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      1 /*	$NetBSD: drm_file.c,v 1.5 2021/12/19 11:21:03 riastradh Exp $	*/
      2 
      3 /*
      4  * \author Rickard E. (Rik) Faith <faith (at) valinux.com>
      5  * \author Daryll Strauss <daryll (at) valinux.com>
      6  * \author Gareth Hughes <gareth (at) valinux.com>
      7  */
      8 
      9 /*
     10  * Created: Mon Jan  4 08:58:31 1999 by faith (at) valinux.com
     11  *
     12  * Copyright 1999 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 <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: drm_file.c,v 1.5 2021/12/19 11:21:03 riastradh Exp $");
     38 
     39 #include <linux/anon_inodes.h>
     40 #include <linux/dma-fence.h>
     41 #include <linux/file.h>
     42 #include <linux/module.h>
     43 #include <linux/pci.h>
     44 #include <linux/poll.h>
     45 #include <linux/slab.h>
     46 
     47 #include <drm/drm_client.h>
     48 #include <drm/drm_drv.h>
     49 #include <drm/drm_file.h>
     50 #include <drm/drm_print.h>
     51 
     52 #include "drm_crtc_internal.h"
     53 #include "drm_internal.h"
     54 #include "drm_legacy.h"
     55 
     56 #ifdef __NetBSD__
     57 #include <sys/poll.h>
     58 #include <sys/select.h>
     59 #endif
     60 
     61 #include <linux/nbsd-namespace.h>
     62 
     63 /* from BKL pushdown */
     64 #ifndef __NetBSD__
     65 DEFINE_MUTEX(drm_global_mutex);
     66 #endif
     67 
     68 /**
     69  * DOC: file operations
     70  *
     71  * Drivers must define the file operations structure that forms the DRM
     72  * userspace API entry point, even though most of those operations are
     73  * implemented in the DRM core. The resulting &struct file_operations must be
     74  * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
     75  * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
     76  * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
     77  * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
     78  * that require 32/64 bit compatibility support must provide their own
     79  * &file_operations.compat_ioctl handler that processes private ioctls and calls
     80  * drm_compat_ioctl() for core ioctls.
     81  *
     82  * In addition drm_read() and drm_poll() provide support for DRM events. DRM
     83  * events are a generic and extensible means to send asynchronous events to
     84  * userspace through the file descriptor. They are used to send vblank event and
     85  * page flip completions by the KMS API. But drivers can also use it for their
     86  * own needs, e.g. to signal completion of rendering.
     87  *
     88  * For the driver-side event interface see drm_event_reserve_init() and
     89  * drm_send_event() as the main starting points.
     90  *
     91  * The memory mapping implementation will vary depending on how the driver
     92  * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
     93  * function, modern drivers should use one of the provided memory-manager
     94  * specific implementations. For GEM-based drivers this is drm_gem_mmap(), and
     95  * for drivers which use the CMA GEM helpers it's drm_gem_cma_mmap().
     96  *
     97  * No other file operations are supported by the DRM userspace API. Overall the
     98  * following is an example &file_operations structure::
     99  *
    100  *     static const example_drm_fops = {
    101  *             .owner = THIS_MODULE,
    102  *             .open = drm_open,
    103  *             .release = drm_release,
    104  *             .unlocked_ioctl = drm_ioctl,
    105  *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
    106  *             .poll = drm_poll,
    107  *             .read = drm_read,
    108  *             .llseek = no_llseek,
    109  *             .mmap = drm_gem_mmap,
    110  *     };
    111  *
    112  * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
    113  * CMA based drivers there is the DEFINE_DRM_GEM_CMA_FOPS() macro to make this
    114  * simpler.
    115  *
    116  * The driver's &file_operations must be stored in &drm_driver.fops.
    117  *
    118  * For driver-private IOCTL handling see the more detailed discussion in
    119  * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
    120  */
    121 
    122 /**
    123  * drm_file_alloc - allocate file context
    124  * @minor: minor to allocate on
    125  *
    126  * This allocates a new DRM file context. It is not linked into any context and
    127  * can be used by the caller freely. Note that the context keeps a pointer to
    128  * @minor, so it must be freed before @minor is.
    129  *
    130  * RETURNS:
    131  * Pointer to newly allocated context, ERR_PTR on failure.
    132  */
    133 struct drm_file *drm_file_alloc(struct drm_minor *minor)
    134 {
    135 	struct drm_device *dev = minor->dev;
    136 	struct drm_file *file;
    137 	int ret;
    138 
    139 	file = kzalloc(sizeof(*file), GFP_KERNEL);
    140 	if (!file)
    141 		return ERR_PTR(-ENOMEM);
    142 
    143 #ifndef __NetBSD__
    144 	file->pid = get_pid(task_pid(current));
    145 #endif
    146 	file->minor = minor;
    147 
    148 	/* for compatibility root is always authenticated */
    149 	file->authenticated = capable(CAP_SYS_ADMIN);
    150 
    151 	INIT_LIST_HEAD(&file->lhead);
    152 	INIT_LIST_HEAD(&file->fbs);
    153 	mutex_init(&file->fbs_lock);
    154 	INIT_LIST_HEAD(&file->blobs);
    155 	INIT_LIST_HEAD(&file->pending_event_list);
    156 	INIT_LIST_HEAD(&file->event_list);
    157 #ifdef __NetBSD__
    158 	DRM_INIT_WAITQUEUE(&file->event_wait, "drmevent");
    159 	DRM_INIT_WAITQUEUE(&file->event_read_wq, "drmevtrd");
    160 	selinit(&file->event_selq);
    161 #else
    162 	init_waitqueue_head(&file->event_wait);
    163 #endif
    164 	file->event_space = 4096; /* set aside 4k for event buffer */
    165 
    166 #ifdef __NetBSD__
    167 	file->event_read_lock = NULL;
    168 #else
    169 	mutex_init(&file->event_read_lock);
    170 #endif
    171 
    172 	if (drm_core_check_feature(dev, DRIVER_GEM))
    173 		drm_gem_open(dev, file);
    174 
    175 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
    176 		drm_syncobj_open(file);
    177 
    178 	drm_prime_init_file_private(&file->prime);
    179 
    180 	if (dev->driver->open) {
    181 		ret = dev->driver->open(dev, file);
    182 		if (ret < 0)
    183 			goto out_prime_destroy;
    184 	}
    185 
    186 	return file;
    187 
    188 out_prime_destroy:
    189 	drm_prime_destroy_file_private(&file->prime);
    190 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
    191 		drm_syncobj_release(file);
    192 	if (drm_core_check_feature(dev, DRIVER_GEM))
    193 		drm_gem_release(dev, file);
    194 #ifdef __NetBSD__
    195 	KASSERT(file->event_read_lock == NULL);
    196 #else
    197 	mutex_destroy(&file->event_read_lock);
    198 #endif
    199 	mutex_destroy(&file->fbs_lock);
    200 #ifdef __NetBSD__
    201 	DRM_DESTROY_WAITQUEUE(&file->event_wait);
    202 	DRM_DESTROY_WAITQUEUE(&file->event_read_wq);
    203 	seldestroy(&file->event_selq);
    204 #else
    205 	put_pid(file->pid);
    206 #endif
    207 	kfree(file);
    208 
    209 	return ERR_PTR(ret);
    210 }
    211 
    212 static void drm_events_release(struct drm_file *file_priv)
    213 {
    214 	struct drm_device *dev = file_priv->minor->dev;
    215 	struct drm_pending_event *e, *et;
    216 	unsigned long flags;
    217 
    218 	spin_lock_irqsave(&dev->event_lock, flags);
    219 
    220 	/* Unlink pending events */
    221 	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
    222 				 pending_link) {
    223 		list_del(&e->pending_link);
    224 		e->file_priv = NULL;
    225 	}
    226 
    227 	/* Remove unconsumed events */
    228 	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
    229 		list_del(&e->link);
    230 		kfree(e);
    231 	}
    232 
    233 	spin_unlock_irqrestore(&dev->event_lock, flags);
    234 }
    235 
    236 /**
    237  * drm_file_free - free file context
    238  * @file: context to free, or NULL
    239  *
    240  * This destroys and deallocates a DRM file context previously allocated via
    241  * drm_file_alloc(). The caller must make sure to unlink it from any contexts
    242  * before calling this.
    243  *
    244  * If NULL is passed, this is a no-op.
    245  *
    246  * RETURNS:
    247  * 0 on success, or error code on failure.
    248  */
    249 void drm_file_free(struct drm_file *file)
    250 {
    251 	struct drm_device *dev;
    252 
    253 	if (!file)
    254 		return;
    255 
    256 	dev = file->minor->dev;
    257 
    258 	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
    259 		  task_pid_nr(current),
    260 #ifdef __NetBSD__
    261 		  (unsigned long)device_unit(file->minor->dev->dev),
    262 #else
    263 		  (long)old_encode_dev(file->minor->kdev->devt),
    264 #endif
    265 		  dev->open_count);
    266 
    267 	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
    268 	    dev->driver->preclose)
    269 		dev->driver->preclose(dev, file);
    270 
    271 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
    272 		drm_legacy_lock_release(dev, file->filp);
    273 
    274 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
    275 		drm_legacy_reclaim_buffers(dev, file);
    276 
    277 	drm_events_release(file);
    278 
    279 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
    280 		drm_fb_release(file);
    281 		drm_property_destroy_user_blobs(dev, file);
    282 	}
    283 
    284 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
    285 		drm_syncobj_release(file);
    286 
    287 	if (drm_core_check_feature(dev, DRIVER_GEM))
    288 		drm_gem_release(dev, file);
    289 
    290 	drm_legacy_ctxbitmap_flush(dev, file);
    291 
    292 	if (drm_is_primary_client(file))
    293 		drm_master_release(file);
    294 
    295 	if (dev->driver->postclose)
    296 		dev->driver->postclose(dev, file);
    297 
    298 	drm_prime_destroy_file_private(&file->prime);
    299 
    300 	WARN_ON(!list_empty(&file->event_list));
    301 
    302 #ifdef __NetBSD__
    303 	DRM_DESTROY_WAITQUEUE(&file->event_wait);
    304 	DRM_DESTROY_WAITQUEUE(&file->event_read_wq);
    305 	seldestroy(&file->event_selq);
    306 #else
    307 	put_pid(file->pid);
    308 	mutex_destroy(&file->event_read_lock);
    309 #endif
    310 	mutex_destroy(&file->fbs_lock);
    311 	kfree(file);
    312 }
    313 
    314 #ifndef __NetBSD__
    315 static void drm_close_helper(struct file *filp)
    316 {
    317 	struct drm_file *file_priv = filp->private_data;
    318 	struct drm_device *dev = file_priv->minor->dev;
    319 
    320 	mutex_lock(&dev->filelist_mutex);
    321 	list_del(&file_priv->lhead);
    322 	mutex_unlock(&dev->filelist_mutex);
    323 
    324 	drm_file_free(file_priv);
    325 }
    326 #endif
    327 
    328 /*
    329  * Check whether DRI will run on this CPU.
    330  *
    331  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
    332  */
    333 __unused
    334 static int drm_cpu_valid(void)
    335 {
    336 #if defined(__sparc__) && !defined(__sparc_v9__)
    337 	return 0;		/* No cmpxchg before v9 sparc. */
    338 #endif
    339 	return 1;
    340 }
    341 
    342 /*
    343  * Called whenever a process opens a drm node
    344  *
    345  * \param filp file pointer.
    346  * \param minor acquired minor-object.
    347  * \return zero on success or a negative number on failure.
    348  *
    349  * Creates and initializes a drm_file structure for the file private data in \p
    350  * filp and add it into the double linked list in \p dev.
    351  */
    352 #ifndef __NetBSD__
    353 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
    354 {
    355 	struct drm_device *dev = minor->dev;
    356 	struct drm_file *priv;
    357 	int ret;
    358 
    359 	if (filp->f_flags & O_EXCL)
    360 		return -EBUSY;	/* No exclusive opens */
    361 	if (!drm_cpu_valid())
    362 		return -EINVAL;
    363 	if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
    364 		return -EINVAL;
    365 
    366 	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
    367 
    368 	priv = drm_file_alloc(minor);
    369 	if (IS_ERR(priv))
    370 		return PTR_ERR(priv);
    371 
    372 	if (drm_is_primary_client(priv)) {
    373 		ret = drm_master_open(priv);
    374 		if (ret) {
    375 			drm_file_free(priv);
    376 			return ret;
    377 		}
    378 	}
    379 
    380 	filp->private_data = priv;
    381 	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
    382 	priv->filp = filp;
    383 
    384 	mutex_lock(&dev->filelist_mutex);
    385 	list_add(&priv->lhead, &dev->filelist);
    386 	mutex_unlock(&dev->filelist_mutex);
    387 
    388 #ifdef __alpha__
    389 	/*
    390 	 * Default the hose
    391 	 */
    392 	if (!dev->hose) {
    393 		struct pci_dev *pci_dev;
    394 		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
    395 		if (pci_dev) {
    396 			dev->hose = pci_dev->sysdata;
    397 			pci_dev_put(pci_dev);
    398 		}
    399 		if (!dev->hose) {
    400 			struct pci_bus *b = list_entry(pci_root_buses.next,
    401 				struct pci_bus, node);
    402 			if (b)
    403 				dev->hose = b->sysdata;
    404 		}
    405 	}
    406 #endif
    407 
    408 	return 0;
    409 }
    410 #endif
    411 
    412 /**
    413  * drm_open - open method for DRM file
    414  * @inode: device inode
    415  * @filp: file pointer.
    416  *
    417  * This function must be used by drivers as their &file_operations.open method.
    418  * It looks up the correct DRM device and instantiates all the per-file
    419  * resources for it. It also calls the &drm_driver.open driver callback.
    420  *
    421  * RETURNS:
    422  *
    423  * 0 on success or negative errno value on falure.
    424  */
    425 #ifndef __NetBSD__
    426 int drm_open(struct inode *inode, struct file *filp)
    427 {
    428 	struct drm_device *dev;
    429 	struct drm_minor *minor;
    430 	int retcode;
    431 	int need_setup = 0;
    432 
    433 	minor = drm_minor_acquire(iminor(inode));
    434 	if (IS_ERR(minor))
    435 		return PTR_ERR(minor);
    436 
    437 	dev = minor->dev;
    438 	if (!dev->open_count++)
    439 		need_setup = 1;
    440 
    441 	/* share address_space across all char-devs of a single device */
    442 	filp->f_mapping = dev->anon_inode->i_mapping;
    443 
    444 	retcode = drm_open_helper(filp, minor);
    445 	if (retcode)
    446 		goto err_undo;
    447 	if (need_setup) {
    448 		retcode = drm_legacy_setup(dev);
    449 		if (retcode) {
    450 			drm_close_helper(filp);
    451 			goto err_undo;
    452 		}
    453 	}
    454 	return 0;
    455 
    456 err_undo:
    457 	dev->open_count--;
    458 	drm_minor_release(minor);
    459 	return retcode;
    460 }
    461 EXPORT_SYMBOL(drm_open);
    462 #endif
    463 
    464 void drm_lastclose(struct drm_device * dev)
    465 {
    466 	DRM_DEBUG("\n");
    467 
    468 	if (dev->driver->lastclose)
    469 		dev->driver->lastclose(dev);
    470 	DRM_DEBUG("driver lastclose completed\n");
    471 
    472 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
    473 		drm_legacy_dev_reinit(dev);
    474 
    475 	drm_client_dev_restore(dev);
    476 }
    477 
    478 /**
    479  * drm_release - release method for DRM file
    480  * @inode: device inode
    481  * @filp: file pointer.
    482  *
    483  * This function must be used by drivers as their &file_operations.release
    484  * method. It frees any resources associated with the open file, and calls the
    485  * &drm_driver.postclose driver callback. If this is the last open file for the
    486  * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
    487  *
    488  * RETURNS:
    489  *
    490  * Always succeeds and returns 0.
    491  */
    492 #ifndef __NetBSD__
    493 int drm_release(struct inode *inode, struct file *filp)
    494 {
    495 	struct drm_file *file_priv = filp->private_data;
    496 	struct drm_minor *minor = file_priv->minor;
    497 	struct drm_device *dev = minor->dev;
    498 
    499 	mutex_lock(&drm_global_mutex);
    500 
    501 	DRM_DEBUG("open_count = %d\n", dev->open_count);
    502 
    503 	drm_close_helper(filp);
    504 
    505 	if (!--dev->open_count)
    506 		drm_lastclose(dev);
    507 
    508 	mutex_unlock(&drm_global_mutex);
    509 
    510 	drm_minor_release(minor);
    511 
    512 	return 0;
    513 }
    514 EXPORT_SYMBOL(drm_release);
    515 #endif
    516 
    517 /**
    518  * drm_read - read method for DRM file
    519  * @filp: file pointer
    520  * @buffer: userspace destination pointer for the read
    521  * @count: count in bytes to read
    522  * @offset: offset to read
    523  *
    524  * This function must be used by drivers as their &file_operations.read
    525  * method iff they use DRM events for asynchronous signalling to userspace.
    526  * Since events are used by the KMS API for vblank and page flip completion this
    527  * means all modern display drivers must use it.
    528  *
    529  * @offset is ignored, DRM events are read like a pipe. Therefore drivers also
    530  * must set the &file_operation.llseek to no_llseek(). Polling support is
    531  * provided by drm_poll().
    532  *
    533  * This function will only ever read a full event. Therefore userspace must
    534  * supply a big enough buffer to fit any event to ensure forward progress. Since
    535  * the maximum event space is currently 4K it's recommended to just use that for
    536  * safety.
    537  *
    538  * RETURNS:
    539  *
    540  * Number of bytes read (always aligned to full events, and can be 0) or a
    541  * negative error code on failure.
    542  */
    543 #ifndef __NetBSD__
    544 ssize_t drm_read(struct file *filp, char __user *buffer,
    545 		 size_t count, loff_t *offset)
    546 {
    547 	struct drm_file *file_priv = filp->private_data;
    548 	struct drm_device *dev = file_priv->minor->dev;
    549 	ssize_t ret;
    550 
    551 	if (!access_ok(buffer, count))
    552 		return -EFAULT;
    553 
    554 	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
    555 	if (ret)
    556 		return ret;
    557 
    558 	for (;;) {
    559 		struct drm_pending_event *e = NULL;
    560 
    561 		spin_lock_irq(&dev->event_lock);
    562 		if (!list_empty(&file_priv->event_list)) {
    563 			e = list_first_entry(&file_priv->event_list,
    564 					struct drm_pending_event, link);
    565 			file_priv->event_space += e->event->length;
    566 			list_del(&e->link);
    567 		}
    568 		spin_unlock_irq(&dev->event_lock);
    569 
    570 		if (e == NULL) {
    571 			if (ret)
    572 				break;
    573 
    574 			if (filp->f_flags & O_NONBLOCK) {
    575 				ret = -EAGAIN;
    576 				break;
    577 			}
    578 
    579 			mutex_unlock(&file_priv->event_read_lock);
    580 			ret = wait_event_interruptible(file_priv->event_wait,
    581 						       !list_empty(&file_priv->event_list));
    582 			if (ret >= 0)
    583 				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
    584 			if (ret)
    585 				return ret;
    586 		} else {
    587 			unsigned length = e->event->length;
    588 
    589 			if (length > count - ret) {
    590 put_back_event:
    591 				spin_lock_irq(&dev->event_lock);
    592 				file_priv->event_space -= length;
    593 				list_add(&e->link, &file_priv->event_list);
    594 				spin_unlock_irq(&dev->event_lock);
    595 				wake_up_interruptible(&file_priv->event_wait);
    596 				break;
    597 			}
    598 
    599 			if (copy_to_user(buffer + ret, e->event, length)) {
    600 				if (ret == 0)
    601 					ret = -EFAULT;
    602 				goto put_back_event;
    603 			}
    604 
    605 			ret += length;
    606 			kfree(e);
    607 		}
    608 	}
    609 	mutex_unlock(&file_priv->event_read_lock);
    610 
    611 	return ret;
    612 }
    613 EXPORT_SYMBOL(drm_read);
    614 #endif
    615 
    616 /**
    617  * drm_poll - poll method for DRM file
    618  * @filp: file pointer
    619  * @wait: poll waiter table
    620  *
    621  * This function must be used by drivers as their &file_operations.read method
    622  * iff they use DRM events for asynchronous signalling to userspace.  Since
    623  * events are used by the KMS API for vblank and page flip completion this means
    624  * all modern display drivers must use it.
    625  *
    626  * See also drm_read().
    627  *
    628  * RETURNS:
    629  *
    630  * Mask of POLL flags indicating the current status of the file.
    631  */
    632 #ifndef __NetBSD__
    633 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
    634 {
    635 	struct drm_file *file_priv = filp->private_data;
    636 	__poll_t mask = 0;
    637 
    638 	poll_wait(filp, &file_priv->event_wait, wait);
    639 
    640 	if (!list_empty(&file_priv->event_list))
    641 		mask |= EPOLLIN | EPOLLRDNORM;
    642 
    643 	return mask;
    644 }
    645 EXPORT_SYMBOL(drm_poll);
    646 #endif
    647 
    648 /**
    649  * drm_event_reserve_init_locked - init a DRM event and reserve space for it
    650  * @dev: DRM device
    651  * @file_priv: DRM file private data
    652  * @p: tracking structure for the pending event
    653  * @e: actual event data to deliver to userspace
    654  *
    655  * This function prepares the passed in event for eventual delivery. If the event
    656  * doesn't get delivered (because the IOCTL fails later on, before queuing up
    657  * anything) then the even must be cancelled and freed using
    658  * drm_event_cancel_free(). Successfully initialized events should be sent out
    659  * using drm_send_event() or drm_send_event_locked() to signal completion of the
    660  * asynchronous event to userspace.
    661  *
    662  * If callers embedded @p into a larger structure it must be allocated with
    663  * kmalloc and @p must be the first member element.
    664  *
    665  * This is the locked version of drm_event_reserve_init() for callers which
    666  * already hold &drm_device.event_lock.
    667  *
    668  * RETURNS:
    669  *
    670  * 0 on success or a negative error code on failure.
    671  */
    672 int drm_event_reserve_init_locked(struct drm_device *dev,
    673 				  struct drm_file *file_priv,
    674 				  struct drm_pending_event *p,
    675 				  struct drm_event *e)
    676 {
    677 	if (file_priv->event_space < e->length)
    678 		return -ENOMEM;
    679 
    680 	file_priv->event_space -= e->length;
    681 
    682 	p->event = e;
    683 	list_add(&p->pending_link, &file_priv->pending_event_list);
    684 	p->file_priv = file_priv;
    685 
    686 	return 0;
    687 }
    688 EXPORT_SYMBOL(drm_event_reserve_init_locked);
    689 
    690 /**
    691  * drm_event_reserve_init - init a DRM event and reserve space for it
    692  * @dev: DRM device
    693  * @file_priv: DRM file private data
    694  * @p: tracking structure for the pending event
    695  * @e: actual event data to deliver to userspace
    696  *
    697  * This function prepares the passed in event for eventual delivery. If the event
    698  * doesn't get delivered (because the IOCTL fails later on, before queuing up
    699  * anything) then the even must be cancelled and freed using
    700  * drm_event_cancel_free(). Successfully initialized events should be sent out
    701  * using drm_send_event() or drm_send_event_locked() to signal completion of the
    702  * asynchronous event to userspace.
    703  *
    704  * If callers embedded @p into a larger structure it must be allocated with
    705  * kmalloc and @p must be the first member element.
    706  *
    707  * Callers which already hold &drm_device.event_lock should use
    708  * drm_event_reserve_init_locked() instead.
    709  *
    710  * RETURNS:
    711  *
    712  * 0 on success or a negative error code on failure.
    713  */
    714 int drm_event_reserve_init(struct drm_device *dev,
    715 			   struct drm_file *file_priv,
    716 			   struct drm_pending_event *p,
    717 			   struct drm_event *e)
    718 {
    719 	unsigned long flags;
    720 	int ret;
    721 
    722 	spin_lock_irqsave(&dev->event_lock, flags);
    723 	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
    724 	spin_unlock_irqrestore(&dev->event_lock, flags);
    725 
    726 	return ret;
    727 }
    728 EXPORT_SYMBOL(drm_event_reserve_init);
    729 
    730 /**
    731  * drm_event_cancel_free - free a DRM event and release its space
    732  * @dev: DRM device
    733  * @p: tracking structure for the pending event
    734  *
    735  * This function frees the event @p initialized with drm_event_reserve_init()
    736  * and releases any allocated space. It is used to cancel an event when the
    737  * nonblocking operation could not be submitted and needed to be aborted.
    738  */
    739 void drm_event_cancel_free(struct drm_device *dev,
    740 			   struct drm_pending_event *p)
    741 {
    742 	unsigned long flags;
    743 	spin_lock_irqsave(&dev->event_lock, flags);
    744 	if (p->file_priv) {
    745 		p->file_priv->event_space += p->event->length;
    746 		list_del(&p->pending_link);
    747 	}
    748 	spin_unlock_irqrestore(&dev->event_lock, flags);
    749 
    750 	if (p->fence)
    751 		dma_fence_put(p->fence);
    752 
    753 	kfree(p);
    754 }
    755 EXPORT_SYMBOL(drm_event_cancel_free);
    756 
    757 /**
    758  * drm_send_event_locked - send DRM event to file descriptor
    759  * @dev: DRM device
    760  * @e: DRM event to deliver
    761  *
    762  * This function sends the event @e, initialized with drm_event_reserve_init(),
    763  * to its associated userspace DRM file. Callers must already hold
    764  * &drm_device.event_lock, see drm_send_event() for the unlocked version.
    765  *
    766  * Note that the core will take care of unlinking and disarming events when the
    767  * corresponding DRM file is closed. Drivers need not worry about whether the
    768  * DRM file for this event still exists and can call this function upon
    769  * completion of the asynchronous work unconditionally.
    770  */
    771 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
    772 {
    773 	assert_spin_locked(&dev->event_lock);
    774 
    775 	if (e->completion) {
    776 		complete_all(e->completion);
    777 		e->completion_release(e->completion);
    778 		e->completion = NULL;
    779 	}
    780 
    781 	if (e->fence) {
    782 		dma_fence_signal(e->fence);
    783 		dma_fence_put(e->fence);
    784 	}
    785 
    786 	if (!e->file_priv) {
    787 		kfree(e);
    788 		return;
    789 	}
    790 
    791 	list_del(&e->pending_link);
    792 	list_add_tail(&e->link,
    793 		      &e->file_priv->event_list);
    794 #ifdef __NetBSD__
    795 	DRM_SPIN_WAKEUP_ONE(&e->file_priv->event_wait, &dev->event_lock);
    796 	selnotify(&e->file_priv->event_selq, POLLIN|POLLRDNORM, NOTE_SUBMIT);
    797 #else
    798 	wake_up_interruptible(&e->file_priv->event_wait);
    799 #endif
    800 }
    801 EXPORT_SYMBOL(drm_send_event_locked);
    802 
    803 /**
    804  * drm_send_event - send DRM event to file descriptor
    805  * @dev: DRM device
    806  * @e: DRM event to deliver
    807  *
    808  * This function sends the event @e, initialized with drm_event_reserve_init(),
    809  * to its associated userspace DRM file. This function acquires
    810  * &drm_device.event_lock, see drm_send_event_locked() for callers which already
    811  * hold this lock.
    812  *
    813  * Note that the core will take care of unlinking and disarming events when the
    814  * corresponding DRM file is closed. Drivers need not worry about whether the
    815  * DRM file for this event still exists and can call this function upon
    816  * completion of the asynchronous work unconditionally.
    817  */
    818 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
    819 {
    820 	unsigned long irqflags;
    821 
    822 	spin_lock_irqsave(&dev->event_lock, irqflags);
    823 	drm_send_event_locked(dev, e);
    824 	spin_unlock_irqrestore(&dev->event_lock, irqflags);
    825 }
    826 EXPORT_SYMBOL(drm_send_event);
    827 
    828 /**
    829  * mock_drm_getfile - Create a new struct file for the drm device
    830  * @minor: drm minor to wrap (e.g. #drm_device.primary)
    831  * @flags: file creation mode (O_RDWR etc)
    832  *
    833  * This create a new struct file that wraps a DRM file context around a
    834  * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
    835  * invoking userspace. The struct file may be operated on using its f_op
    836  * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
    837  * to userspace facing functions as an internal/anonymous client.
    838  *
    839  * RETURNS:
    840  * Pointer to newly created struct file, ERR_PTR on failure.
    841  */
    842 #ifndef __NetBSD__
    843 struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
    844 {
    845 	struct drm_device *dev = minor->dev;
    846 	struct drm_file *priv;
    847 	struct file *file;
    848 
    849 	priv = drm_file_alloc(minor);
    850 	if (IS_ERR(priv))
    851 		return ERR_CAST(priv);
    852 
    853 	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
    854 	if (IS_ERR(file)) {
    855 		drm_file_free(priv);
    856 		return file;
    857 	}
    858 
    859 	/* Everyone shares a single global address space */
    860 	file->f_mapping = dev->anon_inode->i_mapping;
    861 
    862 	drm_dev_get(dev);
    863 	priv->filp = file;
    864 
    865 	return file;
    866 }
    867 EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);
    868 #endif
    869