From: Christoph Hellwig <h...@lst.de>

commit a98d9ae937d256ed679a935fc82d9deaa710d98e upstream.

DMA allocations that can't sleep may return non-remapped addresses, but
we do not properly handle them in the mmap and get_sgtable methods.
Resolve non-vmalloc addresses using virt_to_page to handle this corner
case.

Cc: <sta...@vger.kernel.org>
Acked-by: Catalin Marinas <catalin.mari...@arm.com>
Reviewed-by: Robin Murphy <robin.mur...@arm.com>
Signed-off-by: Christoph Hellwig <h...@lst.de>
Signed-off-by: Will Deacon <will.dea...@arm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/arm64/mm/dma-mapping.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -710,6 +710,11 @@ static int __iommu_mmap_attrs(struct dev
        if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
                return ret;
 
+       if (!is_vmalloc_addr(cpu_addr)) {
+               unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
+               return __swiotlb_mmap_pfn(vma, pfn, size);
+       }
+
        if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
                /*
                 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
@@ -733,6 +738,11 @@ static int __iommu_get_sgtable(struct de
        unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
        struct vm_struct *area = find_vm_area(cpu_addr);
 
+       if (!is_vmalloc_addr(cpu_addr)) {
+               struct page *page = virt_to_page(cpu_addr);
+               return __swiotlb_get_sgtable_page(sgt, page, size);
+       }
+
        if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
                /*
                 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,


Reply via email to