LCOV - code coverage report
Current view: top level - drivers/gpu/drm - drm_file.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 5 307 1.6 %
Date: 2023-07-19 18:55:55 Functions: 1 24 4.2 %

          Line data    Source code
       1             : /*
       2             :  * \author Rickard E. (Rik) Faith <faith@valinux.com>
       3             :  * \author Daryll Strauss <daryll@valinux.com>
       4             :  * \author Gareth Hughes <gareth@valinux.com>
       5             :  */
       6             : 
       7             : /*
       8             :  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
       9             :  *
      10             :  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
      11             :  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
      12             :  * All Rights Reserved.
      13             :  *
      14             :  * Permission is hereby granted, free of charge, to any person obtaining a
      15             :  * copy of this software and associated documentation files (the "Software"),
      16             :  * to deal in the Software without restriction, including without limitation
      17             :  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      18             :  * and/or sell copies of the Software, and to permit persons to whom the
      19             :  * Software is furnished to do so, subject to the following conditions:
      20             :  *
      21             :  * The above copyright notice and this permission notice (including the next
      22             :  * paragraph) shall be included in all copies or substantial portions of the
      23             :  * Software.
      24             :  *
      25             :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      26             :  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      27             :  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
      28             :  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
      29             :  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
      30             :  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
      31             :  * OTHER DEALINGS IN THE SOFTWARE.
      32             :  */
      33             : 
      34             : #include <linux/anon_inodes.h>
      35             : #include <linux/dma-fence.h>
      36             : #include <linux/file.h>
      37             : #include <linux/module.h>
      38             : #include <linux/pci.h>
      39             : #include <linux/poll.h>
      40             : #include <linux/slab.h>
      41             : 
      42             : #include <drm/drm_client.h>
      43             : #include <drm/drm_drv.h>
      44             : #include <drm/drm_file.h>
      45             : #include <drm/drm_gem.h>
      46             : #include <drm/drm_print.h>
      47             : 
      48             : #include "drm_crtc_internal.h"
      49             : #include "drm_internal.h"
      50             : #include "drm_legacy.h"
      51             : 
      52             : /* from BKL pushdown */
      53             : DEFINE_MUTEX(drm_global_mutex);
      54             : 
      55           2 : bool drm_dev_needs_global_mutex(struct drm_device *dev)
      56             : {
      57             :         /*
      58             :          * Legacy drivers rely on all kinds of BKL locking semantics, don't
      59             :          * bother. They also still need BKL locking for their ioctls, so better
      60             :          * safe than sorry.
      61             :          */
      62           2 :         if (drm_core_check_feature(dev, DRIVER_LEGACY))
      63             :                 return true;
      64             : 
      65             :         /*
      66             :          * The deprecated ->load callback must be called after the driver is
      67             :          * already registered. This means such drivers rely on the BKL to make
      68             :          * sure an open can't proceed until the driver is actually fully set up.
      69             :          * Similar hilarity holds for the unload callback.
      70             :          */
      71           2 :         if (dev->driver->load || dev->driver->unload)
      72             :                 return true;
      73             : 
      74             :         /*
      75             :          * Drivers with the lastclose callback assume that it's synchronized
      76             :          * against concurrent opens, which again needs the BKL. The proper fix
      77             :          * is to use the drm_client infrastructure with proper locking for each
      78             :          * client.
      79             :          */
      80           2 :         if (dev->driver->lastclose)
      81             :                 return true;
      82             : 
      83           2 :         return false;
      84             : }
      85             : 
      86             : /**
      87             :  * DOC: file operations
      88             :  *
      89             :  * Drivers must define the file operations structure that forms the DRM
      90             :  * userspace API entry point, even though most of those operations are
      91             :  * implemented in the DRM core. The resulting &struct file_operations must be
      92             :  * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
      93             :  * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
      94             :  * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
      95             :  * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
      96             :  * that require 32/64 bit compatibility support must provide their own
      97             :  * &file_operations.compat_ioctl handler that processes private ioctls and calls
      98             :  * drm_compat_ioctl() for core ioctls.
      99             :  *
     100             :  * In addition drm_read() and drm_poll() provide support for DRM events. DRM
     101             :  * events are a generic and extensible means to send asynchronous events to
     102             :  * userspace through the file descriptor. They are used to send vblank event and
     103             :  * page flip completions by the KMS API. But drivers can also use it for their
     104             :  * own needs, e.g. to signal completion of rendering.
     105             :  *
     106             :  * For the driver-side event interface see drm_event_reserve_init() and
     107             :  * drm_send_event() as the main starting points.
     108             :  *
     109             :  * The memory mapping implementation will vary depending on how the driver
     110             :  * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
     111             :  * function, modern drivers should use one of the provided memory-manager
     112             :  * specific implementations. For GEM-based drivers this is drm_gem_mmap().
     113             :  *
     114             :  * No other file operations are supported by the DRM userspace API. Overall the
     115             :  * following is an example &file_operations structure::
     116             :  *
     117             :  *     static const example_drm_fops = {
     118             :  *             .owner = THIS_MODULE,
     119             :  *             .open = drm_open,
     120             :  *             .release = drm_release,
     121             :  *             .unlocked_ioctl = drm_ioctl,
     122             :  *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
     123             :  *             .poll = drm_poll,
     124             :  *             .read = drm_read,
     125             :  *             .llseek = no_llseek,
     126             :  *             .mmap = drm_gem_mmap,
     127             :  *     };
     128             :  *
     129             :  * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
     130             :  * DMA based drivers there is the DEFINE_DRM_GEM_DMA_FOPS() macro to make this
     131             :  * simpler.
     132             :  *
     133             :  * The driver's &file_operations must be stored in &drm_driver.fops.
     134             :  *
     135             :  * For driver-private IOCTL handling see the more detailed discussion in
     136             :  * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
     137             :  */
     138             : 
     139             : /**
     140             :  * drm_file_alloc - allocate file context
     141             :  * @minor: minor to allocate on
     142             :  *
     143             :  * This allocates a new DRM file context. It is not linked into any context and
     144             :  * can be used by the caller freely. Note that the context keeps a pointer to
     145             :  * @minor, so it must be freed before @minor is.
     146             :  *
     147             :  * RETURNS:
     148             :  * Pointer to newly allocated context, ERR_PTR on failure.
     149             :  */
     150           0 : struct drm_file *drm_file_alloc(struct drm_minor *minor)
     151             : {
     152             :         static atomic64_t ident = ATOMIC_INIT(0);
     153           0 :         struct drm_device *dev = minor->dev;
     154             :         struct drm_file *file;
     155             :         int ret;
     156             : 
     157           0 :         file = kzalloc(sizeof(*file), GFP_KERNEL);
     158           0 :         if (!file)
     159             :                 return ERR_PTR(-ENOMEM);
     160             : 
     161             :         /* Get a unique identifier for fdinfo: */
     162           0 :         file->client_id = atomic64_inc_return(&ident);
     163           0 :         file->pid = get_pid(task_tgid(current));
     164           0 :         file->minor = minor;
     165             : 
     166             :         /* for compatibility root is always authenticated */
     167           0 :         file->authenticated = capable(CAP_SYS_ADMIN);
     168             : 
     169           0 :         INIT_LIST_HEAD(&file->lhead);
     170           0 :         INIT_LIST_HEAD(&file->fbs);
     171           0 :         mutex_init(&file->fbs_lock);
     172           0 :         INIT_LIST_HEAD(&file->blobs);
     173           0 :         INIT_LIST_HEAD(&file->pending_event_list);
     174           0 :         INIT_LIST_HEAD(&file->event_list);
     175           0 :         init_waitqueue_head(&file->event_wait);
     176           0 :         file->event_space = 4096; /* set aside 4k for event buffer */
     177             : 
     178           0 :         spin_lock_init(&file->master_lookup_lock);
     179           0 :         mutex_init(&file->event_read_lock);
     180             : 
     181           0 :         if (drm_core_check_feature(dev, DRIVER_GEM))
     182           0 :                 drm_gem_open(dev, file);
     183             : 
     184           0 :         if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
     185           0 :                 drm_syncobj_open(file);
     186             : 
     187           0 :         drm_prime_init_file_private(&file->prime);
     188             : 
     189           0 :         if (dev->driver->open) {
     190           0 :                 ret = dev->driver->open(dev, file);
     191           0 :                 if (ret < 0)
     192             :                         goto out_prime_destroy;
     193             :         }
     194             : 
     195             :         return file;
     196             : 
     197             : out_prime_destroy:
     198           0 :         drm_prime_destroy_file_private(&file->prime);
     199           0 :         if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
     200           0 :                 drm_syncobj_release(file);
     201           0 :         if (drm_core_check_feature(dev, DRIVER_GEM))
     202           0 :                 drm_gem_release(dev, file);
     203           0 :         put_pid(file->pid);
     204           0 :         kfree(file);
     205             : 
     206           0 :         return ERR_PTR(ret);
     207             : }
     208             : 
     209           0 : static void drm_events_release(struct drm_file *file_priv)
     210             : {
     211           0 :         struct drm_device *dev = file_priv->minor->dev;
     212             :         struct drm_pending_event *e, *et;
     213             :         unsigned long flags;
     214             : 
     215           0 :         spin_lock_irqsave(&dev->event_lock, flags);
     216             : 
     217             :         /* Unlink pending events */
     218           0 :         list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
     219             :                                  pending_link) {
     220           0 :                 list_del(&e->pending_link);
     221           0 :                 e->file_priv = NULL;
     222             :         }
     223             : 
     224             :         /* Remove unconsumed events */
     225           0 :         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
     226           0 :                 list_del(&e->link);
     227           0 :                 kfree(e);
     228             :         }
     229             : 
     230           0 :         spin_unlock_irqrestore(&dev->event_lock, flags);
     231           0 : }
     232             : 
     233             : /**
     234             :  * drm_file_free - free file context
     235             :  * @file: context to free, or NULL
     236             :  *
     237             :  * This destroys and deallocates a DRM file context previously allocated via
     238             :  * drm_file_alloc(). The caller must make sure to unlink it from any contexts
     239             :  * before calling this.
     240             :  *
     241             :  * If NULL is passed, this is a no-op.
     242             :  */
     243           0 : void drm_file_free(struct drm_file *file)
     244             : {
     245             :         struct drm_device *dev;
     246             : 
     247           0 :         if (!file)
     248             :                 return;
     249             : 
     250           0 :         dev = file->minor->dev;
     251             : 
     252           0 :         drm_dbg_core(dev, "comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
     253             :                      current->comm, task_pid_nr(current),
     254             :                      (long)old_encode_dev(file->minor->kdev->devt),
     255             :                      atomic_read(&dev->open_count));
     256             : 
     257             : #ifdef CONFIG_DRM_LEGACY
     258             :         if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
     259             :             dev->driver->preclose)
     260             :                 dev->driver->preclose(dev, file);
     261             : #endif
     262             : 
     263           0 :         if (drm_core_check_feature(dev, DRIVER_LEGACY))
     264             :                 drm_legacy_lock_release(dev, file->filp);
     265             : 
     266           0 :         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
     267             :                 drm_legacy_reclaim_buffers(dev, file);
     268             : 
     269           0 :         drm_events_release(file);
     270             : 
     271           0 :         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
     272           0 :                 drm_fb_release(file);
     273           0 :                 drm_property_destroy_user_blobs(dev, file);
     274             :         }
     275             : 
     276           0 :         if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
     277           0 :                 drm_syncobj_release(file);
     278             : 
     279           0 :         if (drm_core_check_feature(dev, DRIVER_GEM))
     280           0 :                 drm_gem_release(dev, file);
     281             : 
     282           0 :         drm_legacy_ctxbitmap_flush(dev, file);
     283             : 
     284           0 :         if (drm_is_primary_client(file))
     285           0 :                 drm_master_release(file);
     286             : 
     287           0 :         if (dev->driver->postclose)
     288           0 :                 dev->driver->postclose(dev, file);
     289             : 
     290           0 :         drm_prime_destroy_file_private(&file->prime);
     291             : 
     292           0 :         WARN_ON(!list_empty(&file->event_list));
     293             : 
     294           0 :         put_pid(file->pid);
     295           0 :         kfree(file);
     296             : }
     297             : 
     298           0 : static void drm_close_helper(struct file *filp)
     299             : {
     300           0 :         struct drm_file *file_priv = filp->private_data;
     301           0 :         struct drm_device *dev = file_priv->minor->dev;
     302             : 
     303           0 :         mutex_lock(&dev->filelist_mutex);
     304           0 :         list_del(&file_priv->lhead);
     305           0 :         mutex_unlock(&dev->filelist_mutex);
     306             : 
     307           0 :         drm_file_free(file_priv);
     308           0 : }
     309             : 
     310             : /*
     311             :  * Check whether DRI will run on this CPU.
     312             :  *
     313             :  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
     314             :  */
     315             : static int drm_cpu_valid(void)
     316             : {
     317             : #if defined(__sparc__) && !defined(__sparc_v9__)
     318             :         return 0;               /* No cmpxchg before v9 sparc. */
     319             : #endif
     320             :         return 1;
     321             : }
     322             : 
     323             : /*
     324             :  * Called whenever a process opens a drm node
     325             :  *
     326             :  * \param filp file pointer.
     327             :  * \param minor acquired minor-object.
     328             :  * \return zero on success or a negative number on failure.
     329             :  *
     330             :  * Creates and initializes a drm_file structure for the file private data in \p
     331             :  * filp and add it into the double linked list in \p dev.
     332             :  */
     333           0 : int drm_open_helper(struct file *filp, struct drm_minor *minor)
     334             : {
     335           0 :         struct drm_device *dev = minor->dev;
     336             :         struct drm_file *priv;
     337             :         int ret;
     338             : 
     339           0 :         if (filp->f_flags & O_EXCL)
     340             :                 return -EBUSY;  /* No exclusive opens */
     341             :         if (!drm_cpu_valid())
     342             :                 return -EINVAL;
     343           0 :         if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
     344             :             dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
     345             :                 return -EINVAL;
     346             : 
     347           0 :         drm_dbg_core(dev, "comm=\"%s\", pid=%d, minor=%d\n",
     348             :                      current->comm, task_pid_nr(current), minor->index);
     349             : 
     350           0 :         priv = drm_file_alloc(minor);
     351           0 :         if (IS_ERR(priv))
     352           0 :                 return PTR_ERR(priv);
     353             : 
     354           0 :         if (drm_is_primary_client(priv)) {
     355           0 :                 ret = drm_master_open(priv);
     356           0 :                 if (ret) {
     357           0 :                         drm_file_free(priv);
     358           0 :                         return ret;
     359             :                 }
     360             :         }
     361             : 
     362           0 :         filp->private_data = priv;
     363           0 :         filp->f_mode |= FMODE_UNSIGNED_OFFSET;
     364           0 :         priv->filp = filp;
     365             : 
     366           0 :         mutex_lock(&dev->filelist_mutex);
     367           0 :         list_add(&priv->lhead, &dev->filelist);
     368           0 :         mutex_unlock(&dev->filelist_mutex);
     369             : 
     370             : #ifdef CONFIG_DRM_LEGACY
     371             : #ifdef __alpha__
     372             :         /*
     373             :          * Default the hose
     374             :          */
     375             :         if (!dev->hose) {
     376             :                 struct pci_dev *pci_dev;
     377             : 
     378             :                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
     379             :                 if (pci_dev) {
     380             :                         dev->hose = pci_dev->sysdata;
     381             :                         pci_dev_put(pci_dev);
     382             :                 }
     383             :                 if (!dev->hose) {
     384             :                         struct pci_bus *b = list_entry(pci_root_buses.next,
     385             :                                 struct pci_bus, node);
     386             :                         if (b)
     387             :                                 dev->hose = b->sysdata;
     388             :                 }
     389             :         }
     390             : #endif
     391             : #endif
     392             : 
     393           0 :         return 0;
     394             : }
     395             : 
     396             : /**
     397             :  * drm_open - open method for DRM file
     398             :  * @inode: device inode
     399             :  * @filp: file pointer.
     400             :  *
     401             :  * This function must be used by drivers as their &file_operations.open method.
     402             :  * It looks up the correct DRM device and instantiates all the per-file
     403             :  * resources for it. It also calls the &drm_driver.open driver callback.
     404             :  *
     405             :  * RETURNS:
     406             :  *
     407             :  * 0 on success or negative errno value on failure.
     408             :  */
     409           0 : int drm_open(struct inode *inode, struct file *filp)
     410             : {
     411             :         struct drm_device *dev;
     412             :         struct drm_minor *minor;
     413             :         int retcode;
     414           0 :         int need_setup = 0;
     415             : 
     416           0 :         minor = drm_minor_acquire(iminor(inode));
     417           0 :         if (IS_ERR(minor))
     418           0 :                 return PTR_ERR(minor);
     419             : 
     420           0 :         dev = minor->dev;
     421           0 :         if (drm_dev_needs_global_mutex(dev))
     422           0 :                 mutex_lock(&drm_global_mutex);
     423             : 
     424           0 :         if (!atomic_fetch_inc(&dev->open_count))
     425             :                 need_setup = 1;
     426             : 
     427             :         /* share address_space across all char-devs of a single device */
     428           0 :         filp->f_mapping = dev->anon_inode->i_mapping;
     429             : 
     430           0 :         retcode = drm_open_helper(filp, minor);
     431           0 :         if (retcode)
     432             :                 goto err_undo;
     433             :         if (need_setup) {
     434             :                 retcode = drm_legacy_setup(dev);
     435             :                 if (retcode) {
     436             :                         drm_close_helper(filp);
     437             :                         goto err_undo;
     438             :                 }
     439             :         }
     440             : 
     441           0 :         if (drm_dev_needs_global_mutex(dev))
     442           0 :                 mutex_unlock(&drm_global_mutex);
     443             : 
     444             :         return 0;
     445             : 
     446             : err_undo:
     447           0 :         atomic_dec(&dev->open_count);
     448           0 :         if (drm_dev_needs_global_mutex(dev))
     449           0 :                 mutex_unlock(&drm_global_mutex);
     450           0 :         drm_minor_release(minor);
     451           0 :         return retcode;
     452             : }
     453             : EXPORT_SYMBOL(drm_open);
     454             : 
     455           0 : void drm_lastclose(struct drm_device * dev)
     456             : {
     457           0 :         drm_dbg_core(dev, "\n");
     458             : 
     459           0 :         if (dev->driver->lastclose)
     460           0 :                 dev->driver->lastclose(dev);
     461           0 :         drm_dbg_core(dev, "driver lastclose completed\n");
     462             : 
     463           0 :         if (drm_core_check_feature(dev, DRIVER_LEGACY))
     464             :                 drm_legacy_dev_reinit(dev);
     465             : 
     466           0 :         drm_client_dev_restore(dev);
     467           0 : }
     468             : 
     469             : /**
     470             :  * drm_release - release method for DRM file
     471             :  * @inode: device inode
     472             :  * @filp: file pointer.
     473             :  *
     474             :  * This function must be used by drivers as their &file_operations.release
     475             :  * method. It frees any resources associated with the open file, and calls the
     476             :  * &drm_driver.postclose driver callback. If this is the last open file for the
     477             :  * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
     478             :  *
     479             :  * RETURNS:
     480             :  *
     481             :  * Always succeeds and returns 0.
     482             :  */
     483           0 : int drm_release(struct inode *inode, struct file *filp)
     484             : {
     485           0 :         struct drm_file *file_priv = filp->private_data;
     486           0 :         struct drm_minor *minor = file_priv->minor;
     487           0 :         struct drm_device *dev = minor->dev;
     488             : 
     489           0 :         if (drm_dev_needs_global_mutex(dev))
     490           0 :                 mutex_lock(&drm_global_mutex);
     491             : 
     492           0 :         drm_dbg_core(dev, "open_count = %d\n", atomic_read(&dev->open_count));
     493             : 
     494           0 :         drm_close_helper(filp);
     495             : 
     496           0 :         if (atomic_dec_and_test(&dev->open_count))
     497           0 :                 drm_lastclose(dev);
     498             : 
     499           0 :         if (drm_dev_needs_global_mutex(dev))
     500           0 :                 mutex_unlock(&drm_global_mutex);
     501             : 
     502           0 :         drm_minor_release(minor);
     503             : 
     504           0 :         return 0;
     505             : }
     506             : EXPORT_SYMBOL(drm_release);
     507             : 
     508             : /**
     509             :  * drm_release_noglobal - release method for DRM file
     510             :  * @inode: device inode
     511             :  * @filp: file pointer.
     512             :  *
     513             :  * This function may be used by drivers as their &file_operations.release
     514             :  * method. It frees any resources associated with the open file prior to taking
     515             :  * the drm_global_mutex, which then calls the &drm_driver.postclose driver
     516             :  * callback. If this is the last open file for the DRM device also proceeds to
     517             :  * call the &drm_driver.lastclose driver callback.
     518             :  *
     519             :  * RETURNS:
     520             :  *
     521             :  * Always succeeds and returns 0.
     522             :  */
     523           0 : int drm_release_noglobal(struct inode *inode, struct file *filp)
     524             : {
     525           0 :         struct drm_file *file_priv = filp->private_data;
     526           0 :         struct drm_minor *minor = file_priv->minor;
     527           0 :         struct drm_device *dev = minor->dev;
     528             : 
     529           0 :         drm_close_helper(filp);
     530             : 
     531           0 :         if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
     532           0 :                 drm_lastclose(dev);
     533           0 :                 mutex_unlock(&drm_global_mutex);
     534             :         }
     535             : 
     536           0 :         drm_minor_release(minor);
     537             : 
     538           0 :         return 0;
     539             : }
     540             : EXPORT_SYMBOL(drm_release_noglobal);
     541             : 
     542             : /**
     543             :  * drm_read - read method for DRM file
     544             :  * @filp: file pointer
     545             :  * @buffer: userspace destination pointer for the read
     546             :  * @count: count in bytes to read
     547             :  * @offset: offset to read
     548             :  *
     549             :  * This function must be used by drivers as their &file_operations.read
     550             :  * method if they use DRM events for asynchronous signalling to userspace.
     551             :  * Since events are used by the KMS API for vblank and page flip completion this
     552             :  * means all modern display drivers must use it.
     553             :  *
     554             :  * @offset is ignored, DRM events are read like a pipe. Polling support is
     555             :  * provided by drm_poll().
     556             :  *
     557             :  * This function will only ever read a full event. Therefore userspace must
     558             :  * supply a big enough buffer to fit any event to ensure forward progress. Since
     559             :  * the maximum event space is currently 4K it's recommended to just use that for
     560             :  * safety.
     561             :  *
     562             :  * RETURNS:
     563             :  *
     564             :  * Number of bytes read (always aligned to full events, and can be 0) or a
     565             :  * negative error code on failure.
     566             :  */
     567           0 : ssize_t drm_read(struct file *filp, char __user *buffer,
     568             :                  size_t count, loff_t *offset)
     569             : {
     570           0 :         struct drm_file *file_priv = filp->private_data;
     571           0 :         struct drm_device *dev = file_priv->minor->dev;
     572             :         ssize_t ret;
     573             : 
     574           0 :         ret = mutex_lock_interruptible(&file_priv->event_read_lock);
     575           0 :         if (ret)
     576             :                 return ret;
     577             : 
     578             :         for (;;) {
     579           0 :                 struct drm_pending_event *e = NULL;
     580             : 
     581           0 :                 spin_lock_irq(&dev->event_lock);
     582           0 :                 if (!list_empty(&file_priv->event_list)) {
     583           0 :                         e = list_first_entry(&file_priv->event_list,
     584             :                                         struct drm_pending_event, link);
     585           0 :                         file_priv->event_space += e->event->length;
     586           0 :                         list_del(&e->link);
     587             :                 }
     588           0 :                 spin_unlock_irq(&dev->event_lock);
     589             : 
     590           0 :                 if (e == NULL) {
     591           0 :                         if (ret)
     592             :                                 break;
     593             : 
     594           0 :                         if (filp->f_flags & O_NONBLOCK) {
     595             :                                 ret = -EAGAIN;
     596             :                                 break;
     597             :                         }
     598             : 
     599           0 :                         mutex_unlock(&file_priv->event_read_lock);
     600           0 :                         ret = wait_event_interruptible(file_priv->event_wait,
     601             :                                                        !list_empty(&file_priv->event_list));
     602           0 :                         if (ret >= 0)
     603           0 :                                 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
     604           0 :                         if (ret)
     605             :                                 return ret;
     606             :                 } else {
     607           0 :                         unsigned length = e->event->length;
     608             : 
     609           0 :                         if (length > count - ret) {
     610             : put_back_event:
     611           0 :                                 spin_lock_irq(&dev->event_lock);
     612           0 :                                 file_priv->event_space -= length;
     613           0 :                                 list_add(&e->link, &file_priv->event_list);
     614           0 :                                 spin_unlock_irq(&dev->event_lock);
     615           0 :                                 wake_up_interruptible_poll(&file_priv->event_wait,
     616             :                                         EPOLLIN | EPOLLRDNORM);
     617           0 :                                 break;
     618             :                         }
     619             : 
     620           0 :                         if (copy_to_user(buffer + ret, e->event, length)) {
     621           0 :                                 if (ret == 0)
     622           0 :                                         ret = -EFAULT;
     623             :                                 goto put_back_event;
     624             :                         }
     625             : 
     626           0 :                         ret += length;
     627           0 :                         kfree(e);
     628             :                 }
     629             :         }
     630           0 :         mutex_unlock(&file_priv->event_read_lock);
     631             : 
     632           0 :         return ret;
     633             : }
     634             : EXPORT_SYMBOL(drm_read);
     635             : 
     636             : /**
     637             :  * drm_poll - poll method for DRM file
     638             :  * @filp: file pointer
     639             :  * @wait: poll waiter table
     640             :  *
     641             :  * This function must be used by drivers as their &file_operations.read method
     642             :  * if they use DRM events for asynchronous signalling to userspace.  Since
     643             :  * events are used by the KMS API for vblank and page flip completion this means
     644             :  * all modern display drivers must use it.
     645             :  *
     646             :  * See also drm_read().
     647             :  *
     648             :  * RETURNS:
     649             :  *
     650             :  * Mask of POLL flags indicating the current status of the file.
     651             :  */
     652           0 : __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
     653             : {
     654           0 :         struct drm_file *file_priv = filp->private_data;
     655           0 :         __poll_t mask = 0;
     656             : 
     657           0 :         poll_wait(filp, &file_priv->event_wait, wait);
     658             : 
     659           0 :         if (!list_empty(&file_priv->event_list))
     660           0 :                 mask |= EPOLLIN | EPOLLRDNORM;
     661             : 
     662           0 :         return mask;
     663             : }
     664             : EXPORT_SYMBOL(drm_poll);
     665             : 
     666             : /**
     667             :  * drm_event_reserve_init_locked - init a DRM event and reserve space for it
     668             :  * @dev: DRM device
     669             :  * @file_priv: DRM file private data
     670             :  * @p: tracking structure for the pending event
     671             :  * @e: actual event data to deliver to userspace
     672             :  *
     673             :  * This function prepares the passed in event for eventual delivery. If the event
     674             :  * doesn't get delivered (because the IOCTL fails later on, before queuing up
     675             :  * anything) then the even must be cancelled and freed using
     676             :  * drm_event_cancel_free(). Successfully initialized events should be sent out
     677             :  * using drm_send_event() or drm_send_event_locked() to signal completion of the
     678             :  * asynchronous event to userspace.
     679             :  *
     680             :  * If callers embedded @p into a larger structure it must be allocated with
     681             :  * kmalloc and @p must be the first member element.
     682             :  *
     683             :  * This is the locked version of drm_event_reserve_init() for callers which
     684             :  * already hold &drm_device.event_lock.
     685             :  *
     686             :  * RETURNS:
     687             :  *
     688             :  * 0 on success or a negative error code on failure.
     689             :  */
     690           0 : int drm_event_reserve_init_locked(struct drm_device *dev,
     691             :                                   struct drm_file *file_priv,
     692             :                                   struct drm_pending_event *p,
     693             :                                   struct drm_event *e)
     694             : {
     695           0 :         if (file_priv->event_space < e->length)
     696             :                 return -ENOMEM;
     697             : 
     698           0 :         file_priv->event_space -= e->length;
     699             : 
     700           0 :         p->event = e;
     701           0 :         list_add(&p->pending_link, &file_priv->pending_event_list);
     702           0 :         p->file_priv = file_priv;
     703             : 
     704           0 :         return 0;
     705             : }
     706             : EXPORT_SYMBOL(drm_event_reserve_init_locked);
     707             : 
     708             : /**
     709             :  * drm_event_reserve_init - init a DRM event and reserve space for it
     710             :  * @dev: DRM device
     711             :  * @file_priv: DRM file private data
     712             :  * @p: tracking structure for the pending event
     713             :  * @e: actual event data to deliver to userspace
     714             :  *
     715             :  * This function prepares the passed in event for eventual delivery. If the event
     716             :  * doesn't get delivered (because the IOCTL fails later on, before queuing up
     717             :  * anything) then the even must be cancelled and freed using
     718             :  * drm_event_cancel_free(). Successfully initialized events should be sent out
     719             :  * using drm_send_event() or drm_send_event_locked() to signal completion of the
     720             :  * asynchronous event to userspace.
     721             :  *
     722             :  * If callers embedded @p into a larger structure it must be allocated with
     723             :  * kmalloc and @p must be the first member element.
     724             :  *
     725             :  * Callers which already hold &drm_device.event_lock should use
     726             :  * drm_event_reserve_init_locked() instead.
     727             :  *
     728             :  * RETURNS:
     729             :  *
     730             :  * 0 on success or a negative error code on failure.
     731             :  */
     732           0 : int drm_event_reserve_init(struct drm_device *dev,
     733             :                            struct drm_file *file_priv,
     734             :                            struct drm_pending_event *p,
     735             :                            struct drm_event *e)
     736             : {
     737             :         unsigned long flags;
     738             :         int ret;
     739             : 
     740           0 :         spin_lock_irqsave(&dev->event_lock, flags);
     741           0 :         ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
     742           0 :         spin_unlock_irqrestore(&dev->event_lock, flags);
     743             : 
     744           0 :         return ret;
     745             : }
     746             : EXPORT_SYMBOL(drm_event_reserve_init);
     747             : 
     748             : /**
     749             :  * drm_event_cancel_free - free a DRM event and release its space
     750             :  * @dev: DRM device
     751             :  * @p: tracking structure for the pending event
     752             :  *
     753             :  * This function frees the event @p initialized with drm_event_reserve_init()
     754             :  * and releases any allocated space. It is used to cancel an event when the
     755             :  * nonblocking operation could not be submitted and needed to be aborted.
     756             :  */
     757           0 : void drm_event_cancel_free(struct drm_device *dev,
     758             :                            struct drm_pending_event *p)
     759             : {
     760             :         unsigned long flags;
     761             : 
     762           0 :         spin_lock_irqsave(&dev->event_lock, flags);
     763           0 :         if (p->file_priv) {
     764           0 :                 p->file_priv->event_space += p->event->length;
     765           0 :                 list_del(&p->pending_link);
     766             :         }
     767           0 :         spin_unlock_irqrestore(&dev->event_lock, flags);
     768             : 
     769           0 :         if (p->fence)
     770           0 :                 dma_fence_put(p->fence);
     771             : 
     772           0 :         kfree(p);
     773           0 : }
     774             : EXPORT_SYMBOL(drm_event_cancel_free);
     775             : 
     776           0 : static void drm_send_event_helper(struct drm_device *dev,
     777             :                            struct drm_pending_event *e, ktime_t timestamp)
     778             : {
     779             :         assert_spin_locked(&dev->event_lock);
     780             : 
     781           0 :         if (e->completion) {
     782           0 :                 complete_all(e->completion);
     783           0 :                 e->completion_release(e->completion);
     784           0 :                 e->completion = NULL;
     785             :         }
     786             : 
     787           0 :         if (e->fence) {
     788           0 :                 if (timestamp)
     789           0 :                         dma_fence_signal_timestamp(e->fence, timestamp);
     790             :                 else
     791           0 :                         dma_fence_signal(e->fence);
     792           0 :                 dma_fence_put(e->fence);
     793             :         }
     794             : 
     795           0 :         if (!e->file_priv) {
     796           0 :                 kfree(e);
     797             :                 return;
     798             :         }
     799             : 
     800           0 :         list_del(&e->pending_link);
     801           0 :         list_add_tail(&e->link,
     802           0 :                       &e->file_priv->event_list);
     803           0 :         wake_up_interruptible_poll(&e->file_priv->event_wait,
     804             :                 EPOLLIN | EPOLLRDNORM);
     805             : }
     806             : 
     807             : /**
     808             :  * drm_send_event_timestamp_locked - send DRM event to file descriptor
     809             :  * @dev: DRM device
     810             :  * @e: DRM event to deliver
     811             :  * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
     812             :  * time domain
     813             :  *
     814             :  * This function sends the event @e, initialized with drm_event_reserve_init(),
     815             :  * to its associated userspace DRM file. Callers must already hold
     816             :  * &drm_device.event_lock.
     817             :  *
     818             :  * Note that the core will take care of unlinking and disarming events when the
     819             :  * corresponding DRM file is closed. Drivers need not worry about whether the
     820             :  * DRM file for this event still exists and can call this function upon
     821             :  * completion of the asynchronous work unconditionally.
     822             :  */
     823           0 : void drm_send_event_timestamp_locked(struct drm_device *dev,
     824             :                                      struct drm_pending_event *e, ktime_t timestamp)
     825             : {
     826           0 :         drm_send_event_helper(dev, e, timestamp);
     827           0 : }
     828             : EXPORT_SYMBOL(drm_send_event_timestamp_locked);
     829             : 
     830             : /**
     831             :  * drm_send_event_locked - send DRM event to file descriptor
     832             :  * @dev: DRM device
     833             :  * @e: DRM event to deliver
     834             :  *
     835             :  * This function sends the event @e, initialized with drm_event_reserve_init(),
     836             :  * to its associated userspace DRM file. Callers must already hold
     837             :  * &drm_device.event_lock, see drm_send_event() for the unlocked version.
     838             :  *
     839             :  * Note that the core will take care of unlinking and disarming events when the
     840             :  * corresponding DRM file is closed. Drivers need not worry about whether the
     841             :  * DRM file for this event still exists and can call this function upon
     842             :  * completion of the asynchronous work unconditionally.
     843             :  */
     844           0 : void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
     845             : {
     846           0 :         drm_send_event_helper(dev, e, 0);
     847           0 : }
     848             : EXPORT_SYMBOL(drm_send_event_locked);
     849             : 
     850             : /**
     851             :  * drm_send_event - send DRM event to file descriptor
     852             :  * @dev: DRM device
     853             :  * @e: DRM event to deliver
     854             :  *
     855             :  * This function sends the event @e, initialized with drm_event_reserve_init(),
     856             :  * to its associated userspace DRM file. This function acquires
     857             :  * &drm_device.event_lock, see drm_send_event_locked() for callers which already
     858             :  * hold this lock.
     859             :  *
     860             :  * Note that the core will take care of unlinking and disarming events when the
     861             :  * corresponding DRM file is closed. Drivers need not worry about whether the
     862             :  * DRM file for this event still exists and can call this function upon
     863             :  * completion of the asynchronous work unconditionally.
     864             :  */
     865           0 : void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
     866             : {
     867             :         unsigned long irqflags;
     868             : 
     869           0 :         spin_lock_irqsave(&dev->event_lock, irqflags);
     870           0 :         drm_send_event_helper(dev, e, 0);
     871           0 :         spin_unlock_irqrestore(&dev->event_lock, irqflags);
     872           0 : }
     873             : EXPORT_SYMBOL(drm_send_event);
     874             : 
     875           0 : static void print_size(struct drm_printer *p, const char *stat,
     876             :                        const char *region, u64 sz)
     877             : {
     878           0 :         const char *units[] = {"", " KiB", " MiB"};
     879             :         unsigned u;
     880             : 
     881           0 :         for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
     882           0 :                 if (sz < SZ_1K)
     883             :                         break;
     884           0 :                 sz = div_u64(sz, SZ_1K);
     885             :         }
     886             : 
     887           0 :         drm_printf(p, "drm-%s-%s:\t%llu%s\n", stat, region, sz, units[u]);
     888           0 : }
     889             : 
     890             : /**
     891             :  * drm_print_memory_stats - A helper to print memory stats
     892             :  * @p: The printer to print output to
     893             :  * @stats: The collected memory stats
     894             :  * @supported_status: Bitmask of optional stats which are available
     895             :  * @region: The memory region
     896             :  *
     897             :  */
     898           0 : void drm_print_memory_stats(struct drm_printer *p,
     899             :                             const struct drm_memory_stats *stats,
     900             :                             enum drm_gem_object_status supported_status,
     901             :                             const char *region)
     902             : {
     903           0 :         print_size(p, "total", region, stats->private + stats->shared);
     904           0 :         print_size(p, "shared", region, stats->shared);
     905           0 :         print_size(p, "active", region, stats->active);
     906             : 
     907           0 :         if (supported_status & DRM_GEM_OBJECT_RESIDENT)
     908           0 :                 print_size(p, "resident", region, stats->resident);
     909             : 
     910           0 :         if (supported_status & DRM_GEM_OBJECT_PURGEABLE)
     911           0 :                 print_size(p, "purgeable", region, stats->purgeable);
     912           0 : }
     913             : EXPORT_SYMBOL(drm_print_memory_stats);
     914             : 
     915             : /**
     916             :  * drm_show_memory_stats - Helper to collect and show standard fdinfo memory stats
     917             :  * @p: the printer to print output to
     918             :  * @file: the DRM file
     919             :  *
     920             :  * Helper to iterate over GEM objects with a handle allocated in the specified
     921             :  * file.
     922             :  */
     923           0 : void drm_show_memory_stats(struct drm_printer *p, struct drm_file *file)
     924             : {
     925             :         struct drm_gem_object *obj;
     926           0 :         struct drm_memory_stats status = {};
     927             :         enum drm_gem_object_status supported_status;
     928             :         int id;
     929             : 
     930           0 :         spin_lock(&file->table_lock);
     931           0 :         idr_for_each_entry (&file->object_idr, obj, id) {
     932           0 :                 enum drm_gem_object_status s = 0;
     933             : 
     934           0 :                 if (obj->funcs && obj->funcs->status) {
     935           0 :                         s = obj->funcs->status(obj);
     936           0 :                         supported_status = DRM_GEM_OBJECT_RESIDENT |
     937             :                                         DRM_GEM_OBJECT_PURGEABLE;
     938             :                 }
     939             : 
     940           0 :                 if (obj->handle_count > 1) {
     941           0 :                         status.shared += obj->size;
     942             :                 } else {
     943           0 :                         status.private += obj->size;
     944             :                 }
     945             : 
     946           0 :                 if (s & DRM_GEM_OBJECT_RESIDENT) {
     947           0 :                         status.resident += obj->size;
     948             :                 } else {
     949             :                         /* If already purged or not yet backed by pages, don't
     950             :                          * count it as purgeable:
     951             :                          */
     952           0 :                         s &= ~DRM_GEM_OBJECT_PURGEABLE;
     953             :                 }
     954             : 
     955           0 :                 if (!dma_resv_test_signaled(obj->resv, dma_resv_usage_rw(true))) {
     956           0 :                         status.active += obj->size;
     957             : 
     958             :                         /* If still active, don't count as purgeable: */
     959           0 :                         s &= ~DRM_GEM_OBJECT_PURGEABLE;
     960             :                 }
     961             : 
     962           0 :                 if (s & DRM_GEM_OBJECT_PURGEABLE)
     963           0 :                         status.purgeable += obj->size;
     964             :         }
     965           0 :         spin_unlock(&file->table_lock);
     966             : 
     967           0 :         drm_print_memory_stats(p, &status, supported_status, "memory");
     968           0 : }
     969             : EXPORT_SYMBOL(drm_show_memory_stats);
     970             : 
     971             : /**
     972             :  * drm_show_fdinfo - helper for drm file fops
     973             :  * @m: output stream
     974             :  * @f: the device file instance
     975             :  *
     976             :  * Helper to implement fdinfo, for userspace to query usage stats, etc, of a
     977             :  * process using the GPU.  See also &drm_driver.show_fdinfo.
     978             :  *
     979             :  * For text output format description please see Documentation/gpu/drm-usage-stats.rst
     980             :  */
     981           0 : void drm_show_fdinfo(struct seq_file *m, struct file *f)
     982             : {
     983           0 :         struct drm_file *file = f->private_data;
     984           0 :         struct drm_device *dev = file->minor->dev;
     985           0 :         struct drm_printer p = drm_seq_file_printer(m);
     986             : 
     987           0 :         drm_printf(&p, "drm-driver:\t%s\n", dev->driver->name);
     988           0 :         drm_printf(&p, "drm-client-id:\t%llu\n", file->client_id);
     989             : 
     990           0 :         if (dev_is_pci(dev->dev)) {
     991           0 :                 struct pci_dev *pdev = to_pci_dev(dev->dev);
     992             : 
     993           0 :                 drm_printf(&p, "drm-pdev:\t%04x:%02x:%02x.%d\n",
     994           0 :                            pci_domain_nr(pdev->bus), pdev->bus->number,
     995           0 :                            PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
     996             :         }
     997             : 
     998           0 :         if (dev->driver->show_fdinfo)
     999           0 :                 dev->driver->show_fdinfo(&p, file);
    1000           0 : }
    1001             : EXPORT_SYMBOL(drm_show_fdinfo);
    1002             : 
    1003             : /**
    1004             :  * mock_drm_getfile - Create a new struct file for the drm device
    1005             :  * @minor: drm minor to wrap (e.g. #drm_device.primary)
    1006             :  * @flags: file creation mode (O_RDWR etc)
    1007             :  *
    1008             :  * This create a new struct file that wraps a DRM file context around a
    1009             :  * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
    1010             :  * invoking userspace. The struct file may be operated on using its f_op
    1011             :  * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
    1012             :  * to userspace facing functions as an internal/anonymous client.
    1013             :  *
    1014             :  * RETURNS:
    1015             :  * Pointer to newly created struct file, ERR_PTR on failure.
    1016             :  */
    1017           0 : struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
    1018             : {
    1019           0 :         struct drm_device *dev = minor->dev;
    1020             :         struct drm_file *priv;
    1021             :         struct file *file;
    1022             : 
    1023           0 :         priv = drm_file_alloc(minor);
    1024           0 :         if (IS_ERR(priv))
    1025             :                 return ERR_CAST(priv);
    1026             : 
    1027           0 :         file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
    1028           0 :         if (IS_ERR(file)) {
    1029           0 :                 drm_file_free(priv);
    1030           0 :                 return file;
    1031             :         }
    1032             : 
    1033             :         /* Everyone shares a single global address space */
    1034           0 :         file->f_mapping = dev->anon_inode->i_mapping;
    1035             : 
    1036           0 :         drm_dev_get(dev);
    1037           0 :         priv->filp = file;
    1038             : 
    1039           0 :         return file;
    1040             : }
    1041             : EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);

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