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1/*
2 * drm_irq.c IRQ and vblank support
3 *
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the next
15 * paragraph) shall be included in all copies or substantial portions of the
16 * 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 NONINFRINGEMENT. IN NO EVENT SHALL
21 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24 * OTHER DEALINGS IN THE SOFTWARE.
25 */
26
27/*
28 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
29 *
30 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
31 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
32 * All Rights Reserved.
33 *
34 * Permission is hereby granted, free of charge, to any person obtaining a
35 * copy of this software and associated documentation files (the "Software"),
36 * to deal in the Software without restriction, including without limitation
37 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
38 * and/or sell copies of the Software, and to permit persons to whom the
39 * Software is furnished to do so, subject to the following conditions:
40 *
41 * The above copyright notice and this permission notice (including the next
42 * paragraph) shall be included in all copies or substantial portions of the
43 * Software.
44 *
45 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
46 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
47 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
48 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
49 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
50 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
51 * OTHER DEALINGS IN THE SOFTWARE.
52 */
53
54
55#include <linux/export.h>
56#include <linux/interrupt.h> /* For task queue support */
57#include <linux/pci.h>
58#include <linux/vgaarb.h>
59
60#include <drm/drm.h>
61#include <drm/drm_device.h>
62#include <drm/drm_drv.h>
63#include <drm/drm_irq.h>
64#include <drm/drm_print.h>
65#include <drm/drm_vblank.h>
66
67#include "drm_internal.h"
68
69/**
70 * DOC: irq helpers
71 *
72 * The DRM core provides very simple support helpers to enable IRQ handling on a
73 * device through the drm_irq_install() and drm_irq_uninstall() functions. This
74 * only supports devices with a single interrupt on the main device stored in
75 * &drm_device.dev and set as the device paramter in drm_dev_alloc().
76 *
77 * These IRQ helpers are strictly optional. Drivers which roll their own only
78 * need to set &drm_device.irq_enabled to signal the DRM core that vblank
79 * interrupts are working. Since these helpers don't automatically clean up the
80 * requested interrupt like e.g. devm_request_irq() they're not really
81 * recommended.
82 */
83
84/**
85 * drm_irq_install - install IRQ handler
86 * @dev: DRM device
87 * @irq: IRQ number to install the handler for
88 *
89 * Initializes the IRQ related data. Installs the handler, calling the driver
90 * &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before
91 * and after the installation.
92 *
93 * This is the simplified helper interface provided for drivers with no special
94 * needs. Drivers which need to install interrupt handlers for multiple
95 * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
96 * that vblank interrupts are available.
97 *
98 * @irq must match the interrupt number that would be passed to request_irq(),
99 * if called directly instead of using this helper function.
100 *
101 * &drm_driver.irq_handler is called to handle the registered interrupt.
102 *
103 * Returns:
104 * Zero on success or a negative error code on failure.
105 */
106int drm_irq_install(struct drm_device *dev, int irq)
107{
108 int ret;
109 unsigned long sh_flags = 0;
110
111 if (irq == 0)
112 return -EINVAL;
113
114 if (dev->irq_enabled)
115 return -EBUSY;
116 dev->irq_enabled = true;
117
118 DRM_DEBUG("irq=%d\n", irq);
119
120 /* Before installing handler */
121 if (dev->driver->irq_preinstall)
122 dev->driver->irq_preinstall(dev);
123
124 /* PCI devices require shared interrupts. */
125 if (dev->pdev)
126 sh_flags = IRQF_SHARED;
127
128 ret = request_irq(irq, dev->driver->irq_handler,
129 sh_flags, dev->driver->name, dev);
130
131 if (ret < 0) {
132 dev->irq_enabled = false;
133 return ret;
134 }
135
136 /* After installing handler */
137 if (dev->driver->irq_postinstall)
138 ret = dev->driver->irq_postinstall(dev);
139
140 if (ret < 0) {
141 dev->irq_enabled = false;
142 if (drm_core_check_feature(dev, DRIVER_LEGACY))
143 vga_client_register(dev->pdev, NULL, NULL, NULL);
144 free_irq(irq, dev);
145 } else {
146 dev->irq = irq;
147 }
148
149 return ret;
150}
151EXPORT_SYMBOL(drm_irq_install);
152
153/**
154 * drm_irq_uninstall - uninstall the IRQ handler
155 * @dev: DRM device
156 *
157 * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ
158 * handler. This should only be called by drivers which used drm_irq_install()
159 * to set up their interrupt handler. Other drivers must only reset
160 * &drm_device.irq_enabled to false.
161 *
162 * Note that for kernel modesetting drivers it is a bug if this function fails.
163 * The sanity checks are only to catch buggy user modesetting drivers which call
164 * the same function through an ioctl.
165 *
166 * Returns:
167 * Zero on success or a negative error code on failure.
168 */
169int drm_irq_uninstall(struct drm_device *dev)
170{
171 unsigned long irqflags;
172 bool irq_enabled;
173 int i;
174
175 irq_enabled = dev->irq_enabled;
176 dev->irq_enabled = false;
177
178 /*
179 * Wake up any waiters so they don't hang. This is just to paper over
180 * issues for UMS drivers which aren't in full control of their
181 * vblank/irq handling. KMS drivers must ensure that vblanks are all
182 * disabled when uninstalling the irq handler.
183 */
184 if (drm_dev_has_vblank(dev)) {
185 spin_lock_irqsave(&dev->vbl_lock, irqflags);
186 for (i = 0; i < dev->num_crtcs; i++) {
187 struct drm_vblank_crtc *vblank = &dev->vblank[i];
188
189 if (!vblank->enabled)
190 continue;
191
192 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
193
194 drm_vblank_disable_and_save(dev, i);
195 wake_up(&vblank->queue);
196 }
197 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
198 }
199
200 if (!irq_enabled)
201 return -EINVAL;
202
203 DRM_DEBUG("irq=%d\n", dev->irq);
204
205 if (drm_core_check_feature(dev, DRIVER_LEGACY))
206 vga_client_register(dev->pdev, NULL, NULL, NULL);
207
208 if (dev->driver->irq_uninstall)
209 dev->driver->irq_uninstall(dev);
210
211 free_irq(dev->irq, dev);
212
213 return 0;
214}
215EXPORT_SYMBOL(drm_irq_uninstall);
216
217#if IS_ENABLED(CONFIG_DRM_LEGACY)
218int drm_legacy_irq_control(struct drm_device *dev, void *data,
219 struct drm_file *file_priv)
220{
221 struct drm_control *ctl = data;
222 int ret = 0, irq;
223
224 /* if we haven't irq we fallback for compatibility reasons -
225 * this used to be a separate function in drm_dma.h
226 */
227
228 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
229 return 0;
230 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
231 return 0;
232 /* UMS was only ever supported on pci devices. */
233 if (WARN_ON(!dev->pdev))
234 return -EINVAL;
235
236 switch (ctl->func) {
237 case DRM_INST_HANDLER:
238 irq = dev->pdev->irq;
239
240 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
241 ctl->irq != irq)
242 return -EINVAL;
243 mutex_lock(&dev->struct_mutex);
244 ret = drm_irq_install(dev, irq);
245 mutex_unlock(&dev->struct_mutex);
246
247 return ret;
248 case DRM_UNINST_HANDLER:
249 mutex_lock(&dev->struct_mutex);
250 ret = drm_irq_uninstall(dev);
251 mutex_unlock(&dev->struct_mutex);
252
253 return ret;
254 default:
255 return -EINVAL;
256 }
257}
258#endif
1/**
2 * \file drm_irq.c
3 * IRQ support
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
7 */
8
9/*
10 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 *
12 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
22 *
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
25 * Software.
26 *
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
34 */
35
36#include "drmP.h"
37#include "drm_trace.h"
38
39#include <linux/interrupt.h> /* For task queue support */
40#include <linux/slab.h>
41
42#include <linux/vgaarb.h>
43
44/* Access macro for slots in vblank timestamp ringbuffer. */
45#define vblanktimestamp(dev, crtc, count) ( \
46 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
47 ((count) % DRM_VBLANKTIME_RBSIZE)])
48
49/* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
51 */
52#define DRM_TIMESTAMP_MAXRETRIES 3
53
54/* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
56 */
57#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
58
59/**
60 * Get interrupt from bus id.
61 *
62 * \param inode device inode.
63 * \param file_priv DRM file private.
64 * \param cmd command.
65 * \param arg user argument, pointing to a drm_irq_busid structure.
66 * \return zero on success or a negative number on failure.
67 *
68 * Finds the PCI device with the specified bus id and gets its IRQ number.
69 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
70 * to that of the device that this DRM instance attached to.
71 */
72int drm_irq_by_busid(struct drm_device *dev, void *data,
73 struct drm_file *file_priv)
74{
75 struct drm_irq_busid *p = data;
76
77 if (!dev->driver->bus->irq_by_busid)
78 return -EINVAL;
79
80 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
81 return -EINVAL;
82
83 return dev->driver->bus->irq_by_busid(dev, p);
84}
85
86/*
87 * Clear vblank timestamp buffer for a crtc.
88 */
89static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
90{
91 memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
92 DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
93}
94
95/*
96 * Disable vblank irq's on crtc, make sure that last vblank count
97 * of hardware and corresponding consistent software vblank counter
98 * are preserved, even if there are any spurious vblank irq's after
99 * disable.
100 */
101static void vblank_disable_and_save(struct drm_device *dev, int crtc)
102{
103 unsigned long irqflags;
104 u32 vblcount;
105 s64 diff_ns;
106 int vblrc;
107 struct timeval tvblank;
108
109 /* Prevent vblank irq processing while disabling vblank irqs,
110 * so no updates of timestamps or count can happen after we've
111 * disabled. Needed to prevent races in case of delayed irq's.
112 * Disable preemption, so vblank_time_lock is held as short as
113 * possible, even under a kernel with PREEMPT_RT patches.
114 */
115 preempt_disable();
116 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
117
118 dev->driver->disable_vblank(dev, crtc);
119 dev->vblank_enabled[crtc] = 0;
120
121 /* No further vblank irq's will be processed after
122 * this point. Get current hardware vblank count and
123 * vblank timestamp, repeat until they are consistent.
124 *
125 * FIXME: There is still a race condition here and in
126 * drm_update_vblank_count() which can cause off-by-one
127 * reinitialization of software vblank counter. If gpu
128 * vblank counter doesn't increment exactly at the leading
129 * edge of a vblank interval, then we can lose 1 count if
130 * we happen to execute between start of vblank and the
131 * delayed gpu counter increment.
132 */
133 do {
134 dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
135 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
136 } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
137
138 /* Compute time difference to stored timestamp of last vblank
139 * as updated by last invocation of drm_handle_vblank() in vblank irq.
140 */
141 vblcount = atomic_read(&dev->_vblank_count[crtc]);
142 diff_ns = timeval_to_ns(&tvblank) -
143 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
144
145 /* If there is at least 1 msec difference between the last stored
146 * timestamp and tvblank, then we are currently executing our
147 * disable inside a new vblank interval, the tvblank timestamp
148 * corresponds to this new vblank interval and the irq handler
149 * for this vblank didn't run yet and won't run due to our disable.
150 * Therefore we need to do the job of drm_handle_vblank() and
151 * increment the vblank counter by one to account for this vblank.
152 *
153 * Skip this step if there isn't any high precision timestamp
154 * available. In that case we can't account for this and just
155 * hope for the best.
156 */
157 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
158 atomic_inc(&dev->_vblank_count[crtc]);
159 smp_mb__after_atomic_inc();
160 }
161
162 /* Invalidate all timestamps while vblank irq's are off. */
163 clear_vblank_timestamps(dev, crtc);
164
165 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
166 preempt_enable();
167}
168
169static void vblank_disable_fn(unsigned long arg)
170{
171 struct drm_device *dev = (struct drm_device *)arg;
172 unsigned long irqflags;
173 int i;
174
175 if (!dev->vblank_disable_allowed)
176 return;
177
178 for (i = 0; i < dev->num_crtcs; i++) {
179 spin_lock_irqsave(&dev->vbl_lock, irqflags);
180 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
181 dev->vblank_enabled[i]) {
182 DRM_DEBUG("disabling vblank on crtc %d\n", i);
183 vblank_disable_and_save(dev, i);
184 }
185 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
186 }
187}
188
189void drm_vblank_cleanup(struct drm_device *dev)
190{
191 /* Bail if the driver didn't call drm_vblank_init() */
192 if (dev->num_crtcs == 0)
193 return;
194
195 del_timer(&dev->vblank_disable_timer);
196
197 vblank_disable_fn((unsigned long)dev);
198
199 kfree(dev->vbl_queue);
200 kfree(dev->_vblank_count);
201 kfree(dev->vblank_refcount);
202 kfree(dev->vblank_enabled);
203 kfree(dev->last_vblank);
204 kfree(dev->last_vblank_wait);
205 kfree(dev->vblank_inmodeset);
206 kfree(dev->_vblank_time);
207
208 dev->num_crtcs = 0;
209}
210EXPORT_SYMBOL(drm_vblank_cleanup);
211
212int drm_vblank_init(struct drm_device *dev, int num_crtcs)
213{
214 int i, ret = -ENOMEM;
215
216 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
217 (unsigned long)dev);
218 spin_lock_init(&dev->vbl_lock);
219 spin_lock_init(&dev->vblank_time_lock);
220
221 dev->num_crtcs = num_crtcs;
222
223 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
224 GFP_KERNEL);
225 if (!dev->vbl_queue)
226 goto err;
227
228 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
229 if (!dev->_vblank_count)
230 goto err;
231
232 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
233 GFP_KERNEL);
234 if (!dev->vblank_refcount)
235 goto err;
236
237 dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
238 if (!dev->vblank_enabled)
239 goto err;
240
241 dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
242 if (!dev->last_vblank)
243 goto err;
244
245 dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
246 if (!dev->last_vblank_wait)
247 goto err;
248
249 dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
250 if (!dev->vblank_inmodeset)
251 goto err;
252
253 dev->_vblank_time = kcalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE,
254 sizeof(struct timeval), GFP_KERNEL);
255 if (!dev->_vblank_time)
256 goto err;
257
258 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
259
260 /* Driver specific high-precision vblank timestamping supported? */
261 if (dev->driver->get_vblank_timestamp)
262 DRM_INFO("Driver supports precise vblank timestamp query.\n");
263 else
264 DRM_INFO("No driver support for vblank timestamp query.\n");
265
266 /* Zero per-crtc vblank stuff */
267 for (i = 0; i < num_crtcs; i++) {
268 init_waitqueue_head(&dev->vbl_queue[i]);
269 atomic_set(&dev->_vblank_count[i], 0);
270 atomic_set(&dev->vblank_refcount[i], 0);
271 }
272
273 dev->vblank_disable_allowed = 0;
274 return 0;
275
276err:
277 drm_vblank_cleanup(dev);
278 return ret;
279}
280EXPORT_SYMBOL(drm_vblank_init);
281
282static void drm_irq_vgaarb_nokms(void *cookie, bool state)
283{
284 struct drm_device *dev = cookie;
285
286 if (dev->driver->vgaarb_irq) {
287 dev->driver->vgaarb_irq(dev, state);
288 return;
289 }
290
291 if (!dev->irq_enabled)
292 return;
293
294 if (state) {
295 if (dev->driver->irq_uninstall)
296 dev->driver->irq_uninstall(dev);
297 } else {
298 if (dev->driver->irq_preinstall)
299 dev->driver->irq_preinstall(dev);
300 if (dev->driver->irq_postinstall)
301 dev->driver->irq_postinstall(dev);
302 }
303}
304
305/**
306 * Install IRQ handler.
307 *
308 * \param dev DRM device.
309 *
310 * Initializes the IRQ related data. Installs the handler, calling the driver
311 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
312 * before and after the installation.
313 */
314int drm_irq_install(struct drm_device *dev)
315{
316 int ret = 0;
317 unsigned long sh_flags = 0;
318 char *irqname;
319
320 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
321 return -EINVAL;
322
323 if (drm_dev_to_irq(dev) == 0)
324 return -EINVAL;
325
326 mutex_lock(&dev->struct_mutex);
327
328 /* Driver must have been initialized */
329 if (!dev->dev_private) {
330 mutex_unlock(&dev->struct_mutex);
331 return -EINVAL;
332 }
333
334 if (dev->irq_enabled) {
335 mutex_unlock(&dev->struct_mutex);
336 return -EBUSY;
337 }
338 dev->irq_enabled = 1;
339 mutex_unlock(&dev->struct_mutex);
340
341 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
342
343 /* Before installing handler */
344 if (dev->driver->irq_preinstall)
345 dev->driver->irq_preinstall(dev);
346
347 /* Install handler */
348 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
349 sh_flags = IRQF_SHARED;
350
351 if (dev->devname)
352 irqname = dev->devname;
353 else
354 irqname = dev->driver->name;
355
356 ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
357 sh_flags, irqname, dev);
358
359 if (ret < 0) {
360 mutex_lock(&dev->struct_mutex);
361 dev->irq_enabled = 0;
362 mutex_unlock(&dev->struct_mutex);
363 return ret;
364 }
365
366 if (!drm_core_check_feature(dev, DRIVER_MODESET))
367 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
368
369 /* After installing handler */
370 if (dev->driver->irq_postinstall)
371 ret = dev->driver->irq_postinstall(dev);
372
373 if (ret < 0) {
374 mutex_lock(&dev->struct_mutex);
375 dev->irq_enabled = 0;
376 mutex_unlock(&dev->struct_mutex);
377 if (!drm_core_check_feature(dev, DRIVER_MODESET))
378 vga_client_register(dev->pdev, NULL, NULL, NULL);
379 free_irq(drm_dev_to_irq(dev), dev);
380 }
381
382 return ret;
383}
384EXPORT_SYMBOL(drm_irq_install);
385
386/**
387 * Uninstall the IRQ handler.
388 *
389 * \param dev DRM device.
390 *
391 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
392 */
393int drm_irq_uninstall(struct drm_device *dev)
394{
395 unsigned long irqflags;
396 int irq_enabled, i;
397
398 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
399 return -EINVAL;
400
401 mutex_lock(&dev->struct_mutex);
402 irq_enabled = dev->irq_enabled;
403 dev->irq_enabled = 0;
404 mutex_unlock(&dev->struct_mutex);
405
406 /*
407 * Wake up any waiters so they don't hang.
408 */
409 spin_lock_irqsave(&dev->vbl_lock, irqflags);
410 for (i = 0; i < dev->num_crtcs; i++) {
411 DRM_WAKEUP(&dev->vbl_queue[i]);
412 dev->vblank_enabled[i] = 0;
413 dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i);
414 }
415 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
416
417 if (!irq_enabled)
418 return -EINVAL;
419
420 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
421
422 if (!drm_core_check_feature(dev, DRIVER_MODESET))
423 vga_client_register(dev->pdev, NULL, NULL, NULL);
424
425 if (dev->driver->irq_uninstall)
426 dev->driver->irq_uninstall(dev);
427
428 free_irq(drm_dev_to_irq(dev), dev);
429
430 return 0;
431}
432EXPORT_SYMBOL(drm_irq_uninstall);
433
434/**
435 * IRQ control ioctl.
436 *
437 * \param inode device inode.
438 * \param file_priv DRM file private.
439 * \param cmd command.
440 * \param arg user argument, pointing to a drm_control structure.
441 * \return zero on success or a negative number on failure.
442 *
443 * Calls irq_install() or irq_uninstall() according to \p arg.
444 */
445int drm_control(struct drm_device *dev, void *data,
446 struct drm_file *file_priv)
447{
448 struct drm_control *ctl = data;
449
450 /* if we haven't irq we fallback for compatibility reasons -
451 * this used to be a separate function in drm_dma.h
452 */
453
454
455 switch (ctl->func) {
456 case DRM_INST_HANDLER:
457 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
458 return 0;
459 if (drm_core_check_feature(dev, DRIVER_MODESET))
460 return 0;
461 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
462 ctl->irq != drm_dev_to_irq(dev))
463 return -EINVAL;
464 return drm_irq_install(dev);
465 case DRM_UNINST_HANDLER:
466 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
467 return 0;
468 if (drm_core_check_feature(dev, DRIVER_MODESET))
469 return 0;
470 return drm_irq_uninstall(dev);
471 default:
472 return -EINVAL;
473 }
474}
475
476/**
477 * drm_calc_timestamping_constants - Calculate and
478 * store various constants which are later needed by
479 * vblank and swap-completion timestamping, e.g, by
480 * drm_calc_vbltimestamp_from_scanoutpos().
481 * They are derived from crtc's true scanout timing,
482 * so they take things like panel scaling or other
483 * adjustments into account.
484 *
485 * @crtc drm_crtc whose timestamp constants should be updated.
486 *
487 */
488void drm_calc_timestamping_constants(struct drm_crtc *crtc)
489{
490 s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
491 u64 dotclock;
492
493 /* Dot clock in Hz: */
494 dotclock = (u64) crtc->hwmode.clock * 1000;
495
496 /* Fields of interlaced scanout modes are only halve a frame duration.
497 * Double the dotclock to get halve the frame-/line-/pixelduration.
498 */
499 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
500 dotclock *= 2;
501
502 /* Valid dotclock? */
503 if (dotclock > 0) {
504 /* Convert scanline length in pixels and video dot clock to
505 * line duration, frame duration and pixel duration in
506 * nanoseconds:
507 */
508 pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
509 linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
510 1000000000), dotclock);
511 framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
512 } else
513 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
514 crtc->base.id);
515
516 crtc->pixeldur_ns = pixeldur_ns;
517 crtc->linedur_ns = linedur_ns;
518 crtc->framedur_ns = framedur_ns;
519
520 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
521 crtc->base.id, crtc->hwmode.crtc_htotal,
522 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
523 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
524 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
525 (int) linedur_ns, (int) pixeldur_ns);
526}
527EXPORT_SYMBOL(drm_calc_timestamping_constants);
528
529/**
530 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
531 * drivers. Implements calculation of exact vblank timestamps from
532 * given drm_display_mode timings and current video scanout position
533 * of a crtc. This can be called from within get_vblank_timestamp()
534 * implementation of a kms driver to implement the actual timestamping.
535 *
536 * Should return timestamps conforming to the OML_sync_control OpenML
537 * extension specification. The timestamp corresponds to the end of
538 * the vblank interval, aka start of scanout of topmost-leftmost display
539 * pixel in the following video frame.
540 *
541 * Requires support for optional dev->driver->get_scanout_position()
542 * in kms driver, plus a bit of setup code to provide a drm_display_mode
543 * that corresponds to the true scanout timing.
544 *
545 * The current implementation only handles standard video modes. It
546 * returns as no operation if a doublescan or interlaced video mode is
547 * active. Higher level code is expected to handle this.
548 *
549 * @dev: DRM device.
550 * @crtc: Which crtc's vblank timestamp to retrieve.
551 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
552 * On return contains true maximum error of timestamp.
553 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
554 * @flags: Flags to pass to driver:
555 * 0 = Default.
556 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
557 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
558 *
559 * Returns negative value on error, failure or if not supported in current
560 * video mode:
561 *
562 * -EINVAL - Invalid crtc.
563 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
564 * -ENOTSUPP - Function not supported in current display mode.
565 * -EIO - Failed, e.g., due to failed scanout position query.
566 *
567 * Returns or'ed positive status flags on success:
568 *
569 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
570 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
571 *
572 */
573int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
574 int *max_error,
575 struct timeval *vblank_time,
576 unsigned flags,
577 struct drm_crtc *refcrtc)
578{
579 struct timeval stime, raw_time;
580 struct drm_display_mode *mode;
581 int vbl_status, vtotal, vdisplay;
582 int vpos, hpos, i;
583 s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
584 bool invbl;
585
586 if (crtc < 0 || crtc >= dev->num_crtcs) {
587 DRM_ERROR("Invalid crtc %d\n", crtc);
588 return -EINVAL;
589 }
590
591 /* Scanout position query not supported? Should not happen. */
592 if (!dev->driver->get_scanout_position) {
593 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
594 return -EIO;
595 }
596
597 mode = &refcrtc->hwmode;
598 vtotal = mode->crtc_vtotal;
599 vdisplay = mode->crtc_vdisplay;
600
601 /* Durations of frames, lines, pixels in nanoseconds. */
602 framedur_ns = refcrtc->framedur_ns;
603 linedur_ns = refcrtc->linedur_ns;
604 pixeldur_ns = refcrtc->pixeldur_ns;
605
606 /* If mode timing undefined, just return as no-op:
607 * Happens during initial modesetting of a crtc.
608 */
609 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
610 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
611 return -EAGAIN;
612 }
613
614 /* Get current scanout position with system timestamp.
615 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
616 * if single query takes longer than max_error nanoseconds.
617 *
618 * This guarantees a tight bound on maximum error if
619 * code gets preempted or delayed for some reason.
620 */
621 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
622 /* Disable preemption to make it very likely to
623 * succeed in the first iteration even on PREEMPT_RT kernel.
624 */
625 preempt_disable();
626
627 /* Get system timestamp before query. */
628 do_gettimeofday(&stime);
629
630 /* Get vertical and horizontal scanout pos. vpos, hpos. */
631 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
632
633 /* Get system timestamp after query. */
634 do_gettimeofday(&raw_time);
635
636 preempt_enable();
637
638 /* Return as no-op if scanout query unsupported or failed. */
639 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
640 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
641 crtc, vbl_status);
642 return -EIO;
643 }
644
645 duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
646
647 /* Accept result with < max_error nsecs timing uncertainty. */
648 if (duration_ns <= (s64) *max_error)
649 break;
650 }
651
652 /* Noisy system timing? */
653 if (i == DRM_TIMESTAMP_MAXRETRIES) {
654 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
655 crtc, (int) duration_ns/1000, *max_error/1000, i);
656 }
657
658 /* Return upper bound of timestamp precision error. */
659 *max_error = (int) duration_ns;
660
661 /* Check if in vblank area:
662 * vpos is >=0 in video scanout area, but negative
663 * within vblank area, counting down the number of lines until
664 * start of scanout.
665 */
666 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
667
668 /* Convert scanout position into elapsed time at raw_time query
669 * since start of scanout at first display scanline. delta_ns
670 * can be negative if start of scanout hasn't happened yet.
671 */
672 delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
673
674 /* Is vpos outside nominal vblank area, but less than
675 * 1/100 of a frame height away from start of vblank?
676 * If so, assume this isn't a massively delayed vblank
677 * interrupt, but a vblank interrupt that fired a few
678 * microseconds before true start of vblank. Compensate
679 * by adding a full frame duration to the final timestamp.
680 * Happens, e.g., on ATI R500, R600.
681 *
682 * We only do this if DRM_CALLED_FROM_VBLIRQ.
683 */
684 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
685 ((vdisplay - vpos) < vtotal / 100)) {
686 delta_ns = delta_ns - framedur_ns;
687
688 /* Signal this correction as "applied". */
689 vbl_status |= 0x8;
690 }
691
692 /* Subtract time delta from raw timestamp to get final
693 * vblank_time timestamp for end of vblank.
694 */
695 *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
696
697 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
698 crtc, (int)vbl_status, hpos, vpos,
699 (long)raw_time.tv_sec, (long)raw_time.tv_usec,
700 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
701 (int)duration_ns/1000, i);
702
703 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
704 if (invbl)
705 vbl_status |= DRM_VBLANKTIME_INVBL;
706
707 return vbl_status;
708}
709EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
710
711/**
712 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
713 * vblank interval.
714 *
715 * @dev: DRM device
716 * @crtc: which crtc's vblank timestamp to retrieve
717 * @tvblank: Pointer to target struct timeval which should receive the timestamp
718 * @flags: Flags to pass to driver:
719 * 0 = Default.
720 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
721 *
722 * Fetches the system timestamp corresponding to the time of the most recent
723 * vblank interval on specified crtc. May call into kms-driver to
724 * compute the timestamp with a high-precision GPU specific method.
725 *
726 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
727 * call, i.e., it isn't very precisely locked to the true vblank.
728 *
729 * Returns non-zero if timestamp is considered to be very precise.
730 */
731u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
732 struct timeval *tvblank, unsigned flags)
733{
734 int ret = 0;
735
736 /* Define requested maximum error on timestamps (nanoseconds). */
737 int max_error = (int) drm_timestamp_precision * 1000;
738
739 /* Query driver if possible and precision timestamping enabled. */
740 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
741 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
742 tvblank, flags);
743 if (ret > 0)
744 return (u32) ret;
745 }
746
747 /* GPU high precision timestamp query unsupported or failed.
748 * Return gettimeofday timestamp as best estimate.
749 */
750 do_gettimeofday(tvblank);
751
752 return 0;
753}
754EXPORT_SYMBOL(drm_get_last_vbltimestamp);
755
756/**
757 * drm_vblank_count - retrieve "cooked" vblank counter value
758 * @dev: DRM device
759 * @crtc: which counter to retrieve
760 *
761 * Fetches the "cooked" vblank count value that represents the number of
762 * vblank events since the system was booted, including lost events due to
763 * modesetting activity.
764 */
765u32 drm_vblank_count(struct drm_device *dev, int crtc)
766{
767 return atomic_read(&dev->_vblank_count[crtc]);
768}
769EXPORT_SYMBOL(drm_vblank_count);
770
771/**
772 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
773 * and the system timestamp corresponding to that vblank counter value.
774 *
775 * @dev: DRM device
776 * @crtc: which counter to retrieve
777 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
778 *
779 * Fetches the "cooked" vblank count value that represents the number of
780 * vblank events since the system was booted, including lost events due to
781 * modesetting activity. Returns corresponding system timestamp of the time
782 * of the vblank interval that corresponds to the current value vblank counter
783 * value.
784 */
785u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
786 struct timeval *vblanktime)
787{
788 u32 cur_vblank;
789
790 /* Read timestamp from slot of _vblank_time ringbuffer
791 * that corresponds to current vblank count. Retry if
792 * count has incremented during readout. This works like
793 * a seqlock.
794 */
795 do {
796 cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
797 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
798 smp_rmb();
799 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
800
801 return cur_vblank;
802}
803EXPORT_SYMBOL(drm_vblank_count_and_time);
804
805/**
806 * drm_update_vblank_count - update the master vblank counter
807 * @dev: DRM device
808 * @crtc: counter to update
809 *
810 * Call back into the driver to update the appropriate vblank counter
811 * (specified by @crtc). Deal with wraparound, if it occurred, and
812 * update the last read value so we can deal with wraparound on the next
813 * call if necessary.
814 *
815 * Only necessary when going from off->on, to account for frames we
816 * didn't get an interrupt for.
817 *
818 * Note: caller must hold dev->vbl_lock since this reads & writes
819 * device vblank fields.
820 */
821static void drm_update_vblank_count(struct drm_device *dev, int crtc)
822{
823 u32 cur_vblank, diff, tslot, rc;
824 struct timeval t_vblank;
825
826 /*
827 * Interrupts were disabled prior to this call, so deal with counter
828 * wrap if needed.
829 * NOTE! It's possible we lost a full dev->max_vblank_count events
830 * here if the register is small or we had vblank interrupts off for
831 * a long time.
832 *
833 * We repeat the hardware vblank counter & timestamp query until
834 * we get consistent results. This to prevent races between gpu
835 * updating its hardware counter while we are retrieving the
836 * corresponding vblank timestamp.
837 */
838 do {
839 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
840 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
841 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
842
843 /* Deal with counter wrap */
844 diff = cur_vblank - dev->last_vblank[crtc];
845 if (cur_vblank < dev->last_vblank[crtc]) {
846 diff += dev->max_vblank_count;
847
848 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
849 crtc, dev->last_vblank[crtc], cur_vblank, diff);
850 }
851
852 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
853 crtc, diff);
854
855 /* Reinitialize corresponding vblank timestamp if high-precision query
856 * available. Skip this step if query unsupported or failed. Will
857 * reinitialize delayed at next vblank interrupt in that case.
858 */
859 if (rc) {
860 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
861 vblanktimestamp(dev, crtc, tslot) = t_vblank;
862 }
863
864 smp_mb__before_atomic_inc();
865 atomic_add(diff, &dev->_vblank_count[crtc]);
866 smp_mb__after_atomic_inc();
867}
868
869/**
870 * drm_vblank_get - get a reference count on vblank events
871 * @dev: DRM device
872 * @crtc: which CRTC to own
873 *
874 * Acquire a reference count on vblank events to avoid having them disabled
875 * while in use.
876 *
877 * RETURNS
878 * Zero on success, nonzero on failure.
879 */
880int drm_vblank_get(struct drm_device *dev, int crtc)
881{
882 unsigned long irqflags, irqflags2;
883 int ret = 0;
884
885 spin_lock_irqsave(&dev->vbl_lock, irqflags);
886 /* Going from 0->1 means we have to enable interrupts again */
887 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
888 /* Disable preemption while holding vblank_time_lock. Do
889 * it explicitely to guard against PREEMPT_RT kernel.
890 */
891 preempt_disable();
892 spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
893 if (!dev->vblank_enabled[crtc]) {
894 /* Enable vblank irqs under vblank_time_lock protection.
895 * All vblank count & timestamp updates are held off
896 * until we are done reinitializing master counter and
897 * timestamps. Filtercode in drm_handle_vblank() will
898 * prevent double-accounting of same vblank interval.
899 */
900 ret = dev->driver->enable_vblank(dev, crtc);
901 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
902 crtc, ret);
903 if (ret)
904 atomic_dec(&dev->vblank_refcount[crtc]);
905 else {
906 dev->vblank_enabled[crtc] = 1;
907 drm_update_vblank_count(dev, crtc);
908 }
909 }
910 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
911 preempt_enable();
912 } else {
913 if (!dev->vblank_enabled[crtc]) {
914 atomic_dec(&dev->vblank_refcount[crtc]);
915 ret = -EINVAL;
916 }
917 }
918 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
919
920 return ret;
921}
922EXPORT_SYMBOL(drm_vblank_get);
923
924/**
925 * drm_vblank_put - give up ownership of vblank events
926 * @dev: DRM device
927 * @crtc: which counter to give up
928 *
929 * Release ownership of a given vblank counter, turning off interrupts
930 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
931 */
932void drm_vblank_put(struct drm_device *dev, int crtc)
933{
934 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
935
936 /* Last user schedules interrupt disable */
937 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
938 (drm_vblank_offdelay > 0))
939 mod_timer(&dev->vblank_disable_timer,
940 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
941}
942EXPORT_SYMBOL(drm_vblank_put);
943
944void drm_vblank_off(struct drm_device *dev, int crtc)
945{
946 struct drm_pending_vblank_event *e, *t;
947 struct timeval now;
948 unsigned long irqflags;
949 unsigned int seq;
950
951 spin_lock_irqsave(&dev->vbl_lock, irqflags);
952 vblank_disable_and_save(dev, crtc);
953 DRM_WAKEUP(&dev->vbl_queue[crtc]);
954
955 /* Send any queued vblank events, lest the natives grow disquiet */
956 seq = drm_vblank_count_and_time(dev, crtc, &now);
957 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
958 if (e->pipe != crtc)
959 continue;
960 DRM_DEBUG("Sending premature vblank event on disable: \
961 wanted %d, current %d\n",
962 e->event.sequence, seq);
963
964 e->event.sequence = seq;
965 e->event.tv_sec = now.tv_sec;
966 e->event.tv_usec = now.tv_usec;
967 drm_vblank_put(dev, e->pipe);
968 list_move_tail(&e->base.link, &e->base.file_priv->event_list);
969 wake_up_interruptible(&e->base.file_priv->event_wait);
970 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
971 e->event.sequence);
972 }
973
974 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
975}
976EXPORT_SYMBOL(drm_vblank_off);
977
978/**
979 * drm_vblank_pre_modeset - account for vblanks across mode sets
980 * @dev: DRM device
981 * @crtc: CRTC in question
982 * @post: post or pre mode set?
983 *
984 * Account for vblank events across mode setting events, which will likely
985 * reset the hardware frame counter.
986 */
987void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
988{
989 /* vblank is not initialized (IRQ not installed ?) */
990 if (!dev->num_crtcs)
991 return;
992 /*
993 * To avoid all the problems that might happen if interrupts
994 * were enabled/disabled around or between these calls, we just
995 * have the kernel take a reference on the CRTC (just once though
996 * to avoid corrupting the count if multiple, mismatch calls occur),
997 * so that interrupts remain enabled in the interim.
998 */
999 if (!dev->vblank_inmodeset[crtc]) {
1000 dev->vblank_inmodeset[crtc] = 0x1;
1001 if (drm_vblank_get(dev, crtc) == 0)
1002 dev->vblank_inmodeset[crtc] |= 0x2;
1003 }
1004}
1005EXPORT_SYMBOL(drm_vblank_pre_modeset);
1006
1007void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1008{
1009 unsigned long irqflags;
1010
1011 if (dev->vblank_inmodeset[crtc]) {
1012 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1013 dev->vblank_disable_allowed = 1;
1014 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1015
1016 if (dev->vblank_inmodeset[crtc] & 0x2)
1017 drm_vblank_put(dev, crtc);
1018
1019 dev->vblank_inmodeset[crtc] = 0;
1020 }
1021}
1022EXPORT_SYMBOL(drm_vblank_post_modeset);
1023
1024/**
1025 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1026 * @DRM_IOCTL_ARGS: standard ioctl arguments
1027 *
1028 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1029 * ioctls around modesetting so that any lost vblank events are accounted for.
1030 *
1031 * Generally the counter will reset across mode sets. If interrupts are
1032 * enabled around this call, we don't have to do anything since the counter
1033 * will have already been incremented.
1034 */
1035int drm_modeset_ctl(struct drm_device *dev, void *data,
1036 struct drm_file *file_priv)
1037{
1038 struct drm_modeset_ctl *modeset = data;
1039 int ret = 0;
1040 unsigned int crtc;
1041
1042 /* If drm_vblank_init() hasn't been called yet, just no-op */
1043 if (!dev->num_crtcs)
1044 goto out;
1045
1046 crtc = modeset->crtc;
1047 if (crtc >= dev->num_crtcs) {
1048 ret = -EINVAL;
1049 goto out;
1050 }
1051
1052 switch (modeset->cmd) {
1053 case _DRM_PRE_MODESET:
1054 drm_vblank_pre_modeset(dev, crtc);
1055 break;
1056 case _DRM_POST_MODESET:
1057 drm_vblank_post_modeset(dev, crtc);
1058 break;
1059 default:
1060 ret = -EINVAL;
1061 break;
1062 }
1063
1064out:
1065 return ret;
1066}
1067
1068static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1069 union drm_wait_vblank *vblwait,
1070 struct drm_file *file_priv)
1071{
1072 struct drm_pending_vblank_event *e;
1073 struct timeval now;
1074 unsigned long flags;
1075 unsigned int seq;
1076 int ret;
1077
1078 e = kzalloc(sizeof *e, GFP_KERNEL);
1079 if (e == NULL) {
1080 ret = -ENOMEM;
1081 goto err_put;
1082 }
1083
1084 e->pipe = pipe;
1085 e->base.pid = current->pid;
1086 e->event.base.type = DRM_EVENT_VBLANK;
1087 e->event.base.length = sizeof e->event;
1088 e->event.user_data = vblwait->request.signal;
1089 e->base.event = &e->event.base;
1090 e->base.file_priv = file_priv;
1091 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1092
1093 spin_lock_irqsave(&dev->event_lock, flags);
1094
1095 if (file_priv->event_space < sizeof e->event) {
1096 ret = -EBUSY;
1097 goto err_unlock;
1098 }
1099
1100 file_priv->event_space -= sizeof e->event;
1101 seq = drm_vblank_count_and_time(dev, pipe, &now);
1102
1103 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1104 (seq - vblwait->request.sequence) <= (1 << 23)) {
1105 vblwait->request.sequence = seq + 1;
1106 vblwait->reply.sequence = vblwait->request.sequence;
1107 }
1108
1109 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1110 vblwait->request.sequence, seq, pipe);
1111
1112 trace_drm_vblank_event_queued(current->pid, pipe,
1113 vblwait->request.sequence);
1114
1115 e->event.sequence = vblwait->request.sequence;
1116 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1117 e->event.sequence = seq;
1118 e->event.tv_sec = now.tv_sec;
1119 e->event.tv_usec = now.tv_usec;
1120 drm_vblank_put(dev, pipe);
1121 list_add_tail(&e->base.link, &e->base.file_priv->event_list);
1122 wake_up_interruptible(&e->base.file_priv->event_wait);
1123 vblwait->reply.sequence = seq;
1124 trace_drm_vblank_event_delivered(current->pid, pipe,
1125 vblwait->request.sequence);
1126 } else {
1127 list_add_tail(&e->base.link, &dev->vblank_event_list);
1128 vblwait->reply.sequence = vblwait->request.sequence;
1129 }
1130
1131 spin_unlock_irqrestore(&dev->event_lock, flags);
1132
1133 return 0;
1134
1135err_unlock:
1136 spin_unlock_irqrestore(&dev->event_lock, flags);
1137 kfree(e);
1138err_put:
1139 drm_vblank_put(dev, pipe);
1140 return ret;
1141}
1142
1143/**
1144 * Wait for VBLANK.
1145 *
1146 * \param inode device inode.
1147 * \param file_priv DRM file private.
1148 * \param cmd command.
1149 * \param data user argument, pointing to a drm_wait_vblank structure.
1150 * \return zero on success or a negative number on failure.
1151 *
1152 * This function enables the vblank interrupt on the pipe requested, then
1153 * sleeps waiting for the requested sequence number to occur, and drops
1154 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1155 * after a timeout with no further vblank waits scheduled).
1156 */
1157int drm_wait_vblank(struct drm_device *dev, void *data,
1158 struct drm_file *file_priv)
1159{
1160 union drm_wait_vblank *vblwait = data;
1161 int ret = 0;
1162 unsigned int flags, seq, crtc, high_crtc;
1163
1164 if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
1165 return -EINVAL;
1166
1167 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1168 return -EINVAL;
1169
1170 if (vblwait->request.type &
1171 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1172 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1173 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1174 vblwait->request.type,
1175 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1176 _DRM_VBLANK_HIGH_CRTC_MASK));
1177 return -EINVAL;
1178 }
1179
1180 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1181 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1182 if (high_crtc)
1183 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1184 else
1185 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1186 if (crtc >= dev->num_crtcs)
1187 return -EINVAL;
1188
1189 ret = drm_vblank_get(dev, crtc);
1190 if (ret) {
1191 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1192 return ret;
1193 }
1194 seq = drm_vblank_count(dev, crtc);
1195
1196 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1197 case _DRM_VBLANK_RELATIVE:
1198 vblwait->request.sequence += seq;
1199 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1200 case _DRM_VBLANK_ABSOLUTE:
1201 break;
1202 default:
1203 ret = -EINVAL;
1204 goto done;
1205 }
1206
1207 if (flags & _DRM_VBLANK_EVENT)
1208 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1209
1210 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1211 (seq - vblwait->request.sequence) <= (1<<23)) {
1212 vblwait->request.sequence = seq + 1;
1213 }
1214
1215 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1216 vblwait->request.sequence, crtc);
1217 dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1218 DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
1219 (((drm_vblank_count(dev, crtc) -
1220 vblwait->request.sequence) <= (1 << 23)) ||
1221 !dev->irq_enabled));
1222
1223 if (ret != -EINTR) {
1224 struct timeval now;
1225
1226 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1227 vblwait->reply.tval_sec = now.tv_sec;
1228 vblwait->reply.tval_usec = now.tv_usec;
1229
1230 DRM_DEBUG("returning %d to client\n",
1231 vblwait->reply.sequence);
1232 } else {
1233 DRM_DEBUG("vblank wait interrupted by signal\n");
1234 }
1235
1236done:
1237 drm_vblank_put(dev, crtc);
1238 return ret;
1239}
1240
1241void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1242{
1243 struct drm_pending_vblank_event *e, *t;
1244 struct timeval now;
1245 unsigned long flags;
1246 unsigned int seq;
1247
1248 seq = drm_vblank_count_and_time(dev, crtc, &now);
1249
1250 spin_lock_irqsave(&dev->event_lock, flags);
1251
1252 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1253 if (e->pipe != crtc)
1254 continue;
1255 if ((seq - e->event.sequence) > (1<<23))
1256 continue;
1257
1258 DRM_DEBUG("vblank event on %d, current %d\n",
1259 e->event.sequence, seq);
1260
1261 e->event.sequence = seq;
1262 e->event.tv_sec = now.tv_sec;
1263 e->event.tv_usec = now.tv_usec;
1264 drm_vblank_put(dev, e->pipe);
1265 list_move_tail(&e->base.link, &e->base.file_priv->event_list);
1266 wake_up_interruptible(&e->base.file_priv->event_wait);
1267 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
1268 e->event.sequence);
1269 }
1270
1271 spin_unlock_irqrestore(&dev->event_lock, flags);
1272
1273 trace_drm_vblank_event(crtc, seq);
1274}
1275
1276/**
1277 * drm_handle_vblank - handle a vblank event
1278 * @dev: DRM device
1279 * @crtc: where this event occurred
1280 *
1281 * Drivers should call this routine in their vblank interrupt handlers to
1282 * update the vblank counter and send any signals that may be pending.
1283 */
1284bool drm_handle_vblank(struct drm_device *dev, int crtc)
1285{
1286 u32 vblcount;
1287 s64 diff_ns;
1288 struct timeval tvblank;
1289 unsigned long irqflags;
1290
1291 if (!dev->num_crtcs)
1292 return false;
1293
1294 /* Need timestamp lock to prevent concurrent execution with
1295 * vblank enable/disable, as this would cause inconsistent
1296 * or corrupted timestamps and vblank counts.
1297 */
1298 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1299
1300 /* Vblank irq handling disabled. Nothing to do. */
1301 if (!dev->vblank_enabled[crtc]) {
1302 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1303 return false;
1304 }
1305
1306 /* Fetch corresponding timestamp for this vblank interval from
1307 * driver and store it in proper slot of timestamp ringbuffer.
1308 */
1309
1310 /* Get current timestamp and count. */
1311 vblcount = atomic_read(&dev->_vblank_count[crtc]);
1312 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1313
1314 /* Compute time difference to timestamp of last vblank */
1315 diff_ns = timeval_to_ns(&tvblank) -
1316 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1317
1318 /* Update vblank timestamp and count if at least
1319 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1320 * difference between last stored timestamp and current
1321 * timestamp. A smaller difference means basically
1322 * identical timestamps. Happens if this vblank has
1323 * been already processed and this is a redundant call,
1324 * e.g., due to spurious vblank interrupts. We need to
1325 * ignore those for accounting.
1326 */
1327 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1328 /* Store new timestamp in ringbuffer. */
1329 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1330
1331 /* Increment cooked vblank count. This also atomically commits
1332 * the timestamp computed above.
1333 */
1334 smp_mb__before_atomic_inc();
1335 atomic_inc(&dev->_vblank_count[crtc]);
1336 smp_mb__after_atomic_inc();
1337 } else {
1338 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1339 crtc, (int) diff_ns);
1340 }
1341
1342 DRM_WAKEUP(&dev->vbl_queue[crtc]);
1343 drm_handle_vblank_events(dev, crtc);
1344
1345 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1346 return true;
1347}
1348EXPORT_SYMBOL(drm_handle_vblank);