1 files changed, 284 insertions, 0 deletions
diff --git a/arch/x86/crypto/crc32c-intel_glue.c b/arch/x86/crypto/crc32c-intel_glue.c
new file mode 100644
index 000000000..28640c3d6
--- /dev/null
+++ b/arch/x86/crypto/crc32c-intel_glue.c
@@ -0,0 +1,284 @@
+/*
+ * 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 Intel Corporation
+ * Authors: Austin Zhang <austin_zhang@linux.intel.com>
+ *          Kent Liu <kent.liu@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+#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>
+#include <asm/cpu_device_id.h>
+#include <asm/i387.h>
+#include <asm/fpu-internal.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
+
+#ifdef CONFIG_X86_64
+/*
+ * use carryless multiply version of crc32c when buffer
+ * size is >= 512 (when eager fpu is enabled) or
+ * >= 1024 (when eager fpu is disabled) to account
+ * for fpu state save/restore overhead.
+ */
+#define CRC32C_PCL_BREAKEVEN_EAGERFPU	512
+#define CRC32C_PCL_BREAKEVEN_NOEAGERFPU	1024
+
+asmlinkage unsigned int crc_pcl(const u8 *buffer, int len,
+				unsigned int crc_init);
+static int crc32c_pcl_breakeven = CRC32C_PCL_BREAKEVEN_EAGERFPU;
+#if defined(X86_FEATURE_EAGER_FPU)
+#define set_pcl_breakeven_point()					\
+do {									\
+	if (!use_eager_fpu())						\
+		crc32c_pcl_breakeven = CRC32C_PCL_BREAKEVEN_NOEAGERFPU;	\
+} while (0)
+#else
+#define set_pcl_breakeven_point()					\
+	(crc32c_pcl_breakeven = CRC32C_PCL_BREAKEVEN_NOEAGERFPU)
+#endif
+#endif /* CONFIG_X86_64 */
+
+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_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 crc32c_intel_init(struct shash_desc *desc)
+{
+	u32 *mctx = crypto_shash_ctx(desc->tfm);
+	u32 *crcp = shash_desc_ctx(desc);
+
+	*crcp = *mctx;
+
+	return 0;
+}
+
+static int crc32c_intel_update(struct shash_desc *desc, const u8 *data,
+			       unsigned int len)
+{
+	u32 *crcp = shash_desc_ctx(desc);
+
+	*crcp = crc32c_intel_le_hw(*crcp, data, len);
+	return 0;
+}
+
+static int __crc32c_intel_finup(u32 *crcp, const u8 *data, unsigned int len,
+				u8 *out)
+{
+	*(__le32 *)out = ~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len));
+	return 0;
+}
+
+static int crc32c_intel_finup(struct shash_desc *desc, const u8 *data,
+			      unsigned int len, u8 *out)
+{
+	return __crc32c_intel_finup(shash_desc_ctx(desc), data, len, out);
+}
+
+static int crc32c_intel_final(struct shash_desc *desc, u8 *out)
+{
+	u32 *crcp = shash_desc_ctx(desc);
+
+	*(__le32 *)out = ~cpu_to_le32p(crcp);
+	return 0;
+}
+
+static int crc32c_intel_digest(struct shash_desc *desc, const u8 *data,
+			       unsigned int len, u8 *out)
+{
+	return __crc32c_intel_finup(crypto_shash_ctx(desc->tfm), data, len,
+				    out);
+}
+
+static int crc32c_intel_cra_init(struct crypto_tfm *tfm)
+{
+	u32 *key = crypto_tfm_ctx(tfm);
+
+	*key = ~0;
+
+	return 0;
+}
+
+#ifdef CONFIG_X86_64
+static int crc32c_pcl_intel_update(struct shash_desc *desc, const u8 *data,
+			       unsigned int len)
+{
+	u32 *crcp = shash_desc_ctx(desc);
+
+	/*
+	 * use faster PCL version if datasize is large enough to
+	 * overcome kernel fpu state save/restore overhead
+	 */
+	if (len >= crc32c_pcl_breakeven && irq_fpu_usable()) {
+		kernel_fpu_begin();
+		*crcp = crc_pcl(data, len, *crcp);
+		kernel_fpu_end();
+	} else
+		*crcp = crc32c_intel_le_hw(*crcp, data, len);
+	return 0;
+}
+
+static int __crc32c_pcl_intel_finup(u32 *crcp, const u8 *data, unsigned int len,
+				u8 *out)
+{
+	if (len >= crc32c_pcl_breakeven && irq_fpu_usable()) {
+		kernel_fpu_begin();
+		*(__le32 *)out = ~cpu_to_le32(crc_pcl(data, len, *crcp));
+		kernel_fpu_end();
+	} else
+		*(__le32 *)out =
+			~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len));
+	return 0;
+}
+
+static int crc32c_pcl_intel_finup(struct shash_desc *desc, const u8 *data,
+			      unsigned int len, u8 *out)
+{
+	return __crc32c_pcl_intel_finup(shash_desc_ctx(desc), data, len, out);
+}
+
+static int crc32c_pcl_intel_digest(struct shash_desc *desc, const u8 *data,
+			       unsigned int len, u8 *out)
+{
+	return __crc32c_pcl_intel_finup(crypto_shash_ctx(desc->tfm), data, len,
+				    out);
+}
+#endif /* CONFIG_X86_64 */
+
+static struct shash_alg alg = {
+	.setkey			=	crc32c_intel_setkey,
+	.init			=	crc32c_intel_init,
+	.update			=	crc32c_intel_update,
+	.final			=	crc32c_intel_final,
+	.finup			=	crc32c_intel_finup,
+	.digest			=	crc32c_intel_digest,
+	.descsize		=	sizeof(u32),
+	.digestsize		=	CHKSUM_DIGEST_SIZE,
+	.base			=	{
+		.cra_name		=	"crc32c",
+		.cra_driver_name	=	"crc32c-intel",
+		.cra_priority		=	200,
+		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
+		.cra_ctxsize		=	sizeof(u32),
+		.cra_module		=	THIS_MODULE,
+		.cra_init		=	crc32c_intel_cra_init,
+	}
+};
+
+static const struct x86_cpu_id crc32c_cpu_id[] = {
+	X86_FEATURE_MATCH(X86_FEATURE_XMM4_2),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, crc32c_cpu_id);
+
+static int __init crc32c_intel_mod_init(void)
+{
+	if (!x86_match_cpu(crc32c_cpu_id))
+		return -ENODEV;
+#ifdef CONFIG_X86_64
+	if (cpu_has_pclmulqdq) {
+		alg.update = crc32c_pcl_intel_update;
+		alg.finup = crc32c_pcl_intel_finup;
+		alg.digest = crc32c_pcl_intel_digest;
+		set_pcl_breakeven_point();
+	}
+#endif
+	return crypto_register_shash(&alg);
+}
+
+static void __exit crc32c_intel_mod_fini(void)
+{
+	crypto_unregister_shash(&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_CRYPTO("crc32c");
+MODULE_ALIAS_CRYPTO("crc32c-intel");