redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS 

While honouring the DMA_ATTR_FORCE_CONTIGUOUS on arm64 (commit
44176bb38fa4: "arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to
IOMMU"), the existing uses of dma_mmap_attrs() and dma_get_sgtable()
have been broken by passing a physically contiguous vm_struct with an
invalid pages pointer through the common iommu API.

Since the coherent allocation with DMA_ATTR_FORCE_CONTIGUOUS uses CMA,
this patch simply reuses the existing swiotlb logic for mmap and
get_sgtable.

Note that the current implementation of get_sgtable (both swiotlb and
iommu) is broken if dma_declare_coherent_memory() is used since such
memory does not have a corresponding struct page. To be addressed in a
subsequent patch.

Fixes: 44176bb38f ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU")
Reported-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
hifive-unleashed-5.1
Catalin Marinas 2017-04-25 15:42:31 +01:00
parent 2f9a0bec65
commit 92f66f84d9
1 changed files with 49 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

65
arch/arm64/mm/dma-mapping.c
View File

@ -308,24 +308,15 @@ static void __swiotlb_sync_sg_for_device(struct device *dev,
sg->length, dir);
}
static int __swiotlb_mmap(struct device *dev,
struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
static int __swiotlb_mmap_pfn(struct vm_area_struct *vma,
unsigned long pfn, size_t size)
{
int ret = -ENXIO;
unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
PAGE_SHIFT;
unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
is_device_dma_coherent(dev));
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
ret = remap_pfn_range(vma, vma->vm_start,
pfn + off,
@ -336,19 +327,43 @@ static int __swiotlb_mmap(struct device *dev,
return ret;
}
static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)
static int __swiotlb_mmap(struct device *dev,
struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
int ret;
unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
is_device_dma_coherent(dev));
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
return __swiotlb_mmap_pfn(vma, pfn, size);
}
static int __swiotlb_get_sgtable_page(struct sg_table *sgt,
struct page *page, size_t size)
{
int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (!ret)
sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)),
PAGE_ALIGN(size), 0);
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
return ret;
}
static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)
{
struct page *page = phys_to_page(dma_to_phys(dev, handle));
return __swiotlb_get_sgtable_page(sgt, page, size);
}
static int __swiotlb_dma_supported(struct device *hwdev, u64 mask)
{
if (swiotlb)
@ -703,6 +718,15 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
/*
* DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
* hence in the vmalloc space.
*/
unsigned long pfn = vmalloc_to_pfn(cpu_addr);
return __swiotlb_mmap_pfn(vma, pfn, size);
}
area = find_vm_area(cpu_addr);
if (WARN_ON(!area || !area->pages))
return -ENXIO;
@ -717,6 +741,15 @@ static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct vm_struct *area = find_vm_area(cpu_addr);
if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
/*
* DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
* hence in the vmalloc space.
*/
struct page *page = vmalloc_to_page(cpu_addr);
return __swiotlb_get_sgtable_page(sgt, page, size);
}
if (WARN_ON(!area || !area->pages))
return -ENXIO;