5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
10 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
12 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
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:
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
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.
38 #include <linux/interrupt.h> /* For task queue support */
41 * Get interrupt from bus id.
43 * \param inode device inode.
44 * \param file_priv DRM file private.
46 * \param arg user argument, pointing to a drm_irq_busid structure.
47 * \return zero on success or a negative number on failure.
49 * Finds the PCI device with the specified bus id and gets its IRQ number.
50 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
51 * to that of the device that this DRM instance attached to.
53 int drm_irq_by_busid(struct drm_device
*dev
, void *data
,
54 struct drm_file
*file_priv
)
56 struct drm_irq_busid
*p
= data
;
58 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
61 if ((p
->busnum
>> 8) != drm_get_pci_domain(dev
) ||
62 (p
->busnum
& 0xff) != dev
->pdev
->bus
->number
||
63 p
->devnum
!= PCI_SLOT(dev
->pdev
->devfn
) || p
->funcnum
!= PCI_FUNC(dev
->pdev
->devfn
))
66 p
->irq
= dev
->pdev
->irq
;
68 DRM_DEBUG("%d:%d:%d => IRQ %d\n", p
->busnum
, p
->devnum
, p
->funcnum
,
74 static void vblank_disable_fn(unsigned long arg
)
76 struct drm_device
*dev
= (struct drm_device
*)arg
;
77 unsigned long irqflags
;
80 if (!dev
->vblank_disable_allowed
)
83 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
84 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
85 if (atomic_read(&dev
->vblank_refcount
[i
]) == 0 &&
86 dev
->vblank_enabled
[i
]) {
87 DRM_DEBUG("disabling vblank on crtc %d\n", i
);
89 dev
->driver
->get_vblank_counter(dev
, i
);
90 dev
->driver
->disable_vblank(dev
, i
);
91 dev
->vblank_enabled
[i
] = 0;
93 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
97 static void drm_vblank_cleanup(struct drm_device
*dev
)
99 /* Bail if the driver didn't call drm_vblank_init() */
100 if (dev
->num_crtcs
== 0)
103 del_timer(&dev
->vblank_disable_timer
);
105 vblank_disable_fn((unsigned long)dev
);
107 drm_free(dev
->vbl_queue
, sizeof(*dev
->vbl_queue
) * dev
->num_crtcs
,
109 drm_free(dev
->vbl_sigs
, sizeof(*dev
->vbl_sigs
) * dev
->num_crtcs
,
111 drm_free(dev
->_vblank_count
, sizeof(*dev
->_vblank_count
) *
112 dev
->num_crtcs
, DRM_MEM_DRIVER
);
113 drm_free(dev
->vblank_refcount
, sizeof(*dev
->vblank_refcount
) *
114 dev
->num_crtcs
, DRM_MEM_DRIVER
);
115 drm_free(dev
->vblank_enabled
, sizeof(*dev
->vblank_enabled
) *
116 dev
->num_crtcs
, DRM_MEM_DRIVER
);
117 drm_free(dev
->last_vblank
, sizeof(*dev
->last_vblank
) * dev
->num_crtcs
,
119 drm_free(dev
->vblank_inmodeset
, sizeof(*dev
->vblank_inmodeset
) *
120 dev
->num_crtcs
, DRM_MEM_DRIVER
);
125 int drm_vblank_init(struct drm_device
*dev
, int num_crtcs
)
127 int i
, ret
= -ENOMEM
;
129 setup_timer(&dev
->vblank_disable_timer
, vblank_disable_fn
,
131 spin_lock_init(&dev
->vbl_lock
);
132 atomic_set(&dev
->vbl_signal_pending
, 0);
133 dev
->num_crtcs
= num_crtcs
;
135 dev
->vbl_queue
= drm_alloc(sizeof(wait_queue_head_t
) * num_crtcs
,
140 dev
->vbl_sigs
= drm_alloc(sizeof(struct list_head
) * num_crtcs
,
145 dev
->_vblank_count
= drm_alloc(sizeof(atomic_t
) * num_crtcs
,
147 if (!dev
->_vblank_count
)
150 dev
->vblank_refcount
= drm_alloc(sizeof(atomic_t
) * num_crtcs
,
152 if (!dev
->vblank_refcount
)
155 dev
->vblank_enabled
= drm_calloc(num_crtcs
, sizeof(int),
157 if (!dev
->vblank_enabled
)
160 dev
->last_vblank
= drm_calloc(num_crtcs
, sizeof(u32
), DRM_MEM_DRIVER
);
161 if (!dev
->last_vblank
)
164 dev
->vblank_inmodeset
= drm_calloc(num_crtcs
, sizeof(int),
166 if (!dev
->vblank_inmodeset
)
169 /* Zero per-crtc vblank stuff */
170 for (i
= 0; i
< num_crtcs
; i
++) {
171 init_waitqueue_head(&dev
->vbl_queue
[i
]);
172 INIT_LIST_HEAD(&dev
->vbl_sigs
[i
]);
173 atomic_set(&dev
->_vblank_count
[i
], 0);
174 atomic_set(&dev
->vblank_refcount
[i
], 0);
177 dev
->vblank_disable_allowed
= 0;
182 drm_vblank_cleanup(dev
);
185 EXPORT_SYMBOL(drm_vblank_init
);
188 * Install IRQ handler.
190 * \param dev DRM device.
192 * Initializes the IRQ related data. Installs the handler, calling the driver
193 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
194 * before and after the installation.
196 int drm_irq_install(struct drm_device
*dev
)
199 unsigned long sh_flags
= 0;
201 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
204 if (dev
->pdev
->irq
== 0)
207 mutex_lock(&dev
->struct_mutex
);
209 /* Driver must have been initialized */
210 if (!dev
->dev_private
) {
211 mutex_unlock(&dev
->struct_mutex
);
215 if (dev
->irq_enabled
) {
216 mutex_unlock(&dev
->struct_mutex
);
219 dev
->irq_enabled
= 1;
220 mutex_unlock(&dev
->struct_mutex
);
222 DRM_DEBUG("irq=%d\n", dev
->pdev
->irq
);
224 /* Before installing handler */
225 dev
->driver
->irq_preinstall(dev
);
227 /* Install handler */
228 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
229 sh_flags
= IRQF_SHARED
;
231 ret
= request_irq(drm_dev_to_irq(dev
), dev
->driver
->irq_handler
,
232 sh_flags
, dev
->devname
, dev
);
235 mutex_lock(&dev
->struct_mutex
);
236 dev
->irq_enabled
= 0;
237 mutex_unlock(&dev
->struct_mutex
);
241 /* After installing handler */
242 ret
= dev
->driver
->irq_postinstall(dev
);
244 mutex_lock(&dev
->struct_mutex
);
245 dev
->irq_enabled
= 0;
246 mutex_unlock(&dev
->struct_mutex
);
251 EXPORT_SYMBOL(drm_irq_install
);
254 * Uninstall the IRQ handler.
256 * \param dev DRM device.
258 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
260 int drm_irq_uninstall(struct drm_device
* dev
)
264 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
267 mutex_lock(&dev
->struct_mutex
);
268 irq_enabled
= dev
->irq_enabled
;
269 dev
->irq_enabled
= 0;
270 mutex_unlock(&dev
->struct_mutex
);
275 DRM_DEBUG("irq=%d\n", dev
->pdev
->irq
);
277 dev
->driver
->irq_uninstall(dev
);
279 free_irq(dev
->pdev
->irq
, dev
);
281 drm_vblank_cleanup(dev
);
283 dev
->locked_tasklet_func
= NULL
;
287 EXPORT_SYMBOL(drm_irq_uninstall
);
292 * \param inode device inode.
293 * \param file_priv DRM file private.
294 * \param cmd command.
295 * \param arg user argument, pointing to a drm_control structure.
296 * \return zero on success or a negative number on failure.
298 * Calls irq_install() or irq_uninstall() according to \p arg.
300 int drm_control(struct drm_device
*dev
, void *data
,
301 struct drm_file
*file_priv
)
303 struct drm_control
*ctl
= data
;
305 /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */
309 case DRM_INST_HANDLER
:
310 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
312 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
313 ctl
->irq
!= dev
->pdev
->irq
)
315 return drm_irq_install(dev
);
316 case DRM_UNINST_HANDLER
:
317 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
319 return drm_irq_uninstall(dev
);
326 * drm_vblank_count - retrieve "cooked" vblank counter value
328 * @crtc: which counter to retrieve
330 * Fetches the "cooked" vblank count value that represents the number of
331 * vblank events since the system was booted, including lost events due to
332 * modesetting activity.
334 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
336 return atomic_read(&dev
->_vblank_count
[crtc
]);
338 EXPORT_SYMBOL(drm_vblank_count
);
341 * drm_update_vblank_count - update the master vblank counter
343 * @crtc: counter to update
345 * Call back into the driver to update the appropriate vblank counter
346 * (specified by @crtc). Deal with wraparound, if it occurred, and
347 * update the last read value so we can deal with wraparound on the next
350 * Only necessary when going from off->on, to account for frames we
351 * didn't get an interrupt for.
353 * Note: caller must hold dev->vbl_lock since this reads & writes
354 * device vblank fields.
356 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
358 u32 cur_vblank
, diff
;
361 * Interrupts were disabled prior to this call, so deal with counter
363 * NOTE! It's possible we lost a full dev->max_vblank_count events
364 * here if the register is small or we had vblank interrupts off for
367 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
368 diff
= cur_vblank
- dev
->last_vblank
[crtc
];
369 if (cur_vblank
< dev
->last_vblank
[crtc
]) {
370 diff
+= dev
->max_vblank_count
;
372 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
373 crtc
, dev
->last_vblank
[crtc
], cur_vblank
, diff
);
376 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
379 atomic_add(diff
, &dev
->_vblank_count
[crtc
]);
383 * drm_vblank_get - get a reference count on vblank events
385 * @crtc: which CRTC to own
387 * Acquire a reference count on vblank events to avoid having them disabled
391 * Zero on success, nonzero on failure.
393 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
395 unsigned long irqflags
;
398 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
399 /* Going from 0->1 means we have to enable interrupts again */
400 if (atomic_add_return(1, &dev
->vblank_refcount
[crtc
]) == 1 &&
401 !dev
->vblank_enabled
[crtc
]) {
402 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
403 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc
, ret
);
405 atomic_dec(&dev
->vblank_refcount
[crtc
]);
407 dev
->vblank_enabled
[crtc
] = 1;
408 drm_update_vblank_count(dev
, crtc
);
411 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
415 EXPORT_SYMBOL(drm_vblank_get
);
418 * drm_vblank_put - give up ownership of vblank events
420 * @crtc: which counter to give up
422 * Release ownership of a given vblank counter, turning off interrupts
425 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
427 /* Last user schedules interrupt disable */
428 if (atomic_dec_and_test(&dev
->vblank_refcount
[crtc
]))
429 mod_timer(&dev
->vblank_disable_timer
, jiffies
+ 5*DRM_HZ
);
431 EXPORT_SYMBOL(drm_vblank_put
);
434 * drm_modeset_ctl - handle vblank event counter changes across mode switch
435 * @DRM_IOCTL_ARGS: standard ioctl arguments
437 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
438 * ioctls around modesetting so that any lost vblank events are accounted for.
440 * Generally the counter will reset across mode sets. If interrupts are
441 * enabled around this call, we don't have to do anything since the counter
442 * will have already been incremented.
444 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
445 struct drm_file
*file_priv
)
447 struct drm_modeset_ctl
*modeset
= data
;
448 unsigned long irqflags
;
451 /* If drm_vblank_init() hasn't been called yet, just no-op */
455 crtc
= modeset
->crtc
;
456 if (crtc
>= dev
->num_crtcs
) {
462 * To avoid all the problems that might happen if interrupts
463 * were enabled/disabled around or between these calls, we just
464 * have the kernel take a reference on the CRTC (just once though
465 * to avoid corrupting the count if multiple, mismatch calls occur),
466 * so that interrupts remain enabled in the interim.
468 switch (modeset
->cmd
) {
469 case _DRM_PRE_MODESET
:
470 if (!dev
->vblank_inmodeset
[crtc
]) {
471 dev
->vblank_inmodeset
[crtc
] = 1;
472 drm_vblank_get(dev
, crtc
);
475 case _DRM_POST_MODESET
:
476 if (dev
->vblank_inmodeset
[crtc
]) {
477 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
478 dev
->vblank_disable_allowed
= 1;
479 dev
->vblank_inmodeset
[crtc
] = 0;
480 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
481 drm_vblank_put(dev
, crtc
);
496 * \param inode device inode.
497 * \param file_priv DRM file private.
498 * \param cmd command.
499 * \param data user argument, pointing to a drm_wait_vblank structure.
500 * \return zero on success or a negative number on failure.
502 * Verifies the IRQ is installed.
504 * If a signal is requested checks if this task has already scheduled the same signal
505 * for the same vblank sequence number - nothing to be done in
506 * that case. If the number of tasks waiting for the interrupt exceeds 100 the
507 * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this
510 * If a signal is not requested, then calls vblank_wait().
512 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
513 struct drm_file
*file_priv
)
515 union drm_wait_vblank
*vblwait
= data
;
517 unsigned int flags
, seq
, crtc
;
519 if ((!dev
->pdev
->irq
) || (!dev
->irq_enabled
))
522 if (vblwait
->request
.type
&
523 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
)) {
524 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
525 vblwait
->request
.type
,
526 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
));
530 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
531 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
533 if (crtc
>= dev
->num_crtcs
)
536 ret
= drm_vblank_get(dev
, crtc
);
538 DRM_ERROR("failed to acquire vblank counter, %d\n", ret
);
541 seq
= drm_vblank_count(dev
, crtc
);
543 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
544 case _DRM_VBLANK_RELATIVE
:
545 vblwait
->request
.sequence
+= seq
;
546 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
547 case _DRM_VBLANK_ABSOLUTE
:
554 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
555 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
556 vblwait
->request
.sequence
= seq
+ 1;
559 if (flags
& _DRM_VBLANK_SIGNAL
) {
560 unsigned long irqflags
;
561 struct list_head
*vbl_sigs
= &dev
->vbl_sigs
[crtc
];
562 struct drm_vbl_sig
*vbl_sig
;
564 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
566 /* Check if this task has already scheduled the same signal
567 * for the same vblank sequence number; nothing to be done in
570 list_for_each_entry(vbl_sig
, vbl_sigs
, head
) {
571 if (vbl_sig
->sequence
== vblwait
->request
.sequence
572 && vbl_sig
->info
.si_signo
==
573 vblwait
->request
.signal
574 && vbl_sig
->task
== current
) {
575 spin_unlock_irqrestore(&dev
->vbl_lock
,
577 vblwait
->reply
.sequence
= seq
;
582 if (atomic_read(&dev
->vbl_signal_pending
) >= 100) {
583 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
588 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
590 vbl_sig
= drm_calloc(1, sizeof(struct drm_vbl_sig
),
597 /* Get a refcount on the vblank, which will be released by
598 * drm_vbl_send_signals().
600 ret
= drm_vblank_get(dev
, crtc
);
602 drm_free(vbl_sig
, sizeof(struct drm_vbl_sig
),
607 atomic_inc(&dev
->vbl_signal_pending
);
609 vbl_sig
->sequence
= vblwait
->request
.sequence
;
610 vbl_sig
->info
.si_signo
= vblwait
->request
.signal
;
611 vbl_sig
->task
= current
;
613 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
615 list_add_tail(&vbl_sig
->head
, vbl_sigs
);
617 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
619 vblwait
->reply
.sequence
= seq
;
621 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
622 vblwait
->request
.sequence
, crtc
);
623 DRM_WAIT_ON(ret
, dev
->vbl_queue
[crtc
], 3 * DRM_HZ
,
624 ((drm_vblank_count(dev
, crtc
)
625 - vblwait
->request
.sequence
) <= (1 << 23)));
630 do_gettimeofday(&now
);
632 vblwait
->reply
.tval_sec
= now
.tv_sec
;
633 vblwait
->reply
.tval_usec
= now
.tv_usec
;
634 vblwait
->reply
.sequence
= drm_vblank_count(dev
, crtc
);
635 DRM_DEBUG("returning %d to client\n",
636 vblwait
->reply
.sequence
);
638 DRM_DEBUG("vblank wait interrupted by signal\n");
643 drm_vblank_put(dev
, crtc
);
648 * Send the VBLANK signals.
650 * \param dev DRM device.
651 * \param crtc CRTC where the vblank event occurred
653 * Sends a signal for each task in drm_device::vbl_sigs and empties the list.
655 * If a signal is not requested, then calls vblank_wait().
657 static void drm_vbl_send_signals(struct drm_device
*dev
, int crtc
)
659 struct drm_vbl_sig
*vbl_sig
, *tmp
;
660 struct list_head
*vbl_sigs
;
661 unsigned int vbl_seq
;
664 spin_lock_irqsave(&dev
->vbl_lock
, flags
);
666 vbl_sigs
= &dev
->vbl_sigs
[crtc
];
667 vbl_seq
= drm_vblank_count(dev
, crtc
);
669 list_for_each_entry_safe(vbl_sig
, tmp
, vbl_sigs
, head
) {
670 if ((vbl_seq
- vbl_sig
->sequence
) <= (1 << 23)) {
671 vbl_sig
->info
.si_code
= vbl_seq
;
672 send_sig_info(vbl_sig
->info
.si_signo
,
673 &vbl_sig
->info
, vbl_sig
->task
);
675 list_del(&vbl_sig
->head
);
677 drm_free(vbl_sig
, sizeof(*vbl_sig
),
679 atomic_dec(&dev
->vbl_signal_pending
);
680 drm_vblank_put(dev
, crtc
);
684 spin_unlock_irqrestore(&dev
->vbl_lock
, flags
);
688 * drm_handle_vblank - handle a vblank event
690 * @crtc: where this event occurred
692 * Drivers should call this routine in their vblank interrupt handlers to
693 * update the vblank counter and send any signals that may be pending.
695 void drm_handle_vblank(struct drm_device
*dev
, int crtc
)
697 atomic_inc(&dev
->_vblank_count
[crtc
]);
698 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
699 drm_vbl_send_signals(dev
, crtc
);
701 EXPORT_SYMBOL(drm_handle_vblank
);
704 * Tasklet wrapper function.
706 * \param data DRM device in disguise.
708 * Attempts to grab the HW lock and calls the driver callback on success. On
709 * failure, leave the lock marked as contended so the callback can be called
712 static void drm_locked_tasklet_func(unsigned long data
)
714 struct drm_device
*dev
= (struct drm_device
*)data
;
715 unsigned long irqflags
;
716 void (*tasklet_func
)(struct drm_device
*);
718 spin_lock_irqsave(&dev
->tasklet_lock
, irqflags
);
719 tasklet_func
= dev
->locked_tasklet_func
;
720 spin_unlock_irqrestore(&dev
->tasklet_lock
, irqflags
);
723 !drm_lock_take(&dev
->lock
,
724 DRM_KERNEL_CONTEXT
)) {
728 dev
->lock
.lock_time
= jiffies
;
729 atomic_inc(&dev
->counts
[_DRM_STAT_LOCKS
]);
731 spin_lock_irqsave(&dev
->tasklet_lock
, irqflags
);
732 tasklet_func
= dev
->locked_tasklet_func
;
733 dev
->locked_tasklet_func
= NULL
;
734 spin_unlock_irqrestore(&dev
->tasklet_lock
, irqflags
);
736 if (tasklet_func
!= NULL
)
739 drm_lock_free(&dev
->lock
,
744 * Schedule a tasklet to call back a driver hook with the HW lock held.
746 * \param dev DRM device.
747 * \param func Driver callback.
749 * This is intended for triggering actions that require the HW lock from an
750 * interrupt handler. The lock will be grabbed ASAP after the interrupt handler
751 * completes. Note that the callback may be called from interrupt or process
752 * context, it must not make any assumptions about this. Also, the HW lock will
753 * be held with the kernel context or any client context.
755 void drm_locked_tasklet(struct drm_device
*dev
, void (*func
)(struct drm_device
*))
757 unsigned long irqflags
;
758 static DECLARE_TASKLET(drm_tasklet
, drm_locked_tasklet_func
, 0);
760 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
) ||
761 test_bit(TASKLET_STATE_SCHED
, &drm_tasklet
.state
))
764 spin_lock_irqsave(&dev
->tasklet_lock
, irqflags
);
766 if (dev
->locked_tasklet_func
) {
767 spin_unlock_irqrestore(&dev
->tasklet_lock
, irqflags
);
771 dev
->locked_tasklet_func
= func
;
773 spin_unlock_irqrestore(&dev
->tasklet_lock
, irqflags
);
775 drm_tasklet
.data
= (unsigned long)dev
;
777 tasklet_hi_schedule(&drm_tasklet
);
779 EXPORT_SYMBOL(drm_locked_tasklet
);
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