1 files changed, 94 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
new file mode 100644
index 00000000..2783fda7
--- /dev/null
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -0,0 +1,94 @@
+/*
+ * arch/xtensa/kernel/pci-dma.c
+ *
+ * DMA coherent memory allocation.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * Copyright (C) 2002 - 2005 Tensilica Inc.
+ *
+ * Based on version for i386.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/gfp.h>
+#include <asm/io.h>
+#include <asm/cacheflush.h>
+
+/*
+ * Note: We assume that the full memory space is always mapped to 'kseg'
+ *	 Otherwise we have to use page attributes (not implemented).
+ */
+
+void *
+dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
+{
+	unsigned long ret;
+	unsigned long uncached = 0;
+
+	/* ignore region speicifiers */
+
+	flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
+		flag |= GFP_DMA;
+	ret = (unsigned long)__get_free_pages(flag, get_order(size));
+
+	if (ret == 0)
+		return NULL;
+
+	/* We currently don't support coherent memory outside KSEG */
+
+	if (ret < XCHAL_KSEG_CACHED_VADDR
+	    || ret >= XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE)
+		BUG();
+
+
+	if (ret != 0) {
+		memset((void*) ret, 0, size);
+		uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR;
+		*handle = virt_to_bus((void*)ret);
+		__flush_invalidate_dcache_range(ret, size);
+	}
+
+	return (void*)uncached;
+}
+
+void dma_free_coherent(struct device *hwdev, size_t size,
+			 void *vaddr, dma_addr_t dma_handle)
+{
+	long addr=(long)vaddr+XCHAL_KSEG_CACHED_VADDR-XCHAL_KSEG_BYPASS_VADDR;
+
+	if (addr < 0 || addr >= XCHAL_KSEG_SIZE)
+		BUG();
+
+	free_pages(addr, get_order(size));
+}
+
+
+void consistent_sync(void *vaddr, size_t size, int direction)
+{
+	switch (direction) {
+	case PCI_DMA_NONE:
+		BUG();
+	case PCI_DMA_FROMDEVICE:        /* invalidate only */
+		__invalidate_dcache_range((unsigned long)vaddr,
+				          (unsigned long)size);
+		break;
+
+	case PCI_DMA_TODEVICE:          /* writeback only */
+	case PCI_DMA_BIDIRECTIONAL:     /* writeback and invalidate */
+		__flush_invalidate_dcache_range((unsigned long)vaddr,
+				    		(unsigned long)size);
+		break;
+	}
+}