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-rw-r--r--crypto/scatterwalk.h63
1 files changed, 63 insertions, 0 deletions
diff --git a/crypto/scatterwalk.h b/crypto/scatterwalk.h
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+++ b/crypto/scatterwalk.h
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+/*
+ * 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 */