diff options
Diffstat (limited to 'arch/arc/plat-arcfpga/include/plat/dma_addr.h')
| -rw-r--r-- | arch/arc/plat-arcfpga/include/plat/dma_addr.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arc/plat-arcfpga/include/plat/dma_addr.h b/arch/arc/plat-arcfpga/include/plat/dma_addr.h new file mode 100644 index 00000000000..0e963431b72 --- /dev/null +++ b/arch/arc/plat-arcfpga/include/plat/dma_addr.h @@ -0,0 +1,45 @@ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * vineetg: Feb 2009 + * -For AA4 board, kernel to DMA address APIs + */ + +/* + * kernel addresses are 0x800_000 based, while Bus addr are 0 based + */ + +#ifndef __PLAT_DMA_ADDR_H +#define __PLAT_DMA_ADDR_H + +#include <linux/device.h> + +static inline unsigned long plat_dma_addr_to_kernel(struct device *dev, + dma_addr_t dma_addr) +{ + return dma_addr + PAGE_OFFSET; +} + +static inline dma_addr_t plat_kernel_addr_to_dma(struct device *dev, void *ptr) +{ + unsigned long addr = (unsigned long)ptr; + /* + * To Catch buggy drivers which can call DMA map API with kernel vaddr + * i.e. for buffers alloc via vmalloc or ioremap which are not + * gaurnateed to be PHY contiguous and hence unfit for DMA anyways. + * On ARC kernel virtual address is 0x7000_0000 to 0x7FFF_FFFF, so + * ideally we want to check this range here, but our implementation is + * better as it checks for even worse user virtual address as well. + */ + if (likely(addr >= PAGE_OFFSET)) + return addr - PAGE_OFFSET; + + BUG(); + return addr; +} + +#endif |