/* * \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 #include #include #include #include #include "drm_crtc_internal.h" #include "drm_internal.h" #include "drm_legacy.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 resulting &struct file_operations must be * stored in the &drm_driver.fops field. The mandatory functions are drm_open(), * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no * need to sprinkle #ifdef into the code. Drivers which implement private ioctls * that require 32/64 bit compatibility support must provide their own * &file_operations.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. * * For the driver-side event interface see drm_event_reserve_init() and * drm_send_event() as the main starting points. * * 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(), and * for drivers which use the CMA GEM helpers it's drm_gem_cma_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, * .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n * .poll = drm_poll, * .read = drm_read, * .llseek = no_llseek, * .mmap = drm_gem_mmap, * }; * * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for * CMA based drivers there is the DEFINE_DRM_GEM_CMA_FOPS() macro to make this * simpler. * * The driver's &file_operations must be stored in &drm_driver.fops. * * For driver-private IOCTL handling see the more detailed discussion in * :ref:`IOCTL support in the userland interfaces chapter`. */ /** * drm_file_alloc - allocate file context * @minor: minor to allocate on * * This allocates a new DRM file context. It is not linked into any context and * can be used by the caller freely. Note that the context keeps a pointer to * @minor, so it must be freed before @minor is. * * RETURNS: * Pointer to newly allocated context, ERR_PTR on failure. */ struct drm_file *drm_file_alloc(struct drm_minor *minor) { struct drm_device *dev = minor->dev; struct drm_file *file; int ret; file = kzalloc(sizeof(*file), GFP_KERNEL); if (!file) return ERR_PTR(-ENOMEM); file->pid = get_pid(task_pid(current)); file->minor = minor; /* for compatibility root is always authenticated */ file->authenticated = capable(CAP_SYS_ADMIN); INIT_LIST_HEAD(&file->lhead); INIT_LIST_HEAD(&file->fbs); mutex_init(&file->fbs_lock); INIT_LIST_HEAD(&file->blobs); INIT_LIST_HEAD(&file->pending_event_list); INIT_LIST_HEAD(&file->event_list); init_waitqueue_head(&file->event_wait); file->event_space = 4096; /* set aside 4k for event buffer */ mutex_init(&file->event_read_lock); if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_open(dev, file); if (drm_core_check_feature(dev, DRIVER_SYNCOBJ)) drm_syncobj_open(file); drm_prime_init_file_private(&file->prime); if (dev->driver->open) { ret = dev->driver->open(dev, file); if (ret < 0) goto out_prime_destroy; } return file; out_prime_destroy: drm_prime_destroy_file_private(&file->prime); if (drm_core_check_feature(dev, DRIVER_SYNCOBJ)) drm_syncobj_release(file); if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_release(dev, file); put_pid(file->pid); kfree(file); return ERR_PTR(ret); } 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_file_free - free file context * @file: context to free, or NULL * * This destroys and deallocates a DRM file context previously allocated via * drm_file_alloc(). The caller must make sure to unlink it from any contexts * before calling this. * * If NULL is passed, this is a no-op. * * RETURNS: * 0 on success, or error code on failure. */ void drm_file_free(struct drm_file *file) { struct drm_device *dev; if (!file) return; dev = file->minor->dev; DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n", task_pid_nr(current), (long)old_encode_dev(file->minor->kdev->devt), dev->open_count); if (drm_core_check_feature(dev, DRIVER_LEGACY) && dev->driver->preclose) dev->driver->preclose(dev, file); if (drm_core_check_feature(dev, DRIVER_LEGACY)) drm_legacy_lock_release(dev, file->filp); if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) drm_legacy_reclaim_buffers(dev, file); drm_events_release(file); if (drm_core_check_feature(dev, DRIVER_MODESET)) { drm_fb_release(file); drm_property_destroy_user_blobs(dev, file); } if (drm_core_check_feature(dev, DRIVER_SYNCOBJ)) drm_syncobj_release(file); if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_release(dev, file); drm_legacy_ctxbitmap_flush(dev, file); if (drm_is_primary_client(file)) drm_master_release(file); if (dev->driver->postclose) dev->driver->postclose(dev, file); drm_prime_destroy_file_private(&file->prime); WARN_ON(!list_empty(&file->event_list)); put_pid(file->pid); kfree(file); } static void drm_close_helper(struct file *filp) { struct drm_file *file_priv = filp->private_data; struct drm_device *dev = file_priv->minor->dev; mutex_lock(&dev->filelist_mutex); list_del(&file_priv->lhead); mutex_unlock(&dev->filelist_mutex); drm_file_free(file_priv); } /* * 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; } /* * Called whenever a process opens a drm node * * \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 = drm_file_alloc(minor); if (IS_ERR(priv)) return PTR_ERR(priv); if (drm_is_primary_client(priv)) { ret = drm_master_open(priv); if (ret) { drm_file_free(priv); return ret; } } filp->private_data = priv; filp->f_mode |= FMODE_UNSIGNED_OFFSET; priv->filp = filp; 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; } /** * drm_open - open method for DRM file * @inode: device inode * @filp: file pointer. * * This function must be used by drivers as their &file_operations.open method. * It looks up the correct DRM device and instantiates all the per-file * resources for it. It also calls the &drm_driver.open driver callback. * * 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_legacy_setup(dev); if (retcode) { drm_close_helper(filp); goto err_undo; } } return 0; err_undo: dev->open_count--; drm_minor_release(minor); return retcode; } EXPORT_SYMBOL(drm_open); 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_LEGACY)) drm_legacy_dev_reinit(dev); drm_client_dev_restore(dev); } /** * drm_release - release method for DRM file * @inode: device inode * @filp: file pointer. * * This function must be used by drivers as their &file_operations.release * method. It frees any resources associated with the open file, and calls the * &drm_driver.postclose driver callback. If this is the last open file for the * DRM device also proceeds to call the &drm_driver.lastclose driver callback. * * 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); drm_close_helper(filp); if (!--dev->open_count) drm_lastclose(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 &file_operations.read * 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 ignored, DRM events are read like a pipe. Therefore drivers also * must set the &file_operation.llseek 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(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); wake_up_interruptible(&file_priv->event_wait); 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 &file_operations.read 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. */ __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait) { struct drm_file *file_priv = filp->private_data; __poll_t mask = 0; poll_wait(filp, &file_priv->event_wait, wait); if (!list_empty(&file_priv->event_list)) mask |= EPOLLIN | EPOLLRDNORM; 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 &drm_device.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 &drm_device.event_lock should use * drm_event_reserve_init_locked() 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 its 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. It is used to cancel an event when the * nonblocking operation could not be submitted and needed to be aborted. */ 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); if (p->fence) dma_fence_put(p->fence); 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 * &drm_device.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) { complete_all(e->completion); e->completion_release(e->completion); e->completion = NULL; } if (e->fence) { dma_fence_signal(e->fence); dma_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 * &drm_device.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);