// 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); }