crypto: atmel-authenc - add support to authenc(hmac(shaX), Y(aes)) modes

This patchs allows to combine the AES and SHA hardware accelerators on
some Atmel SoCs. Doing so, AES blocks are only written to/read from the
AES hardware. Those blocks are also transferred from the AES to the SHA
accelerator internally, without additionnal accesses to the system busses.

Hence, the AES and SHA accelerators work in parallel to process all the
data blocks, instead of serializing the process by (de)crypting those
blocks first then authenticating them after like the generic
crypto/authenc.c driver does.

Of course, both the AES and SHA hardware accelerators need to be available
before we can start to process the data blocks. Hence we use their crypto
request queue to synchronize both drivers.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/Kconfig

@@ -415,6 +415,18 @@ config CRYPTO_DEV_BFIN_CRC
 	  Newer Blackfin processors have CRC hardware. Select this if you
 	  want to use the Blackfin CRC module.
 
+config CRYPTO_DEV_ATMEL_AUTHENC
+	tristate "Support for Atmel IPSEC/SSL hw accelerator"
+	depends on (ARCH_AT91 && HAS_DMA) || COMPILE_TEST
+	select CRYPTO_AUTHENC
+	select CRYPTO_DEV_ATMEL_AES
+	select CRYPTO_DEV_ATMEL_SHA
+	help
+	  Some Atmel processors can combine the AES and SHA hw accelerators
+	  to enhance support of IPSEC/SSL.
+	  Select this if you want to use the Atmel modules for
+	  authenc(hmac(shaX),Y(cbc)) algorithms.
+
 config CRYPTO_DEV_ATMEL_AES
 	tristate "Support for Atmel AES hw accelerator"
 	depends on HAS_DMA

drivers/crypto/atmel-aes-regs.h

@@ -68,6 +68,22 @@
 #define AES_CTRR	0x98
 #define AES_GCMHR(x)	(0x9c + ((x) * 0x04))
 
+#define AES_EMR		0xb0
+#define AES_EMR_APEN		BIT(0)	/* Auto Padding Enable */
+#define AES_EMR_APM		BIT(1)	/* Auto Padding Mode */
+#define AES_EMR_APM_IPSEC	0x0
+#define AES_EMR_APM_SSL		BIT(1)
+#define AES_EMR_PLIPEN		BIT(4)	/* PLIP Enable */
+#define AES_EMR_PLIPD		BIT(5)	/* PLIP Decipher */
+#define AES_EMR_PADLEN_MASK	(0xFu << 8)
+#define AES_EMR_PADLEN_OFFSET	8
+#define AES_EMR_PADLEN(padlen)	(((padlen) << AES_EMR_PADLEN_OFFSET) &\
+				 AES_EMR_PADLEN_MASK)
+#define AES_EMR_NHEAD_MASK	(0xFu << 16)
+#define AES_EMR_NHEAD_OFFSET	16
+#define AES_EMR_NHEAD(nhead)	(((nhead) << AES_EMR_NHEAD_OFFSET) &\
+				 AES_EMR_NHEAD_MASK)
+
 #define AES_TWR(x)	(0xc0 + ((x) * 0x04))
 #define AES_ALPHAR(x)	(0xd0 + ((x) * 0x04))