mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 16:24:13 +08:00
40ac971eab
xen-swiotlb can use vmalloc backed addresses for dma coherent allocations
and uses the common helpers. Properly handle them to unbreak Xen on
ARM platforms.
Fixes: 1b65c4e5a9 ("swiotlb-xen: use xen_alloc/free_coherent_pages")
Signed-off-by: Roman Skakun <roman_skakun@epam.com>
Reviewed-by: Andrii Anisov <andrii_anisov@epam.com>
[hch: split the patch, renamed the helpers]
Signed-off-by: Christoph Hellwig <hch@lst.de>
94 lines
2.5 KiB
C
94 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Helpers for DMA ops implementations. These generally rely on the fact that
|
|
* the allocated memory contains normal pages in the direct kernel mapping.
|
|
*/
|
|
#include <linux/dma-map-ops.h>
|
|
|
|
static struct page *dma_common_vaddr_to_page(void *cpu_addr)
|
|
{
|
|
if (is_vmalloc_addr(cpu_addr))
|
|
return vmalloc_to_page(cpu_addr);
|
|
return virt_to_page(cpu_addr);
|
|
}
|
|
|
|
/*
|
|
* Create scatter-list for the already allocated DMA buffer.
|
|
*/
|
|
int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
|
|
void *cpu_addr, dma_addr_t dma_addr, size_t size,
|
|
unsigned long attrs)
|
|
{
|
|
struct page *page = dma_common_vaddr_to_page(cpu_addr);
|
|
int ret;
|
|
|
|
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
|
|
if (!ret)
|
|
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Create userspace mapping for the DMA-coherent memory.
|
|
*/
|
|
int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
|
|
void *cpu_addr, dma_addr_t dma_addr, size_t size,
|
|
unsigned long attrs)
|
|
{
|
|
#ifdef CONFIG_MMU
|
|
unsigned long user_count = vma_pages(vma);
|
|
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
|
|
unsigned long off = vma->vm_pgoff;
|
|
struct page *page = dma_common_vaddr_to_page(cpu_addr);
|
|
int ret = -ENXIO;
|
|
|
|
vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
|
|
|
|
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
|
|
return ret;
|
|
|
|
if (off >= count || user_count > count - off)
|
|
return -ENXIO;
|
|
|
|
return remap_pfn_range(vma, vma->vm_start,
|
|
page_to_pfn(page) + vma->vm_pgoff,
|
|
user_count << PAGE_SHIFT, vma->vm_page_prot);
|
|
#else
|
|
return -ENXIO;
|
|
#endif /* CONFIG_MMU */
|
|
}
|
|
|
|
struct page *dma_common_alloc_pages(struct device *dev, size_t size,
|
|
dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
|
|
{
|
|
const struct dma_map_ops *ops = get_dma_ops(dev);
|
|
struct page *page;
|
|
|
|
page = dma_alloc_contiguous(dev, size, gfp);
|
|
if (!page)
|
|
page = alloc_pages_node(dev_to_node(dev), gfp, get_order(size));
|
|
if (!page)
|
|
return NULL;
|
|
|
|
*dma_handle = ops->map_page(dev, page, 0, size, dir,
|
|
DMA_ATTR_SKIP_CPU_SYNC);
|
|
if (*dma_handle == DMA_MAPPING_ERROR) {
|
|
dma_free_contiguous(dev, page, size);
|
|
return NULL;
|
|
}
|
|
|
|
memset(page_address(page), 0, size);
|
|
return page;
|
|
}
|
|
|
|
void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
|
|
dma_addr_t dma_handle, enum dma_data_direction dir)
|
|
{
|
|
const struct dma_map_ops *ops = get_dma_ops(dev);
|
|
|
|
if (ops->unmap_page)
|
|
ops->unmap_page(dev, dma_handle, size, dir,
|
|
DMA_ATTR_SKIP_CPU_SYNC);
|
|
dma_free_contiguous(dev, page, size);
|
|
}
|