[PATCH 4.19 015/276] arm64/iommu: handle non-remapped addresses in ->mmap and ->get_sgtable

[Greg Kroah-Hartman]

From: Christoph Hellwig <hch@xxxxxx>

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: <stable@xxxxxxxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 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
@@ -664,6 +664,11 @@ 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,
@@ -687,6 +692,11 @@ 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,