s390/crc32-vx: add crypto API module for optimized CRC-32 algorithms

Add a crypto API module to access the vector extension based CRC-32
implementations.  Users can request the optimized implementation through
the shash crypto API interface.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 310 insertions, 0 deletions

diff --git a/arch/s390/crypto/crc32-vx.c b/arch/s390/crypto/crc32-vx.c
new file mode 100644
index 000000000000..577ae1d4ae89
--- /dev/null
+++ b/arch/s390/crypto/crc32-vx.c
@@ -0,0 +1,310 @@
+/*
+ * Crypto-API module for CRC-32 algorithms implemented with the
+ * z/Architecture Vector Extension Facility.
+ *
+ * Copyright IBM Corp. 2015
+ * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ */
+#define KMSG_COMPONENT	"crc32-vx"
+#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/cpufeature.h>
+#include <linux/crc32.h>
+#include <crypto/internal/hash.h>
+#include <asm/fpu/api.h>
+
+
+#define CRC32_BLOCK_SIZE	1
+#define CRC32_DIGEST_SIZE	4
+
+#define VX_MIN_LEN		64
+#define VX_ALIGNMENT		16L
+#define VX_ALIGN_MASK		(VX_ALIGNMENT - 1)
+
+struct crc_ctx {
+	u32 key;
+};
+
+struct crc_desc_ctx {
+	u32 crc;
+};
+
+/* Prototypes for functions in assembly files */
+u32 crc32_le_vgfm_16(u32 crc, unsigned char const *buf, size_t size);
+u32 crc32_be_vgfm_16(u32 crc, unsigned char const *buf, size_t size);
+u32 crc32c_le_vgfm_16(u32 crc, unsigned char const *buf, size_t size);
+
+/*
+ * DEFINE_CRC32_VX() - Define a CRC-32 function using the vector extension
+ *
+ * Creates a function to perform a particular CRC-32 computation. Depending
+ * on the message buffer, the hardware-accelerated or software implementation
+ * is used.   Note that the message buffer is aligned to improve fetch
+ * operations of VECTOR LOAD MULTIPLE instructions.
+ *
+ */
+#define DEFINE_CRC32_VX(___fname, ___crc32_vx, ___crc32_sw)		    \
+	static u32 __pure ___fname(u32 crc,				    \
+				unsigned char const *data, size_t datalen)  \
+	{								    \
+		struct kernel_fpu vxstate;				    \
+		unsigned long prealign, aligned, remaining;		    \
+									    \
+		if ((unsigned long)data & VX_ALIGN_MASK) {		    \
+			prealign = VX_ALIGNMENT -			    \
+				  ((unsigned long)data & VX_ALIGN_MASK);    \
+			datalen -= prealign;				    \
+			crc = ___crc32_sw(crc, data, prealign);		    \
+			data = (void *)((unsigned long)data + prealign);    \
+		}							    \
+									    \
+		if (datalen < VX_MIN_LEN)				    \
+			return ___crc32_sw(crc, data, datalen);		    \
+									    \
+		aligned = datalen & ~VX_ALIGN_MASK;			    \
+		remaining = datalen & VX_ALIGN_MASK;			    \
+									    \
+		kernel_fpu_begin(&vxstate, KERNEL_VXR_LOW);		    \
+		crc = ___crc32_vx(crc, data, aligned);			    \
+		kernel_fpu_end(&vxstate);				    \
+									    \
+		if (remaining)						    \
+			crc = ___crc32_sw(crc, data + aligned, remaining);  \
+									    \
+		return crc;						    \
+	}
+
+DEFINE_CRC32_VX(crc32_le_vx, crc32_le_vgfm_16, crc32_le)
+DEFINE_CRC32_VX(crc32_be_vx, crc32_be_vgfm_16, crc32_be)
+DEFINE_CRC32_VX(crc32c_le_vx, crc32c_le_vgfm_16, __crc32c_le)
+
+
+static int crc32_vx_cra_init_zero(struct crypto_tfm *tfm)
+{
+	struct crc_ctx *mctx = crypto_tfm_ctx(tfm);
+
+	mctx->key = 0;
+	return 0;
+}
+
+static int crc32_vx_cra_init_invert(struct crypto_tfm *tfm)
+{
+	struct crc_ctx *mctx = crypto_tfm_ctx(tfm);
+
+	mctx->key = ~0;
+	return 0;
+}
+
+static int crc32_vx_init(struct shash_desc *desc)
+{
+	struct crc_ctx *mctx = crypto_shash_ctx(desc->tfm);
+	struct crc_desc_ctx *ctx = shash_desc_ctx(desc);
+
+	ctx->crc = mctx->key;
+	return 0;
+}
+
+static int crc32_vx_setkey(struct crypto_shash *tfm, const u8 *newkey,
+			   unsigned int newkeylen)
+{
+	struct crc_ctx *mctx = crypto_shash_ctx(tfm);
+
+	if (newkeylen != sizeof(mctx->key)) {
+		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	mctx->key = le32_to_cpu(*(__le32 *)newkey);
+	return 0;
+}
+
+static int crc32be_vx_setkey(struct crypto_shash *tfm, const u8 *newkey,
+			     unsigned int newkeylen)
+{
+	struct crc_ctx *mctx = crypto_shash_ctx(tfm);
+
+	if (newkeylen != sizeof(mctx->key)) {
+		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	mctx->key = be32_to_cpu(*(__be32 *)newkey);
+	return 0;
+}
+
+static int crc32le_vx_final(struct shash_desc *desc, u8 *out)
+{
+	struct crc_desc_ctx *ctx = shash_desc_ctx(desc);
+
+	*(__le32 *)out = cpu_to_le32p(&ctx->crc);
+	return 0;
+}
+
+static int crc32be_vx_final(struct shash_desc *desc, u8 *out)
+{
+	struct crc_desc_ctx *ctx = shash_desc_ctx(desc);
+
+	*(__be32 *)out = cpu_to_be32p(&ctx->crc);
+	return 0;
+}
+
+static int crc32c_vx_final(struct shash_desc *desc, u8 *out)
+{
+	struct crc_desc_ctx *ctx = shash_desc_ctx(desc);
+
+	/*
+	 * Perform a final XOR with 0xFFFFFFFF to be in sync
+	 * with the generic crc32c shash implementation.
+	 */
+	*(__le32 *)out = ~cpu_to_le32p(&ctx->crc);
+	return 0;
+}
+
+static int __crc32le_vx_finup(u32 *crc, const u8 *data, unsigned int len,
+			      u8 *out)
+{
+	*(__le32 *)out = cpu_to_le32(crc32_le_vx(*crc, data, len));
+	return 0;
+}
+
+static int __crc32be_vx_finup(u32 *crc, const u8 *data, unsigned int len,
+			      u8 *out)
+{
+	*(__be32 *)out = cpu_to_be32(crc32_be_vx(*crc, data, len));
+	return 0;
+}
+
+static int __crc32c_vx_finup(u32 *crc, const u8 *data, unsigned int len,
+			     u8 *out)
+{
+	/*
+	 * Perform a final XOR with 0xFFFFFFFF to be in sync
+	 * with the generic crc32c shash implementation.
+	 */
+	*(__le32 *)out = ~cpu_to_le32(crc32c_le_vx(*crc, data, len));
+	return 0;
+}
+
+
+#define CRC32_VX_FINUP(alg, func)					      \
+	static int alg ## _vx_finup(struct shash_desc *desc, const u8 *data,  \
+				   unsigned int datalen, u8 *out)	      \
+	{								      \
+		return __ ## alg ## _vx_finup(shash_desc_ctx(desc),	      \
+					      data, datalen, out);	      \
+	}
+
+CRC32_VX_FINUP(crc32le, crc32_le_vx)
+CRC32_VX_FINUP(crc32be, crc32_be_vx)
+CRC32_VX_FINUP(crc32c, crc32c_le_vx)
+
+#define CRC32_VX_DIGEST(alg, func)					      \
+	static int alg ## _vx_digest(struct shash_desc *desc, const u8 *data, \
+				     unsigned int len, u8 *out)		      \
+	{								      \
+		return __ ## alg ## _vx_finup(crypto_shash_ctx(desc->tfm),    \
+					      data, len, out);		      \
+	}
+
+CRC32_VX_DIGEST(crc32le, crc32_le_vx)
+CRC32_VX_DIGEST(crc32be, crc32_be_vx)
+CRC32_VX_DIGEST(crc32c, crc32c_le_vx)
+
+#define CRC32_VX_UPDATE(alg, func)					      \
+	static int alg ## _vx_update(struct shash_desc *desc, const u8 *data, \
+				     unsigned int datalen)		      \
+	{								      \
+		struct crc_desc_ctx *ctx = shash_desc_ctx(desc);	      \
+		ctx->crc = func(ctx->crc, data, datalen);		      \
+		return 0;						      \
+	}
+
+CRC32_VX_UPDATE(crc32le, crc32_le_vx)
+CRC32_VX_UPDATE(crc32be, crc32_be_vx)
+CRC32_VX_UPDATE(crc32c, crc32c_le_vx)
+
+
+static struct shash_alg crc32_vx_algs[] = {
+	/* CRC-32 LE */
+	{
+		.init		=	crc32_vx_init,
+		.setkey		=	crc32_vx_setkey,
+		.update		=	crc32le_vx_update,
+		.final		=	crc32le_vx_final,
+		.finup		=	crc32le_vx_finup,
+		.digest		=	crc32le_vx_digest,
+		.descsize	=	sizeof(struct crc_desc_ctx),
+		.digestsize	=	CRC32_DIGEST_SIZE,
+		.base		=	{
+			.cra_name	 = "crc32",
+			.cra_driver_name = "crc32-vx",
+			.cra_priority	 = 200,
+			.cra_blocksize	 = CRC32_BLOCK_SIZE,
+			.cra_ctxsize	 = sizeof(struct crc_ctx),
+			.cra_module	 = THIS_MODULE,
+			.cra_init	 = crc32_vx_cra_init_zero,
+		},
+	},
+	/* CRC-32 BE */
+	{
+		.init		=	crc32_vx_init,
+		.setkey		=	crc32be_vx_setkey,
+		.update		=	crc32be_vx_update,
+		.final		=	crc32be_vx_final,
+		.finup		=	crc32be_vx_finup,
+		.digest		=	crc32be_vx_digest,
+		.descsize	=	sizeof(struct crc_desc_ctx),
+		.digestsize	=	CRC32_DIGEST_SIZE,
+		.base		=	{
+			.cra_name	 = "crc32be",
+			.cra_driver_name = "crc32be-vx",
+			.cra_priority	 = 200,
+			.cra_blocksize	 = CRC32_BLOCK_SIZE,
+			.cra_ctxsize	 = sizeof(struct crc_ctx),
+			.cra_module	 = THIS_MODULE,
+			.cra_init	 = crc32_vx_cra_init_zero,
+		},
+	},
+	/* CRC-32C LE */
+	{
+		.init		=	crc32_vx_init,
+		.setkey		=	crc32_vx_setkey,
+		.update		=	crc32c_vx_update,
+		.final		=	crc32c_vx_final,
+		.finup		=	crc32c_vx_finup,
+		.digest		=	crc32c_vx_digest,
+		.descsize	=	sizeof(struct crc_desc_ctx),
+		.digestsize	=	CRC32_DIGEST_SIZE,
+		.base		=	{
+			.cra_name	 = "crc32c",
+			.cra_driver_name = "crc32c-vx",
+			.cra_priority	 = 200,
+			.cra_blocksize	 = CRC32_BLOCK_SIZE,
+			.cra_ctxsize	 = sizeof(struct crc_ctx),
+			.cra_module	 = THIS_MODULE,
+			.cra_init	 = crc32_vx_cra_init_invert,
+		},
+	},
+};
+
+
+static int __init crc_vx_mod_init(void)
+{
+	return crypto_register_shashes(crc32_vx_algs,
+				       ARRAY_SIZE(crc32_vx_algs));
+}
+
+static void __exit crc_vx_mod_exit(void)
+{
+	crypto_unregister_shashes(crc32_vx_algs, ARRAY_SIZE(crc32_vx_algs));
+}
+
+module_cpu_feature_match(VXRS, crc_vx_mod_init);
+module_exit(crc_vx_mod_exit);
+
+MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS_CRYPTO("crc32");
+MODULE_ALIAS_CRYPTO("crc32-vx");
+MODULE_ALIAS_CRYPTO("crc32c");
+MODULE_ALIAS_CRYPTO("crc32c-vx");