1 files changed, 197 insertions, 0 deletions

diff --git a/arch/x86/crypto/crc32c-intel.c b/arch/x86/crypto/crc32c-intel.c
new file mode 100644
index 000000000000..070afc5b6c94
--- /dev/null
+++ b/arch/x86/crypto/crc32c-intel.c
@@ -0,0 +1,197 @@
+/*
+ * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
+ * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
+ * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
+ * http://www.intel.com/products/processor/manuals/
+ * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
+ * Volume 2A: Instruction Set Reference, A-M
+ *
+ * Copyright (c) 2008 Austin Zhang <austin_zhang@linux.intel.com>
+ * Copyright (c) 2008 Kent Liu <kent.liu@intel.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.
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <crypto/internal/hash.h>
+
+#include <asm/cpufeature.h>
+
+#define CHKSUM_BLOCK_SIZE       1
+#define CHKSUM_DIGEST_SIZE      4
+
+#define SCALE_F sizeof(unsigned long)
+
+#ifdef CONFIG_X86_64
+#define REX_PRE "0x48, "
+#else
+#define REX_PRE
+#endif
+
+static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length)
+{
+        while (length--) {
+                __asm__ __volatile__(
+                        ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
+                        :"=S"(crc)
+                        :"0"(crc), "c"(*data)
+                );
+                data++;
+        }
+
+        return crc;
+}
+
+static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len)
+{
+        unsigned int iquotient = len / SCALE_F;
+        unsigned int iremainder = len % SCALE_F;
+        unsigned long *ptmp = (unsigned long *)p;
+
+        while (iquotient--) {
+                __asm__ __volatile__(
+                        ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
+                        :"=S"(crc)
+                        :"0"(crc), "c"(*ptmp)
+                );
+                ptmp++;
+        }
+
+        if (iremainder)
+                crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
+                                 iremainder);
+
+        return crc;
+}
+
+/*
+ * 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 crc32c_intel_setkey(struct crypto_ahash *hash, const u8 *key,
+                        unsigned int keylen)
+{
+        u32 *mctx = crypto_ahash_ctx(hash);
+
+        if (keylen != sizeof(u32)) {
+                crypto_ahash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
+                return -EINVAL;
+        }
+        *mctx = le32_to_cpup((__le32 *)key);
+        return 0;
+}
+
+static int crc32c_intel_init(struct ahash_request *req)
+{
+        u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
+        u32 *crcp = ahash_request_ctx(req);
+
+        *crcp = *mctx;
+
+        return 0;
+}
+
+static int crc32c_intel_update(struct ahash_request *req)
+{
+        struct crypto_hash_walk walk;
+        u32 *crcp = ahash_request_ctx(req);
+        u32 crc = *crcp;
+        int nbytes;
+
+        for (nbytes = crypto_hash_walk_first(req, &walk); nbytes;
+           nbytes = crypto_hash_walk_done(&walk, 0))
+        crc = crc32c_intel_le_hw(crc, walk.data, nbytes);
+
+        *crcp = crc;
+        return 0;
+}
+
+static int crc32c_intel_final(struct ahash_request *req)
+{
+        u32 *crcp = ahash_request_ctx(req);
+
+        *(__le32 *)req->result = ~cpu_to_le32p(crcp);
+        return 0;
+}
+
+static int crc32c_intel_digest(struct ahash_request *req)
+{
+        struct crypto_hash_walk walk;
+        u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
+        u32 crc = *mctx;
+        int nbytes;
+
+        for (nbytes = crypto_hash_walk_first(req, &walk); nbytes;
+           nbytes = crypto_hash_walk_done(&walk, 0))
+                crc = crc32c_intel_le_hw(crc, walk.data, nbytes);
+
+        *(__le32 *)req->result = ~cpu_to_le32(crc);
+        return 0;
+}
+
+static int crc32c_intel_cra_init(struct crypto_tfm *tfm)
+{
+        u32 *key = crypto_tfm_ctx(tfm);
+
+        *key = ~0;
+
+        tfm->crt_ahash.reqsize = sizeof(u32);
+
+        return 0;
+}
+
+static struct crypto_alg alg = {
+        .cra_name               =       "crc32c",
+        .cra_driver_name        =       "crc32c-intel",
+        .cra_priority           =       200,
+        .cra_flags              =       CRYPTO_ALG_TYPE_AHASH,
+        .cra_blocksize          =       CHKSUM_BLOCK_SIZE,
+        .cra_alignmask          =       3,
+        .cra_ctxsize            =       sizeof(u32),
+        .cra_module             =       THIS_MODULE,
+        .cra_list               =       LIST_HEAD_INIT(alg.cra_list),
+        .cra_init               =       crc32c_intel_cra_init,
+        .cra_type               =       &crypto_ahash_type,
+        .cra_u                  =       {
+                .ahash = {
+                        .digestsize    =       CHKSUM_DIGEST_SIZE,
+                        .setkey        =       crc32c_intel_setkey,
+                        .init          =       crc32c_intel_init,
+                        .update        =       crc32c_intel_update,
+                        .final         =       crc32c_intel_final,
+                        .digest        =       crc32c_intel_digest,
+                }
+        }
+};
+
+
+static int __init crc32c_intel_mod_init(void)
+{
+        if (cpu_has_xmm4_2)
+                return crypto_register_alg(&alg);
+        else
+                return -ENODEV;
+}
+
+static void __exit crc32c_intel_mod_fini(void)
+{
+        crypto_unregister_alg(&alg);
+}
+
+module_init(crc32c_intel_mod_init);
+module_exit(crc32c_intel_mod_fini);
+
+MODULE_AUTHOR("Austin Zhang <austin.zhang@intel.com>, Kent Liu <kent.liu@intel.com>");
+MODULE_DESCRIPTION("CRC32c (Castagnoli) optimization using Intel Hardware.");
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS("crc32c");
+MODULE_ALIAS("crc32c-intel");
+