static int __init atomic_pool_init(void)
{
	pgprot_t prot = __pgprot(PROT_NORMAL_NC);
	unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
	struct page *page;
	void *addr;
	unsigned int pool_size_order = get_order(atomic_pool_size);

	if (dev_get_cma_area(NULL))
		page = dma_alloc_from_contiguous(NULL, nr_pages,
							pool_size_order);
	else
		page = alloc_pages(GFP_DMA, pool_size_order);

	if (page) {
		int ret;
		void *page_addr = page_address(page);

		memset(page_addr, 0, atomic_pool_size);
		__dma_flush_range(page_addr, page_addr + atomic_pool_size);

		atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
		if (!atomic_pool)
			goto free_page;

		addr = dma_common_contiguous_remap(page, atomic_pool_size,
					VM_USERMAP, prot, atomic_pool_init);

		if (!addr)
			goto destroy_genpool;

		ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
					page_to_phys(page),
					atomic_pool_size, -1);
		if (ret)
			goto remove_mapping;

		gen_pool_set_algo(atomic_pool,
				  gen_pool_first_fit_order_align,
				  (void *)PAGE_SHIFT);

		pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
			atomic_pool_size / 1024);
		return 0;
	}
	goto out;

remove_mapping:
	dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
destroy_genpool:
	gen_pool_destroy(atomic_pool);
	atomic_pool = NULL;
free_page:
	if (!dma_release_from_contiguous(NULL, page, nr_pages))
		__free_pages(page, pool_size_order);
out:
	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
		atomic_pool_size / 1024);
	return -ENOMEM;
}
static int __init atomic_pool_init(void)
{
	pgprot_t prot = __pgprot(PROT_NORMAL_NC);
	unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
	struct page *page;
	void *addr;
	unsigned int pool_size_order = get_order(atomic_pool_size);

	if (dev_get_cma_area(NULL))
		page = dma_alloc_from_contiguous(NULL, nr_pages,
							pool_size_order);
	else
		page = alloc_pages(GFP_DMA, pool_size_order);

	if (page) {
		int ret;
		void *page_addr = page_address(page);

		memset(page_addr, 0, atomic_pool_size);
		__dma_flush_range(page_addr, page_addr + atomic_pool_size);

		atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
		if (!atomic_pool)
			goto free_page;

		addr = dma_common_contiguous_remap(page, atomic_pool_size,
					VM_USERMAP, prot, atomic_pool_init);

		if (!addr)
			goto destroy_genpool;

		ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
					page_to_phys(page),
					atomic_pool_size, -1);
		if (ret)
			goto remove_mapping;

		gen_pool_set_algo(atomic_pool,
				  gen_pool_first_fit_order_align,
				  (void *)PAGE_SHIFT);

		pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
			atomic_pool_size / 1024);
		return 0;
	}
	goto out;

remove_mapping:
	dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
destroy_genpool:
	gen_pool_destroy(atomic_pool);
	atomic_pool = NULL;
free_page:
	if (!dma_release_from_contiguous(NULL, page, nr_pages))
		__free_pages(page, pool_size_order);
out:
	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
		atomic_pool_size / 1024);
	return -ENOMEM;
}