1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2014 The Linux Foundation
5 #include <linux/dma-map-ops.h>
6 #include <linux/slab.h>
7 #include <linux/vmalloc.h>
9 struct page **dma_common_find_pages(void *cpu_addr)
11 struct vm_struct *area = find_vm_area(cpu_addr);
13 if (!area || area->flags != VM_DMA_COHERENT)
19 * Remaps an array of PAGE_SIZE pages into another vm_area.
20 * Cannot be used in non-sleeping contexts
22 void *dma_common_pages_remap(struct page **pages, size_t size,
23 pgprot_t prot, const void *caller)
27 vaddr = vmap(pages, PAGE_ALIGN(size) >> PAGE_SHIFT,
28 VM_DMA_COHERENT, prot);
30 find_vm_area(vaddr)->pages = pages;
35 * Remaps an allocated contiguous region into another vm_area.
36 * Cannot be used in non-sleeping contexts
38 void *dma_common_contiguous_remap(struct page *page, size_t size,
39 pgprot_t prot, const void *caller)
41 int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
46 pages = kvmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
49 for (i = 0; i < count; i++)
50 pages[i] = nth_page(page, i);
51 vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
58 * Unmaps a range previously mapped by dma_common_*_remap
60 void dma_common_free_remap(void *cpu_addr, size_t size)
62 struct vm_struct *area = find_vm_area(cpu_addr);
64 if (!area || area->flags != VM_DMA_COHERENT) {
65 WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);