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// 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;
}
static struct vm_struct *__dma_common_pages_remap(struct page **pages,
size_t size, pgprot_t prot, const void *caller)
{
struct vm_struct *area;
area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
if (!area)
return NULL;
if (map_vm_area(area, prot, pages)) {
vunmap(area->addr);
return NULL;
}
return area;
}
/*
* 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)
{
struct vm_struct *area;
area = __dma_common_pages_remap(pages, size, prot, caller);
if (!area)
return NULL;
area->pages = pages;
return area->addr;
}
/*
* 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 i;
struct page **pages;
struct vm_struct *area;
pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
if (!pages)
return NULL;
for (i = 0; i < (size >> PAGE_SHIFT); i++)
pages[i] = nth_page(page, i);
area = __dma_common_pages_remap(pages, size, prot, caller);
kfree(pages);
if (!area)
return NULL;
return area->addr;
}
/*
* 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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