// SPDX-License-Identifier: GPL-2.0/* * Copyright (c) 2014 The Linux Foundation */#include <linux/dma-map-ops.h>#include <linux/slab.h>#include <linux/vmalloc.h> struct page **dma_common_find_pages(void *cpu_addr){	struct vm_struct *area = find_vm_area(cpu_addr); 	if (!area || area->flags != VM_DMA_COHERENT)		return NULL;	return area->pages;} /* * Remaps an array of PAGE_SIZE pages into another vm_area. * Cannot be used in non-sleeping contexts */void *dma_common_pages_remap(struct page **pages, size_t size,			 pgprot_t prot, const void *caller){	void *vaddr; 	vaddr = vmap(pages, PAGE_ALIGN(size) >> PAGE_SHIFT,		     VM_DMA_COHERENT, prot);	if (vaddr)		find_vm_area(vaddr)->pages = pages;	return vaddr;} /* * Remaps an allocated contiguous region into another vm_area. * Cannot be used in non-sleeping contexts */void *dma_common_contiguous_remap(struct page *page, size_t size,			pgprot_t prot, const void *caller){	int count = PAGE_ALIGN(size) >> PAGE_SHIFT;	struct page **pages;	void *vaddr;	int i; 	pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);	if (!pages)		return NULL;	for (i = 0; i < count; i++)		pages[i] = nth_page(page, i);	vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);	kfree(pages); 	return vaddr;} /* * Unmaps a range previously mapped by dma_common_*_remap */void dma_common_free_remap(void *cpu_addr, size_t size){	struct vm_struct *area = find_vm_area(cpu_addr); 	if (!area || area->flags != VM_DMA_COHERENT) {		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);		return;	} 	vunmap(cpu_addr);}