crypto: crc32 - add crc32 pclmulqdq implementation and wrappers for table implementation
This patch adds crc32 algorithms to shash crypto api. One is wrapper to
gerneric crc32_le function. Second is crc32 pclmulqdq implementation. It
use hardware provided PCLMULQDQ instruction to accelerate the CRC32 disposal.
This instruction present from Intel Westmere and AMD Bulldozer CPUs.
For intel core i5 I got 450MB/s for table implementation and 2100MB/s
for pclmulqdq implementation.
Signed-off-by: Alexander Boyko <alexander_boyko@xyratex.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/crc32.c b/crypto/crc32.c
new file mode 100644
index 0000000..9d1c415
--- /dev/null
+++ b/crypto/crc32.c
@@ -0,0 +1,158 @@
+/* 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");