CooCenter-System-kernel/drivers/gpu/drm/vc4/vc4_bo.c

/*
 *  Copyright © 2015 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/* DOC: VC4 GEM BO management support.
 *
 * The VC4 GPU architecture (both scanout and rendering) has direct
 * access to system memory with no MMU in between.  To support it, we
 * use the GEM CMA helper functions to allocate contiguous ranges of
 * physical memory for our BOs.
 */

#include "vc4_drv.h"

struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t size)
{
	struct drm_gem_cma_object *cma_obj;

	cma_obj = drm_gem_cma_create(dev, size);
	if (IS_ERR(cma_obj))
		return NULL;
	else
		return to_vc4_bo(&cma_obj->base);
}

int vc4_dumb_create(struct drm_file *file_priv,
		    struct drm_device *dev,
		    struct drm_mode_create_dumb *args)
{
	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
	struct vc4_bo *bo = NULL;
	int ret;

	if (args->pitch < min_pitch)
		args->pitch = min_pitch;

	if (args->size < args->pitch * args->height)
		args->size = args->pitch * args->height;

	bo = vc4_bo_create(dev, roundup(args->size, PAGE_SIZE));
	if (!bo)
		return -ENOMEM;

	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
	drm_gem_object_unreference_unlocked(&bo->base.base);

	return ret;
}