Initial commit: OpenHarmony-v4.0-ReleaseOpenHarmony-v4.0-Release

1 files changed, 93 insertions, 0 deletions

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
new file mode 100644
index 000000000..16f6ba896
--- /dev/null
+++ b/crypto/scatterwalk.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cryptographic API.
+ *
+ * Cipher operations.
+ *
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ *               2002 Adam J. Richter <adam@yggdrasil.com>
+ *               2004 Jean-Luc Cooke <jlcooke@certainkey.com>
+ */
+
+#include <crypto/scatterwalk.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+
+static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
+{
+        void *src = out ? buf : sgdata;
+        void *dst = out ? sgdata : buf;
+
+        memcpy(dst, src, nbytes);
+}
+
+void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
+                            size_t nbytes, int out)
+{
+        for (;;) {
+                unsigned int len_this_page = scatterwalk_pagelen(walk);
+                u8 *vaddr;
+
+                if (len_this_page > nbytes)
+                        len_this_page = nbytes;
+
+                if (out != 2) {
+                        vaddr = scatterwalk_map(walk);
+                        memcpy_dir(buf, vaddr, len_this_page, out);
+                        scatterwalk_unmap(vaddr);
+                }
+
+                scatterwalk_advance(walk, len_this_page);
+
+                if (nbytes == len_this_page)
+                        break;
+
+                buf += len_this_page;
+                nbytes -= len_this_page;
+
+                scatterwalk_pagedone(walk, out & 1, 1);
+        }
+}
+EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
+
+void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
+                              unsigned int start, unsigned int nbytes, int out)
+{
+        struct scatter_walk walk;
+        struct scatterlist tmp[2];
+
+        if (!nbytes)
+                return;
+
+        sg = scatterwalk_ffwd(tmp, sg, start);
+
+        scatterwalk_start(&walk, sg);
+        scatterwalk_copychunks(buf, &walk, nbytes, out);
+        scatterwalk_done(&walk, out, 0);
+}
+EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
+
+struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
+                                     struct scatterlist *src,
+                                     unsigned int len)
+{
+        for (;;) {
+                if (!len)
+                        return src;
+
+                if (src->length > len)
+                        break;
+
+                len -= src->length;
+                src = sg_next(src);
+        }
+
+        sg_init_table(dst, 2);
+        sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
+        scatterwalk_crypto_chain(dst, sg_next(src), 2);
+
+        return dst;
+}
+EXPORT_SYMBOL_GPL(scatterwalk_ffwd);