crypto: aesni-intel - Add AES-NI accelerated CTR mode

To take advantage of the hardware pipeline implementation of AES-NI
instructions. CTR mode cryption is implemented in ASM to schedule
multiple AES-NI instructions one after another. This way, some latency
of AES-NI instruction can be eliminated.

Performance testing based on dm-crypt should 50% reduction of
ecryption/decryption time.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 115 insertions, 0 deletions

diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index 20bb0e1ac681..822846a9eba9 100644
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -32,6 +32,9 @@
 #define IN	IN1
 #define KEY	%xmm2
 #define IV	%xmm3
+#define BSWAP_MASK %xmm10
+#define CTR	%xmm11
+#define INC	%xmm12
 
 #define KEYP	%rdi
 #define OUTP	%rsi
@@ -42,6 +45,7 @@
 #define T1	%r10
 #define TKEYP	T1
 #define T2	%r11
+#define TCTR_LOW T2
 
 _key_expansion_128:
 _key_expansion_256a:
@@ -724,3 +728,114 @@ ENTRY(aesni_cbc_dec)
 	movups IV, (IVP)
 .Lcbc_dec_just_ret:
 	ret
+
+.align 16
+.Lbswap_mask:
+	.byte 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
+
+/*
+ * _aesni_inc_init:	internal ABI
+ *	setup registers used by _aesni_inc
+ * input:
+ *	IV
+ * output:
+ *	CTR:	== IV, in little endian
+ *	TCTR_LOW: == lower qword of CTR
+ *	INC:	== 1, in little endian
+ *	BSWAP_MASK == endian swapping mask
+ */
+_aesni_inc_init:
+	movaps .Lbswap_mask, BSWAP_MASK
+	movaps IV, CTR
+	PSHUFB_XMM BSWAP_MASK CTR
+	mov $1, TCTR_LOW
+	movq TCTR_LOW, INC
+	movq CTR, TCTR_LOW
+	ret
+
+/*
+ * _aesni_inc:		internal ABI
+ *	Increase IV by 1, IV is in big endian
+ * input:
+ *	IV
+ *	CTR:	== IV, in little endian
+ *	TCTR_LOW: == lower qword of CTR
+ *	INC:	== 1, in little endian
+ *	BSWAP_MASK == endian swapping mask
+ * output:
+ *	IV:	Increase by 1
+ * changed:
+ *	CTR:	== output IV, in little endian
+ *	TCTR_LOW: == lower qword of CTR
+ */
+_aesni_inc:
+	paddq INC, CTR
+	add $1, TCTR_LOW
+	jnc .Linc_low
+	pslldq $8, INC
+	paddq INC, CTR
+	psrldq $8, INC
+.Linc_low:
+	movaps CTR, IV
+	PSHUFB_XMM BSWAP_MASK IV
+	ret
+
+/*
+ * void aesni_ctr_enc(struct crypto_aes_ctx *ctx, const u8 *dst, u8 *src,
+ *		      size_t len, u8 *iv)
+ */
+ENTRY(aesni_ctr_enc)
+	cmp $16, LEN
+	jb .Lctr_enc_just_ret
+	mov 480(KEYP), KLEN
+	movups (IVP), IV
+	call _aesni_inc_init
+	cmp $64, LEN
+	jb .Lctr_enc_loop1
+.align 4
+.Lctr_enc_loop4:
+	movaps IV, STATE1
+	call _aesni_inc
+	movups (INP), IN1
+	movaps IV, STATE2
+	call _aesni_inc
+	movups 0x10(INP), IN2
+	movaps IV, STATE3
+	call _aesni_inc
+	movups 0x20(INP), IN3
+	movaps IV, STATE4
+	call _aesni_inc
+	movups 0x30(INP), IN4
+	call _aesni_enc4
+	pxor IN1, STATE1
+	movups STATE1, (OUTP)
+	pxor IN2, STATE2
+	movups STATE2, 0x10(OUTP)
+	pxor IN3, STATE3
+	movups STATE3, 0x20(OUTP)
+	pxor IN4, STATE4
+	movups STATE4, 0x30(OUTP)
+	sub $64, LEN
+	add $64, INP
+	add $64, OUTP
+	cmp $64, LEN
+	jge .Lctr_enc_loop4
+	cmp $16, LEN
+	jb .Lctr_enc_ret
+.align 4
+.Lctr_enc_loop1:
+	movaps IV, STATE
+	call _aesni_inc
+	movups (INP), IN
+	call _aesni_enc1
+	pxor IN, STATE
+	movups STATE, (OUTP)
+	sub $16, LEN
+	add $16, INP
+	add $16, OUTP
+	cmp $16, LEN
+	jge .Lctr_enc_loop1
+.Lctr_enc_ret:
+	movups IV, (IVP)
+.Lctr_enc_just_ret:
+	ret