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Diffstat (limited to 'crypto/scatterwalk.h')
| -rw-r--r-- | crypto/scatterwalk.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/crypto/scatterwalk.h b/crypto/scatterwalk.h new file mode 100644 index 00000000000..02aa56c649b --- /dev/null +++ b/crypto/scatterwalk.h @@ -0,0 +1,63 @@ +/* + * Cryptographic API. + * + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com> + * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com> + * + * 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 _CRYPTO_SCATTERWALK_H +#define _CRYPTO_SCATTERWALK_H +#include <linux/mm.h> +#include <asm/scatterlist.h> + +struct scatter_walk { + struct scatterlist *sg; + struct page *page; + void *data; + unsigned int len_this_page; + unsigned int len_this_segment; + unsigned int offset; +}; + +/* Define sg_next is an inline routine now in case we want to change + scatterlist to a linked list later. */ +static inline struct scatterlist *sg_next(struct scatterlist *sg) +{ + return sg + 1; +} + +static inline int scatterwalk_samebuf(struct scatter_walk *walk_in, + struct scatter_walk *walk_out) +{ + return walk_in->page == walk_out->page && + walk_in->offset == walk_out->offset; +} + +static inline int scatterwalk_across_pages(struct scatter_walk *walk, + unsigned int nbytes) +{ + return nbytes > walk->len_this_page; +} + +static inline void scatterwalk_advance(struct scatter_walk *walk, + unsigned int nbytes) +{ + walk->data += nbytes; + walk->offset += nbytes; + walk->len_this_page -= nbytes; + walk->len_this_segment -= nbytes; +} + +void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); +int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out); +void scatterwalk_map(struct scatter_walk *walk, int out); +void scatterwalk_done(struct scatter_walk *walk, int out, int more); + +#endif /* _CRYPTO_SCATTERWALK_H */ |