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 <drm/drmP.h>
#include <drm/drm_auth.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_atomic.h>
#include <drm/drm_print.h>

#include "drm_internal.h"
#include "drm_crtc_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
 * @data: data pointer for the ioctl
 * @file_priv: drm file for the ioctl call
 *
 * 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.
 *
 * Returns:
 * Zero on success, negative errno on failure.
 */
int drm_mode_addfb(struct drm_device *dev,
		   void *data, struct drm_file *file_priv)
{
	struct drm_mode_fb_cmd *or = data;
	struct drm_mode_fb_cmd2 r = {};
	int ret;

	/* convert to new format and call new ioctl */
	r.fb_id = or->fb_id;
	r.width = or->width;
	r.height = or->height;
	r.pitches[0] = or->pitch;
	r.pixel_format = drm_mode_legacy_fb_format(or->bpp, or->depth);
	r.handles[0] = or->handle;

	if (r.pixel_format == DRM_FORMAT_XRGB2101010 &&
	    dev->driver->driver_features & DRIVER_PREFER_XBGR_30BPP)
		r.pixel_format = DRM_FORMAT_XBGR2101010;

	ret = drm_mode_addfb2(dev, &r, file_priv);
	if (ret)
		return ret;

	or->fb_id = r.fb_id;

	return 0;
}

static int fb_plane_width(int width,
			  const struct drm_format_info *format, int plane)
{
	if (plane == 0)
		return width;

	return DIV_ROUND_UP(width, format->hsub);
}

static int fb_plane_height(int height,
			   const struct drm_format_info *format, int plane)
{
	if (plane == 0)
		return height;

	return DIV_ROUND_UP(height, format->vsub);
}

static int framebuffer_check(struct drm_device *dev,
			     const struct drm_mode_fb_cmd2 *r)
{
	const struct drm_format_info *info;
	int i;

	/* check if the format is supported at all */
	info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
	if (!info) {
		struct drm_format_name_buf format_name;

		DRM_DEBUG_KMS("bad framebuffer format %s\n",
			      drm_get_format_name(r->pixel_format,
						  &format_name));
		return -EINVAL;
	}

	/* now let the driver pick its own format info */
	info = drm_get_format_info(dev, r);

	if (r->width == 0) {
		DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
		return -EINVAL;
	}

	if (r->height == 0) {
		DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
		return -EINVAL;
	}

	for (i = 0; i < info->num_planes; i++) {
		unsigned int width = fb_plane_width(r->width, info, i);
		unsigned int height = fb_plane_height(r->height, info, i);
		unsigned int cpp = info->cpp[i];

		if (!r->handles[i]) {
			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
			return -EINVAL;
		}

		if ((uint64_t) width * cpp > UINT_MAX)
			return -ERANGE;

		if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
			return -ERANGE;