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1/*2 * Copyright (c) 2006-2008 Intel Corporation3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>4 * Copyright (c) 2008 Red Hat Inc.5 * Copyright (c) 2016 Intel Corporation6 *7 * Permission to use, copy, modify, distribute, and sell this software and its8 * documentation for any purpose is hereby granted without fee, provided that9 * the above copyright notice appear in all copies and that both that copyright10 * notice and this permission notice appear in supporting documentation, and11 * that the name of the copyright holders not be used in advertising or12 * publicity pertaining to distribution of the software without specific,13 * written prior permission. The copyright holders make no representations14 * about the suitability of this software for any purpose. It is provided "as15 * is" without express or implied warranty.16 *17 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,18 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO19 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR20 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,21 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER22 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE23 * OF THIS SOFTWARE.24 */25 26#include <drm/drm_device.h>27#include <drm/drm_drv.h>28#include <drm/drm_gem.h>29#include <drm/drm_mode.h>30 31#include "drm_crtc_internal.h"32#include "drm_internal.h"33 34/**35 * DOC: overview36 *37 * The KMS API doesn't standardize backing storage object creation and leaves it38 * to driver-specific ioctls. Furthermore actually creating a buffer object even39 * for GEM-based drivers is done through a driver-specific ioctl - GEM only has40 * a common userspace interface for sharing and destroying objects. While not an41 * issue for full-fledged graphics stacks that include device-specific userspace42 * components (in libdrm for instance), this limit makes DRM-based early boot43 * graphics unnecessarily complex.44 *45 * Dumb objects partly alleviate the problem by providing a standard API to46 * create dumb buffers suitable for scanout, which can then be used to create47 * KMS frame buffers.48 *49 * To support dumb objects drivers must implement the &drm_driver.dumb_create50 * and &drm_driver.dumb_map_offset operations (the latter defaults to51 * drm_gem_dumb_map_offset() if not set). Drivers that don't use GEM handles52 * additionally need to implement the &drm_driver.dumb_destroy operation. See53 * the callbacks for further details.54 *55 * Note that dumb objects may not be used for gpu acceleration, as has been56 * attempted on some ARM embedded platforms. Such drivers really must have57 * a hardware-specific ioctl to allocate suitable buffer objects.58 */59 60int drm_mode_create_dumb(struct drm_device *dev,61 struct drm_mode_create_dumb *args,62 struct drm_file *file_priv)63{64 u32 cpp, stride, size;65 66 if (!dev->driver->dumb_create)67 return -ENOSYS;68 if (!args->width || !args->height || !args->bpp)69 return -EINVAL;70 71 /* overflow checks for 32bit size calculations */72 if (args->bpp > U32_MAX - 8)73 return -EINVAL;74 cpp = DIV_ROUND_UP(args->bpp, 8);75 if (cpp > U32_MAX / args->width)76 return -EINVAL;77 stride = cpp * args->width;78 if (args->height > U32_MAX / stride)79 return -EINVAL;80 81 /* test for wrap-around */82 size = args->height * stride;83 if (PAGE_ALIGN(size) == 0)84 return -EINVAL;85 86 /*87 * handle, pitch and size are output parameters. Zero them out to88 * prevent drivers from accidentally using uninitialized data. Since89 * not all existing userspace is clearing these fields properly we90 * cannot reject IOCTL with garbage in them.91 */92 args->handle = 0;93 args->pitch = 0;94 args->size = 0;95 96 return dev->driver->dumb_create(file_priv, dev, args);97}98 99int drm_mode_create_dumb_ioctl(struct drm_device *dev,100 void *data, struct drm_file *file_priv)101{102 return drm_mode_create_dumb(dev, data, file_priv);103}104 105/**106 * drm_mode_mmap_dumb_ioctl - create an mmap offset for a dumb backing storage buffer107 * @dev: DRM device108 * @data: ioctl data109 * @file_priv: DRM file info110 *111 * Allocate an offset in the drm device node's address space to be able to112 * memory map a dumb buffer.113 *114 * Called by the user via ioctl.115 *116 * Returns:117 * Zero on success, negative errno on failure.118 */119int drm_mode_mmap_dumb_ioctl(struct drm_device *dev,120 void *data, struct drm_file *file_priv)121{122 struct drm_mode_map_dumb *args = data;123 124 if (!dev->driver->dumb_create)125 return -ENOSYS;126 127 if (dev->driver->dumb_map_offset)128 return dev->driver->dumb_map_offset(file_priv, dev,129 args->handle,130 &args->offset);131 else132 return drm_gem_dumb_map_offset(file_priv, dev, args->handle,133 &args->offset);134}135 136int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle,137 struct drm_file *file_priv)138{139 if (!dev->driver->dumb_create)140 return -ENOSYS;141 142 return drm_gem_handle_delete(file_priv, handle);143}144 145int drm_mode_destroy_dumb_ioctl(struct drm_device *dev,146 void *data, struct drm_file *file_priv)147{148 struct drm_mode_destroy_dumb *args = data;149 150 return drm_mode_destroy_dumb(dev, args->handle, file_priv);151}152