diff options
Diffstat (limited to 'drivers/gpu/drm/drm_gem.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gem.c | 722 |
1 files changed, 722 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c new file mode 100644 index 00000000..83114b5e --- /dev/null +++ b/drivers/gpu/drm/drm_gem.c @@ -0,0 +1,722 @@ +/* + * 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; + + if (ret != 0) + 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; + + if (ret != 0) + 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(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(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(vma); + +out_unlock: + mutex_unlock(&dev->struct_mutex); + + return ret; +} +EXPORT_SYMBOL(drm_gem_mmap); |