/* * 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 * */ #include #include #include #include #include #include #include #include #include #include #include #include #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. */ } /** * 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_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); 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->filp); 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_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); drm_gem_object_release_handle(handle, obj, filp); 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 ->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 dev->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->filp); // if (ret) { // drm_gem_handle_delete(file_priv, *handlep); // return ret; // } 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->filp); 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); #if 0 /** * 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; 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. obj->size). Otherwise * just use drm_gem_create_mmap_offset(). */ 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. */ 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 = file_inode(obj->filp)->i_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--) page_cache_release(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 */ page_cache_release(pages[i]); } drm_free_large(pages); } EXPORT_SYMBOL(drm_gem_put_pages); #endif /** * drm_gem_object_lookup - look up a GEM object from it's handle * @dev: DRM device * @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_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); /** * 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(dev, 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); // printf("%s object %p name %d refcount %d\n", // __FUNCTION__, obj, obj->name, obj->refcount.refcount); 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; // printf("%s object %p handle %d refcount %d\n", // __FUNCTION__, obj, handle, obj->refcount.refcount); return 0; } #if 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); } #endif void drm_gem_object_release(struct drm_gem_object *obj) { WARN_ON(obj->dma_buf); if (obj->filp) free(obj->filp); } 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 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; WARN_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); #if 0 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); 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); #endif