diff options
Diffstat (limited to 'drivers/gpu/drm/drm_gem.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gem.c | 1436 |
1 files changed, 1436 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c new file mode 100644 index 000000000..b87ed4238 --- /dev/null +++ b/drivers/gpu/drm/drm_gem.c @@ -0,0 +1,1436 @@ +/* + * 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/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_vma_offset_manager_destroy(dev->vma_offset_manager); +} + +/** + * 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_base(&dev->object_name_idr, 1); + + vma_offset_manager = drmm_kzalloc(dev, 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 drmm_add_action(dev, drm_gem_init_release, 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; + dma_resv_init(&obj->_resv); + if (!obj->resv) + obj->resv = &obj->_resv; + + drm_vma_node_reset(&obj->vma_node); + INIT_LIST_HEAD(&obj->lru_node); +} +EXPORT_SYMBOL(drm_gem_private_object_init); + +/** + * 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_put_unlocked(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + bool final = false; + + if (WARN_ON(READ_ONCE(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_put(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; + + if (obj->funcs->close) + obj->funcs->close(obj, file_priv); + + drm_prime_remove_buf_handle(&file_priv->prime, id); + drm_vma_node_revoke(&obj->vma_node, file_priv); + + drm_gem_object_handle_put_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; + + 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_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) +{ + struct drm_gem_object *obj; + int ret; + + obj = drm_gem_object_lookup(file, handle); + if (!obj) + return -ENOENT; + + /* Don't allow imported objects to be mapped */ + if (obj->import_attach) { + ret = -EINVAL; + goto out; + } + + ret = drm_gem_create_mmap_offset(obj); + if (ret) + goto out; + + *offset = drm_vma_node_offset_addr(&obj->vma_node); +out: + drm_gem_object_put(obj); + + return ret; +} +EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset); + +int drm_gem_dumb_destroy(struct drm_file *file, + struct drm_device *dev, + u32 handle) +{ + return drm_gem_handle_delete(file, handle); +} + +/** + * 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_get(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 (obj->funcs->open) { + ret = obj->funcs->open(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_put_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: 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) +{ + 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); + +/* + * Move pages to appropriate lru and release the pagevec, decrementing the + * ref count of those pages. + */ +static void drm_gem_check_release_pagevec(struct pagevec *pvec) +{ + check_move_unevictable_pages(pvec); + __pagevec_release(pvec); + cond_resched(); +} + +/** + * 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) +{ + struct address_space *mapping; + struct page *p, **pages; + struct pagevec pvec; + int i, npages; + + + if (WARN_ON(!obj->filp)) + return ERR_PTR(-EINVAL); + + /* 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 = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + if (pages == NULL) + return ERR_PTR(-ENOMEM); + + mapping_set_unevictable(mapping); + + 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: + mapping_clear_unevictable(mapping); + pagevec_init(&pvec); + while (i--) { + if (!pagevec_add(&pvec, pages[i])) + drm_gem_check_release_pagevec(&pvec); + } + if (pagevec_count(&pvec)) + drm_gem_check_release_pagevec(&pvec); + + kvfree(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; + struct address_space *mapping; + struct pagevec pvec; + + mapping = file_inode(obj->filp)->i_mapping; + mapping_clear_unevictable(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; + + pagevec_init(&pvec); + for (i = 0; i < npages; i++) { + if (!pages[i]) + continue; + + if (dirty) + set_page_dirty(pages[i]); + + if (accessed) + mark_page_accessed(pages[i]); + + /* Undo the reference we took when populating the table */ + if (!pagevec_add(&pvec, pages[i])) + drm_gem_check_release_pagevec(&pvec); + } + if (pagevec_count(&pvec)) + drm_gem_check_release_pagevec(&pvec); + + kvfree(pages); +} +EXPORT_SYMBOL(drm_gem_put_pages); + +static int objects_lookup(struct drm_file *filp, u32 *handle, int count, + struct drm_gem_object **objs) +{ + int i, ret = 0; + struct drm_gem_object *obj; + + spin_lock(&filp->table_lock); + + for (i = 0; i < count; i++) { + /* Check if we currently have a reference on the object */ + obj = idr_find(&filp->object_idr, handle[i]); + if (!obj) { + ret = -ENOENT; + break; + } + drm_gem_object_get(obj); + objs[i] = obj; + } + spin_unlock(&filp->table_lock); + + return ret; +} + +/** + * 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) +{ + int ret; + u32 *handles; + struct drm_gem_object **objs; + + if (!count) + return 0; + + objs = kvmalloc_array(count, sizeof(struct drm_gem_object *), + GFP_KERNEL | __GFP_ZERO); + if (!objs) + return -ENOMEM; + + *objs_out = objs; + + handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL); + if (!handles) { + ret = -ENOMEM; + goto out; + } + + if (copy_from_user(handles, bo_handles, count * sizeof(u32))) { + ret = -EFAULT; + DRM_DEBUG("Failed to copy in GEM handles\n"); + goto out; + } + + ret = objects_lookup(filp, handles, count, objs); +out: + kvfree(handles); + return ret; + +} +EXPORT_SYMBOL(drm_gem_objects_lookup); + +/** + * 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) +{ + struct drm_gem_object *obj = NULL; + + objects_lookup(filp, &handle, 1, &obj); + return obj; +} +EXPORT_SYMBOL(drm_gem_object_lookup); + +/** + * 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) +{ + long ret; + struct drm_gem_object *obj; + + obj = drm_gem_object_lookup(filep, handle); + if (!obj) { + DRM_DEBUG("Failed to look up GEM BO %d\n", handle); + return -EINVAL; + } + + ret = dma_resv_wait_timeout(obj->resv, dma_resv_usage_rw(wait_all), + true, timeout); + if (ret == 0) + ret = -ETIME; + else if (ret > 0) + ret = 0; + + drm_gem_object_put(obj); + + return ret; +} +EXPORT_SYMBOL(drm_gem_dma_resv_wait); + +/** + * 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 -EOPNOTSUPP; + + 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 -EOPNOTSUPP; + + 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_put(obj); + return ret; +} + +/** + * 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) +{ + struct drm_gem_open *args = data; + struct drm_gem_object *obj; + int ret; + u32 handle; + + if (!drm_core_check_feature(dev, DRIVER_GEM)) + return -EOPNOTSUPP; + + mutex_lock(&dev->object_name_lock); + obj = idr_find(&dev->object_name_idr, (int) args->name); + if (obj) { + drm_gem_object_get(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); + if (ret) + goto err; + + args->handle = handle; + args->size = obj->size; + +err: + drm_gem_object_put(obj); + return ret; +} + +/** + * 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) +{ + idr_init_base(&file_private->object_idr, 1); + 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 inverse 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); + + dma_resv_fini(&obj->_resv); + drm_gem_free_mmap_offset(obj); + drm_gem_lru_remove(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. + * + * Frees the object + */ +void +drm_gem_object_free(struct kref *kref) +{ + struct drm_gem_object *obj = + container_of(kref, struct drm_gem_object, refcount); + + if (WARN_ON(!obj->funcs->free)) + return; + + obj->funcs->free(obj); +} +EXPORT_SYMBOL(drm_gem_object_free); + +/** + * 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_get(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_put(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 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) +{ + int ret; + + /* Check for valid size. */ + if (obj_size < vma->vm_end - vma->vm_start) + return -EINVAL; + + /* 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_get(obj); + + vma->vm_private_data = obj; + vma->vm_ops = obj->funcs->vm_ops; + + if (obj->funcs->mmap) { + ret = obj->funcs->mmap(obj, vma); + if (ret) + goto err_drm_gem_object_put; + WARN_ON(!(vma->vm_flags & VM_DONTEXPAND)); + } else { + if (!vma->vm_ops) { + ret = -EINVAL; + goto err_drm_gem_object_put; + } + + vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; + vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); + } + + return 0; + +err_drm_gem_object_put: + drm_gem_object_put(obj); + return ret; +} +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_dev_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_put(obj); + return -EACCES; + } + + ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, + vma); + + drm_gem_object_put(obj); + + return ret; +} +EXPORT_SYMBOL(drm_gem_mmap); + +void drm_gem_print_info(struct drm_printer *p, unsigned int indent, + const struct drm_gem_object *obj) +{ + drm_printf_indent(p, indent, "name=%d\n", obj->name); + drm_printf_indent(p, indent, "refcount=%u\n", + kref_read(&obj->refcount)); + drm_printf_indent(p, indent, "start=%08lx\n", + drm_vma_node_start(&obj->vma_node)); + drm_printf_indent(p, indent, "size=%zu\n", obj->size); + drm_printf_indent(p, indent, "imported=%s\n", + str_yes_no(obj->import_attach)); + + if (obj->funcs->print_info) + obj->funcs->print_info(p, indent, obj); +} + +int drm_gem_pin(struct drm_gem_object *obj) +{ + if (obj->funcs->pin) + return obj->funcs->pin(obj); + else + return 0; +} + +void drm_gem_unpin(struct drm_gem_object *obj) +{ + if (obj->funcs->unpin) + obj->funcs->unpin(obj); +} + +int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map) +{ + int ret; + + if (!obj->funcs->vmap) + return -EOPNOTSUPP; + + ret = obj->funcs->vmap(obj, map); + if (ret) + return ret; + else if (iosys_map_is_null(map)) + return -ENOMEM; + + return 0; +} +EXPORT_SYMBOL(drm_gem_vmap); + +void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) +{ + if (iosys_map_is_null(map)) + return; + + if (obj->funcs->vunmap) + obj->funcs->vunmap(obj, map); + + /* Always set the mapping to NULL. Callers may rely on this. */ + iosys_map_clear(map); +} +EXPORT_SYMBOL(drm_gem_vunmap); + +/** + * 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) +{ + int contended = -1; + int i, ret; + + ww_acquire_init(acquire_ctx, &reservation_ww_class); + +retry: + if (contended != -1) { + struct drm_gem_object *obj = objs[contended]; + + ret = dma_resv_lock_slow_interruptible(obj->resv, + acquire_ctx); + if (ret) { + ww_acquire_fini(acquire_ctx); + return ret; + } + } + + for (i = 0; i < count; i++) { + if (i == contended) + continue; + + ret = dma_resv_lock_interruptible(objs[i]->resv, + acquire_ctx); + if (ret) { + int j; + + for (j = 0; j < i; j++) + dma_resv_unlock(objs[j]->resv); + + if (contended != -1 && contended >= i) + dma_resv_unlock(objs[contended]->resv); + + if (ret == -EDEADLK) { + contended = i; + goto retry; + } + + ww_acquire_fini(acquire_ctx); + return ret; + } + } + + ww_acquire_done(acquire_ctx); + + return 0; +} +EXPORT_SYMBOL(drm_gem_lock_reservations); + +void +drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, + struct ww_acquire_ctx *acquire_ctx) +{ + int i; + + for (i = 0; i < count; i++) + dma_resv_unlock(objs[i]->resv); + + ww_acquire_fini(acquire_ctx); +} +EXPORT_SYMBOL(drm_gem_unlock_reservations); + +/** + * 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) +{ + lru->lock = lock; + lru->count = 0; + INIT_LIST_HEAD(&lru->list); +} +EXPORT_SYMBOL(drm_gem_lru_init); + +static void +drm_gem_lru_remove_locked(struct drm_gem_object *obj) +{ + obj->lru->count -= obj->size >> PAGE_SHIFT; + WARN_ON(obj->lru->count < 0); + list_del(&obj->lru_node); + obj->lru = NULL; +} + +/** + * 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) +{ + struct drm_gem_lru *lru = obj->lru; + + if (!lru) + return; + + mutex_lock(lru->lock); + drm_gem_lru_remove_locked(obj); + mutex_unlock(lru->lock); +} +EXPORT_SYMBOL(drm_gem_lru_remove); + +static void +drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj) +{ + lockdep_assert_held_once(lru->lock); + + if (obj->lru) + drm_gem_lru_remove_locked(obj); + + lru->count += obj->size >> PAGE_SHIFT; + list_add_tail(&obj->lru_node, &lru->list); + obj->lru = lru; +} + +/** + * 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) +{ + mutex_lock(lru->lock); + drm_gem_lru_move_tail_locked(lru, obj); + mutex_unlock(lru->lock); +} +EXPORT_SYMBOL(drm_gem_lru_move_tail); + +/** + * 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)) +{ + struct drm_gem_lru still_in_lru; + struct drm_gem_object *obj; + unsigned freed = 0; + + drm_gem_lru_init(&still_in_lru, lru->lock); + + mutex_lock(lru->lock); + + while (freed < nr_to_scan) { + obj = list_first_entry_or_null(&lru->list, typeof(*obj), lru_node); + + if (!obj) + break; + + drm_gem_lru_move_tail_locked(&still_in_lru, obj); + + /* + * If it's in the process of being freed, gem_object->free() + * may be blocked on lock waiting to remove it. So just + * skip it. + */ + if (!kref_get_unless_zero(&obj->refcount)) + continue; + + /* + * Now that we own a reference, we can drop the lock for the + * rest of the loop body, to reduce contention with other + * code paths that need the LRU lock + */ + mutex_unlock(lru->lock); + + /* + * Note that this still needs to be trylock, since we can + * hit shrinker in response to trying to get backing pages + * for this obj (ie. while it's lock is already held) + */ + if (!dma_resv_trylock(obj->resv)) { + *remaining += obj->size >> PAGE_SHIFT; + goto tail; + } + + if (shrink(obj)) { + freed += obj->size >> PAGE_SHIFT; + + /* + * If we succeeded in releasing the object's backing + * pages, we expect the driver to have moved the object + * out of this LRU + */ + WARN_ON(obj->lru == &still_in_lru); + WARN_ON(obj->lru == lru); + } + + dma_resv_unlock(obj->resv); + +tail: + drm_gem_object_put(obj); + mutex_lock(lru->lock); + } + + /* + * Move objects we've skipped over out of the temporary still_in_lru + * back into this LRU + */ + list_for_each_entry (obj, &still_in_lru.list, lru_node) + obj->lru = lru; + list_splice_tail(&still_in_lru.list, &lru->list); + lru->count += still_in_lru.count; + + mutex_unlock(lru->lock); + + return freed; +} +EXPORT_SYMBOL(drm_gem_lru_scan); |