![]() |
|
|||
0001 /* 0002 * Copyright (c) 2006-2008 Intel Corporation 0003 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie> 0004 * Copyright (c) 2008 Red Hat Inc. 0005 * Copyright (c) 2016 Intel Corporation 0006 * 0007 * Permission to use, copy, modify, distribute, and sell this software and its 0008 * documentation for any purpose is hereby granted without fee, provided that 0009 * the above copyright notice appear in all copies and that both that copyright 0010 * notice and this permission notice appear in supporting documentation, and 0011 * that the name of the copyright holders not be used in advertising or 0012 * publicity pertaining to distribution of the software without specific, 0013 * written prior permission. The copyright holders make no representations 0014 * about the suitability of this software for any purpose. It is provided "as 0015 * is" without express or implied warranty. 0016 * 0017 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 0018 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 0019 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 0020 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 0021 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 0022 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 0023 * OF THIS SOFTWARE. 0024 */ 0025 0026 #include <drm/drm_device.h> 0027 #include <drm/drm_drv.h> 0028 #include <drm/drm_gem.h> 0029 #include <drm/drm_mode.h> 0030 0031 #include "drm_crtc_internal.h" 0032 #include "drm_internal.h" 0033 0034 /** 0035 * DOC: overview 0036 * 0037 * The KMS API doesn't standardize backing storage object creation and leaves it 0038 * to driver-specific ioctls. Furthermore actually creating a buffer object even 0039 * for GEM-based drivers is done through a driver-specific ioctl - GEM only has 0040 * a common userspace interface for sharing and destroying objects. While not an 0041 * issue for full-fledged graphics stacks that include device-specific userspace 0042 * components (in libdrm for instance), this limit makes DRM-based early boot 0043 * graphics unnecessarily complex. 0044 * 0045 * Dumb objects partly alleviate the problem by providing a standard API to 0046 * create dumb buffers suitable for scanout, which can then be used to create 0047 * KMS frame buffers. 0048 * 0049 * To support dumb objects drivers must implement the &drm_driver.dumb_create 0050 * and &drm_driver.dumb_map_offset operations (the latter defaults to 0051 * drm_gem_dumb_map_offset() if not set). Drivers that don't use GEM handles 0052 * additionally need to implement the &drm_driver.dumb_destroy operation. See 0053 * the callbacks for further details. 0054 * 0055 * Note that dumb objects may not be used for gpu acceleration, as has been 0056 * attempted on some ARM embedded platforms. Such drivers really must have 0057 * a hardware-specific ioctl to allocate suitable buffer objects. 0058 */ 0059 0060 int drm_mode_create_dumb(struct drm_device *dev, 0061 struct drm_mode_create_dumb *args, 0062 struct drm_file *file_priv) 0063 { 0064 u32 cpp, stride, size; 0065 0066 if (!dev->driver->dumb_create) 0067 return -ENOSYS; 0068 if (!args->width || !args->height || !args->bpp) 0069 return -EINVAL; 0070 0071 /* overflow checks for 32bit size calculations */ 0072 if (args->bpp > U32_MAX - 8) 0073 return -EINVAL; 0074 cpp = DIV_ROUND_UP(args->bpp, 8); 0075 if (cpp > U32_MAX / args->width) 0076 return -EINVAL; 0077 stride = cpp * args->width; 0078 if (args->height > U32_MAX / stride) 0079 return -EINVAL; 0080 0081 /* test for wrap-around */ 0082 size = args->height * stride; 0083 if (PAGE_ALIGN(size) == 0) 0084 return -EINVAL; 0085 0086 /* 0087 * handle, pitch and size are output parameters. Zero them out to 0088 * prevent drivers from accidentally using uninitialized data. Since 0089 * not all existing userspace is clearing these fields properly we 0090 * cannot reject IOCTL with garbage in them. 0091 */ 0092 args->handle = 0; 0093 args->pitch = 0; 0094 args->size = 0; 0095 0096 return dev->driver->dumb_create(file_priv, dev, args); 0097 } 0098 0099 int drm_mode_create_dumb_ioctl(struct drm_device *dev, 0100 void *data, struct drm_file *file_priv) 0101 { 0102 return drm_mode_create_dumb(dev, data, file_priv); 0103 } 0104 0105 /** 0106 * drm_mode_mmap_dumb_ioctl - create an mmap offset for a dumb backing storage buffer 0107 * @dev: DRM device 0108 * @data: ioctl data 0109 * @file_priv: DRM file info 0110 * 0111 * Allocate an offset in the drm device node's address space to be able to 0112 * memory map a dumb buffer. 0113 * 0114 * Called by the user via ioctl. 0115 * 0116 * Returns: 0117 * Zero on success, negative errno on failure. 0118 */ 0119 int drm_mode_mmap_dumb_ioctl(struct drm_device *dev, 0120 void *data, struct drm_file *file_priv) 0121 { 0122 struct drm_mode_map_dumb *args = data; 0123 0124 if (!dev->driver->dumb_create) 0125 return -ENOSYS; 0126 0127 if (dev->driver->dumb_map_offset) 0128 return dev->driver->dumb_map_offset(file_priv, dev, 0129 args->handle, 0130 &args->offset); 0131 else 0132 return drm_gem_dumb_map_offset(file_priv, dev, args->handle, 0133 &args->offset); 0134 } 0135 0136 int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle, 0137 struct drm_file *file_priv) 0138 { 0139 if (!dev->driver->dumb_create) 0140 return -ENOSYS; 0141 0142 if (dev->driver->dumb_destroy) 0143 return dev->driver->dumb_destroy(file_priv, dev, handle); 0144 else 0145 return drm_gem_dumb_destroy(file_priv, dev, handle); 0146 } 0147 0148 int drm_mode_destroy_dumb_ioctl(struct drm_device *dev, 0149 void *data, struct drm_file *file_priv) 0150 { 0151 struct drm_mode_destroy_dumb *args = data; 0152 0153 return drm_mode_destroy_dumb(dev, args->handle, file_priv); 0154 }
[ Source navigation ] | [ Diff markup ] | [ Identifier search ] | [ general search ] |
This page was automatically generated by the 2.1.0 LXR engine. The LXR team |
![]() ![]() |