1 files changed, 44 insertions, 0 deletions
diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
new file mode 100644
index 000000000..882680e81
--- /dev/null
+++ b/arch/hexagon/kernel/dma.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DMA implementation for Hexagon
+ *
+ * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/dma-map-ops.h>
+#include <linux/memblock.h>
+#include <asm/page.h>
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir)
+{
+	void *addr = phys_to_virt(paddr);
+
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		hexagon_clean_dcache_range((unsigned long) addr,
+		(unsigned long) addr + size);
+		break;
+	case DMA_FROM_DEVICE:
+		hexagon_inv_dcache_range((unsigned long) addr,
+		(unsigned long) addr + size);
+		break;
+	case DMA_BIDIRECTIONAL:
+		flush_dcache_range((unsigned long) addr,
+		(unsigned long) addr + size);
+		break;
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Our max_low_pfn should have been backed off by 16MB in mm/init.c to create
+ * DMA coherent space.  Use that for the pool.
+ */
+static int __init hexagon_dma_init(void)
+{
+	return dma_init_global_coherent(PFN_PHYS(max_low_pfn),
+					hexagon_coherent_pool_size);
+}
+core_initcall(hexagon_dma_init);