1 files changed, 201 insertions, 0 deletions

diff --git a/arch/x86/crypto/crc32-pclmul_glue.c b/arch/x86/crypto/crc32-pclmul_glue.c
new file mode 100644
index 000000000000..9d014a74ef96
--- /dev/null
+++ b/arch/x86/crypto/crc32-pclmul_glue.c
@@ -0,0 +1,201 @@
+/* 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
+ *
+ * Wrappers for kernel crypto shash api to pclmulqdq crc32 imlementation.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/crc32.h>
+#include <crypto/internal/hash.h>
+
+#include <asm/cpufeature.h>
+#include <asm/cpu_device_id.h>
+#include <asm/i387.h>
+
+#define CHKSUM_BLOCK_SIZE       1
+#define CHKSUM_DIGEST_SIZE      4
+
+#define PCLMUL_MIN_LEN          64L     /* minimum size of buffer
+                                         * for crc32_pclmul_le_16 */
+#define SCALE_F                 16L     /* size of xmm register */
+#define SCALE_F_MASK            (SCALE_F - 1)
+
+u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32);
+
+static u32 __attribute__((pure))
+        crc32_pclmul_le(u32 crc, unsigned char const *p, size_t len)
+{
+        unsigned int iquotient;
+        unsigned int iremainder;
+        unsigned int prealign;
+
+        if (len < PCLMUL_MIN_LEN + SCALE_F_MASK || !irq_fpu_usable())
+                return crc32_le(crc, p, len);
+
+        if ((long)p & SCALE_F_MASK) {
+                /* align p to 16 byte */
+                prealign = SCALE_F - ((long)p & SCALE_F_MASK);
+
+                crc = crc32_le(crc, p, prealign);
+                len -= prealign;
+                p = (unsigned char *)(((unsigned long)p + SCALE_F_MASK) &
+                                     ~SCALE_F_MASK);
+        }
+        iquotient = len & (~SCALE_F_MASK);
+        iremainder = len & SCALE_F_MASK;
+
+        kernel_fpu_begin();
+        crc = crc32_pclmul_le_16(p, iquotient, crc);
+        kernel_fpu_end();
+
+        if (iremainder)
+                crc = crc32_le(crc, p + iquotient, iremainder);
+
+        return crc;
+}
+
+static int crc32_pclmul_cra_init(struct crypto_tfm *tfm)
+{
+        u32 *key = crypto_tfm_ctx(tfm);
+
+        *key = 0;
+
+        return 0;
+}
+
+static int crc32_pclmul_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_pclmul_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_pclmul_update(struct shash_desc *desc, const u8 *data,
+                               unsigned int len)
+{
+        u32 *crcp = shash_desc_ctx(desc);
+
+        *crcp = crc32_pclmul_le(*crcp, data, len);
+        return 0;
+}
+
+/* No final XOR 0xFFFFFFFF, like crc32_le */
+static int __crc32_pclmul_finup(u32 *crcp, const u8 *data, unsigned int len,
+                                u8 *out)
+{
+        *(__le32 *)out = cpu_to_le32(crc32_pclmul_le(*crcp, data, len));
+        return 0;
+}
+
+static int crc32_pclmul_finup(struct shash_desc *desc, const u8 *data,
+                              unsigned int len, u8 *out)
+{
+        return __crc32_pclmul_finup(shash_desc_ctx(desc), data, len, out);
+}
+
+static int crc32_pclmul_final(struct shash_desc *desc, u8 *out)
+{
+        u32 *crcp = shash_desc_ctx(desc);
+
+        *(__le32 *)out = cpu_to_le32p(crcp);
+        return 0;
+}
+
+static int crc32_pclmul_digest(struct shash_desc *desc, const u8 *data,
+                               unsigned int len, u8 *out)
+{
+        return __crc32_pclmul_finup(crypto_shash_ctx(desc->tfm), data, len,
+                                    out);
+}
+
+static struct shash_alg alg = {
+        .setkey         = crc32_pclmul_setkey,
+        .init           = crc32_pclmul_init,
+        .update         = crc32_pclmul_update,
+        .final          = crc32_pclmul_final,
+        .finup          = crc32_pclmul_finup,
+        .digest         = crc32_pclmul_digest,
+        .descsize       = sizeof(u32),
+        .digestsize     = CHKSUM_DIGEST_SIZE,
+        .base           = {
+                        .cra_name               = "crc32",
+                        .cra_driver_name        = "crc32-pclmul",
+                        .cra_priority           = 200,
+                        .cra_blocksize          = CHKSUM_BLOCK_SIZE,
+                        .cra_ctxsize            = sizeof(u32),
+                        .cra_module             = THIS_MODULE,
+                        .cra_init               = crc32_pclmul_cra_init,
+        }
+};
+
+static const struct x86_cpu_id crc32pclmul_cpu_id[] = {
+        X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
+        {}
+};
+MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id);
+
+
+static int __init crc32_pclmul_mod_init(void)
+{
+
+        if (!x86_match_cpu(crc32pclmul_cpu_id)) {
+                pr_info("PCLMULQDQ-NI instructions are not detected.\n");
+                return -ENODEV;
+        }
+        return crypto_register_shash(&alg);
+}
+
+static void __exit crc32_pclmul_mod_fini(void)
+{
+        crypto_unregister_shash(&alg);
+}
+
+module_init(crc32_pclmul_mod_init);
+module_exit(crc32_pclmul_mod_fini);
+
+MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS("crc32");
+MODULE_ALIAS("crc32-pclmul");