1 files changed, 37 insertions, 0 deletions

diff --git a/arch/mips/sgi-ip32/ip32-dma.c b/arch/mips/sgi-ip32/ip32-dma.c
new file mode 100644
index 000000000..20c6da9d7
--- /dev/null
+++ b/arch/mips/sgi-ip32/ip32-dma.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2006  Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <linux/dma-direct.h>
+#include <asm/ip32/crime.h>
+
+/*
+ * Few notes.
+ * 1. CPU sees memory as two chunks: 0-256M@0x0, and the rest @0x40000000+256M
+ * 2. PCI sees memory as one big chunk @0x0 (or we could use 0x40000000 for
+ *    native-endian)
+ * 3. All other devices see memory as one big chunk at 0x40000000
+ * 4. Non-PCI devices will pass NULL as struct device*
+ *
+ * Thus we translate differently, depending on device.
+ */
+
+#define RAM_OFFSET_MASK 0x3fffffffUL
+
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+        dma_addr_t dma_addr = paddr & RAM_OFFSET_MASK;
+
+        if (!dev)
+                dma_addr += CRIME_HI_MEM_BASE;
+        return dma_addr;
+}
+
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+{
+        phys_addr_t paddr = dma_addr & RAM_OFFSET_MASK;
+
+        if (dma_addr >= 256*1024*1024)
+                paddr += CRIME_HI_MEM_BASE;
+        return paddr;
+}