OpenRISC: DMA

Simple DMA implementation.  Allows for allocation of coherent memory
(simply uncached) for DMA operations.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 134 insertions, 0 deletions

diff --git a/arch/openrisc/include/asm/dma-mapping.h b/arch/openrisc/include/asm/dma-mapping.h
new file mode 100644
index 0000000..052f877
--- /dev/null
+++ b/arch/openrisc/include/asm/dma-mapping.h
@@ -0,0 +1,134 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_DMA_MAPPING_H
+#define __ASM_OPENRISC_DMA_MAPPING_H
+
+/*
+ * See Documentation/PCI/PCI-DMA-mapping.txt and
+ * Documentation/DMA-API.txt for documentation.
+ *
+ * This file is written with the intention of eventually moving over
+ * to largely using asm-generic/dma-mapping-common.h in its place.
+ */
+
+#include <linux/dma-debug.h>
+#include <asm-generic/dma-coherent.h>
+#include <linux/kmemcheck.h>
+
+#define DMA_ERROR_CODE		(~(dma_addr_t)0x0)
+
+int dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
+#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
+#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
+
+void *or1k_dma_alloc_coherent(struct device *dev, size_t size,
+			      dma_addr_t *dma_handle, gfp_t flag);
+void or1k_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+			    dma_addr_t dma_handle);
+dma_addr_t or1k_map_page(struct device *dev, struct page *page,
+			 unsigned long offset, size_t size,
+			 enum dma_data_direction dir,
+			 struct dma_attrs *attrs);
+void or1k_unmap_page(struct device *dev, dma_addr_t dma_handle,
+		     size_t size, enum dma_data_direction dir,
+		     struct dma_attrs *attrs);
+void or1k_sync_single_for_cpu(struct device *dev,
+			      dma_addr_t dma_handle, size_t size,
+			      enum dma_data_direction dir);
+void or1k_sync_single_for_device(struct device *dev,
+			         dma_addr_t dma_handle, size_t size,
+			         enum dma_data_direction dir);
+
+static inline void *dma_alloc_coherent(struct device *dev, size_t size,
+					dma_addr_t *dma_handle, gfp_t flag)
+{
+	void *memory;
+
+	memory = or1k_dma_alloc_coherent(dev, size, dma_handle, flag);
+
+	debug_dma_alloc_coherent(dev, size, *dma_handle, memory);
+	return memory;
+}
+
+static inline void dma_free_coherent(struct device *dev, size_t size,
+				     void *cpu_addr, dma_addr_t dma_handle)
+{
+	debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
+	or1k_dma_free_coherent(dev, size, cpu_addr, dma_handle);
+}
+
+static inline dma_addr_t dma_map_single(struct device *dev, void *ptr,
+					size_t size,
+					enum dma_data_direction dir)
+{
+	dma_addr_t addr;
+
+	kmemcheck_mark_initialized(ptr, size);
+	BUG_ON(!valid_dma_direction(dir));
+	addr = or1k_map_page(dev, virt_to_page(ptr),
+			     (unsigned long)ptr & ~PAGE_MASK, size,
+			     dir, NULL);
+	debug_dma_map_page(dev, virt_to_page(ptr),
+			   (unsigned long)ptr & ~PAGE_MASK, size,
+			   dir, addr, true);
+	return addr;
+}
+
+static inline void dma_unmap_single(struct device *dev, dma_addr_t addr,
+					  size_t size,
+					  enum dma_data_direction dir)
+{
+	BUG_ON(!valid_dma_direction(dir));
+	or1k_unmap_page(dev, addr, size, dir, NULL);
+	debug_dma_unmap_page(dev, addr, size, dir, true);
+}
+
+static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
+					   size_t size,
+					   enum dma_data_direction dir)
+{
+	BUG_ON(!valid_dma_direction(dir));
+	or1k_sync_single_for_cpu(dev, addr, size, dir);
+	debug_dma_sync_single_for_cpu(dev, addr, size, dir);
+}
+
+static inline void dma_sync_single_for_device(struct device *dev,
+					      dma_addr_t addr, size_t size,
+					      enum dma_data_direction dir)
+{
+	BUG_ON(!valid_dma_direction(dir));
+	or1k_sync_single_for_device(dev, addr, size, dir);
+	debug_dma_sync_single_for_device(dev, addr, size, dir);
+}
+
+static inline int dma_supported(struct device *dev, u64 dma_mask)
+{
+	/* Support 32 bit DMA mask exclusively */
+	return dma_mask == 0xffffffffULL;
+}
+
+static inline int dma_set_mask(struct device *dev, u64 dma_mask)
+{
+	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
+		return -EIO;
+
+	*dev->dma_mask = dma_mask;
+
+	return 0;
+}
+#endif	/* __ASM_OPENRISC_DMA_MAPPING_H */