| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (c) 2014 The Linux Foundation |
| */ |
| #include <linux/dma-mapping.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, 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 = 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; |
| } |
| |
| unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size)); |
| vunmap(cpu_addr); |
| } |