tile pci: enable IOMMU to support DMA for legacy devices

This change uses the TRIO IOMMU to map the PCI DMA space and physical
memory at different addresses.  We also now use the dma_mapping_ops
to provide support for non-PCI DMA, PCIe DMA (64-bit) and legacy PCI
DMA (32-bit).  We use the kernel's software I/O TLB framework
(i.e. bounce buffers) for the legacy 32-bit PCI device support since
there are a limited number of TLB entries in the IOMMU and it is
non-trivial to handle indexing, searching, matching, etc.  For 32-bit
devices the performance impact of bounce buffers should not be a concern.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/arch/tile/include/asm/device.h b/arch/tile/include/asm/device.h
new file mode 100644
index 000000000000..5182705bd056
--- /dev/null
+++ b/arch/tile/include/asm/device.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ * Arch specific extensions to struct device
+ */
+
+#ifndef _ASM_TILE_DEVICE_H
+#define _ASM_TILE_DEVICE_H
+
+struct dev_archdata {
+	/* DMA operations on that device */
+        struct dma_map_ops	*dma_ops;
+
+	/* Offset of the DMA address from the PA. */
+	dma_addr_t		dma_offset;
+
+	/* Highest DMA address that can be generated by this device. */
+	dma_addr_t		max_direct_dma_addr;
+};
+
+struct pdev_archdata {
+};
+
+#endif /* _ASM_TILE_DEVICE_H */