips_ptr == NULL) {
144 DRM_ERROR("Variable clips_ptr must be specified.\n");
145 ret = -EINVAL;
146 goto out_clips;
147 }
148
149 clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
150 if (clips == NULL) {
151 DRM_ERROR("Failed to allocate clip rect list.\n");
152 ret = -ENOMEM;
153 goto out_clips;
154 }
155
156 ret = copy_from_user(clips, clips_ptr, num_clips * sizeof(*clips));
157 if (ret) {
158 DRM_ERROR("Failed to copy clip rects from userspace.\n");
159 ret = -EFAULT;
160 goto out_no_copy;
161 }
162
163 ret = mutex_lock_interruptible(&dev->mode_config.mutex);
164 if (unlikely(ret != 0)) {
165 ret = -ERESTARTSYS;
166 goto out_no_mode_mutex;
167 }
168
169 obj = drm_mode_object_find(dev, arg->fb_id, DRM_MODE_OBJECT_FB);
170 if (!obj) {
171 DRM_ERROR("Invalid framebuffer id.\n");
172 ret = -EINVAL;
173 goto out_no_fb;
174 }
175 vfb = vmw_framebuffer_to_vfb(obj_to_fb(obj));
176
177 ret = ttm_read_lock(&vmaster->lock, true);
178 if (unlikely(ret != 0))
179 goto out_no_ttm_lock;
180
181 ret = vmw_user_surface_lookup_handle(dev_priv, tfile, arg->sid,
182 &surface);
183 if (ret)
184 goto out_no_surface;
185
186 ret = vmw_kms_present(dev_priv, file_priv,
187 vfb, surface, arg->sid,
188 arg->dest_x, arg->dest_y,
189 clips, num_clips);
190
191 /* vmw_user_surface_lookup takes one ref so does new_fb */
192 vmw_surface_unreference(&surface);
193
194out_no_surface:
195 ttm_read_unlock(&vmaster->lock);
196out_no_ttm_lock:
197out_no_fb:
198 mutex_unlock(&dev->mode_config.mutex);
199out_no_mode_mutex:
200out_no_copy:
201 kfree(clips);
202out_clips:
203 return ret;
204}
205
206int vmw_present_readback_ioctl(struct drm_device *dev, void *data,
207 struct drm_file *file_priv)
208{
209 struct vmw_private *dev_priv = vmw_priv(dev);
210 struct drm_vmw_present_readback_arg *arg =
211 (struct drm_vmw_present_readback_arg *)data;
212 struct drm_vmw_fence_rep __user *user_fence_rep =
213 (struct drm_vmw_fence_rep __user *)
214 (unsigned long)arg->fence_rep;
215 struct vmw_master *vmaster = vmw_master(file_priv->master);
216 struct drm_vmw_rect __user *clips_ptr;
217 struct drm_vmw_rect *clips = NULL;
218 struct drm_mode_object *obj;
219 struct vmw_framebuffer *vfb;
220 uint32_t num_clips;
221 int ret;
222
223 num_clips = arg->num_clips;
224 clips_ptr = (struct drm_vmw_rect *)(unsigned long)arg->clips_ptr;
225
226 if (unlikely(num_clips == 0))
227 return 0;
228
229 if (clips_ptr == NULL) {
230 DRM_ERROR("Argument clips_ptr must be specified.\n");
231 ret = -EINVAL;
232 goto out_clips;
233 }
234
235 clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
236 if (clips == NULL) {
237 DRM_ERROR("Failed to allocate clip rect list.\n");
238 ret = -ENOMEM;
239 goto out_clips;
240 }
241
242 ret = copy_from_user(clips, clips_ptr, num_clips * sizeof(*clips));
243 if (ret) {
244 DRM_ERROR("Failed to copy clip rects from userspace.\n");
245 ret = -EFAULT;
246 goto out_no_copy;
247 }
248
249 ret = mutex_lock_interruptible(&dev->mode_config.mutex);
250 if (unlikely(ret != 0)) {
251 ret = -ERESTARTSYS;
252 goto out_no_mode_mutex;
253 }
254
255 obj = drm_mode_object_find(dev, arg->fb_id, DRM_MODE_OBJECT_FB);
256 if (!obj) {
257 DRM_ERROR("Invalid framebuffer id.\n");
258 ret = -EINVAL;
259 goto out_no_fb;
260 }
261
262 vfb = vmw_framebuffer_to_vfb(obj_to_fb(obj));
263 if (!vfb->dmabuf) {
264 DRM_ERROR("Framebuffer not dmabuf backed.\n");
265 ret = -EINVAL;
266 goto out_no_fb;
267 }
268
269 ret = ttm_read_lock(&vmaster->lock, true);
270 if (unlikely(ret != 0))
271 goto out_no_ttm_lock;
272
273 ret = vmw_kms_readback(dev_priv, file_priv,
274 vfb, user_fence_rep,
275 clips, num_clips);
276
277 ttm_read_unlock(&vmaster->lock);
278out_no_ttm_lock:
279out_no_fb:
280 mutex_unlock(&dev->mode_config.mutex);
281out_no_mode_mutex:
282out_no_copy:
283 kfree(clips);
284out_clips:
285 return ret;
286}
287
288
289/**
290 * vmw_fops_poll - wrapper around the drm_poll function
291 *
292 * @filp: See the linux fops poll documentation.
293 * @wait: See the linux fops poll documentation.
294 *
295 * Wrapper around the drm_poll function that makes sure the device is
296 * processing the fifo if drm_poll decides to wait.
297 */
298unsigned int vmw_fops_poll(struct file *filp, struct poll_table_struct *wait)
299{
300 struct drm_file *file_priv = filp->private_data;
301 struct vmw_private *dev_priv =
302 vmw_priv(file_priv->minor->dev);
303
304 vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
305 return drm_poll(filp, wait);
306}
307
308
309/**
310 * vmw_fops_read - wrapper around the drm_read function
311 *
312 * @filp: See the linux fops read documentation.
313 * @buffer: See the linux fops read documentation.
314 * @count: See the linux fops read documentation.
315 * offset: See the linux fops read documentation.
316 *
317 * Wrapper around the drm_read function that makes sure the device is
318 * processing the fifo if drm_read decides to wait.
319 */
320ssize_t vmw_fops_read(struct file *filp, char __user *buffer,
321 size_t count, loff_t *offset)
322{
323 struct drm_file *file_priv = filp->private_data;
324 struct vmw_private *dev_priv =
325 vmw_priv(file_priv->minor->dev);
326
327 vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
328 return drm_read(filp, buffer, count, offset);
329}