crypto: powerpc - Add CRC-T10DIF acceleration

T10DIF is a CRC16 used heavily in NVMe.

It turns out we can accelerate it with a CRC32 library and a few
little tricks.

Provide the accelerator based the refactored CRC32 code.

Cc: Anton Blanchard <anton@samba.org>
Thanks-to: Hong Bo Peng <penghb@cn.ibm.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index f37e9cc..9cf63dd 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -513,6 +513,15 @@
 	  'crct10dif-plcmul' module, which is faster when computing the
 	  crct10dif checksum as compared with the generic table implementation.
 
+config CRYPTO_CRCT10DIF_VPMSUM
+	tristate "CRC32T10DIF powerpc64 hardware acceleration"
+	depends on PPC64 && ALTIVEC && CRC_T10DIF
+	select CRYPTO_HASH
+	help
+	  CRC10T10DIF algorithm implemented using vector polynomial
+	  multiply-sum (vpmsum) instructions, introduced in POWER8. Enable on
+	  POWER8 and newer processors for improved performance.
+
 config CRYPTO_GHASH
 	tristate "GHASH digest algorithm"
 	select CRYPTO_GF128MUL