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- // 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;
- }
- unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
- vunmap(cpu_addr);
- }
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