| /* |
| * 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> |
| * |
| */ |
| |
| #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 "drmP.h" |
| |
| /** @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 |
| |
| /** |
| * Initialize the GEM device fields |
| */ |
| |
| int |
| drm_gem_init(struct drm_device *dev) |
| { |
| struct drm_gem_mm *mm; |
| |
| spin_lock_init(&dev->object_name_lock); |
| idr_init(&dev->object_name_idr); |
| |
| mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL); |
| if (!mm) { |
| DRM_ERROR("out of memory\n"); |
| return -ENOMEM; |
| } |
| |
| dev->mm_private = mm; |
| |
| if (drm_ht_create(&mm->offset_hash, 12)) { |
| kfree(mm); |
| return -ENOMEM; |
| } |
| |
| if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START, |
| DRM_FILE_PAGE_OFFSET_SIZE)) { |
| drm_ht_remove(&mm->offset_hash); |
| kfree(mm); |
| return -ENOMEM; |
| } |
| |
| 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); |
| kfree(mm); |
| dev->mm_private = NULL; |
| } |
| |
| /** |
| * 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) |
| { |
| BUG_ON((size & (PAGE_SIZE - 1)) != 0); |
| |
| obj->dev = dev; |
| obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); |
| if (IS_ERR(obj->filp)) |
| return PTR_ERR(obj->filp); |
| |
| kref_init(&obj->refcount); |
| atomic_set(&obj->handle_count, 0); |
| obj->size = size; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_gem_object_init); |
| |
| /** |
| * 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. |
| */ |
| int 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); |
| atomic_set(&obj->handle_count, 0); |
| obj->size = size; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_gem_private_object_init); |
| |
| /** |
| * Allocate a GEM object of the specified size with shmfs backing store |
| */ |
| struct drm_gem_object * |
| drm_gem_object_alloc(struct drm_device *dev, size_t size) |
| { |
| struct drm_gem_object *obj; |
| |
| obj = kzalloc(sizeof(*obj), GFP_KERNEL); |
| if (!obj) |
| goto free; |
| |
| if (drm_gem_object_init(dev, obj, size) != 0) |
| goto free; |
| |
| if (dev->driver->gem_init_object != NULL && |
| dev->driver->gem_init_object(obj) != 0) { |
| goto fput; |
| } |
| return obj; |
| fput: |
| /* Object_init mangles the global counters - readjust them. */ |
| fput(obj->filp); |
| free: |
| kfree(obj); |
| return NULL; |
| } |
| EXPORT_SYMBOL(drm_gem_object_alloc); |
| |
| /** |
| * Removes the mapping from handle to filp for this object. |
| */ |
| int |
| drm_gem_handle_delete(struct drm_file *filp, u32 handle) |
| { |
| struct drm_device *dev; |
| 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. |
| */ |
| spin_lock(&filp->table_lock); |
| |
| /* Check if we currently have a reference on the object */ |
| obj = idr_find(&filp->object_idr, handle); |
| if (obj == NULL) { |
| spin_unlock(&filp->table_lock); |
| return -EINVAL; |
| } |
| dev = obj->dev; |
| |
| /* Release reference and decrement refcount. */ |
| idr_remove(&filp->object_idr, handle); |
| spin_unlock(&filp->table_lock); |
| |
| if (obj->import_attach) |
| drm_prime_remove_imported_buf_handle(&filp->prime, |
| obj->import_attach->dmabuf); |
| |
| if (dev->driver->gem_close_object) |
| dev->driver->gem_close_object(obj, filp); |
| drm_gem_object_handle_unreference_unlocked(obj); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_gem_handle_delete); |
| |
| /** |
| * 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. |
| */ |
| int |
| drm_gem_handle_create(struct drm_file *file_priv, |
| struct drm_gem_object *obj, |
| u32 *handlep) |
| { |
| struct drm_device *dev = obj->dev; |
| int ret; |
| |
| /* |
| * Get the user-visible handle using idr. |
| */ |
| again: |
| /* ensure there is space available to allocate a handle */ |
| if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0) |
| return -ENOMEM; |
| |
| /* do the allocation under our spinlock */ |
| spin_lock(&file_priv->table_lock); |
| ret = idr_get_new_above(&file_priv->object_idr, obj, 1, (int *)handlep); |
| spin_unlock(&file_priv->table_lock); |
| if (ret == -EAGAIN) |
| goto again; |
| else if (ret) |
| return ret; |
| |
| drm_gem_object_handle_reference(obj); |
| |
| if (dev->driver->gem_open_object) { |
| ret = dev->driver->gem_open_object(obj, file_priv); |
| if (ret) { |
| drm_gem_handle_delete(file_priv, *handlep); |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| 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(). |
| */ |
| 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_map_list *list = &obj->map_list; |
| |
| drm_ht_remove_item(&mm->offset_hash, &list->hash); |
| drm_mm_put_block(list->file_offset_node); |
| kfree(list->map); |
| list->map = NULL; |
| } |
| EXPORT_SYMBOL(drm_gem_free_mmap_offset); |
| |
| /** |
| * 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. |
| */ |
| int |
| drm_gem_create_mmap_offset(struct drm_gem_object *obj) |
| { |
| struct drm_device *dev = obj->dev; |
| struct drm_gem_mm *mm = dev->mm_private; |
| struct drm_map_list *list; |
| struct drm_local_map *map; |
| int ret = 0; |
| |
| /* Set the object up for mmap'ing */ |
| list = &obj->map_list; |
| list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL); |
| if (!list->map) |
| return -ENOMEM; |
| |
| map = list->map; |
| map->type = _DRM_GEM; |
| map->size = obj->size; |
| map->handle = obj; |
| |
| /* Get a DRM GEM mmap offset allocated... */ |
| list->file_offset_node = drm_mm_search_free(&mm->offset_manager, |
| obj->size / PAGE_SIZE, 0, 0); |
| |
| if (!list->file_offset_node) { |
| DRM_ERROR("failed to allocate offset for bo %d\n", obj->name); |
| ret = -ENOSPC; |
| goto out_free_list; |
| } |
| |
| list->file_offset_node = drm_mm_get_block(list->file_offset_node, |
| obj->size / PAGE_SIZE, 0); |
| if (!list->file_offset_node) { |
| ret = -ENOMEM; |
| goto out_free_list; |
| } |
| |
| list->hash.key = list->file_offset_node->start; |
| ret = drm_ht_insert_item(&mm->offset_hash, &list->hash); |
| if (ret) { |
| DRM_ERROR("failed to add to map hash\n"); |
| goto out_free_mm; |
| } |
| |
| return 0; |
| |
| out_free_mm: |
| drm_mm_put_block(list->file_offset_node); |
| out_free_list: |
| kfree(list->map); |
| list->map = NULL; |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_gem_create_mmap_offset); |
| |
| /** Returns a reference to the object named by the handle. */ |
| struct drm_gem_object * |
| drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp, |
| u32 handle) |
| { |
| struct drm_gem_object *obj; |
| |
| spin_lock(&filp->table_lock); |
| |
| /* Check if we currently have a reference on the object */ |
| obj = idr_find(&filp->object_idr, handle); |
| if (obj == NULL) { |
| spin_unlock(&filp->table_lock); |
| return NULL; |
| } |
| |
| drm_gem_object_reference(obj); |
| |
| spin_unlock(&filp->table_lock); |
| |
| return obj; |
| } |
| EXPORT_SYMBOL(drm_gem_object_lookup); |
| |
| /** |
| * 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 (!(dev->driver->driver_features & DRIVER_GEM)) |
| return -ENODEV; |
| |
| ret = drm_gem_handle_delete(file_priv, args->handle); |
| |
| return ret; |
| } |
| |
| /** |
| * 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 (!(dev->driver->driver_features & DRIVER_GEM)) |
| return -ENODEV; |
| |
| obj = drm_gem_object_lookup(dev, file_priv, args->handle); |
| if (obj == NULL) |
| return -ENOENT; |
| |
| again: |
| if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| spin_lock(&dev->object_name_lock); |
| if (!obj->name) { |
| ret = idr_get_new_above(&dev->object_name_idr, obj, 1, |
| &obj->name); |
| args->name = (uint64_t) obj->name; |
| spin_unlock(&dev->object_name_lock); |
| |
| if (ret == -EAGAIN) |
| goto again; |
| else if (ret) |
| goto err; |
| |
| /* Allocate a reference for the name table. */ |
| drm_gem_object_reference(obj); |
| } else { |
| args->name = (uint64_t) obj->name; |
| spin_unlock(&dev->object_name_lock); |
| ret = 0; |
| } |
| |
| err: |
| drm_gem_object_unreference_unlocked(obj); |
| return ret; |
| } |
| |
| /** |
| * 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 (!(dev->driver->driver_features & DRIVER_GEM)) |
| return -ENODEV; |
| |
| spin_lock(&dev->object_name_lock); |
| obj = idr_find(&dev->object_name_idr, (int) args->name); |
| if (obj) |
| drm_gem_object_reference(obj); |
| spin_unlock(&dev->object_name_lock); |
| if (!obj) |
| return -ENOENT; |
| |
| ret = drm_gem_handle_create(file_priv, obj, &handle); |
| drm_gem_object_unreference_unlocked(obj); |
| if (ret) |
| return ret; |
| |
| args->handle = handle; |
| args->size = obj->size; |
| |
| return 0; |
| } |
| |
| /** |
| * 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); |
| spin_lock_init(&file_private->table_lock); |
| } |
| |
| /** |
| * Called at device 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 (obj->import_attach) |
| drm_prime_remove_imported_buf_handle(&file_priv->prime, |
| obj->import_attach->dmabuf); |
| |
| if (dev->driver->gem_close_object) |
| dev->driver->gem_close_object(obj, file_priv); |
| |
| drm_gem_object_handle_unreference_unlocked(obj); |
| |
| return 0; |
| } |
| |
| /** |
| * 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_remove_all(&file_private->object_idr); |
| idr_destroy(&file_private->object_idr); |
| } |
| |
| void |
| drm_gem_object_release(struct drm_gem_object *obj) |
| { |
| if (obj->filp) |
| fput(obj->filp); |
| } |
| EXPORT_SYMBOL(drm_gem_object_release); |
| |
| /** |
| * Called after the last reference to the object has been lost. |
| * Must be called holding struct_ mutex |
| * |
| * Frees the object |
| */ |
| void |
| drm_gem_object_free(struct kref *kref) |
| { |
| struct drm_gem_object *obj = (struct drm_gem_object *) kref; |
| struct drm_device *dev = obj->dev; |
| |
| BUG_ON(!mutex_is_locked(&dev->struct_mutex)); |
| |
| if (dev->driver->gem_free_object != NULL) |
| dev->driver->gem_free_object(obj); |
| } |
| EXPORT_SYMBOL(drm_gem_object_free); |
| |
| static void drm_gem_object_ref_bug(struct kref *list_kref) |
| { |
| BUG(); |
| } |
| |
| /** |
| * 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 |
| */ |
| void drm_gem_object_handle_free(struct drm_gem_object *obj) |
| { |
| struct drm_device *dev = obj->dev; |
| |
| /* Remove any name for this object */ |
| spin_lock(&dev->object_name_lock); |
| if (obj->name) { |
| idr_remove(&dev->object_name_idr, obj->name); |
| obj->name = 0; |
| spin_unlock(&dev->object_name_lock); |
| /* |
| * The object name held a reference to this object, drop |
| * that now. |
| * |
| * This cannot be the last reference, since the handle holds one too. |
| */ |
| kref_put(&obj->refcount, drm_gem_object_ref_bug); |
| } else |
| spin_unlock(&dev->object_name_lock); |
| |
| } |
| EXPORT_SYMBOL(drm_gem_object_handle_free); |
| |
| void drm_gem_vm_open(struct vm_area_struct *vma) |
| { |
| struct drm_gem_object *obj = vma->vm_private_data; |
| |
| drm_gem_object_reference(obj); |
| |
| mutex_lock(&obj->dev->struct_mutex); |
| drm_vm_open_locked(obj->dev, vma); |
| mutex_unlock(&obj->dev->struct_mutex); |
| } |
| EXPORT_SYMBOL(drm_gem_vm_open); |
| |
| void drm_gem_vm_close(struct vm_area_struct *vma) |
| { |
| struct drm_gem_object *obj = vma->vm_private_data; |
| struct drm_device *dev = obj->dev; |
| |
| mutex_lock(&dev->struct_mutex); |
| drm_vm_close_locked(obj->dev, vma); |
| drm_gem_object_unreference(obj); |
| mutex_unlock(&dev->struct_mutex); |
| } |
| EXPORT_SYMBOL(drm_gem_vm_close); |
| |
| |
| /** |
| * 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. |
| * |
| * If we find the 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), we set up the driver fault handler so that any accesses |
| * to the object can be trapped, to perform migration, GTT binding, surface |
| * register allocation, or performance monitoring. |
| */ |
| 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_mm *mm = dev->mm_private; |
| struct drm_local_map *map = NULL; |
| struct drm_gem_object *obj; |
| struct drm_hash_item *hash; |
| int ret = 0; |
| |
| if (drm_device_is_unplugged(dev)) |
| return -ENODEV; |
| |
| mutex_lock(&dev->struct_mutex); |
| |
| if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) { |
| mutex_unlock(&dev->struct_mutex); |
| return drm_mmap(filp, vma); |
| } |
| |
| map = drm_hash_entry(hash, struct drm_map_list, hash)->map; |
| if (!map || |
| ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) { |
| ret = -EPERM; |
| goto out_unlock; |
| } |
| |
| /* Check for valid size. */ |
| if (map->size < vma->vm_end - vma->vm_start) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| obj = map->handle; |
| if (!obj->dev->driver->gem_vm_ops) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND; |
| vma->vm_ops = obj->dev->driver->gem_vm_ops; |
| vma->vm_private_data = map->handle; |
| vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); |
| |
| /* 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_reference(obj); |
| |
| drm_vm_open_locked(dev, vma); |
| |
| out_unlock: |
| mutex_unlock(&dev->struct_mutex); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_gem_mmap); |