Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / crypto / crc32.c

diff --git a/kernel/crypto/crc32.c b/kernel/crypto/crc32.c
new file mode 100644 (file)
index 0000000..187ded2
--- /dev/null
+++ b/kernel/crypto/crc32.c
@@ -0,0 +1,159 @@
+/* GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see http://www.gnu.org/licenses
+ *
+ * Please  visit http://www.xyratex.com/contact if you need additional
+ * information or have any questions.
+ *
+ * GPL HEADER END
+ */
+
+/*
+ * Copyright 2012 Xyratex Technology Limited
+ */
+
+/*
+ * This is crypto api shash wrappers to crc32_le.
+ */
+
+#include <linux/crc32.h>
+#include <crypto/internal/hash.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+
+#define CHKSUM_BLOCK_SIZE      1
+#define CHKSUM_DIGEST_SIZE     4
+
+static u32 __crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+       return crc32_le(crc, p, len);
+}
+
+/** No default init with ~0 */
+static int crc32_cra_init(struct crypto_tfm *tfm)
+{
+       u32 *key = crypto_tfm_ctx(tfm);
+
+       *key = 0;
+
+       return 0;
+}
+
+
+/*
+ * Setting the seed allows arbitrary accumulators and flexible XOR policy
+ * If your algorithm starts with ~0, then XOR with ~0 before you set
+ * the seed.
+ */
+static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
+                       unsigned int keylen)
+{
+       u32 *mctx = crypto_shash_ctx(hash);
+
+       if (keylen != sizeof(u32)) {
+               crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
+               return -EINVAL;
+       }
+       *mctx = le32_to_cpup((__le32 *)key);
+       return 0;
+}
+
+static int crc32_init(struct shash_desc *desc)
+{
+       u32 *mctx = crypto_shash_ctx(desc->tfm);
+       u32 *crcp = shash_desc_ctx(desc);
+
+       *crcp = *mctx;
+
+       return 0;
+}
+
+static int crc32_update(struct shash_desc *desc, const u8 *data,
+                       unsigned int len)
+{
+       u32 *crcp = shash_desc_ctx(desc);
+
+       *crcp = __crc32_le(*crcp, data, len);
+       return 0;
+}
+
+/* No final XOR 0xFFFFFFFF, like crc32_le */
+static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
+                        u8 *out)
+{
+       *(__le32 *)out = cpu_to_le32(__crc32_le(*crcp, data, len));
+       return 0;
+}
+
+static int crc32_finup(struct shash_desc *desc, const u8 *data,
+                      unsigned int len, u8 *out)
+{
+       return __crc32_finup(shash_desc_ctx(desc), data, len, out);
+}
+
+static int crc32_final(struct shash_desc *desc, u8 *out)
+{
+       u32 *crcp = shash_desc_ctx(desc);
+
+       *(__le32 *)out = cpu_to_le32p(crcp);
+       return 0;
+}
+
+static int crc32_digest(struct shash_desc *desc, const u8 *data,
+                       unsigned int len, u8 *out)
+{
+       return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
+                            out);
+}
+static struct shash_alg alg = {
+       .setkey         = crc32_setkey,
+       .init           = crc32_init,
+       .update         = crc32_update,
+       .final          = crc32_final,
+       .finup          = crc32_finup,
+       .digest         = crc32_digest,
+       .descsize       = sizeof(u32),
+       .digestsize     = CHKSUM_DIGEST_SIZE,
+       .base           = {
+               .cra_name               = "crc32",
+               .cra_driver_name        = "crc32-table",
+               .cra_priority           = 100,
+               .cra_blocksize          = CHKSUM_BLOCK_SIZE,
+               .cra_ctxsize            = sizeof(u32),
+               .cra_module             = THIS_MODULE,
+               .cra_init               = crc32_cra_init,
+       }
+};
+
+static int __init crc32_mod_init(void)
+{
+       return crypto_register_shash(&alg);
+}
+
+static void __exit crc32_mod_fini(void)
+{
+       crypto_unregister_shash(&alg);
+}
+
+module_init(crc32_mod_init);
+module_exit(crc32_mod_fini);
+
+MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
+MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CRYPTO("crc32");