| /* |
| * 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 <drm/drmP.h> |
| #include <drm/drm_vma_manager.h> |
| #include <drm/drm_gem.h> |
| #include "drm_internal.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 |
| |
| /** |
| * drm_gem_init - Initialize the GEM device fields |
| * @dev: drm_devic structure to initialize |
| */ |
| int |
| drm_gem_init(struct drm_device *dev) |
| { |
| struct drm_vma_offset_manager *vma_offset_manager; |
| |
| mutex_init(&dev->object_name_lock); |
| idr_init(&dev->object_name_idr); |
| |
| vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL); |
| if (!vma_offset_manager) { |
| DRM_ERROR("out of memory\n"); |
| return -ENOMEM; |
| } |
| |
| 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) |
| { |
| |
| 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 file *filp; |
| |
| drm_gem_private_object_init(dev, obj, size); |
| |
| filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); |
| if (IS_ERR(filp)) |
| return PTR_ERR(filp); |
| |
| 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_unreference_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_unreference_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 (drm_core_check_feature(dev, DRIVER_PRIME)) |
| drm_gem_remove_prime_handles(obj, file_priv); |
| drm_vma_node_revoke(&obj->vma_node, file_priv); |
| |
| if (dev->driver->gem_close_object) |
| dev->driver->gem_close_object(obj, file_priv); |
| |
| drm_gem_object_handle_unreference_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. |
| */ |
| spin_lock(&filp->table_lock); |
| |
| /* Check if we currently have a reference on the object */ |
| obj = idr_replace(&filp->object_idr, NULL, handle); |
| spin_unlock(&filp->table_lock); |
| 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. */ |
| spin_lock(&filp->table_lock); |
| idr_remove(&filp->object_idr, handle); |
| spin_unlock(&filp->table_lock); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_gem_handle_delete); |
| |
| /** |
| * 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_reference(obj); |
| |
| /* |
| * Get the user-visible handle using idr. Preload and perform |
| * allocation under our spinlock. |
| */ |
| idr_preload(GFP_KERNEL); |
| spin_lock(&file_priv->table_lock); |
| |
| ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); |
| |
| spin_unlock(&file_priv->table_lock); |
| 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: |
| spin_lock(&file_priv->table_lock); |
| idr_remove(&file_priv->object_idr, handle); |
| spin_unlock(&file_priv->table_lock); |
| err_unref: |
| drm_gem_object_handle_unreference_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. |
| */ |
| 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; |
| |
| 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; |
| |
| 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_get_pages - helper to allocate backing pages for a GEM object |
| * from shmem |
| * @obj: obj in question |
| * |
| * This reads the page-array of the shmem-backing storage of the given gem |
| * object. An array of pages is returned. If a page is not allocated or |
| * swapped-out, this will allocate/swap-in the required pages. Note that the |
| * whole object is covered by the page-array and pinned in memory. |
| * |
| * Use drm_gem_put_pages() to release the array and unpin all pages. |
| * |
| * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()). |
| * If you require other GFP-masks, you have to do those allocations yourself. |
| * |
| * Note that you are not allowed to change gfp-zones during runtime. That is, |
| * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as |
| * set during initialization. If you have special zone constraints, set them |
| * after drm_gem_init_object() via mapping_set_gfp_mask(). shmem-core takes care |
| * to keep pages in the required zone during swap-in. |
| */ |
| struct page **drm_gem_get_pages(struct drm_gem_object *obj) |
| { |
| struct address_space *mapping; |
| struct page *p, **pages; |
| int i, npages; |
| |
| /* This is the shared memory object that backs the GEM resource */ |
| mapping = obj->filp->f_mapping; |
| |
| /* We already BUG_ON() for non-page-aligned sizes in |
| * drm_gem_object_init(), so we should never hit this unless |
| * driver author is doing something really wrong: |
| */ |
| WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); |
| |
| npages = obj->size >> PAGE_SHIFT; |
| |
| pages = drm_malloc_ab(npages, sizeof(struct page *)); |
| if (pages == NULL) |
| return ERR_PTR(-ENOMEM); |
| |
| for (i = 0; i < npages; i++) { |
| p = shmem_read_mapping_page(mapping, i); |
| if (IS_ERR(p)) |
| goto fail; |
| pages[i] = p; |
| |
| /* Make sure shmem keeps __GFP_DMA32 allocated pages in the |
| * correct region during swapin. Note that this requires |
| * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping) |
| * so shmem can relocate pages during swapin if required. |
| */ |
| BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) && |
| (page_to_pfn(p) >= 0x00100000UL)); |
| } |
| |
| return pages; |
| |
| fail: |
| while (i--) |
| put_page(pages[i]); |
| |
| drm_free_large(pages); |
| return ERR_CAST(p); |
| } |
| EXPORT_SYMBOL(drm_gem_get_pages); |
| |
| /** |
| * drm_gem_put_pages - helper to free backing pages for a GEM object |
| * @obj: obj in question |
| * @pages: pages to free |
| * @dirty: if true, pages will be marked as dirty |
| * @accessed: if true, the pages will be marked as accessed |
| */ |
| void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, |
| bool dirty, bool accessed) |
| { |
| int i, npages; |
| |
| /* We already BUG_ON() for non-page-aligned sizes in |
| * drm_gem_object_init(), so we should never hit this unless |
| * driver author is doing something really wrong: |
| */ |
| WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); |
| |
| npages = obj->size >> PAGE_SHIFT; |
| |
| for (i = 0; i < npages; i++) { |
| if (dirty) |
| set_page_dirty(pages[i]); |
| |
| if (accessed) |
| mark_page_accessed(pages[i]); |
| |
| /* Undo the reference we took when populating the table */ |
| put_page(pages[i]); |
| } |
| |
| drm_free_large(pages); |
| } |
| EXPORT_SYMBOL(drm_gem_put_pages); |
| |
| /** |
| * 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; |
| |
| spin_lock(&filp->table_lock); |
| |
| /* Check if we currently have a reference on the object */ |
| obj = idr_find(&filp->object_idr, handle); |
| if (obj) |
| drm_gem_object_reference(obj); |
| |
| spin_unlock(&filp->table_lock); |
| |
| 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 -ENODEV; |
| |
| 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 -ENODEV; |
| |
| 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_unreference_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 -ENODEV; |
| |
| mutex_lock(&dev->object_name_lock); |
| obj = idr_find(&dev->object_name_idr, (int) args->name); |
| if (obj) { |
| drm_gem_object_reference(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_unreference_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); |
| spin_lock_init(&file_private->table_lock); |
| } |
| |
| /** |
| * 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); |
| |
| if (obj->filp) |
| fput(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_unreference_unlocked - release a GEM BO 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_unreference(). |
| */ |
| void |
| drm_gem_object_unreference_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_unreference_unlocked); |
| |
| /** |
| * drm_gem_object_unreference - release a GEM BO 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_unreference_unlocked() instead. |
| */ |
| void |
| drm_gem_object_unreference(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_unreference); |
| |
| /** |
| * 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_reference(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_unreference_unlocked(obj); |
| } |
| EXPORT_SYMBOL(drm_gem_vm_close); |
| |
| /** |
| * 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)); |
| |
| /* 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); |
| |
| 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_device_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_unreference_unlocked(obj); |
| return -EACCES; |
| } |
| |
| ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, |
| vma); |
| |
| drm_gem_object_unreference_unlocked(obj); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_gem_mmap); |