path: root/drivers/gpu/drm/drm_framebuffer.c

/*
 * 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 <linux/export.h>
#include <linux/uaccess.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_uapi.h>
#include <drm/drm_auth.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem.h>
#include <drm/drm_print.h>
#include <drm/drm_util.h>

#include "drm_crtc_internal.h"
#include "drm_internal.h"

/**
 * DOC: overview
 *
 * Frame buffers are abstract memory objects that provide a source of pixels to
 * scanout to a CRTC. Applications explicitly request the creation of frame
 * buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and receive an opaque
 * handle that can be passed to the KMS CRTC control, plane configuration and
 * page flip functions.
 *
 * Frame buffers rely on the underlying memory manager for allocating backing
 * storage. When creating a frame buffer applications pass a memory handle
 * (or a list of memory handles for multi-planar formats) through the
 * &struct drm_mode_fb_cmd2 argument. For drivers using GEM as their userspace
 * buffer management interface this would be a GEM handle.  Drivers are however
 * free to use their own backing storage object handles, e.g. vmwgfx directly
 * exposes special TTM handles to userspace and so expects TTM handles in the
 * create ioctl and not GEM handles.
 *
 * Framebuffers are tracked with &struct drm_framebuffer. They are published
 * using drm_framebuffer_init() - after calling that function userspace can use
 * and access the framebuffer object. The helper function
 * drm_helper_mode_fill_fb_struct() can be used to pre-fill the required
 * metadata fields.
 *
 * The lifetime of a drm framebuffer is controlled with a reference count,
 * drivers can grab additional references with drm_framebuffer_get() and drop
 * them again with drm_framebuffer_put(). For driver-private framebuffers for
 * which the last reference is never dropped (e.g. for the fbdev framebuffer
 * when the struct &struct drm_framebuffer is embedded into the fbdev helper
 * struct) drivers can manually clean up a framebuffer at module unload time
 * with drm_framebuffer_unregister_private(). But doing this is not
 * recommended, and it's better to have a normal free-standing &struct
 * drm_framebuffer.
 */

int drm_framebuffer_check_src_coords(uint32_t src_x, uint32_t src_y,
				     uint32_t src_w, uint32_t src_h,
				     const struct drm_framebuffer *fb)
{
	unsigned int fb_width, fb_height;

	fb_width = fb->width << 16;
	fb_height = fb->height << 16;

	/* Make sure source coordinates are inside the fb. */
	if (src_w > fb_width ||
	    src_x > fb_width - src_w ||
	    src_h > fb_height ||
	    src_y > fb_height - src_h) {
		DRM_DEBUG_KMS("Invalid source coordinates "
			      "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
			      src_w >> 16, ((src_w & 0xffff) * 15625) >> 10,
			      src_h >> 16, ((src_h & 0xffff) * 15625) >> 10,
			      src_x >> 16, ((src_x & 0xffff) * 15625) >> 10,
			      src_y >> 16, ((src_y & 0xffff) * 15625) >> 10,
			      fb->width, fb->height);
		return -ENOSPC;
	}

	return 0;
}

/**
 * drm_mode_addfb - add an FB to the graphics configuration
 * @dev: drm device for the ioctl
 * @or: pointer to request structure
 * @file_priv: drm file
 *
 * Add a new FB to the specified CRTC, given a user request. This is the
 * original addfb ioctl which only supported RGB formats.
 *
 * Called by the user via ioctl, or by an in-kernel client.
 *
 * Returns:
 * Zero on success, negative errno on failure.
 */
int drm_mode_addfb(struct drm_device *dev, struct drm_mode_fb_cmd *or,
		   struct drm_file *file_priv)
{
	struct drm_mode_fb_cmd2 r = {};
	int ret;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -EOPNOTSUPP;

	r.pixel_format = drm_driver_legacy_fb_format(dev, or->bpp, or->depth);
	if (r.pixel_format == DRM_FORMAT_INVALID) {
		DRM_DEBUG("bad {bpp:%d, depth:%d}\n", or->bpp, or->depth);
		return -EINVAL;
	}

	/* convert to new format and call new ioctl */
	r.fb_id = or->fb_id;
	r.width = or->