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Diffstat (limited to 'arch/mn10300/include/asm/scatterlist.h')
-rw-r--r-- | arch/mn10300/include/asm/scatterlist.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/mn10300/include/asm/scatterlist.h b/arch/mn10300/include/asm/scatterlist.h new file mode 100644 index 00000000000..67535901b9f --- /dev/null +++ b/arch/mn10300/include/asm/scatterlist.h @@ -0,0 +1,55 @@ +/* MN10300 Scatterlist definitions + * + * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd. + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#ifndef _ASM_SCATTERLIST_H +#define _ASM_SCATTERLIST_H + +#include <asm/types.h> + +/* + * Drivers must set either ->address or (preferred) page and ->offset + * to indicate where data must be transferred to/from. + * + * Using page is recommended since it handles highmem data as well as + * low mem. ->address is restricted to data which has a virtual mapping, and + * it will go away in the future. Updating to page can be automated very + * easily -- something like + * + * sg->address = some_ptr; + * + * can be rewritten as + * + * sg_set_page(virt_to_page(some_ptr)); + * sg->offset = (unsigned long) some_ptr & ~PAGE_MASK; + * + * and that's it. There's no excuse for not highmem enabling YOUR driver. /jens + */ +struct scatterlist { +#ifdef CONFIG_DEBUG_SG + unsigned long sg_magic; +#endif + unsigned long page_link; + unsigned int offset; /* for highmem, page offset */ + dma_addr_t dma_address; + unsigned int length; +}; + +#define ISA_DMA_THRESHOLD (0x00ffffff) + +/* + * These macros should be used after a pci_map_sg call has been done + * to get bus addresses of each of the SG entries and their lengths. + * You should only work with the number of sg entries pci_map_sg + * returns. + */ +#define sg_dma_address(sg) ((sg)->dma_address) +#define sg_dma_len(sg) ((sg)->length) + +#endif /* _ASM_SCATTERLIST_H */ |