1 files changed, 76 insertions, 0 deletions
diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c
new file mode 100644
index 000000000..e244ebe63
--- /dev/null
+++ b/arch/mn10300/mm/dma-alloc.c
@@ -0,0 +1,76 @@
+/* MN10300 Dynamic DMA mapping support
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * Derived from: arch/i386/kernel/pci-dma.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <asm/io.h>
+
+static unsigned long pci_sram_allocated = 0xbc000000;
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			 dma_addr_t *dma_handle, int gfp)
+{
+	unsigned long addr;
+	void *ret;
+
+	pr_debug("dma_alloc_coherent(%s,%zu,%x)\n",
+		 dev ? dev_name(dev) : "?", size, gfp);
+
+	if (0xbe000000 - pci_sram_allocated >= size) {
+		size = (size + 255) & ~255;
+		addr = pci_sram_allocated;
+		pci_sram_allocated += size;
+		ret = (void *) addr;
+		goto done;
+	}
+
+	/* ignore region specifiers */
+	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+	if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
+		gfp |= GFP_DMA;
+
+	addr = __get_free_pages(gfp, get_order(size));
+	if (!addr)
+		return NULL;
+
+	/* map the coherent memory through the uncached memory window */
+	ret = (void *) (addr | 0x20000000);
+
+	/* fill the memory with obvious rubbish */
+	memset((void *) addr, 0xfb, size);
+
+	/* write back and evict all cache lines covering this region */
+	mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);
+
+done:
+	*dma_handle = virt_to_bus((void *) addr);
+	printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle);
+	return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+		       dma_addr_t dma_handle)
+{
+	unsigned long addr = (unsigned long) vaddr & ~0x20000000;
+
+	if (addr >= 0x9c000000)
+		return;
+
+	free_pages(addr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);