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sys/dev/drm/core/drm_dumb_buffers.c
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/* | |||||
* 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/drm_device.h> | |||||
#include <drm/drm_drv.h> | |||||
#include <drm/drm_gem.h> | |||||
#include <drm/drm_mode.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 &drm_driver.dumb_create | |||||
* operation. &drm_driver.dumb_destroy defaults to drm_gem_dumb_destroy() if | |||||
* not set and &drm_driver.dumb_map_offset defaults to | |||||
* drm_gem_dumb_map_offset(). See the callbacks 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(struct drm_device *dev, | |||||
struct drm_mode_create_dumb *args, | |||||
struct drm_file *file_priv) | |||||
{ | |||||
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 */ | |||||
if (args->bpp > U32_MAX - 8) | |||||
return -EINVAL; | |||||
cpp = DIV_ROUND_UP(args->bpp, 8); | |||||
if (cpp > U32_MAX / args->width) | |||||
return -EINVAL; | |||||
stride = cpp * args->width; | |||||
if (args->height > U32_MAX / 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); | |||||
} | |||||
int drm_mode_create_dumb_ioctl(struct drm_device *dev, | |||||
void *data, struct drm_file *file_priv) | |||||
{ | |||||
return drm_mode_create_dumb(dev, data, file_priv); | |||||
} | |||||
/** | |||||
* 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; | |||||
if (!dev->driver->dumb_create) | |||||
return -ENOSYS; | |||||
if (dev->driver->dumb_map_offset) | |||||
return dev->driver->dumb_map_offset(file_priv, dev, | |||||
args->handle, | |||||
&args->offset); | |||||
else | |||||
return drm_gem_dumb_map_offset(file_priv, dev, args->handle, | |||||
&args->offset); | |||||
} | |||||
int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle, | |||||
struct drm_file *file_priv) | |||||
{ | |||||
if (!dev->driver->dumb_create) | |||||
return -ENOSYS; | |||||
if (dev->driver->dumb_destroy) | |||||
return dev->driver->dumb_destroy(file_priv, dev, handle); | |||||
else | |||||
return drm_gem_dumb_destroy(file_priv, dev, handle); | |||||
} | |||||
int drm_mode_destroy_dumb_ioctl(struct drm_device *dev, | |||||
void *data, struct drm_file *file_priv) | |||||
{ | |||||
struct drm_mode_destroy_dumb *args = data; | |||||
return drm_mode_destroy_dumb(dev, args->handle, file_priv); | |||||
} |