mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-17 01:04:19 +08:00
e82b9b3086
vunmap will remove ptes. Link: https://lkml.kernel.org/r/20210322021806.892164-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Cédric Le Goater <clg@kaod.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
// 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);
|
|
}
|