linux/kernel/dma/remap.c
Eric Auger 8e36baf97b dma-remap: align the size in dma_common_*_remap()
Running a guest with a virtio-iommu protecting virtio devices
is broken since commit 515e5b6d90 ("dma-mapping: use vmap insted
of reimplementing it"). Before the conversion, the size was
page aligned in __get_vm_area_node(). Doing so fixes the
regression.

Fixes: 515e5b6d90 ("dma-mapping: use vmap insted of reimplementing it")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-23 14:14:41 +02:00

72 lines
1.6 KiB
C

// 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, 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);
}