/* * Copyright © 2008 Intel Corporation * * 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 * THE AUTHORS OR COPYRIGHT HOLDERS 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. * * Authors: * Eric Anholt <eric@anholt.net> * */ /*- * Copyright (c) 2011 The FreeBSD Foundation * All rights reserved. * * This software was developed by Konstantin Belousov under sponsorship from * the FreeBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <linux/types.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/fs.h> #include <linux/file.h> #include <linux/module.h> #include <linux/mman.h> #include <linux/pagemap.h> #include <linux/shmem_fs.h> #include <linux/dma-buf.h> #include <drm/drmP.h> #include <drm/drm_vma_manager.h> #include <drm/drm_gem.h> #include <drm/drm_print.h> #include "drm_internal.h" #ifdef __DragonFly__ struct drm_gem_mm { struct drm_mm offset_manager; /**< Offset mgmt for buffer objects */ struct drm_open_hash offset_hash; /**< User token hash table for maps */ struct unrhdr *idxunr; }; #endif /** @file drm_gem.c * * This file provides some of the base ioctls and library routines for * the graphics memory manager implemented by each device driver. * * Because various devices have different requirements in terms of * synchronization and migration strategies, implementing that is left up to * the driver, and all that the general API provides should be generic -- * allocating objects, reading/writing data with the cpu, freeing objects. * Even there, platform-dependent optimizations for reading/writing data with * the CPU mean we'll likely hook those out to driver-specific calls. However, * the DRI2 implementation wants to have at least allocate/mmap be generic. * * The goal was to have swap-backed object allocation managed through * struct file. However, file descriptors as handles to a struct file have * two major failings: * - Process limits prevent more than 1024 or so being used at a time by * default. * - Inability to allocate high fds will aggravate the X Server's select() * handling, and likely that of many GL client applications as well. * * This led to a plan of using our own integer IDs (called handles, following * DRM terminology) to mimic fds, and implement the fd syscalls we need as * ioctls. The objects themselves will still include the struct file so * that we can transition to fds if the required kernel infrastructure shows * up at a later date, and as our interface with shmfs for memory allocation. */ /* * We make up offsets for buffer objects so we can recognize them at * mmap time. */ /* pgoff in mmap is an unsigned long, so we need to make sure that * the faked up offset will fit */ #if BITS_PER_LONG == 64 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16) #else #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) #endif /** * drm_gem_init - Initialize the GEM device fields * @dev: drm_devic structure to initialize */ int drm_gem_init(struct drm_device *dev) { struct drm_gem_mm *mm; struct drm_vma_offset_manager *vma_offset_manager; lockinit(&dev->object_name_lock, "objnam", 0, LK_CANRECURSE); idr_init(&dev->object_name_idr); mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL); vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL); if (!vma_offset_manager) { DRM_ERROR("out of memory\n"); return -ENOMEM; } dev->mm_private = mm; if (drm_ht_create(&mm->offset_hash, 12)) { kfree(mm); return -ENOMEM; } mm->idxunr = new_unrhdr(0, DRM_GEM_MAX_IDX, NULL); drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START, DRM_FILE_PAGE_OFFSET_SIZE); dev->vma_offset_manager = vma_offset_manager; drm_vma_offset_manager_init(vma_offset_manager, DRM_FILE_PAGE_OFFSET_START, DRM_FILE_PAGE_OFFSET_SIZE); return 0; } void drm_gem_destroy(struct drm_device *dev) { struct drm_gem_mm *mm = dev->mm_private; drm_mm_takedown(&mm->offset_manager); drm_ht_remove(&mm->offset_hash); delete_unrhdr(mm->idxunr); kfree(mm); dev->mm_private = NULL; drm_vma_offset_manager_destroy(dev->vma_offset_manager); kfree(dev->vma_offset_manager); dev->vma_offset_manager = NULL; } /** * drm_gem_object_init - initialize an allocated shmem-backed GEM object * @dev: drm_device the object should be initialized for * @obj: drm_gem_object to initialize * @size: object size * * Initialize an already allocated GEM object of the specified size with * shmfs backing store. */ int drm_gem_object_init(struct drm_device *dev, struct drm_gem_object *obj, size_t size) { struct vm_object *filp; drm_gem_private_object_init(dev, obj, size); filp = default_pager_alloc(NULL, size, VM_PROT_READ | VM_PROT_WRITE, 0); obj->filp = filp; return 0; } EXPORT_SYMBOL(drm_gem_object_init); /** * drm_gem_private_object_init - initialize an allocated private GEM object * @dev: drm_device the object should be initialized for * @obj: drm_gem_object to initialize * @size: object size * * Initialize an already allocated GEM object of the specified size with * no GEM provided backing store. Instead the caller is responsible for * backing the object and handling it. */ void drm_gem_private_object_init(struct drm_device *dev, struct drm_gem_object *obj, size_t size) { BUG_ON((size & (PAGE_SIZE - 1)) != 0); obj->dev = dev; obj->filp = NULL; kref_init(&obj->refcount); obj->handle_count = 0; obj->size = size; drm_vma_node_reset(&obj->vma_node); } EXPORT_SYMBOL(drm_gem_private_object_init); static void drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp) { /* * Note: obj->dma_buf can't disappear as long as we still hold a * handle reference in obj->handle_count. */ mutex_lock(&filp->prime.lock); if (obj->dma_buf) { drm_prime_remove_buf_handle_locked(&filp->prime, obj->dma_buf); } mutex_unlock(&filp->prime.lock); } /** * drm_gem_object_handle_free - release resources bound to userspace handles * @obj: GEM object to clean up. * * Called after the last handle to the object has been closed * * Removes any name for the object. Note that this must be * called before drm_gem_object_free or we'll be touching * freed memory */ static void drm_gem_object_handle_free(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; /* Remove any name for this object */ if (obj->name) { idr_remove(&dev->object_name_idr, obj->name); obj->name = 0; } } static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) { /* Unbreak the reference cycle if we have an exported dma_buf. */ if (obj->dma_buf) { dma_buf_put(obj->dma_buf); obj->dma_buf = NULL; } } static void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; bool final = false; if (WARN_ON(obj->handle_count == 0)) return; /* * Must bump handle count first as this may be the last * ref, in which case the object would disappear before we * checked for a name */ mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { drm_gem_object_handle_free(obj); drm_gem_object_exported_dma_buf_free(obj); final = true; } mutex_unlock(&dev->object_name_lock); if (final) drm_gem_object_put_unlocked(obj); } /* * Called at device or object close to release the file's * handle references on objects. */ static int drm_gem_object_release_handle(int id, void *ptr, void *data) { struct drm_file *file_priv = data; struct drm_gem_object *obj = ptr; struct drm_device *dev = obj->dev; if (dev->driver->gem_close_object) dev->driver->gem_close_object(obj, file_priv); if (drm_core_check_feature(dev, DRIVER_PRIME)) drm_gem_remove_prime_handles(obj, file_priv); drm_vma_node_revoke(&obj->vma_node, file_priv); drm_gem_object_handle_put_unlocked(obj); return 0; } /** * drm_gem_handle_delete - deletes the given file-private handle * @filp: drm file-private structure to use for the handle look up * @handle: userspace handle to delete * * Removes the GEM handle from the @filp lookup table which has been added with * drm_gem_handle_create(). If this is the last handle also cleans up linked * resources like GEM names. */ int drm_gem_handle_delete(struct drm_file *filp, u32 handle) { struct drm_gem_object *obj; /* This is gross. The idr system doesn't let us try a delete and * return an error code. It just spews if you fail at deleting. * So, we have to grab a lock around finding the object and then * doing the delete on it and dropping the refcount, or the user * could race us to double-decrement the refcount and cause a * use-after-free later. Given the frequency of our handle lookups, * we may want to use ida for number allocation and a hash table * for the pointers, anyway. */ lockmgr(&filp->table_lock, LK_EXCLUSIVE); /* Check if we currently have a reference on the object */ obj = idr_replace(&filp->object_idr, NULL, handle); lockmgr(&filp->table_lock, LK_RELEASE); if (IS_ERR_OR_NULL(obj)) return -EINVAL; /* Release driver's reference and decrement refcount. */ drm_gem_object_release_handle(handle, obj, filp); /* And finally make the handle available for future allocations. */ lockmgr(&filp->table_lock, LK_EXCLUSIVE); idr_remove(&filp->object_idr, handle); lockmgr(&filp->table_lock, LK_RELEASE); return 0; } EXPORT_SYMBOL(drm_gem_handle_delete); /** * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object * @file: drm file-private structure containing the gem object * @dev: corresponding drm_device * @handle: gem object handle * @offset: return location for the fake mmap offset * * This implements the &drm_driver.dumb_map_offset kms driver callback for * drivers which use gem to manage their backing storage. * * Returns: * 0 on success or a negative error code on failure. */ int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev, u32 handle, u64 *offset) { struct drm_gem_object *obj; int ret; obj = drm_gem_object_lookup(file, handle); if (!obj) return -ENOENT; /* Don't allow imported objects to be mapped */ if (obj->import_attach) { ret = -EINVAL; goto out; } ret = drm_gem_create_mmap_offset(obj); if (ret) goto out; *offset = drm_vma_node_offset_addr(&obj->vma_node); out: drm_gem_object_put_unlocked(obj); return ret; } EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset); /** * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers * @file: drm file-private structure to remove the dumb handle from * @dev: corresponding drm_device * @handle: the dumb handle to remove * * This implements the &drm_driver.dumb_destroy kms driver callback for drivers * which use gem to manage their backing storage. */ int drm_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev, uint32_t handle) { return drm_gem_handle_delete(file, handle); } EXPORT_SYMBOL(drm_gem_dumb_destroy); /** * drm_gem_handle_create_tail - internal functions to create a handle * @file_priv: drm file-private structure to register the handle for * @obj: object to register * @handlep: pointer to return the created handle to the caller * * This expects the &drm_device.object_name_lock to be held already and will * drop it before returning. Used to avoid races in establishing new handles * when importing an object from either an flink name or a dma-buf. * * Handles must be release again through drm_gem_handle_delete(). This is done * when userspace closes @file_priv for all attached handles, or through the * GEM_CLOSE ioctl for individual handles. */ int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep) { struct drm_device *dev = obj->dev; u32 handle; int ret; WARN_ON(!mutex_is_locked(&dev->object_name_lock)); if (obj->handle_count++ == 0) drm_gem_object_get(obj); /* * Get the user-visible handle using idr. Preload and perform * allocation under our spinlock. */ idr_preload(GFP_KERNEL); lockmgr(&file_priv->table_lock, LK_EXCLUSIVE); ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); lockmgr(&file_priv->table_lock, LK_RELEASE); idr_preload_end(); mutex_unlock(&dev->object_name_lock); if (ret < 0) goto err_unref; handle = ret; ret = drm_vma_node_allow(&obj->vma_node, file_priv); if (ret) goto err_remove; if (dev->driver->gem_open_object) { ret = dev->driver->gem_open_object(obj, file_priv); if (ret) goto err_revoke; } *handlep = handle; return 0; err_revoke: drm_vma_node_revoke(&obj->vma_node, file_priv); err_remove: lockmgr(&file_priv->table_lock, LK_EXCLUSIVE); idr_remove(&file_priv->object_idr, handle); lockmgr(&file_priv->table_lock, LK_RELEASE); err_unref: drm_gem_object_handle_put_unlocked(obj); return ret; } /** * drm_gem_handle_create - create a gem handle for an object * @file_priv: drm file-private structure to register the handle for * @obj: object to register * @handlep: pionter to return the created handle to the caller * * Create a handle for this object. This adds a handle reference to the object, * which includes a regular reference count. Callers will likely want to * dereference the object afterwards. * * Since this publishes @obj to userspace it must be fully set up by this point, * drivers must call this last in their buffer object creation callbacks. */ int drm_gem_handle_create(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep) { mutex_lock(&obj->dev->object_name_lock); return drm_gem_handle_create_tail(file_priv, obj, handlep); } EXPORT_SYMBOL(drm_gem_handle_create); /** * drm_gem_free_mmap_offset - release a fake mmap offset for an object * @obj: obj in question * * This routine frees fake offsets allocated by drm_gem_create_mmap_offset(). * * Note that drm_gem_object_release() already calls this function, so drivers * don't have to take care of releasing the mmap offset themselves when freeing * the GEM object. */ void drm_gem_free_mmap_offset(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; struct drm_gem_mm *mm = dev->mm_private; struct drm_hash_item *list; if (!obj->on_map) return; list = &obj->map_list; drm_ht_remove_item(&mm->offset_hash, list); free_unr(mm->idxunr, list->key); obj->on_map = false; drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node); } EXPORT_SYMBOL(drm_gem_free_mmap_offset); /** * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object * @obj: obj in question * @size: the virtual size * * GEM memory mapping works by handing back to userspace a fake mmap offset * it can use in a subsequent mmap(2) call. The DRM core code then looks * up the object based on the offset and sets up the various memory mapping * structures. * * This routine allocates and attaches a fake offset for @obj, in cases where * the virtual size differs from the physical size (ie. &drm_gem_object.size). * Otherwise just use drm_gem_create_mmap_offset(). * * This function is idempotent and handles an already allocated mmap offset * transparently. Drivers do not need to check for this case. */ int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size) { struct drm_device *dev = obj->dev; struct drm_gem_mm *mm = dev->mm_private; int ret = 0; if (obj->on_map) return (0); obj->map_list.key = alloc_unr(mm->idxunr); ret = drm_ht_insert_item(&mm->offset_hash, &obj->map_list); if (ret != 0) { DRM_ERROR("failed to add to map hash\n"); free_unr(mm->idxunr, obj->map_list.key); return (ret); } obj->on_map = true; return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node, size / PAGE_SIZE); } EXPORT_SYMBOL(drm_gem_create_mmap_offset_size); /** * drm_gem_create_mmap_offset - create a fake mmap offset for an object * @obj: obj in question * * GEM memory mapping works by handing back to userspace a fake mmap offset * it can use in a subsequent mmap(2) call. The DRM core code then looks * up the object based on the offset and sets up the various memory mapping * structures. * * This routine allocates and attaches a fake offset for @obj. * * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release * the fake offset again. */ int drm_gem_create_mmap_offset(struct drm_gem_object *obj) { return drm_gem_create_mmap_offset_size(obj, obj->size); } EXPORT_SYMBOL(drm_gem_create_mmap_offset); /** * drm_gem_object_lookup - look up a GEM object from it's handle * @filp: DRM file private date * @handle: userspace handle * * Returns: * * A reference to the object named by the handle if such exists on @filp, NULL * otherwise. */ struct drm_gem_object * drm_gem_object_lookup(struct drm_file *filp, u32 handle) { struct drm_gem_object *obj; lockmgr(&filp->table_lock, LK_EXCLUSIVE); /* Check if we currently have a reference on the object */ obj = idr_find(&filp->object_idr, handle); if (obj) drm_gem_object_get(obj); lockmgr(&filp->table_lock, LK_RELEASE); return obj; } EXPORT_SYMBOL(drm_gem_object_lookup); /** * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl * @dev: drm_device * @data: ioctl data * @file_priv: drm file-private structure * * Releases the handle to an mm object. */ int drm_gem_close_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_gem_close *args = data; int ret; if (!drm_core_check_feature(dev, DRIVER_GEM)) return -EOPNOTSUPP; ret = drm_gem_handle_delete(file_priv, args->handle); return ret; } /** * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl * @dev: drm_device * @data: ioctl data * @file_priv: drm file-private structure * * Create a global name for an object, returning the name. * * Note that the name does not hold a reference; when the object * is freed, the name goes away. */ int drm_gem_flink_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_gem_flink *args = data; struct drm_gem_object *obj; int ret; if (!drm_core_check_feature(dev, DRIVER_GEM)) return -EOPNOTSUPP; obj = drm_gem_object_lookup(file_priv, args->handle); if (obj == NULL) return -ENOENT; mutex_lock(&dev->object_name_lock); /* prevent races with concurrent gem_close. */ if (obj->handle_count == 0) { ret = -ENOENT; goto err; } if (!obj->name) { ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL); if (ret < 0) goto err; obj->name = ret; } args->name = (uint64_t) obj->name; ret = 0; err: mutex_unlock(&dev->object_name_lock); drm_gem_object_put_unlocked(obj); return ret; } /** * drm_gem_open - implementation of the GEM_OPEN ioctl * @dev: drm_device * @data: ioctl data * @file_priv: drm file-private structure * * Open an object using the global name, returning a handle and the size. * * This handle (of course) holds a reference to the object, so the object * will not go away until the handle is deleted. */ int drm_gem_open_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_gem_open *args = data; struct drm_gem_object *obj; int ret; u32 handle; if (!drm_core_check_feature(dev, DRIVER_GEM)) return -EOPNOTSUPP; mutex_lock(&dev->object_name_lock); obj = idr_find(&dev->object_name_idr, (int) args->name); if (obj) { drm_gem_object_get(obj); } else { mutex_unlock(&dev->object_name_lock); return -ENOENT; } /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */ ret = drm_gem_handle_create_tail(file_priv, obj, &handle); drm_gem_object_put_unlocked(obj); if (ret) return ret; args->handle = handle; args->size = obj->size; return 0; } /** * gem_gem_open - initalizes GEM file-private structures at devnode open time * @dev: drm_device which is being opened by userspace * @file_private: drm file-private structure to set up * * Called at device open time, sets up the structure for handling refcounting * of mm objects. */ void drm_gem_open(struct drm_device *dev, struct drm_file *file_private) { idr_init(&file_private->object_idr); lockinit(&file_private->table_lock, "fptab", 0, 0); } /** * drm_gem_release - release file-private GEM resources * @dev: drm_device which is being closed by userspace * @file_private: drm file-private structure to clean up * * Called at close time when the filp is going away. * * Releases any remaining references on objects by this filp. */ void drm_gem_release(struct drm_device *dev, struct drm_file *file_private) { idr_for_each(&file_private->object_idr, &drm_gem_object_release_handle, file_private); idr_destroy(&file_private->object_idr); } /** * drm_gem_object_release - release GEM buffer object resources * @obj: GEM buffer object * * This releases any structures and resources used by @obj and is the invers of * drm_gem_object_init(). */ void drm_gem_object_release(struct drm_gem_object *obj) { WARN_ON(obj->dma_buf); /* * obj->vm_obj can be NULL for private gem objects. */ vm_object_deallocate(obj->filp); drm_gem_free_mmap_offset(obj); } EXPORT_SYMBOL(drm_gem_object_release); /** * drm_gem_object_free - free a GEM object * @kref: kref of the object to free * * Called after the last reference to the object has been lost. * Must be called holding &drm_device.struct_mutex. * * Frees the object */ void drm_gem_object_free(struct kref *kref) { struct drm_gem_object *obj = container_of(kref, struct drm_gem_object, refcount); struct drm_device *dev = obj->dev; if (dev->driver->gem_free_object_unlocked) { dev->driver->gem_free_object_unlocked(obj); } else if (dev->driver->gem_free_object) { WARN_ON(!mutex_is_locked(&dev->struct_mutex)); dev->driver->gem_free_object(obj); } } EXPORT_SYMBOL(drm_gem_object_free); /** * drm_gem_object_put_unlocked - drop a GEM buffer object reference * @obj: GEM buffer object * * This releases a reference to @obj. Callers must not hold the * &drm_device.struct_mutex lock when calling this function. * * See also __drm_gem_object_put(). */ void drm_gem_object_put_unlocked(struct drm_gem_object *obj) { struct drm_device *dev; if (!obj) return; dev = obj->dev; might_lock(&dev->struct_mutex); if (dev->driver->gem_free_object_unlocked) kref_put(&obj->refcount, drm_gem_object_free); else if (kref_put_mutex(&obj->refcount, drm_gem_object_free, &dev->struct_mutex)) mutex_unlock(&dev->struct_mutex); } EXPORT_SYMBOL(drm_gem_object_put_unlocked); /** * drm_gem_object_put - release a GEM buffer object reference * @obj: GEM buffer object * * This releases a reference to @obj. Callers must hold the * &drm_device.struct_mutex lock when calling this function, even when the * driver doesn't use &drm_device.struct_mutex for anything. * * For drivers not encumbered with legacy locking use * drm_gem_object_put_unlocked() instead. */ void drm_gem_object_put(struct drm_gem_object *obj) { if (obj) { WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex)); kref_put(&obj->refcount, drm_gem_object_free); } } EXPORT_SYMBOL(drm_gem_object_put); /** * drm_gem_vm_open - vma->ops->open implementation for GEM * @vma: VM area structure * * This function implements the #vm_operations_struct open() callback for GEM * drivers. This must be used together with drm_gem_vm_close(). */ void drm_gem_vm_open(struct vm_area_struct *vma) { struct drm_gem_object *obj = vma->vm_private_data; drm_gem_object_get(obj); } EXPORT_SYMBOL(drm_gem_vm_open); /** * drm_gem_vm_close - vma->ops->close implementation for GEM * @vma: VM area structure * * This function implements the #vm_operations_struct close() callback for GEM * drivers. This must be used together with drm_gem_vm_open(). */ void drm_gem_vm_close(struct vm_area_struct *vma) { struct drm_gem_object *obj = vma->vm_private_data; drm_gem_object_put_unlocked(obj); } EXPORT_SYMBOL(drm_gem_vm_close); #if 0 /** * drm_gem_mmap_obj - memory map a GEM object * @obj: the GEM object to map * @obj_size: the object size to be mapped, in bytes * @vma: VMA for the area to be mapped * * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops * provided by the driver. Depending on their requirements, drivers can either * provide a fault handler in their gem_vm_ops (in which case any accesses to * the object will be trapped, to perform migration, GTT binding, surface * register allocation, or performance monitoring), or mmap the buffer memory * synchronously after calling drm_gem_mmap_obj. * * This function is mainly intended to implement the DMABUF mmap operation, when * the GEM object is not looked up based on its fake offset. To implement the * DRM mmap operation, drivers should use the drm_gem_mmap() function. * * drm_gem_mmap_obj() assumes the user is granted access to the buffer while * drm_gem_mmap() prevents unprivileged users from mapping random objects. So * callers must verify access restrictions before calling this helper. * * Return 0 or success or -EINVAL if the object size is smaller than the VMA * size, or if no gem_vm_ops are provided. */ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, struct vm_area_struct *vma) { struct drm_device *dev = obj->dev; /* Check for valid size. */ if (obj_size < vma->vm_end - vma->vm_start) return -EINVAL; if (!dev->driver->gem_vm_ops) return -EINVAL; vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_ops = dev->driver->gem_vm_ops; vma->vm_private_data = obj; vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); /* Take a ref for this mapping of the object, so that the fault * handler can dereference the mmap offset's pointer to the object. * This reference is cleaned up by the corresponding vm_close * (which should happen whether the vma was created by this call, or * by a vm_open due to mremap or partial unmap or whatever). */ drm_gem_object_get(obj); return 0; } EXPORT_SYMBOL(drm_gem_mmap_obj); /** * drm_gem_mmap - memory map routine for GEM objects * @filp: DRM file pointer * @vma: VMA for the area to be mapped * * If a driver supports GEM object mapping, mmap calls on the DRM file * descriptor will end up here. * * Look up the GEM object based on the offset passed in (vma->vm_pgoff will * contain the fake offset we created when the GTT map ioctl was called on * the object) and map it with a call to drm_gem_mmap_obj(). * * If the caller is not granted access to the buffer object, the mmap will fail * with EACCES. Please see the vma manager for more information. */ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) { struct drm_file *priv = filp->private_data; struct drm_device *dev = priv->minor->dev; struct drm_gem_object *obj = NULL; struct drm_vma_offset_node *node; int ret; if (drm_dev_is_unplugged(dev)) return -ENODEV; drm_vma_offset_lock_lookup(dev->vma_offset_manager); node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager, vma->vm_pgoff, vma_pages(vma)); if (likely(node)) { obj = container_of(node, struct drm_gem_object, vma_node); /* * When the object is being freed, after it hits 0-refcnt it * proceeds to tear down the object. In the process it will * attempt to remove the VMA offset and so acquire this * mgr->vm_lock. Therefore if we find an object with a 0-refcnt * that matches our range, we know it is in the process of being * destroyed and will be freed as soon as we release the lock - * so we have to check for the 0-refcnted object and treat it as * invalid. */ if (!kref_get_unless_zero(&obj->refcount)) obj = NULL; } drm_vma_offset_unlock_lookup(dev->vma_offset_manager); if (!obj) return -EINVAL; if (!drm_vma_node_is_allowed(node, priv)) { drm_gem_object_put_unlocked(obj); return -EACCES; } if (node->readonly) { if (vma->vm_flags & VM_WRITE) { drm_gem_object_put_unlocked(obj); return -EINVAL; } vma->vm_flags &= ~VM_MAYWRITE; } ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, vma); drm_gem_object_put_unlocked(obj); return ret; } EXPORT_SYMBOL(drm_gem_mmap); #endif void drm_gem_print_info(struct drm_printer *p, unsigned int indent, const struct drm_gem_object *obj) { #ifdef __DragonFly__ drm_printf_indent(p, indent, "gem_obj=%p\n", obj); #endif drm_printf_indent(p, indent, "name=%d\n", obj->name); drm_printf_indent(p, indent, "refcount=%u\n", kref_read(&obj->refcount)); drm_printf_indent(p, indent, "start=%08lx\n", drm_vma_node_start(&obj->vma_node)); drm_printf_indent(p, indent, "size=%zu\n", obj->size); drm_printf_indent(p, indent, "imported=%s\n", obj->import_attach ? "yes" : "no"); if (obj->dev->driver->gem_print_info) obj->dev->driver->gem_print_info(p, indent, obj); } #ifdef __DragonFly__ static struct drm_gem_object * drm_gem_object_from_offset(struct drm_device *dev, vm_ooffset_t offset) { struct drm_gem_object *obj; struct drm_gem_mm *mm = dev->mm_private; struct drm_hash_item *hash; if ((offset & DRM_GEM_MAPPING_MASK) != DRM_GEM_MAPPING_KEY) return (NULL); offset &= ~DRM_GEM_MAPPING_KEY; if (drm_ht_find_item(&mm->offset_hash, DRM_GEM_MAPPING_IDX(offset), &hash) != 0) { return (NULL); } obj = container_of(hash, struct drm_gem_object, map_list); return (obj); } int drm_gem_mmap_single(struct drm_device *dev, vm_ooffset_t *offset, vm_size_t size, struct vm_object **obj_res, int nprot) { struct drm_gem_object *gem_obj; struct vm_object *vm_obj; DRM_LOCK(dev); gem_obj = drm_gem_object_from_offset(dev, *offset); DRM_DEBUG("gem_obj=%p, offset=0x%lx\n", gem_obj, *offset); if (gem_obj == NULL) { DRM_UNLOCK(dev); return (ENODEV); } drm_gem_object_reference(gem_obj); DRM_UNLOCK(dev); vm_obj = cdev_pager_allocate(gem_obj, OBJT_MGTDEVICE, dev->driver->gem_vm_ops, size, nprot, DRM_GEM_MAPPING_MAPOFF(*offset), curthread->td_ucred); if (vm_obj == NULL) { drm_gem_object_unreference_unlocked(gem_obj); return (EINVAL); } *offset = DRM_GEM_MAPPING_MAPOFF(*offset); *obj_res = vm_obj; return (0); } #endif
