/* * \file drm_fops.c * File operations for DRM * * \author Rickard E. (Rik) Faith * \author Daryll Strauss * \author Gareth Hughes */ /* * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com * * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #include #include #include #include #include "drm_legacy.h" #include "drm_internal.h" /* from BKL pushdown */ DEFINE_MUTEX(drm_global_mutex); /** * DOC: file operations * * Drivers must define the file operations structure that forms the DRM * userspace API entry point, even though most of those operations are * implemented in the DRM core. The mandatory functions are drm_open(), * drm_read(), drm_ioctl() and drm_compat_ioctl if CONFIG_COMPAT is enabled. * Drivers which implement private ioctls that require 32/64 bit compatibility * support must provided their onw .compat_ioctl() handler that processes * private ioctls and calls drm_compat_ioctl() for core ioctls. * * In addition drm_read() and drm_poll() provide support for DRM events. DRM * events are a generic and extensible means to send asynchronous events to * userspace through the file descriptor. They are used to send vblank event and * page flip completions by the KMS API. But drivers can also use it for their * own needs, e.g. to signal completion of rendering. * * The memory mapping implementation will vary depending on how the driver * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap() * function, modern drivers should use one of the provided memory-manager * specific implementations. For GEM-based drivers this is drm_gem_mmap(). * * No other file operations are supported by the DRM userspace API. Overall the * following is an example #file_operations structure:: * * static const example_drm_fops = { * .owner = THIS_MODULE, * .open = drm_open, * .release = drm_release, * .unlocked_ioctl = drm_ioctl, * #ifdef CONFIG_COMPAT * .compat_ioctl = drm_compat_ioctl, * #endif * .poll = drm_poll, * .read = drm_read, * .llseek = no_llseek, * .mmap = drm_gem_mmap, * }; */ static int drm_open_helper(struct file *filp, struct drm_minor *minor); static int drm_setup(struct drm_device * dev) { int ret; if (dev->driver->firstopen && !drm_core_check_feature(dev, DRIVER_MODESET)) { ret = dev->driver->firstopen(dev); if (ret != 0) return ret; } ret = drm_legacy_dma_setup(dev); if (ret < 0) return ret; DRM_DEBUG("\n"); return 0; } /** * drm_open - open method for DRM file * @inode: device inode * @filp: file pointer. * * This function must be used by drivers as their .open() #file_operations * method. It looks up the correct DRM device and instantiates all the per-file * resources for it. * * RETURNS: * * 0 on success or negative errno value on falure. */ int drm_open(struct inode *inode, struct file *filp) { struct drm_device *dev; struct drm_minor *minor; int retcode; int need_setup = 0; minor = drm_minor_acquire(iminor(inode)); if (IS_ERR(minor)) return PTR_ERR(minor); dev = minor->dev; if (!dev->open_count++) need_setup = 1; /* share address_space across all char-devs of a single device */ filp->f_mapping = dev->anon_inode->i_mapping; retcode = drm_open_helper(filp, minor); if (retcode) goto err_undo; if (need_setup) { retcode = drm_setup(dev); if (retcode) goto err_undo; } return 0; err_undo: dev->open_count--; drm_minor_release(minor); return retcode; } EXPORT_SYMBOL(drm_open); /* * Check whether DRI will run on this CPU. * * \return non-zero if the DRI will run on this CPU, or zero otherwise. */ static int drm_cpu_valid(void) { #if defined(__sparc__) && !defined(__sparc_v9__) return 0; /* No cmpxchg before v9 sparc. */ #endif return 1; } /* * drm_new_set_master - Allocate a new master object and become master for the * associated master realm. * * @dev: The associated device. * @fpriv: File private identifying the client. * * This function must be called with dev::struct_mutex held. * Returns negative error code on failure. Zero on success. */ int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) { struct drm_master *old_master; int ret; lockdep_assert_held_once(&dev->master_mutex); /* create a new master */ fpriv->minor->master = drm_master_create(fpriv->minor); if (!fpriv->minor->master) return -ENOMEM; /* take another reference for the copy in the local file priv */ old_master = fpriv->master; fpriv->master = drm_master_get(fpriv->minor->master); if (dev->driver->master_create) { ret = dev->driver->master_create(dev, fpriv->master); if (ret) goto out_err; } if (dev->driver->master_set) { ret = dev->driver->master_set(dev, fpriv, true); if (ret) goto out_err; } fpriv->is_master = 1; fpriv->allowed_master = 1; fpriv->authenticated = 1; if (old_master) drm_master_put(&old_master); return 0; out_err: /* drop both references and restore old master on failure */ drm_master_put(&fpriv->minor->master); drm_master_put(&fpriv->master); fpriv->master = old_master; return ret; } /* * Called whenever a process opens /dev/drm. * * \param filp file pointer. * \param minor acquired minor-object. * \return zero on success or a negative number on failure. * * Creates and initializes a drm_file structure for the file private data in \p * filp and add it into the double linked list in \p dev. */ static int drm_open_helper(struct file *filp, struct drm_minor *minor) { struct drm_device *dev = minor->dev; struct drm_file *priv; int ret; if (filp->f_flags & O_EXCL) return -EBUSY; /* No exclusive opens */ if (!drm_cpu_valid()) return -EINVAL; if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF) return -EINVAL; DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index); priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; filp->private_data = priv; priv->filp = filp; priv->uid = current_euid(); priv->pid = get_pid(task_pid(current)); priv->minor = minor; /* for compatibility root is always authenticated */ priv->authenticated = capable(CAP_SYS_ADMIN); priv->lock_count = 0; INIT_LIST_HEAD(&priv->lhead); INIT_LIST_HEAD(&priv->fbs); mutex_init(&priv->fbs_lock); INIT_LIST_HEAD(&priv->blobs); INIT_LIST_HEAD(&priv->pending_event_list); INIT_LIST_HEAD(&priv->event_list); init_waitqueue_head(&priv->event_wait); priv->event_space = 4096; /* set aside 4k for event buffer */ mutex_init(&priv->event_read_lock); if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_open(dev, priv); if (drm_core_check_feature(dev, DRIVER_PRIME)) drm_prime_init_file_private(&priv->prime); if (dev->driver->open) { ret = dev->driver->open(dev, priv); if (ret < 0) goto out_prime_destroy; } /* if there is no current master make this fd it, but do not create * any master object for render clients */ mutex_lock(&dev->master_mutex); if (drm_is_primary_client(priv) && !priv->minor->master) { /* create a new master */ ret = drm_new_set_master(dev, priv); if (ret) goto out_close; } else if (drm_is_primary_client(priv)) { /* get a reference to the master */ priv->master = drm_master_get(priv->minor->master); } mutex_unlock(&dev->master_mutex); mutex_lock(&dev->filelist_mutex); list_add(&priv->lhead, &dev->filelist); mutex_unlock(&dev->filelist_mutex); #ifdef __alpha__ /* * Default the hose */ if (!dev->hose) { struct pci_dev *pci_dev; pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL); if (pci_dev) { dev->hose = pci_dev->sysdata; pci_dev_put(pci_dev); } if (!dev->hose) { struct pci_bus *b = list_entry(pci_root_buses.next, struct pci_bus, node); if (b) dev->hose = b->sysdata; } } #endif return 0; out_close: mutex_unlock(&dev->master_mutex); if (dev->driver->postclose) dev->driver->postclose(dev, priv); out_prime_destroy: if (drm_core_check_feature(dev, DRIVER_PRIME)) drm_prime_destroy_file_private(&priv->prime); if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_release(dev, priv); put_pid(priv->pid); kfree(priv); filp->private_data = NULL; return ret; } static void drm_master_release(struct drm_device *dev, struct file *filp) { struct drm_file *file_priv = filp->private_data; if (drm_legacy_i_have_hw_lock(dev, file_priv)) { DRM_DEBUG("File %p released, freeing lock for context %d\n", filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock)); drm_legacy_lock_free(&file_priv->master->lock, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock)); } } static void drm_events_release(struct drm_file *file_priv) { struct drm_device *dev = file_priv->minor->dev; struct drm_pending_event *e, *et; unsigned long flags; spin_lock_irqsave(&dev->event_lock, flags); /* Unlink pending events */ list_for_each_entry_safe(e, et, &file_priv->pending_event_list, pending_link) { list_del(&e->pending_link); e->file_priv = NULL; } /* Remove unconsumed events */ list_for_each_entry_safe(e, et, &file_priv->event_list, link) { list_del(&e->link); kfree(e); } spin_unlock_irqrestore(&dev->event_lock, flags); } /* * drm_legacy_dev_reinit * * Reinitializes a legacy/ums drm device in it's lastclose function. */ static void drm_legacy_dev_reinit(struct drm_device *dev) { if (dev->irq_enabled) drm_irq_uninstall(dev); mutex_lock(&dev->struct_mutex); drm_legacy_agp_clear(dev); drm_legacy_sg_cleanup(dev); drm_legacy_vma_flush(dev); drm_legacy_dma_takedown(dev); mutex_unlock(&dev->struct_mutex); dev->sigdata.lock = NULL; dev->context_flag = 0; dev->last_context = 0; dev->if_version = 0; DRM_DEBUG("lastclose completed\n"); } /* * Take down the DRM device. * * \param dev DRM device structure. * * Frees every resource in \p dev. * * \sa drm_device */ void drm_lastclose(struct drm_device * dev) { DRM_DEBUG("\n"); if (dev->driver->lastclose) dev->driver->lastclose(dev); DRM_DEBUG("driver lastclose completed\n"); if (!drm_core_check_feature(dev, DRIVER_MODESET)) drm_legacy_dev_reinit(dev); } /** * drm_release - release method for DRM file * @inode: device inode * @filp: file pointer. * * This function must be used by drivers as their .release() #file_operations * method. It frees any resources associated with the open file, and if this is * the last open file for the DRM device also proceeds to call drm_lastclose(). * * RETURNS: * * Always succeeds and returns 0. */ int drm_release(struct inode *inode, struct file *filp) { struct drm_file *file_priv = filp->private_data; struct drm_minor *minor = file_priv->minor; struct drm_device *dev = minor->dev; mutex_lock(&drm_global_mutex); DRM_DEBUG("open_count = %d\n", dev->open_count); mutex_lock(&dev->filelist_mutex); list_del(&file_priv->lhead); mutex_unlock(&dev->filelist_mutex); mutex_lock(&dev->struct_mutex); if (file_priv->magic) idr_remove(&file_priv->master->magic_map, file_priv->magic); mutex_unlock(&dev->struct_mutex); if (dev->driver->preclose) dev->driver->preclose(dev, file_priv); /* ======================================================== * Begin inline drm_release */ DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n", task_pid_nr(current), (long)old_encode_dev(file_priv->minor->kdev->devt), dev->open_count); /* if the master has gone away we can't do anything with the lock */ if (file_priv->minor->master) drm_master_release(dev, filp); if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) drm_legacy_reclaim_buffers(dev, file_priv); drm_events_release(file_priv); if (drm_core_check_feature(dev, DRIVER_MODESET)) { drm_fb_release(file_priv); drm_property_destroy_user_blobs(dev, file_priv); } if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_release(dev, file_priv); drm_legacy_ctxbitmap_flush(dev, file_priv); mutex_lock(&dev->master_mutex); if (file_priv->is_master) { struct drm_master *master = file_priv->master; /* * Since the master is disappearing, so is the * possibility to lock. */ mutex_lock(&dev->struct_mutex); if (master->lock.hw_lock) { if (dev->sigdata.lock == master->lock.hw_lock) dev->sigdata.lock = NULL; master->lock.hw_lock = NULL; master->lock.file_priv = NULL; wake_up_interruptible_all(&master->lock.lock_queue); } mutex_unlock(&dev->struct_mutex); if (file_priv->minor->master == file_priv->master) { /* drop the reference held my the minor */ if (dev->driver->master_drop) dev->driver->master_drop(dev, file_priv, true); drm_master_put(&file_priv->minor->master); } } /* drop the master reference held by the file priv */ if (file_priv->master) drm_master_put(&file_priv->master); file_priv->is_master = 0; mutex_unlock(&dev->master_mutex); if (dev->driver->postclose) dev->driver->postclose(dev, file_priv); if (drm_core_check_feature(dev, DRIVER_PRIME)) drm_prime_destroy_file_private(&file_priv->prime); WARN_ON(!list_empty(&file_priv->event_list)); put_pid(file_priv->pid); kfree(file_priv); /* ======================================================== * End inline drm_release */ if (!--dev->open_count) { drm_lastclose(dev); if (drm_device_is_unplugged(dev)) drm_put_dev(dev); } mutex_unlock(&drm_global_mutex); drm_minor_release(minor); return 0; } EXPORT_SYMBOL(drm_release); /** * drm_read - read method for DRM file * @filp: file pointer * @buffer: userspace destination pointer for the read * @count: count in bytes to read * @offset: offset to read * * This function must be used by drivers as their .read() #file_operations * method iff they use DRM events for asynchronous signalling to userspace. * Since events are used by the KMS API for vblank and page flip completion this * means all modern display drivers must use it. * * @offset is ignore, DRM events are read like a pipe. Therefore drivers also * must set the .llseek() #file_operation to no_llseek(). Polling support is * provided by drm_poll(). * * This function will only ever read a full event. Therefore userspace must * supply a big enough buffer to fit any event to ensure forward progress. Since * the maximum event space is currently 4K it's recommended to just use that for * safety. * * RETURNS: * * Number of bytes read (always aligned to full events, and can be 0) or a * negative error code on failure. */ ssize_t drm_read(struct file *filp, char __user *buffer, size_t count, loff_t *offset) { struct drm_file *file_priv = filp->private_data; struct drm_device *dev = file_priv->minor->dev; ssize_t ret; if (!access_ok(VERIFY_WRITE, buffer, count)) return -EFAULT; ret = mutex_lock_interruptible(&file_priv->event_read_lock); if (ret) return ret; for (;;) { struct drm_pending_event *e = NULL; spin_lock_irq(&dev->event_lock); if (!list_empty(&file_priv->event_list)) { e = list_first_entry(&file_priv->event_list, struct drm_pending_event, link); file_priv->event_space += e->event->length; list_del(&e->link); } spin_unlock_irq(&dev->event_lock); if (e == NULL) { if (ret) break; if (filp->f_flags & O_NONBLOCK) { ret = -EAGAIN; break; } mutex_unlock(&file_priv->event_read_lock); ret = wait_event_interruptible(file_priv->event_wait, !list_empty(&file_priv->event_list)); if (ret >= 0) ret = mutex_lock_interruptible(&file_priv->event_read_lock); if (ret) return ret; } else { unsigned length = e->event->length; if (length > count - ret) { put_back_event: spin_lock_irq(&dev->event_lock); file_priv->event_space -= length; list_add(&e->link, &file_priv->event_list); spin_unlock_irq(&dev->event_lock); break; } if (copy_to_user(buffer + ret, e->event, length)) { if (ret == 0) ret = -EFAULT; goto put_back_event; } ret += length; kfree(e); } } mutex_unlock(&file_priv->event_read_lock); return ret; } EXPORT_SYMBOL(drm_read); /** * drm_poll - poll method for DRM file * @filp: file pointer * @wait: poll waiter table * * This function must be used by drivers as their .read() #file_operations * method iff they use DRM events for asynchronous signalling to userspace. * Since events are used by the KMS API for vblank and page flip completion this * means all modern display drivers must use it. * * See also drm_read(). * * RETURNS: * * Mask of POLL flags indicating the current status of the file. */ unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait) { struct drm_file *file_priv = filp->private_data; unsigned int mask = 0; poll_wait(filp, &file_priv->event_wait, wait); if (!list_empty(&file_priv->event_list)) mask |= POLLIN | POLLRDNORM; return mask; } EXPORT_SYMBOL(drm_poll); /** * drm_event_reserve_init_locked - init a DRM event and reserve space for it * @dev: DRM device * @file_priv: DRM file private data * @p: tracking structure for the pending event * @e: actual event data to deliver to userspace * * This function prepares the passed in event for eventual delivery. If the event * doesn't get delivered (because the IOCTL fails later on, before queuing up * anything) then the even must be cancelled and freed using * drm_event_cancel_free(). Successfully initialized events should be sent out * using drm_send_event() or drm_send_event_locked() to signal completion of the * asynchronous event to userspace. * * If callers embedded @p into a larger structure it must be allocated with * kmalloc and @p must be the first member element. * * This is the locked version of drm_event_reserve_init() for callers which * already hold dev->event_lock. * * RETURNS: * * 0 on success or a negative error code on failure. */ int drm_event_reserve_init_locked(struct drm_device *dev, struct drm_file *file_priv, struct drm_pending_event *p, struct drm_event *e) { if (file_priv->event_space < e->length) return -ENOMEM; file_priv->event_space -= e->length; p->event = e; list_add(&p->pending_link, &file_priv->pending_event_list); p->file_priv = file_priv; return 0; } EXPORT_SYMBOL(drm_event_reserve_init_locked); /** * drm_event_reserve_init - init a DRM event and reserve space for it * @dev: DRM device * @file_priv: DRM file private data * @p: tracking structure for the pending event * @e: actual event data to deliver to userspace * * This function prepares the passed in event for eventual delivery. If the event * doesn't get delivered (because the IOCTL fails later on, before queuing up * anything) then the even must be cancelled and freed using * drm_event_cancel_free(). Successfully initialized events should be sent out * using drm_send_event() or drm_send_event_locked() to signal completion of the * asynchronous event to userspace. * * If callers embedded @p into a larger structure it must be allocated with * kmalloc and @p must be the first member element. * * Callers which already hold dev->event_lock should use * drm_event_reserve_init() instead. * * RETURNS: * * 0 on success or a negative error code on failure. */ int drm_event_reserve_init(struct drm_device *dev, struct drm_file *file_priv, struct drm_pending_event *p, struct drm_event *e) { unsigned long flags; int ret; spin_lock_irqsave(&dev->event_lock, flags); ret = drm_event_reserve_init_locked(dev, file_priv, p, e); spin_unlock_irqrestore(&dev->event_lock, flags); return ret; } EXPORT_SYMBOL(drm_event_reserve_init); /** * drm_event_cancel_free - free a DRM event and release it's space * @dev: DRM device * @p: tracking structure for the pending event * * This function frees the event @p initialized with drm_event_reserve_init() * and releases any allocated space. */ void drm_event_cancel_free(struct drm_device *dev, struct drm_pending_event *p) { unsigned long flags; spin_lock_irqsave(&dev->event_lock, flags); if (p->file_priv) { p->file_priv->event_space += p->event->length; list_del(&p->pending_link); } spin_unlock_irqrestore(&dev->event_lock, flags); kfree(p); } EXPORT_SYMBOL(drm_event_cancel_free); /** * drm_send_event_locked - send DRM event to file descriptor * @dev: DRM device * @e: DRM event to deliver * * This function sends the event @e, initialized with drm_event_reserve_init(), * to its associated userspace DRM file. Callers must already hold * dev->event_lock, see drm_send_event() for the unlocked version. * * Note that the core will take care of unlinking and disarming events when the * corresponding DRM file is closed. Drivers need not worry about whether the * DRM file for this event still exists and can call this function upon * completion of the asynchronous work unconditionally. */ void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e) { assert_spin_locked(&dev->event_lock); if (e->completion) { /* ->completion might disappear as soon as it signalled. */ complete_all(e->completion); e->completion = NULL; } if (e->fence) { fence_signal(e->fence); fence_put(e->fence); } if (!e->file_priv) { kfree(e); return; } list_del(&e->pending_link); list_add_tail(&e->link, &e->file_priv->event_list); wake_up_interruptible(&e->file_priv->event_wait); } EXPORT_SYMBOL(drm_send_event_locked); /** * drm_send_event - send DRM event to file descriptor * @dev: DRM device * @e: DRM event to deliver * * This function sends the event @e, initialized with drm_event_reserve_init(), * to its associated userspace DRM file. This function acquires dev->event_lock, * see drm_send_event_locked() for callers which already hold this lock. * * Note that the core will take care of unlinking and disarming events when the * corresponding DRM file is closed. Drivers need not worry about whether the * DRM file for this event still exists and can call this function upon * completion of the asynchronous work unconditionally. */ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e) { unsigned long irqflags; spin_lock_irqsave(&dev->event_lock, irqflags); drm_send_event_locked(dev, e); spin_unlock_irqrestore(&dev->event_lock, irqflags); } EXPORT_SYMBOL(drm_send_event);