s390/crypt: Add protected key AES module

This patch introduces a new in-kernel-crypto blockcipher
called 'paes' which implements AES with protected keys.
The paes blockcipher can be used similar to the aes
blockcipher but uses secure key material to derive the
working protected key and so offers an encryption
implementation where never a clear key value is exposed
in memory.

The paes module is only available for the s390 platform
providing a minimal hardware support of CPACF enabled
with at least MSA level 3. Upon module initialization
these requirements are checked.

Includes additional contribution from Harald Freudenberger.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/crypto/Makefile

@@ -6,7 +6,7 @@ obj-$(CONFIG_CRYPTO_SHA1_S390) += sha1_s390.o sha_common.o
 obj-$(CONFIG_CRYPTO_SHA256_S390) += sha256_s390.o sha_common.o
 obj-$(CONFIG_CRYPTO_SHA512_S390) += sha512_s390.o sha_common.o
 obj-$(CONFIG_CRYPTO_DES_S390) += des_s390.o
-obj-$(CONFIG_CRYPTO_AES_S390) += aes_s390.o
+obj-$(CONFIG_CRYPTO_AES_S390) += aes_s390.o paes_s390.o
 obj-$(CONFIG_S390_PRNG) += prng.o
 obj-$(CONFIG_CRYPTO_GHASH_S390) += ghash_s390.o
 obj-$(CONFIG_CRYPTO_CRC32_S390) += crc32-vx_s390.o

arch/s390/include/asm/cpacf.h

@@ -28,8 +28,9 @@
 #define CPACF_PPNO		0xb93c		/* MSA5 */
 
 /*
- * Decryption modifier bit
+ * En/decryption modifier bits
  */
+#define CPACF_ENCRYPT		0x00
 #define CPACF_DECRYPT		0x80
 
 /*
@@ -42,8 +43,13 @@
 #define CPACF_KM_AES_128	0x12
 #define CPACF_KM_AES_192	0x13
 #define CPACF_KM_AES_256	0x14
+#define CPACF_KM_PAES_128	0x1a
+#define CPACF_KM_PAES_192	0x1b
+#define CPACF_KM_PAES_256	0x1c
 #define CPACF_KM_XTS_128	0x32
 #define CPACF_KM_XTS_256	0x34
+#define CPACF_KM_PXTS_128	0x3a
+#define CPACF_KM_PXTS_256	0x3c
 
 /*
  * Function codes for the KMC (CIPHER MESSAGE WITH CHAINING)
@@ -56,6 +62,9 @@
 #define CPACF_KMC_AES_128	0x12
 #define CPACF_KMC_AES_192	0x13
 #define CPACF_KMC_AES_256	0x14
+#define CPACF_KMC_PAES_128	0x1a
+#define CPACF_KMC_PAES_192	0x1b
+#define CPACF_KMC_PAES_256	0x1c
 #define CPACF_KMC_PRNG		0x43
 
 /*
@@ -69,6 +78,9 @@
 #define CPACF_KMCTR_AES_128	0x12
 #define CPACF_KMCTR_AES_192	0x13
 #define CPACF_KMCTR_AES_256	0x14
+#define CPACF_KMCTR_PAES_128	0x1a
+#define CPACF_KMCTR_PAES_192	0x1b
+#define CPACF_KMCTR_PAES_256	0x1c
 
 /*
  * Function codes for the KIMD (COMPUTE INTERMEDIATE MESSAGE DIGEST)

drivers/crypto/Kconfig

@@ -137,6 +137,7 @@ config CRYPTO_AES_S390
 	depends on S390
 	select CRYPTO_ALGAPI
 	select CRYPTO_BLKCIPHER
+	select PKEY
 	help
 	  This is the s390 hardware accelerated implementation of the
 	  AES cipher algorithms (FIPS-197).