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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 * 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
8/*
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
10 *
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
21 *
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
24 * Software.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
33 */
34
35#include <drm/drmP.h>
36#include "drm_trace.h"
37#include "drm_internal.h"
38
39#include <linux/interrupt.h> /* For task queue support */
40#include <linux/slab.h>
41
42#include <linux/vgaarb.h>
43#include <linux/export.h>
44
45/* Retry timestamp calculation up to 3 times to satisfy
46 * drm_timestamp_precision before giving up.
47 */
48#define DRM_TIMESTAMP_MAXRETRIES 3
49
50/* Threshold in nanoseconds for detection of redundant
51 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
52 */
53#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
54
55static bool
56drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
57 struct timeval *tvblank, unsigned flags);
58
59static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
60
61/*
62 * Default to use monotonic timestamps for wait-for-vblank and page-flip
63 * complete events.
64 */
65unsigned int drm_timestamp_monotonic = 1;
66
67static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
68
69module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
70module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
71module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
72MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
73MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
74MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
75
76static void store_vblank(struct drm_device *dev, unsigned int pipe,
77 u32 vblank_count_inc,
78 struct timeval *t_vblank, u32 last)
79{
80 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
81
82 assert_spin_locked(&dev->vblank_time_lock);
83
84 vblank->last = last;
85
86 write_seqlock(&vblank->seqlock);
87 vblank->time = *t_vblank;
88 vblank->count += vblank_count_inc;
89 write_sequnlock(&vblank->seqlock);
90}
91
92/*
93 * Reset the stored timestamp for the current vblank count to correspond
94 * to the last vblank occurred.
95 *
96 * Only to be called from drm_crtc_vblank_on().
97 *
98 * Note: caller must hold dev->vbl_lock since this reads & writes
99 * device vblank fields.
100 */
101static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
102{
103 u32 cur_vblank;
104 bool rc;
105 struct timeval t_vblank;
106 int count = DRM_TIMESTAMP_MAXRETRIES;
107
108 spin_lock(&dev->vblank_time_lock);
109
110 /*
111 * sample the current counter to avoid random jumps
112 * when drm_vblank_enable() applies the diff
113 */
114 do {
115 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
116 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
117 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
118
119 /*
120 * Only reinitialize corresponding vblank timestamp if high-precision query
121 * available and didn't fail. Otherwise reinitialize delayed at next vblank
122 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
123 */
124 if (!rc)
125 t_vblank = (struct timeval) {0, 0};
126
127 /*
128 * +1 to make sure user will never see the same
129 * vblank counter value before and after a modeset
130 */
131 store_vblank(dev, pipe, 1, &t_vblank, cur_vblank);
132
133 spin_unlock(&dev->vblank_time_lock);
134}
135
136/*
137 * Call back into the driver to update the appropriate vblank counter
138 * (specified by @pipe). Deal with wraparound, if it occurred, and
139 * update the last read value so we can deal with wraparound on the next
140 * call if necessary.
141 *
142 * Only necessary when going from off->on, to account for frames we
143 * didn't get an interrupt for.
144 *
145 * Note: caller must hold dev->vbl_lock since this reads & writes
146 * device vblank fields.
147 */
148static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
149 unsigned long flags)
150{
151 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
152 u32 cur_vblank, diff;
153 bool rc;
154 struct timeval t_vblank;
155 int count = DRM_TIMESTAMP_MAXRETRIES;
156 int framedur_ns = vblank->framedur_ns;
157
158 /*
159 * Interrupts were disabled prior to this call, so deal with counter
160 * wrap if needed.
161 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
162 * here if the register is small or we had vblank interrupts off for
163 * a long time.
164 *
165 * We repeat the hardware vblank counter & timestamp query until
166 * we get consistent results. This to prevent races between gpu
167 * updating its hardware counter while we are retrieving the
168 * corresponding vblank timestamp.
169 */
170 do {
171 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
172 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
173 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
174
175 if (dev->max_vblank_count != 0) {
176 /* trust the hw counter when it's around */
177 diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
178 } else if (rc && framedur_ns) {
179 const struct timeval *t_old;
180 u64 diff_ns;
181
182 t_old = &vblank->time;
183 diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
184
185 /*
186 * Figure out how many vblanks we've missed based
187 * on the difference in the timestamps and the
188 * frame/field duration.
189 */
190 diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
191
192 if (diff == 0 && flags & DRM_CALLED_FROM_VBLIRQ)
193 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
194 " diff_ns = %lld, framedur_ns = %d)\n",
195 pipe, (long long) diff_ns, framedur_ns);
196 } else {
197 /* some kind of default for drivers w/o accurate vbl timestamping */
198 diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
199 }
200
201 /*
202 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
203 * interval? If so then vblank irqs keep running and it will likely
204 * happen that the hardware vblank counter is not trustworthy as it
205 * might reset at some point in that interval and vblank timestamps
206 * are not trustworthy either in that interval. Iow. this can result
207 * in a bogus diff >> 1 which must be avoided as it would cause
208 * random large forward jumps of the software vblank counter.
209 */
210 if (diff > 1 && (vblank->inmodeset & 0x2)) {
211 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
212 " due to pre-modeset.\n", pipe, diff);
213 diff = 1;
214 }
215
216 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
217 " current=%u, diff=%u, hw=%u hw_last=%u\n",
218 pipe, vblank->count, diff, cur_vblank, vblank->last);
219
220 if (diff == 0) {
221 WARN_ON_ONCE(cur_vblank != vblank->last);
222 return;
223 }
224
225 /*
226 * Only reinitialize corresponding vblank timestamp if high-precision query
227 * available and didn't fail, or we were called from the vblank interrupt.
228 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
229 * for now, to mark the vblanktimestamp as invalid.
230 */
231 if (!rc && (flags & DRM_CALLED_FROM_VBLIRQ) == 0)
232 t_vblank = (struct timeval) {0, 0};
233
234 store_vblank(dev, pipe, diff, &t_vblank, cur_vblank);
235}
236
237static u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
238{
239 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
240
241 if (WARN_ON(pipe >= dev->num_crtcs))
242 return 0;
243
244 return vblank->count;
245}
246
247/**
248 * drm_accurate_vblank_count - retrieve the master vblank counter
249 * @crtc: which counter to retrieve
250 *
251 * This function is similar to @drm_crtc_vblank_count but this
252 * function interpolates to handle a race with vblank irq's.
253 *
254 * This is mostly useful for hardware that can obtain the scanout
255 * position, but doesn't have a frame counter.
256 */
257u32 drm_accurate_vblank_count(struct drm_crtc *crtc)
258{
259 struct drm_device *dev = crtc->dev;
260 unsigned int pipe = drm_crtc_index(crtc);
261 u32 vblank;
262 unsigned long flags;
263
264 WARN(!dev->driver->get_vblank_timestamp,
265 "This function requires support for accurate vblank timestamps.");
266
267 spin_lock_irqsave(&dev->vblank_time_lock, flags);
268
269 drm_update_vblank_count(dev, pipe, 0);
270 vblank = drm_vblank_count(dev, pipe);
271
272 spin_unlock_irqrestore(&dev->vblank_time_lock, flags);
273
274 return vblank;
275}
276EXPORT_SYMBOL(drm_accurate_vblank_count);
277
278/*
279 * Disable vblank irq's on crtc, make sure that last vblank count
280 * of hardware and corresponding consistent software vblank counter
281 * are preserved, even if there are any spurious vblank irq's after
282 * disable.
283 */
284static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
285{
286 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
287 unsigned long irqflags;
288
289 /* Prevent vblank irq processing while disabling vblank irqs,
290 * so no updates of timestamps or count can happen after we've
291 * disabled. Needed to prevent races in case of delayed irq's.
292 */
293 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
294
295 /*
296 * Only disable vblank interrupts if they're enabled. This avoids
297 * calling the ->disable_vblank() operation in atomic context with the
298 * hardware potentially runtime suspended.
299 */
300 if (vblank->enabled) {
301 dev->driver->disable_vblank(dev, pipe);
302 vblank->enabled = false;
303 }
304
305 /*
306 * Always update the count and timestamp to maintain the
307 * appearance that the counter has been ticking all along until
308 * this time. This makes the count account for the entire time
309 * between drm_crtc_vblank_on() and drm_crtc_vblank_off().
310 */
311 drm_update_vblank_count(dev, pipe, 0);
312
313 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
314}
315
316static void vblank_disable_fn(unsigned long arg)
317{
318 struct drm_vblank_crtc *vblank = (void *)arg;
319 struct drm_device *dev = vblank->dev;
320 unsigned int pipe = vblank->pipe;
321 unsigned long irqflags;
322
323 spin_lock_irqsave(&dev->vbl_lock, irqflags);
324 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
325 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
326 vblank_disable_and_save(dev, pipe);
327 }
328 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
329}
330
331/**
332 * drm_vblank_cleanup - cleanup vblank support
333 * @dev: DRM device
334 *
335 * This function cleans up any resources allocated in drm_vblank_init.
336 */
337void drm_vblank_cleanup(struct drm_device *dev)
338{
339 unsigned int pipe;
340
341 /* Bail if the driver didn't call drm_vblank_init() */
342 if (dev->num_crtcs == 0)
343 return;
344
345 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
346 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
347
348 WARN_ON(vblank->enabled &&
349 drm_core_check_feature(dev, DRIVER_MODESET));
350
351 del_timer_sync(&vblank->disable_timer);
352 }
353
354 kfree(dev->vblank);
355
356 dev->num_crtcs = 0;
357}
358EXPORT_SYMBOL(drm_vblank_cleanup);
359
360/**
361 * drm_vblank_init - initialize vblank support
362 * @dev: DRM device
363 * @num_crtcs: number of CRTCs supported by @dev
364 *
365 * This function initializes vblank support for @num_crtcs display pipelines.
366 *
367 * Returns:
368 * Zero on success or a negative error code on failure.
369 */
370int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
371{
372 int ret = -ENOMEM;
373 unsigned int i;
374
375 spin_lock_init(&dev->vbl_lock);
376 spin_lock_init(&dev->vblank_time_lock);
377
378 dev->num_crtcs = num_crtcs;
379
380 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
381 if (!dev->vblank)
382 goto err;
383
384 for (i = 0; i < num_crtcs; i++) {
385 struct drm_vblank_crtc *vblank = &dev->vblank[i];
386
387 vblank->dev = dev;
388 vblank->pipe = i;
389 init_waitqueue_head(&vblank->queue);
390 setup_timer(&vblank->disable_timer, vblank_disable_fn,
391 (unsigned long)vblank);
392 seqlock_init(&vblank->seqlock);
393 }
394
395 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
396
397 /* Driver specific high-precision vblank timestamping supported? */
398 if (dev->driver->get_vblank_timestamp)
399 DRM_INFO("Driver supports precise vblank timestamp query.\n");
400 else
401 DRM_INFO("No driver support for vblank timestamp query.\n");
402
403 /* Must have precise timestamping for reliable vblank instant disable */
404 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
405 dev->vblank_disable_immediate = false;
406 DRM_INFO("Setting vblank_disable_immediate to false because "
407 "get_vblank_timestamp == NULL\n");
408 }
409
410 return 0;
411
412err:
413 dev->num_crtcs = 0;
414 return ret;
415}
416EXPORT_SYMBOL(drm_vblank_init);
417
418static void drm_irq_vgaarb_nokms(void *cookie, bool state)
419{
420 struct drm_device *dev = cookie;
421
422 if (dev->driver->vgaarb_irq) {
423 dev->driver->vgaarb_irq(dev, state);
424 return;
425 }
426
427 if (!dev->irq_enabled)
428 return;
429
430 if (state) {
431 if (dev->driver->irq_uninstall)
432 dev->driver->irq_uninstall(dev);
433 } else {
434 if (dev->driver->irq_preinstall)
435 dev->driver->irq_preinstall(dev);
436 if (dev->driver->irq_postinstall)
437 dev->driver->irq_postinstall(dev);
438 }
439}
440
441/**
442 * drm_irq_install - install IRQ handler
443 * @dev: DRM device
444 * @irq: IRQ number to install the handler for
445 *
446 * Initializes the IRQ related data. Installs the handler, calling the driver
447 * irq_preinstall() and irq_postinstall() functions before and after the
448 * installation.
449 *
450 * This is the simplified helper interface provided for drivers with no special
451 * needs. Drivers which need to install interrupt handlers for multiple
452 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
453 * that vblank interrupts are available.
454 *
455 * Returns:
456 * Zero on success or a negative error code on failure.
457 */
458int drm_irq_install(struct drm_device *dev, int irq)
459{
460 int ret;
461 unsigned long sh_flags = 0;
462
463 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
464 return -EINVAL;
465
466 if (irq == 0)
467 return -EINVAL;
468
469 /* Driver must have been initialized */
470 if (!dev->dev_private)
471 return -EINVAL;
472
473 if (dev->irq_enabled)
474 return -EBUSY;
475 dev->irq_enabled = true;
476
477 DRM_DEBUG("irq=%d\n", irq);
478
479 /* Before installing handler */
480 if (dev->driver->irq_preinstall)
481 dev->driver->irq_preinstall(dev);
482
483 /* Install handler */
484 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
485 sh_flags = IRQF_SHARED;
486
487 ret = request_irq(irq, dev->driver->irq_handler,
488 sh_flags, dev->driver->name, dev);
489
490 if (ret < 0) {
491 dev->irq_enabled = false;
492 return ret;
493 }
494
495 if (drm_core_check_feature(dev, DRIVER_LEGACY))
496 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
497
498 /* After installing handler */
499 if (dev->driver->irq_postinstall)
500 ret = dev->driver->irq_postinstall(dev);
501
502 if (ret < 0) {
503 dev->irq_enabled = false;
504 if (drm_core_check_feature(dev, DRIVER_LEGACY))
505 vga_client_register(dev->pdev, NULL, NULL, NULL);
506 free_irq(irq, dev);
507 } else {
508 dev->irq = irq;
509 }
510
511 return ret;
512}
513EXPORT_SYMBOL(drm_irq_install);
514
515/**
516 * drm_irq_uninstall - uninstall the IRQ handler
517 * @dev: DRM device
518 *
519 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
520 * This should only be called by drivers which used drm_irq_install() to set up
521 * their interrupt handler. Other drivers must only reset
522 * drm_device->irq_enabled to false.
523 *
524 * Note that for kernel modesetting drivers it is a bug if this function fails.
525 * The sanity checks are only to catch buggy user modesetting drivers which call
526 * the same function through an ioctl.
527 *
528 * Returns:
529 * Zero on success or a negative error code on failure.
530 */
531int drm_irq_uninstall(struct drm_device *dev)
532{
533 unsigned long irqflags;
534 bool irq_enabled;
535 int i;
536
537 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
538 return -EINVAL;
539
540 irq_enabled = dev->irq_enabled;
541 dev->irq_enabled = false;
542
543 /*
544 * Wake up any waiters so they don't hang. This is just to paper over
545 * issues for UMS drivers which aren't in full control of their
546 * vblank/irq handling. KMS drivers must ensure that vblanks are all
547 * disabled when uninstalling the irq handler.
548 */
549 if (dev->num_crtcs) {
550 spin_lock_irqsave(&dev->vbl_lock, irqflags);
551 for (i = 0; i < dev->num_crtcs; i++) {
552 struct drm_vblank_crtc *vblank = &dev->vblank[i];
553
554 if (!vblank->enabled)
555 continue;
556
557 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
558
559 vblank_disable_and_save(dev, i);
560 wake_up(&vblank->queue);
561 }
562 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
563 }
564
565 if (!irq_enabled)
566 return -EINVAL;
567
568 DRM_DEBUG("irq=%d\n", dev->irq);
569
570 if (drm_core_check_feature(dev, DRIVER_LEGACY))
571 vga_client_register(dev->pdev, NULL, NULL, NULL);
572
573 if (dev->driver->irq_uninstall)
574 dev->driver->irq_uninstall(dev);
575
576 free_irq(dev->irq, dev);
577
578 return 0;
579}
580EXPORT_SYMBOL(drm_irq_uninstall);
581
582/*
583 * IRQ control ioctl.
584 *
585 * \param inode device inode.
586 * \param file_priv DRM file private.
587 * \param cmd command.
588 * \param arg user argument, pointing to a drm_control structure.
589 * \return zero on success or a negative number on failure.
590 *
591 * Calls irq_install() or irq_uninstall() according to \p arg.
592 */
593int drm_control(struct drm_device *dev, void *data,
594 struct drm_file *file_priv)
595{
596 struct drm_control *ctl = data;
597 int ret = 0, irq;
598
599 /* if we haven't irq we fallback for compatibility reasons -
600 * this used to be a separate function in drm_dma.h
601 */
602
603 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
604 return 0;
605 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
606 return 0;
607 /* UMS was only ever supported on pci devices. */
608 if (WARN_ON(!dev->pdev))
609 return -EINVAL;
610
611 switch (ctl->func) {
612 case DRM_INST_HANDLER:
613 irq = dev->pdev->irq;
614
615 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
616 ctl->irq != irq)
617 return -EINVAL;
618 mutex_lock(&dev->struct_mutex);
619 ret = drm_irq_install(dev, irq);
620 mutex_unlock(&dev->struct_mutex);
621
622 return ret;
623 case DRM_UNINST_HANDLER:
624 mutex_lock(&dev->struct_mutex);
625 ret = drm_irq_uninstall(dev);
626 mutex_unlock(&dev->struct_mutex);
627
628 return ret;
629 default:
630 return -EINVAL;
631 }
632}
633
634/**
635 * drm_calc_timestamping_constants - calculate vblank timestamp constants
636 * @crtc: drm_crtc whose timestamp constants should be updated.
637 * @mode: display mode containing the scanout timings
638 *
639 * Calculate and store various constants which are later
640 * needed by vblank and swap-completion timestamping, e.g,
641 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
642 * derived from CRTC's true scanout timing, so they take
643 * things like panel scaling or other adjustments into account.
644 */
645void drm_calc_timestamping_constants(struct drm_crtc *crtc,
646 const struct drm_display_mode *mode)
647{
648 struct drm_device *dev = crtc->dev;
649 unsigned int pipe = drm_crtc_index(crtc);
650 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
651 int linedur_ns = 0, framedur_ns = 0;
652 int dotclock = mode->crtc_clock;
653
654 if (!dev->num_crtcs)
655 return;
656
657 if (WARN_ON(pipe >= dev->num_crtcs))
658 return;
659
660 /* Valid dotclock? */
661 if (dotclock > 0) {
662 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
663
664 /*
665 * Convert scanline length in pixels and video
666 * dot clock to line duration and frame duration
667 * in nanoseconds:
668 */
669 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
670 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
671
672 /*
673 * Fields of interlaced scanout modes are only half a frame duration.
674 */
675 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
676 framedur_ns /= 2;
677 } else
678 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
679 crtc->base.id);
680
681 vblank->linedur_ns = linedur_ns;
682 vblank->framedur_ns = framedur_ns;
683
684 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
685 crtc->base.id, mode->crtc_htotal,
686 mode->crtc_vtotal, mode->crtc_vdisplay);
687 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
688 crtc->base.id, dotclock, framedur_ns, linedur_ns);
689}
690EXPORT_SYMBOL(drm_calc_timestamping_constants);
691
692/**
693 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
694 * @dev: DRM device
695 * @pipe: index of CRTC whose vblank timestamp to retrieve
696 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
697 * On return contains true maximum error of timestamp
698 * @vblank_time: Pointer to struct timeval which should receive the timestamp
699 * @flags: Flags to pass to driver:
700 * 0 = Default,
701 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
702 * @mode: mode which defines the scanout timings
703 *
704 * Implements calculation of exact vblank timestamps from given drm_display_mode
705 * timings and current video scanout position of a CRTC. This can be called from
706 * within get_vblank_timestamp() implementation of a kms driver to implement the
707 * actual timestamping.
708 *
709 * Should return timestamps conforming to the OML_sync_control OpenML
710 * extension specification. The timestamp corresponds to the end of
711 * the vblank interval, aka start of scanout of topmost-leftmost display
712 * pixel in the following video frame.
713 *
714 * Requires support for optional dev->driver->get_scanout_position()
715 * in kms driver, plus a bit of setup code to provide a drm_display_mode
716 * that corresponds to the true scanout timing.
717 *
718 * The current implementation only handles standard video modes. It
719 * returns as no operation if a doublescan or interlaced video mode is
720 * active. Higher level code is expected to handle this.
721 *
722 * Returns:
723 * Negative value on error, failure or if not supported in current
724 * video mode:
725 *
726 * -EINVAL Invalid CRTC.
727 * -EAGAIN Temporary unavailable, e.g., called before initial modeset.
728 * -ENOTSUPP Function not supported in current display mode.
729 * -EIO Failed, e.g., due to failed scanout position query.
730 *
731 * Returns or'ed positive status flags on success:
732 *
733 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
734 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
735 *
736 */
737int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
738 unsigned int pipe,
739 int *max_error,
740 struct timeval *vblank_time,
741 unsigned flags,
742 const struct drm_display_mode *mode)
743{
744 struct timeval tv_etime;
745 ktime_t stime, etime;
746 unsigned int vbl_status;
747 int ret = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
748 int vpos, hpos, i;
749 int delta_ns, duration_ns;
750
751 if (pipe >= dev->num_crtcs) {
752 DRM_ERROR("Invalid crtc %u\n", pipe);
753 return -EINVAL;
754 }
755
756 /* Scanout position query not supported? Should not happen. */
757 if (!dev->driver->get_scanout_position) {
758 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
759 return -EIO;
760 }
761
762 /* If mode timing undefined, just return as no-op:
763 * Happens during initial modesetting of a crtc.
764 */
765 if (mode->crtc_clock == 0) {
766 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
767 return -EAGAIN;
768 }
769
770 /* Get current scanout position with system timestamp.
771 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
772 * if single query takes longer than max_error nanoseconds.
773 *
774 * This guarantees a tight bound on maximum error if
775 * code gets preempted or delayed for some reason.
776 */
777 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
778 /*
779 * Get vertical and horizontal scanout position vpos, hpos,
780 * and bounding timestamps stime, etime, pre/post query.
781 */
782 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
783 &vpos, &hpos,
784 &stime, &etime,
785 mode);
786
787 /* Return as no-op if scanout query unsupported or failed. */
788 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
789 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
790 pipe, vbl_status);
791 return -EIO;
792 }
793
794 /* Compute uncertainty in timestamp of scanout position query. */
795 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
796
797 /* Accept result with < max_error nsecs timing uncertainty. */
798 if (duration_ns <= *max_error)
799 break;
800 }
801
802 /* Noisy system timing? */
803 if (i == DRM_TIMESTAMP_MAXRETRIES) {
804 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
805 pipe, duration_ns/1000, *max_error/1000, i);
806 }
807
808 /* Return upper bound of timestamp precision error. */
809 *max_error = duration_ns;
810
811 /* Check if in vblank area:
812 * vpos is >=0 in video scanout area, but negative
813 * within vblank area, counting down the number of lines until
814 * start of scanout.
815 */
816 if (vbl_status & DRM_SCANOUTPOS_IN_VBLANK)
817 ret |= DRM_VBLANKTIME_IN_VBLANK;
818
819 /* Convert scanout position into elapsed time at raw_time query
820 * since start of scanout at first display scanline. delta_ns
821 * can be negative if start of scanout hasn't happened yet.
822 */
823 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
824 mode->crtc_clock);
825
826 if (!drm_timestamp_monotonic)
827 etime = ktime_mono_to_real(etime);
828
829 /* save this only for debugging purposes */
830 tv_etime = ktime_to_timeval(etime);
831 /* Subtract time delta from raw timestamp to get final
832 * vblank_time timestamp for end of vblank.
833 */
834 etime = ktime_sub_ns(etime, delta_ns);
835 *vblank_time = ktime_to_timeval(etime);
836
837 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
838 pipe, vbl_status, hpos, vpos,
839 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
840 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
841 duration_ns/1000, i);
842
843 return ret;
844}
845EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
846
847static struct timeval get_drm_timestamp(void)
848{
849 ktime_t now;
850
851 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
852 return ktime_to_timeval(now);
853}
854
855/**
856 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
857 * vblank interval
858 * @dev: DRM device
859 * @pipe: index of CRTC whose vblank timestamp to retrieve
860 * @tvblank: Pointer to target struct timeval which should receive the timestamp
861 * @flags: Flags to pass to driver:
862 * 0 = Default,
863 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
864 *
865 * Fetches the system timestamp corresponding to the time of the most recent
866 * vblank interval on specified CRTC. May call into kms-driver to
867 * compute the timestamp with a high-precision GPU specific method.
868 *
869 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
870 * call, i.e., it isn't very precisely locked to the true vblank.
871 *
872 * Returns:
873 * True if timestamp is considered to be very precise, false otherwise.
874 */
875static bool
876drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
877 struct timeval *tvblank, unsigned flags)
878{
879 int ret;
880
881 /* Define requested maximum error on timestamps (nanoseconds). */
882 int max_error = (int) drm_timestamp_precision * 1000;
883
884 /* Query driver if possible and precision timestamping enabled. */
885 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
886 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
887 tvblank, flags);
888 if (ret > 0)
889 return true;
890 }
891
892 /* GPU high precision timestamp query unsupported or failed.
893 * Return current monotonic/gettimeofday timestamp as best estimate.
894 */
895 *tvblank = get_drm_timestamp();
896
897 return false;
898}
899
900/**
901 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
902 * @crtc: which counter to retrieve
903 *
904 * Fetches the "cooked" vblank count value that represents the number of
905 * vblank events since the system was booted, including lost events due to
906 * modesetting activity.
907 *
908 * Returns:
909 * The software vblank counter.
910 */
911u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
912{
913 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
914}
915EXPORT_SYMBOL(drm_crtc_vblank_count);
916
917/**
918 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
919 * system timestamp corresponding to that vblank counter value.
920 * @dev: DRM device
921 * @pipe: index of CRTC whose counter to retrieve
922 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
923 *
924 * Fetches the "cooked" vblank count value that represents the number of
925 * vblank events since the system was booted, including lost events due to
926 * modesetting activity. Returns corresponding system timestamp of the time
927 * of the vblank interval that corresponds to the current vblank counter value.
928 *
929 * This is the legacy version of drm_crtc_vblank_count_and_time().
930 */
931static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
932 struct timeval *vblanktime)
933{
934 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
935 u32 vblank_count;
936 unsigned int seq;
937
938 if (WARN_ON(pipe >= dev->num_crtcs)) {
939 *vblanktime = (struct timeval) { 0 };
940 return 0;
941 }
942
943 do {
944 seq = read_seqbegin(&vblank->seqlock);
945 vblank_count = vblank->count;
946 *vblanktime = vblank->time;
947 } while (read_seqretry(&vblank->seqlock, seq));
948
949 return vblank_count;
950}
951
952/**
953 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
954 * and the system timestamp corresponding to that vblank counter value
955 * @crtc: which counter to retrieve
956 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
957 *
958 * Fetches the "cooked" vblank count value that represents the number of
959 * vblank events since the system was booted, including lost events due to
960 * modesetting activity. Returns corresponding system timestamp of the time
961 * of the vblank interval that corresponds to the current vblank counter value.
962 */
963u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
964 struct timeval *vblanktime)
965{
966 return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
967 vblanktime);
968}
969EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
970
971static void send_vblank_event(struct drm_device *dev,
972 struct drm_pending_vblank_event *e,
973 unsigned long seq, struct timeval *now)
974{
975 e->event.sequence = seq;
976 e->event.tv_sec = now->tv_sec;
977 e->event.tv_usec = now->tv_usec;
978
979 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
980 e->event.sequence);
981
982 drm_send_event_locked(dev, &e->base);
983}
984
985/**
986 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
987 * @crtc: the source CRTC of the vblank event
988 * @e: the event to send
989 *
990 * A lot of drivers need to generate vblank events for the very next vblank
991 * interrupt. For example when the page flip interrupt happens when the page
992 * flip gets armed, but not when it actually executes within the next vblank
993 * period. This helper function implements exactly the required vblank arming
994 * behaviour.
995 *
996 * NOTE: Drivers using this to send out the event in struct &drm_crtc_state
997 * as part of an atomic commit must ensure that the next vblank happens at
998 * exactly the same time as the atomic commit is committed to the hardware. This
999 * function itself does **not** protect again the next vblank interrupt racing
1000 * with either this function call or the atomic commit operation. A possible
1001 * sequence could be:
1002 *
1003 * 1. Driver commits new hardware state into vblank-synchronized registers.
1004 * 2. A vblank happens, committing the hardware state. Also the corresponding
1005 * vblank interrupt is fired off and fully processed by the interrupt
1006 * handler.
1007 * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event().
1008 * 4. The event is only send out for the next vblank, which is wrong.
1009 *
1010 * An equivalent race can happen when the driver calls
1011 * drm_crtc_arm_vblank_event() before writing out the new hardware state.
1012 *
1013 * The only way to make this work safely is to prevent the vblank from firing
1014 * (and the hardware from committing anything else) until the entire atomic
1015 * commit sequence has run to completion. If the hardware does not have such a
1016 * feature (e.g. using a "go" bit), then it is unsafe to use this functions.
1017 * Instead drivers need to manually send out the event from their interrupt
1018 * handler by calling drm_crtc_send_vblank_event() and make sure that there's no
1019 * possible race with the hardware committing the atomic update.
1020 *
1021 * Caller must hold event lock. Caller must also hold a vblank reference for
1022 * the event @e, which will be dropped when the next vblank arrives.
1023 */
1024void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
1025 struct drm_pending_vblank_event *e)
1026{
1027 struct drm_device *dev = crtc->dev;
1028 unsigned int pipe = drm_crtc_index(crtc);
1029
1030 assert_spin_locked(&dev->event_lock);
1031
1032 e->pipe = pipe;
1033 e->event.sequence = drm_vblank_count(dev, pipe);
1034 list_add_tail(&e->base.link, &dev->vblank_event_list);
1035}
1036EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
1037
1038/**
1039 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1040 * @crtc: the source CRTC of the vblank event
1041 * @e: the event to send
1042 *
1043 * Updates sequence # and timestamp on event for the most recently processed
1044 * vblank, and sends it to userspace. Caller must hold event lock.
1045 *
1046 * See drm_crtc_arm_vblank_event() for a helper which can be used in certain
1047 * situation, especially to send out events for atomic commit operations.
1048 */
1049void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
1050 struct drm_pending_vblank_event *e)
1051{
1052 struct drm_device *dev = crtc->dev;
1053 unsigned int seq, pipe = drm_crtc_index(crtc);
1054 struct timeval now;
1055
1056 if (dev->num_crtcs > 0) {
1057 seq = drm_vblank_count_and_time(dev, pipe, &now);
1058 } else {
1059 seq = 0;
1060
1061 now = get_drm_timestamp();
1062 }
1063 e->pipe = pipe;
1064 send_vblank_event(dev, e, seq, &now);
1065}
1066EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1067
1068/**
1069 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1070 * @dev: DRM device
1071 * @pipe: CRTC index
1072 *
1073 * Returns:
1074 * Zero on success or a negative error code on failure.
1075 */
1076static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1077{
1078 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1079 int ret = 0;
1080
1081 assert_spin_locked(&dev->vbl_lock);
1082
1083 spin_lock(&dev->vblank_time_lock);
1084
1085 if (!vblank->enabled) {
1086 /*
1087 * Enable vblank irqs under vblank_time_lock protection.
1088 * All vblank count & timestamp updates are held off
1089 * until we are done reinitializing master counter and
1090 * timestamps. Filtercode in drm_handle_vblank() will
1091 * prevent double-accounting of same vblank interval.
1092 */
1093 ret = dev->driver->enable_vblank(dev, pipe);
1094 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1095 if (ret)
1096 atomic_dec(&vblank->refcount);
1097 else {
1098 vblank->enabled = true;
1099 drm_update_vblank_count(dev, pipe, 0);
1100 }
1101 }
1102
1103 spin_unlock(&dev->vblank_time_lock);
1104
1105 return ret;
1106}
1107
1108/**
1109 * drm_vblank_get - get a reference count on vblank events
1110 * @dev: DRM device
1111 * @pipe: index of CRTC to own
1112 *
1113 * Acquire a reference count on vblank events to avoid having them disabled
1114 * while in use.
1115 *
1116 * This is the legacy version of drm_crtc_vblank_get().
1117 *
1118 * Returns:
1119 * Zero on success or a negative error code on failure.
1120 */
1121static int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1122{
1123 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1124 unsigned long irqflags;
1125 int ret = 0;
1126
1127 if (!dev->num_crtcs)
1128 return -EINVAL;
1129
1130 if (WARN_ON(pipe >= dev->num_crtcs))
1131 return -EINVAL;
1132
1133 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1134 /* Going from 0->1 means we have to enable interrupts again */
1135 if (atomic_add_return(1, &vblank->refcount) == 1) {
1136 ret = drm_vblank_enable(dev, pipe);
1137 } else {
1138 if (!vblank->enabled) {
1139 atomic_dec(&vblank->refcount);
1140 ret = -EINVAL;
1141 }
1142 }
1143 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1144
1145 return ret;
1146}
1147
1148/**
1149 * drm_crtc_vblank_get - get a reference count on vblank events
1150 * @crtc: which CRTC to own
1151 *
1152 * Acquire a reference count on vblank events to avoid having them disabled
1153 * while in use.
1154 *
1155 * Returns:
1156 * Zero on success or a negative error code on failure.
1157 */
1158int drm_crtc_vblank_get(struct drm_crtc *crtc)
1159{
1160 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1161}
1162EXPORT_SYMBOL(drm_crtc_vblank_get);
1163
1164/**
1165 * drm_vblank_put - release ownership of vblank events
1166 * @dev: DRM device
1167 * @pipe: index of CRTC to release
1168 *
1169 * Release ownership of a given vblank counter, turning off interrupts
1170 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1171 *
1172 * This is the legacy version of drm_crtc_vblank_put().
1173 */
1174static void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1175{
1176 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1177
1178 if (WARN_ON(pipe >= dev->num_crtcs))
1179 return;
1180
1181 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1182 return;
1183
1184 /* Last user schedules interrupt disable */
1185 if (atomic_dec_and_test(&vblank->refcount)) {
1186 if (drm_vblank_offdelay == 0)
1187 return;
1188 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1189 vblank_disable_fn((unsigned long)vblank);
1190 else
1191 mod_timer(&vblank->disable_timer,
1192 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1193 }
1194}
1195
1196/**
1197 * drm_crtc_vblank_put - give up ownership of vblank events
1198 * @crtc: which counter to give up
1199 *
1200 * Release ownership of a given vblank counter, turning off interrupts
1201 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1202 */
1203void drm_crtc_vblank_put(struct drm_crtc *crtc)
1204{
1205 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1206}
1207EXPORT_SYMBOL(drm_crtc_vblank_put);
1208
1209/**
1210 * drm_wait_one_vblank - wait for one vblank
1211 * @dev: DRM device
1212 * @pipe: CRTC index
1213 *
1214 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1215 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1216 * due to lack of driver support or because the crtc is off.
1217 */
1218void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1219{
1220 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1221 int ret;
1222 u32 last;
1223
1224 if (WARN_ON(pipe >= dev->num_crtcs))
1225 return;
1226
1227 ret = drm_vblank_get(dev, pipe);
1228 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1229 return;
1230
1231 last = drm_vblank_count(dev, pipe);
1232
1233 ret = wait_event_timeout(vblank->queue,
1234 last != drm_vblank_count(dev, pipe),
1235 msecs_to_jiffies(100));
1236
1237 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1238
1239 drm_vblank_put(dev, pipe);
1240}
1241EXPORT_SYMBOL(drm_wait_one_vblank);
1242
1243/**
1244 * drm_crtc_wait_one_vblank - wait for one vblank
1245 * @crtc: DRM crtc
1246 *
1247 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1248 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1249 * due to lack of driver support or because the crtc is off.
1250 */
1251void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1252{
1253 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1254}
1255EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1256
1257/**
1258 * drm_crtc_vblank_off - disable vblank events on a CRTC
1259 * @crtc: CRTC in question
1260 *
1261 * Drivers can use this function to shut down the vblank interrupt handling when
1262 * disabling a crtc. This function ensures that the latest vblank frame count is
1263 * stored so that drm_vblank_on can restore it again.
1264 *
1265 * Drivers must use this function when the hardware vblank counter can get
1266 * reset, e.g. when suspending.
1267 */
1268void drm_crtc_vblank_off(struct drm_crtc *crtc)
1269{
1270 struct drm_device *dev = crtc->dev;
1271 unsigned int pipe = drm_crtc_index(crtc);
1272 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1273 struct drm_pending_vblank_event *e, *t;
1274 struct timeval now;
1275 unsigned long irqflags;
1276 unsigned int seq;
1277
1278 if (WARN_ON(pipe >= dev->num_crtcs))
1279 return;
1280
1281 spin_lock_irqsave(&dev->event_lock, irqflags);
1282
1283 spin_lock(&dev->vbl_lock);
1284 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1285 pipe, vblank->enabled, vblank->inmodeset);
1286
1287 /* Avoid redundant vblank disables without previous
1288 * drm_crtc_vblank_on(). */
1289 if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
1290 vblank_disable_and_save(dev, pipe);
1291
1292 wake_up(&vblank->queue);
1293
1294 /*
1295 * Prevent subsequent drm_vblank_get() from re-enabling
1296 * the vblank interrupt by bumping the refcount.
1297 */
1298 if (!vblank->inmodeset) {
1299 atomic_inc(&vblank->refcount);
1300 vblank->inmodeset = 1;
1301 }
1302 spin_unlock(&dev->vbl_lock);
1303
1304 /* Send any queued vblank events, lest the natives grow disquiet */
1305 seq = drm_vblank_count_and_time(dev, pipe, &now);
1306
1307 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1308 if (e->pipe != pipe)
1309 continue;
1310 DRM_DEBUG("Sending premature vblank event on disable: "
1311 "wanted %u, current %u\n",
1312 e->event.sequence, seq);
1313 list_del(&e->base.link);
1314 drm_vblank_put(dev, pipe);
1315 send_vblank_event(dev, e, seq, &now);
1316 }
1317 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1318}
1319EXPORT_SYMBOL(drm_crtc_vblank_off);
1320
1321/**
1322 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1323 * @crtc: CRTC in question
1324 *
1325 * Drivers can use this function to reset the vblank state to off at load time.
1326 * Drivers should use this together with the drm_crtc_vblank_off() and
1327 * drm_crtc_vblank_on() functions. The difference compared to
1328 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1329 * and hence doesn't need to call any driver hooks.
1330 */
1331void drm_crtc_vblank_reset(struct drm_crtc *crtc)
1332{
1333 struct drm_device *dev = crtc->dev;
1334 unsigned long irqflags;
1335 unsigned int pipe = drm_crtc_index(crtc);
1336 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1337
1338 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1339 /*
1340 * Prevent subsequent drm_vblank_get() from enabling the vblank
1341 * interrupt by bumping the refcount.
1342 */
1343 if (!vblank->inmodeset) {
1344 atomic_inc(&vblank->refcount);
1345 vblank->inmodeset = 1;
1346 }
1347 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1348
1349 WARN_ON(!list_empty(&dev->vblank_event_list));
1350}
1351EXPORT_SYMBOL(drm_crtc_vblank_reset);
1352
1353/**
1354 * drm_crtc_vblank_on - enable vblank events on a CRTC
1355 * @crtc: CRTC in question
1356 *
1357 * This functions restores the vblank interrupt state captured with
1358 * drm_crtc_vblank_off() again. Note that calls to drm_crtc_vblank_on() and
1359 * drm_crtc_vblank_off() can be unbalanced and so can also be unconditionally called
1360 * in driver load code to reflect the current hardware state of the crtc.
1361 */
1362void drm_crtc_vblank_on(struct drm_crtc *crtc)
1363{
1364 struct drm_device *dev = crtc->dev;
1365 unsigned int pipe = drm_crtc_index(crtc);
1366 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1367 unsigned long irqflags;
1368
1369 if (WARN_ON(pipe >= dev->num_crtcs))
1370 return;
1371
1372 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1373 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1374 pipe, vblank->enabled, vblank->inmodeset);
1375
1376 /* Drop our private "prevent drm_vblank_get" refcount */
1377 if (vblank->inmodeset) {
1378 atomic_dec(&vblank->refcount);
1379 vblank->inmodeset = 0;
1380 }
1381
1382 drm_reset_vblank_timestamp(dev, pipe);
1383
1384 /*
1385 * re-enable interrupts if there are users left, or the
1386 * user wishes vblank interrupts to be enabled all the time.
1387 */
1388 if (atomic_read(&vblank->refcount) != 0 || drm_vblank_offdelay == 0)
1389 WARN_ON(drm_vblank_enable(dev, pipe));
1390 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1391}
1392EXPORT_SYMBOL(drm_crtc_vblank_on);
1393
1394static void drm_legacy_vblank_pre_modeset(struct drm_device *dev,
1395 unsigned int pipe)
1396{
1397 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1398
1399 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1400 if (!dev->num_crtcs)
1401 return;
1402
1403 if (WARN_ON(pipe >= dev->num_crtcs))
1404 return;
1405
1406 /*
1407 * To avoid all the problems that might happen if interrupts
1408 * were enabled/disabled around or between these calls, we just
1409 * have the kernel take a reference on the CRTC (just once though
1410 * to avoid corrupting the count if multiple, mismatch calls occur),
1411 * so that interrupts remain enabled in the interim.
1412 */
1413 if (!vblank->inmodeset) {
1414 vblank->inmodeset = 0x1;
1415 if (drm_vblank_get(dev, pipe) == 0)
1416 vblank->inmodeset |= 0x2;
1417 }
1418}
1419
1420static void drm_legacy_vblank_post_modeset(struct drm_device *dev,
1421 unsigned int pipe)
1422{
1423 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1424 unsigned long irqflags;
1425
1426 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1427 if (!dev->num_crtcs)
1428 return;
1429
1430 if (WARN_ON(pipe >= dev->num_crtcs))
1431 return;
1432
1433 if (vblank->inmodeset) {
1434 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1435 drm_reset_vblank_timestamp(dev, pipe);
1436 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1437
1438 if (vblank->inmodeset & 0x2)
1439 drm_vblank_put(dev, pipe);
1440
1441 vblank->inmodeset = 0;
1442 }
1443}
1444
1445/*
1446 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1447 * @DRM_IOCTL_ARGS: standard ioctl arguments
1448 *
1449 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1450 * ioctls around modesetting so that any lost vblank events are accounted for.
1451 *
1452 * Generally the counter will reset across mode sets. If interrupts are
1453 * enabled around this call, we don't have to do anything since the counter
1454 * will have already been incremented.
1455 */
1456int drm_modeset_ctl(struct drm_device *dev, void *data,
1457 struct drm_file *file_priv)
1458{
1459 struct drm_modeset_ctl *modeset = data;
1460 unsigned int pipe;
1461
1462 /* If drm_vblank_init() hasn't been called yet, just no-op */
1463 if (!dev->num_crtcs)
1464 return 0;
1465
1466 /* KMS drivers handle this internally */
1467 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1468 return 0;
1469
1470 pipe = modeset->crtc;
1471 if (pipe >= dev->num_crtcs)
1472 return -EINVAL;
1473
1474 switch (modeset->cmd) {
1475 case _DRM_PRE_MODESET:
1476 drm_legacy_vblank_pre_modeset(dev, pipe);
1477 break;
1478 case _DRM_POST_MODESET:
1479 drm_legacy_vblank_post_modeset(dev, pipe);
1480 break;
1481 default:
1482 return -EINVAL;
1483 }
1484
1485 return 0;
1486}
1487
1488static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1489 union drm_wait_vblank *vblwait,
1490 struct drm_file *file_priv)
1491{
1492 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1493 struct drm_pending_vblank_event *e;
1494 struct timeval now;
1495 unsigned long flags;
1496 unsigned int seq;
1497 int ret;
1498
1499 e = kzalloc(sizeof(*e), GFP_KERNEL);
1500 if (e == NULL) {
1501 ret = -ENOMEM;
1502 goto err_put;
1503 }
1504
1505 e->pipe = pipe;
1506 e->base.pid = current->pid;
1507 e->event.base.type = DRM_EVENT_VBLANK;
1508 e->event.base.length = sizeof(e->event);
1509 e->event.user_data = vblwait->request.signal;
1510
1511 spin_lock_irqsave(&dev->event_lock, flags);
1512
1513 /*
1514 * drm_crtc_vblank_off() might have been called after we called
1515 * drm_vblank_get(). drm_crtc_vblank_off() holds event_lock around the
1516 * vblank disable, so no need for further locking. The reference from
1517 * drm_vblank_get() protects against vblank disable from another source.
1518 */
1519 if (!vblank->enabled) {
1520 ret = -EINVAL;
1521 goto err_unlock;
1522 }
1523
1524 ret = drm_event_reserve_init_locked(dev, file_priv, &e->base,
1525 &e->event.base);
1526
1527 if (ret)
1528 goto err_unlock;
1529
1530 seq = drm_vblank_count_and_time(dev, pipe, &now);
1531
1532 DRM_DEBUG("event on vblank count %u, current %u, crtc %u\n",
1533 vblwait->request.sequence, seq, pipe);
1534
1535 trace_drm_vblank_event_queued(current->pid, pipe,
1536 vblwait->request.sequence);
1537
1538 e->event.sequence = vblwait->request.sequence;
1539 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1540 drm_vblank_put(dev, pipe);
1541 send_vblank_event(dev, e, seq, &now);
1542 vblwait->reply.sequence = seq;
1543 } else {
1544 /* drm_handle_vblank_events will call drm_vblank_put */
1545 list_add_tail(&e->base.link, &dev->vblank_event_list);
1546 vblwait->reply.sequence = vblwait->request.sequence;
1547 }
1548
1549 spin_unlock_irqrestore(&dev->event_lock, flags);
1550
1551 return 0;
1552
1553err_unlock:
1554 spin_unlock_irqrestore(&dev->event_lock, flags);
1555 kfree(e);
1556err_put:
1557 drm_vblank_put(dev, pipe);
1558 return ret;
1559}
1560
1561/*
1562 * Wait for VBLANK.
1563 *
1564 * \param inode device inode.
1565 * \param file_priv DRM file private.
1566 * \param cmd command.
1567 * \param data user argument, pointing to a drm_wait_vblank structure.
1568 * \return zero on success or a negative number on failure.
1569 *
1570 * This function enables the vblank interrupt on the pipe requested, then
1571 * sleeps waiting for the requested sequence number to occur, and drops
1572 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1573 * after a timeout with no further vblank waits scheduled).
1574 */
1575int drm_wait_vblank(struct drm_device *dev, void *data,
1576 struct drm_file *file_priv)
1577{
1578 struct drm_vblank_crtc *vblank;
1579 union drm_wait_vblank *vblwait = data;
1580 int ret;
1581 unsigned int flags, seq, pipe, high_pipe;
1582
1583 if (!dev->irq_enabled)
1584 return -EINVAL;
1585
1586 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1587 return -EINVAL;
1588
1589 if (vblwait->request.type &
1590 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1591 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1592 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1593 vblwait->request.type,
1594 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1595 _DRM_VBLANK_HIGH_CRTC_MASK));
1596 return -EINVAL;
1597 }
1598
1599 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1600 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1601 if (high_pipe)
1602 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1603 else
1604 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1605 if (pipe >= dev->num_crtcs)
1606 return -EINVAL;
1607
1608 vblank = &dev->vblank[pipe];
1609
1610 ret = drm_vblank_get(dev, pipe);
1611 if (ret) {
1612 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1613 return ret;
1614 }
1615 seq = drm_vblank_count(dev, pipe);
1616
1617 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1618 case _DRM_VBLANK_RELATIVE:
1619 vblwait->request.sequence += seq;
1620 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1621 case _DRM_VBLANK_ABSOLUTE:
1622 break;
1623 default:
1624 ret = -EINVAL;
1625 goto done;
1626 }
1627
1628 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1629 (seq - vblwait->request.sequence) <= (1 << 23)) {
1630 vblwait->request.sequence = seq + 1;
1631 }
1632
1633 if (flags & _DRM_VBLANK_EVENT) {
1634 /* must hold on to the vblank ref until the event fires
1635 * drm_vblank_put will be called asynchronously
1636 */
1637 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1638 }
1639
1640 DRM_DEBUG("waiting on vblank count %u, crtc %u\n",
1641 vblwait->request.sequence, pipe);
1642 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1643 (((drm_vblank_count(dev, pipe) -
1644 vblwait->request.sequence) <= (1 << 23)) ||
1645 !vblank->enabled ||
1646 !dev->irq_enabled));
1647
1648 if (ret != -EINTR) {
1649 struct timeval now;
1650
1651 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1652 vblwait->reply.tval_sec = now.tv_sec;
1653 vblwait->reply.tval_usec = now.tv_usec;
1654
1655 DRM_DEBUG("returning %u to client\n",
1656 vblwait->reply.sequence);
1657 } else {
1658 DRM_DEBUG("vblank wait interrupted by signal\n");
1659 }
1660
1661done:
1662 drm_vblank_put(dev, pipe);
1663 return ret;
1664}
1665
1666static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1667{
1668 struct drm_pending_vblank_event *e, *t;
1669 struct timeval now;
1670 unsigned int seq;
1671
1672 assert_spin_locked(&dev->event_lock);
1673
1674 seq = drm_vblank_count_and_time(dev, pipe, &now);
1675
1676 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1677 if (e->pipe != pipe)
1678 continue;
1679 if ((seq - e->event.sequence) > (1<<23))
1680 continue;
1681
1682 DRM_DEBUG("vblank event on %u, current %u\n",
1683 e->event.sequence, seq);
1684
1685 list_del(&e->base.link);
1686 drm_vblank_put(dev, pipe);
1687 send_vblank_event(dev, e, seq, &now);
1688 }
1689
1690 trace_drm_vblank_event(pipe, seq);
1691}
1692
1693/**
1694 * drm_handle_vblank - handle a vblank event
1695 * @dev: DRM device
1696 * @pipe: index of CRTC where this event occurred
1697 *
1698 * Drivers should call this routine in their vblank interrupt handlers to
1699 * update the vblank counter and send any signals that may be pending.
1700 *
1701 * This is the legacy version of drm_crtc_handle_vblank().
1702 */
1703bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1704{
1705 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1706 unsigned long irqflags;
1707
1708 if (WARN_ON_ONCE(!dev->num_crtcs))
1709 return false;
1710
1711 if (WARN_ON(pipe >= dev->num_crtcs))
1712 return false;
1713
1714 spin_lock_irqsave(&dev->event_lock, irqflags);
1715
1716 /* Need timestamp lock to prevent concurrent execution with
1717 * vblank enable/disable, as this would cause inconsistent
1718 * or corrupted timestamps and vblank counts.
1719 */
1720 spin_lock(&dev->vblank_time_lock);
1721
1722 /* Vblank irq handling disabled. Nothing to do. */
1723 if (!vblank->enabled) {
1724 spin_unlock(&dev->vblank_time_lock);
1725 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1726 return false;
1727 }
1728
1729 drm_update_vblank_count(dev, pipe, DRM_CALLED_FROM_VBLIRQ);
1730
1731 spin_unlock(&dev->vblank_time_lock);
1732
1733 wake_up(&vblank->queue);
1734 drm_handle_vblank_events(dev, pipe);
1735
1736 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1737
1738 return true;
1739}
1740EXPORT_SYMBOL(drm_handle_vblank);
1741
1742/**
1743 * drm_crtc_handle_vblank - handle a vblank event
1744 * @crtc: where this event occurred
1745 *
1746 * Drivers should call this routine in their vblank interrupt handlers to
1747 * update the vblank counter and send any signals that may be pending.
1748 *
1749 * This is the native KMS version of drm_handle_vblank().
1750 *
1751 * Returns:
1752 * True if the event was successfully handled, false on failure.
1753 */
1754bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1755{
1756 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1757}
1758EXPORT_SYMBOL(drm_crtc_handle_vblank);
1759
1760/**
1761 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1762 * @dev: DRM device
1763 * @pipe: CRTC for which to read the counter
1764 *
1765 * Drivers can plug this into the .get_vblank_counter() function if
1766 * there is no useable hardware frame counter available.
1767 *
1768 * Returns:
1769 * 0
1770 */
1771u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
1772{
1773 WARN_ON_ONCE(dev->max_vblank_count != 0);
1774 return 0;
1775}
1776EXPORT_SYMBOL(drm_vblank_no_hw_counter);