1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/dma-direct.h b/arch/arm64/include/asm/dma-direct.h
new file mode 100644
index 000000000000..abb1b40ec751
--- /dev/null
+++ b/arch/arm64/include/asm/dma-direct.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_DMA_DIRECT_H
+#define __ASM_DMA_DIRECT_H
+
+#include <linux/jump_label.h>
+#include <linux/swiotlb.h>
+
+#include <asm/cache.h>
+
+DECLARE_STATIC_KEY_FALSE(swiotlb_noncoherent_bounce);
+
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	dma_addr_t dev_addr = (dma_addr_t)paddr;
+
+	return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+	phys_addr_t paddr = (phys_addr_t)dev_addr;
+
+	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return false;
+
+	/*
+	 * Force swiotlb buffer bouncing when ARCH_DMA_MINALIGN < CWG. The
+	 * swiotlb bounce buffers are aligned to (1 << IO_TLB_SHIFT).
+	 */
+	if (static_branch_unlikely(&swiotlb_noncoherent_bounce) &&
+	    !is_device_dma_coherent(dev) &&
+	    !is_swiotlb_buffer(dma_to_phys(dev, addr)))
+		return false;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+
+#endif /* __ASM_DMA_DIRECT_H */