1 files changed, 107 insertions, 0 deletions

diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
new file mode 100644
index 000000000000..07b6f17122d2
--- /dev/null
+++ b/include/crypto/scatterwalk.h
@@ -0,0 +1,107 @@
+/*
+ * Cryptographic scatter and gather helpers.
+ *
+ * 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>
+ * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * 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 <asm/kmap_types.h>
+#include <crypto/algapi.h>
+#include <linux/hardirq.h>
+#include <linux/highmem.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+
+static inline enum km_type crypto_kmap_type(int out)
+{
+        enum km_type type;
+
+        if (in_softirq())
+                type = out * (KM_SOFTIRQ1 - KM_SOFTIRQ0) + KM_SOFTIRQ0;
+        else
+                type = out * (KM_USER1 - KM_USER0) + KM_USER0;
+
+        return type;
+}
+
+static inline void *crypto_kmap(struct page *page, int out)
+{
+        return kmap_atomic(page, crypto_kmap_type(out));
+}
+
+static inline void crypto_kunmap(void *vaddr, int out)
+{
+        kunmap_atomic(vaddr, crypto_kmap_type(out));
+}
+
+static inline void crypto_yield(u32 flags)
+{
+        if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
+                cond_resched();
+}
+
+static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
+                                                struct scatter_walk *walk_out)
+{
+        return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
+                 (int)(walk_in->offset - walk_out->offset));
+}
+
+static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
+{
+        unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
+        unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
+        return len_this_page > len ? len : len_this_page;
+}
+
+static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
+                                             unsigned int nbytes)
+{
+        unsigned int len_this_page = scatterwalk_pagelen(walk);
+        return nbytes > len_this_page ? len_this_page : nbytes;
+}
+
+static inline void scatterwalk_advance(struct scatter_walk *walk,
+                                       unsigned int nbytes)
+{
+        walk->offset += nbytes;
+}
+
+static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
+                                               unsigned int alignmask)
+{
+        return !(walk->offset & alignmask);
+}
+
+static inline struct page *scatterwalk_page(struct scatter_walk *walk)
+{
+        return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
+}
+
+static inline void scatterwalk_unmap(void *vaddr, int out)
+{
+        crypto_kunmap(vaddr, out);
+}
+
+void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
+void 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);
+
+void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
+                              unsigned int start, unsigned int nbytes, int out);
+
+#endif  /* _CRYPTO_SCATTERWALK_H */