| /* |
| * Copyright (c) 2006-2008 Intel Corporation |
| * Copyright (c) 2007 Dave Airlie <airlied@linux.ie> |
| * Copyright (c) 2008 Red Hat Inc. |
| * Copyright (c) 2016 Intel Corporation |
| * |
| * Permission to use, copy, modify, distribute, and sell this software and its |
| * documentation for any purpose is hereby granted without fee, provided that |
| * the above copyright notice appear in all copies and that both that copyright |
| * notice and this permission notice appear in supporting documentation, and |
| * that the name of the copyright holders not be used in advertising or |
| * publicity pertaining to distribution of the software without specific, |
| * written prior permission. The copyright holders make no representations |
| * about the suitability of this software for any purpose. It is provided "as |
| * is" without express or implied warranty. |
| * |
| * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
| * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO |
| * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR |
| * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, |
| * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER |
| * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE |
| * OF THIS SOFTWARE. |
| */ |
| |
| #include <drm/drmP.h> |
| |
| #include "drm_crtc_internal.h" |
| |
| /** |
| * DOC: overview |
| * |
| * The KMS API doesn't standardize backing storage object creation and leaves it |
| * to driver-specific ioctls. Furthermore actually creating a buffer object even |
| * for GEM-based drivers is done through a driver-specific ioctl - GEM only has |
| * a common userspace interface for sharing and destroying objects. While not an |
| * issue for full-fledged graphics stacks that include device-specific userspace |
| * components (in libdrm for instance), this limit makes DRM-based early boot |
| * graphics unnecessarily complex. |
| * |
| * Dumb objects partly alleviate the problem by providing a standard API to |
| * create dumb buffers suitable for scanout, which can then be used to create |
| * KMS frame buffers. |
| * |
| * To support dumb objects drivers must implement the dumb_create, |
| * dumb_destroy and dumb_map_offset operations from struct &drm_driver. See |
| * there for further details. |
| * |
| * Note that dumb objects may not be used for gpu acceleration, as has been |
| * attempted on some ARM embedded platforms. Such drivers really must have |
| * a hardware-specific ioctl to allocate suitable buffer objects. |
| */ |
| |
| int drm_mode_create_dumb_ioctl(struct drm_device *dev, |
| void *data, struct drm_file *file_priv) |
| { |
| struct drm_mode_create_dumb *args = data; |
| u32 cpp, stride, size; |
| |
| if (!dev->driver->dumb_create) |
| return -ENOSYS; |
| if (!args->width || !args->height || !args->bpp) |
| return -EINVAL; |
| |
| /* overflow checks for 32bit size calculations */ |
| /* NOTE: DIV_ROUND_UP() can overflow */ |
| cpp = DIV_ROUND_UP(args->bpp, 8); |
| if (!cpp || cpp > 0xffffffffU / args->width) |
| return -EINVAL; |
| stride = cpp * args->width; |
| if (args->height > 0xffffffffU / stride) |
| return -EINVAL; |
| |
| /* test for wrap-around */ |
| size = args->height * stride; |
| if (PAGE_ALIGN(size) == 0) |
| return -EINVAL; |
| |
| /* |
| * handle, pitch and size are output parameters. Zero them out to |
| * prevent drivers from accidentally using uninitialized data. Since |
| * not all existing userspace is clearing these fields properly we |
| * cannot reject IOCTL with garbage in them. |
| */ |
| args->handle = 0; |
| args->pitch = 0; |
| args->size = 0; |
| |
| return dev->driver->dumb_create(file_priv, dev, args); |
| } |
| |
| /** |
| * drm_mode_mmap_dumb_ioctl - create an mmap offset for a dumb backing storage buffer |
| * @dev: DRM device |
| * @data: ioctl data |
| * @file_priv: DRM file info |
| * |
| * Allocate an offset in the drm device node's address space to be able to |
| * memory map a dumb buffer. |
| * |
| * Called by the user via ioctl. |
| * |
| * Returns: |
| * Zero on success, negative errno on failure. |
| */ |
| int drm_mode_mmap_dumb_ioctl(struct drm_device *dev, |
| void *data, struct drm_file *file_priv) |
| { |
| struct drm_mode_map_dumb *args = data; |
| |
| /* call driver ioctl to get mmap offset */ |
| if (!dev->driver->dumb_map_offset) |
| return -ENOSYS; |
| |
| return dev->driver->dumb_map_offset(file_priv, dev, args->handle, &args->offset); |
| } |
| |
| int drm_mode_destroy_dumb_ioctl(struct drm_device *dev, |
| void *data, struct drm_file *file_priv) |
| { |
| struct drm_mode_destroy_dumb *args = data; |
| |
| if (!dev->driver->dumb_destroy) |
| return -ENOSYS; |
| |
| return dev->driver->dumb_destroy(file_priv, dev, args->handle); |
| } |
| |