/* * 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 <[email protected]> * */ #include <linux/dma-buf.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/iosys-map.h> #include <linux/mem_encrypt.h> #include <linux/mm.h> #include <linux/mman.h> #include <linux/module.h> #include <linux/pagemap.h> #include <linux/pagevec.h> #include <linux/shmem_fs.h> #include <linux/slab.h> #include <linux/string_helpers.h> #include <linux/types.h> #include <linux/uaccess.h> #include <drm/drm.h> #include <drm/drm_device.h> #include <drm/drm_drv.h> #include <drm/drm_file.h> #include <drm/drm_gem.h> #include <drm/drm_managed.h> #include <drm/drm_print.h> #include <drm/drm_vma_manager.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. */ static void drm_gem_init_release(struct drm_device *dev, void *ptr) { … } /** * drm_gem_init - Initialize the GEM device fields * @dev: drm_devic structure to initialize */ int drm_gem_init(struct drm_device *dev) { … } /** * 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) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * drm_gem_private_object_fini - Finalize a failed drm_gem_object * @obj: drm_gem_object * * Uninitialize an already allocated GEM object when it initialized failed */ void drm_gem_private_object_fini(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); /** * 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) { … } static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) { … } static void drm_gem_object_handle_put_unlocked(struct drm_gem_object *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) { … } /** * 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) { … } EXPORT_SYMBOL(…); /** * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object * @file: drm file-private structure containing the gem object * @dev: corresponding drm_device * @handle: gem object handle * @offset: return location for the fake mmap offset * * This implements the &drm_driver.dumb_map_offset kms driver callback for * drivers which use gem to manage their backing storage. * * Returns: * 0 on success or a negative error code on failure. */ int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev, u32 handle, u64 *offset) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } /** * 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: pointer to return the created handle to the caller * * Create a handle for this object. This adds a handle reference to the object, * which includes a regular reference count. Callers will likely want to * dereference the object afterwards. * * Since this publishes @obj to userspace it must be fully set up by this point, * drivers must call this last in their buffer object creation callbacks. */ int drm_gem_handle_create(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /* * Move folios to appropriate lru and release the folios, decrementing the * ref count of those folios. */ static void drm_gem_check_release_batch(struct folio_batch *fbatch) { … } /** * 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_object_init() via mapping_set_gfp_mask(). shmem-core takes care * to keep pages in the required zone during swap-in. * * This function is only valid on objects initialized with * drm_gem_object_init(), but not for those initialized with * drm_gem_private_object_init() only. */ struct page **drm_gem_get_pages(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); static int objects_lookup(struct drm_file *filp, u32 *handle, int count, struct drm_gem_object **objs) { … } /** * drm_gem_objects_lookup - look up GEM objects from an array of handles * @filp: DRM file private date * @bo_handles: user pointer to array of userspace handle * @count: size of handle array * @objs_out: returned pointer to array of drm_gem_object pointers * * Takes an array of userspace handles and returns a newly allocated array of * GEM objects. * * For a single handle lookup, use drm_gem_object_lookup(). * * Returns: * * @objs filled in with GEM object pointers. Returned GEM objects need to be * released with drm_gem_object_put(). -ENOENT is returned on a lookup * failure. 0 is returned on success. * */ int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles, int count, struct drm_gem_object ***objs_out) { … } EXPORT_SYMBOL(…); /** * drm_gem_object_lookup - look up a GEM object from its 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. * * If looking up an array of handles, use drm_gem_objects_lookup(). */ struct drm_gem_object * drm_gem_object_lookup(struct drm_file *filp, u32 handle) { … } EXPORT_SYMBOL(…); /** * drm_gem_dma_resv_wait - Wait on GEM object's reservation's objects * shared and/or exclusive fences. * @filep: DRM file private date * @handle: userspace handle * @wait_all: if true, wait on all fences, else wait on just exclusive fence * @timeout: timeout value in jiffies or zero to return immediately * * Returns: * * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or * greater than 0 on success. */ long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle, bool wait_all, unsigned long timeout) { … } EXPORT_SYMBOL(…); /** * 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) { … } /** * 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) { … } /** * drm_gem_open_ioctl - 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) { … } /** * drm_gem_open - initializes 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) { … } /** * 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) { … } /** * 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 inverse of * drm_gem_object_init(). */ void drm_gem_object_release(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); /** * 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. * * Frees the object */ void drm_gem_object_free(struct kref *kref) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * 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 object's * vm_ops. Depending on their requirements, GEM objects can either * provide a fault handler in their 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 vm_ops are provided. */ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, struct vm_area_struct *vma) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); void drm_gem_print_info(struct drm_printer *p, unsigned int indent, const struct drm_gem_object *obj) { … } int drm_gem_pin_locked(struct drm_gem_object *obj) { … } void drm_gem_unpin_locked(struct drm_gem_object *obj) { … } int drm_gem_pin(struct drm_gem_object *obj) { … } void drm_gem_unpin(struct drm_gem_object *obj) { … } int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map) { … } EXPORT_SYMBOL(…); void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) { … } EXPORT_SYMBOL(…); void drm_gem_lock(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); void drm_gem_unlock(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map) { … } EXPORT_SYMBOL(…); void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map) { … } EXPORT_SYMBOL(…); /** * drm_gem_lock_reservations - Sets up the ww context and acquires * the lock on an array of GEM objects. * * Once you've locked your reservations, you'll want to set up space * for your shared fences (if applicable), submit your job, then * drm_gem_unlock_reservations(). * * @objs: drm_gem_objects to lock * @count: Number of objects in @objs * @acquire_ctx: struct ww_acquire_ctx that will be initialized as * part of tracking this set of locked reservations. */ int drm_gem_lock_reservations(struct drm_gem_object **objs, int count, struct ww_acquire_ctx *acquire_ctx) { … } EXPORT_SYMBOL(…); void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, struct ww_acquire_ctx *acquire_ctx) { … } EXPORT_SYMBOL(…); /** * drm_gem_lru_init - initialize a LRU * * @lru: The LRU to initialize * @lock: The lock protecting the LRU */ void drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock) { … } EXPORT_SYMBOL(…); static void drm_gem_lru_remove_locked(struct drm_gem_object *obj) { … } /** * drm_gem_lru_remove - remove object from whatever LRU it is in * * If the object is currently in any LRU, remove it. * * @obj: The GEM object to remove from current LRU */ void drm_gem_lru_remove(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); /** * drm_gem_lru_move_tail_locked - move the object to the tail of the LRU * * Like &drm_gem_lru_move_tail but lru lock must be held * * @lru: The LRU to move the object into. * @obj: The GEM object to move into this LRU */ void drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); /** * drm_gem_lru_move_tail - move the object to the tail of the LRU * * If the object is already in this LRU it will be moved to the * tail. Otherwise it will be removed from whichever other LRU * it is in (if any) and moved into this LRU. * * @lru: The LRU to move the object into. * @obj: The GEM object to move into this LRU */ void drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…); /** * drm_gem_lru_scan - helper to implement shrinker.scan_objects * * If the shrink callback succeeds, it is expected that the driver * move the object out of this LRU. * * If the LRU possibly contain active buffers, it is the responsibility * of the shrink callback to check for this (ie. dma_resv_test_signaled()) * or if necessary block until the buffer becomes idle. * * @lru: The LRU to scan * @nr_to_scan: The number of pages to try to reclaim * @remaining: The number of pages left to reclaim, should be initialized by caller * @shrink: Callback to try to shrink/reclaim the object. */ unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned int nr_to_scan, unsigned long *remaining, bool (*shrink)(struct drm_gem_object *obj)) { … } EXPORT_SYMBOL(…); /** * drm_gem_evict - helper to evict backing pages for a GEM object * @obj: obj in question */ int drm_gem_evict(struct drm_gem_object *obj) { … } EXPORT_SYMBOL(…);