1 files changed, 95 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/pci_direct_iommu.c b/arch/ppc64/kernel/pci_direct_iommu.c
new file mode 100644
index 000000000000..b8f7f58824f4
--- /dev/null
+++ b/arch/ppc64/kernel/pci_direct_iommu.c
@@ -0,0 +1,95 @@
+/*
+ * Support for DMA from PCI devices to main memory on
+ * machines without an iommu or with directly addressable
+ * RAM (typically a pmac with 2Gb of RAM or less)
+ *
+ * Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/sections.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/pci-bridge.h>
+#include <asm/machdep.h>
+#include <asm/pmac_feature.h>
+#include <asm/abs_addr.h>
+
+#include "pci.h"
+
+static void *pci_direct_alloc_coherent(struct device *hwdev, size_t size,
+				   dma_addr_t *dma_handle, unsigned int __nocast flag)
+{
+	void *ret;
+
+	ret = (void *)__get_free_pages(flag, get_order(size));
+	if (ret != NULL) {
+		memset(ret, 0, size);
+		*dma_handle = virt_to_abs(ret);
+	}
+	return ret;
+}
+
+static void pci_direct_free_coherent(struct device *hwdev, size_t size,
+				 void *vaddr, dma_addr_t dma_handle)
+{
+	free_pages((unsigned long)vaddr, get_order(size));
+}
+
+static dma_addr_t pci_direct_map_single(struct device *hwdev, void *ptr,
+		size_t size, enum dma_data_direction direction)
+{
+	return virt_to_abs(ptr);
+}
+
+static void pci_direct_unmap_single(struct device *hwdev, dma_addr_t dma_addr,
+		size_t size, enum dma_data_direction direction)
+{
+}
+
+static int pci_direct_map_sg(struct device *hwdev, struct scatterlist *sg,
+		int nents, enum dma_data_direction direction)
+{
+	int i;
+
+	for (i = 0; i < nents; i++, sg++) {
+		sg->dma_address = page_to_phys(sg->page) + sg->offset;
+		sg->dma_length = sg->length;
+	}
+
+	return nents;
+}
+
+static void pci_direct_unmap_sg(struct device *hwdev, struct scatterlist *sg,
+		int nents, enum dma_data_direction direction)
+{
+}
+
+static int pci_direct_dma_supported(struct device *dev, u64 mask)
+{
+	return mask < 0x100000000ull;
+}
+
+void __init pci_direct_iommu_init(void)
+{
+	pci_dma_ops.alloc_coherent = pci_direct_alloc_coherent;
+	pci_dma_ops.free_coherent = pci_direct_free_coherent;
+	pci_dma_ops.map_single = pci_direct_map_single;
+	pci_dma_ops.unmap_single = pci_direct_unmap_single;
+	pci_dma_ops.map_sg = pci_direct_map_sg;
+	pci_dma_ops.unmap_sg = pci_direct_unmap_sg;
+	pci_dma_ops.dma_supported = pci_direct_dma_supported;
+}