[PATCH v4 15/20] crypto: arm64/aes-blk - yield NEON after every block of input

From: Ard Biesheuvel
Date: Tue Dec 26 2017 - 05:31:33 EST


Avoid excessive scheduling delays under a preemptible kernel by
yielding the NEON after every block of input.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/crypto/aes-ce.S | 15 +-
arch/arm64/crypto/aes-modes.S | 331 ++++++++++++--------
2 files changed, 216 insertions(+), 130 deletions(-)

diff --git a/arch/arm64/crypto/aes-ce.S b/arch/arm64/crypto/aes-ce.S
index 50330f5c3adc..623e74ed1c67 100644
--- a/arch/arm64/crypto/aes-ce.S
+++ b/arch/arm64/crypto/aes-ce.S
@@ -30,18 +30,21 @@
.endm

/* prepare for encryption with key in rk[] */
- .macro enc_prepare, rounds, rk, ignore
- load_round_keys \rounds, \rk
+ .macro enc_prepare, rounds, rk, temp
+ mov \temp, \rk
+ load_round_keys \rounds, \temp
.endm

/* prepare for encryption (again) but with new key in rk[] */
- .macro enc_switch_key, rounds, rk, ignore
- load_round_keys \rounds, \rk
+ .macro enc_switch_key, rounds, rk, temp
+ mov \temp, \rk
+ load_round_keys \rounds, \temp
.endm

/* prepare for decryption with key in rk[] */
- .macro dec_prepare, rounds, rk, ignore
- load_round_keys \rounds, \rk
+ .macro dec_prepare, rounds, rk, temp
+ mov \temp, \rk
+ load_round_keys \rounds, \temp
.endm

.macro do_enc_Nx, de, mc, k, i0, i1, i2, i3
diff --git a/arch/arm64/crypto/aes-modes.S b/arch/arm64/crypto/aes-modes.S
index a68412e1e3a4..483a7130cf0e 100644
--- a/arch/arm64/crypto/aes-modes.S
+++ b/arch/arm64/crypto/aes-modes.S
@@ -14,12 +14,12 @@
.align 4

aes_encrypt_block4x:
- encrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
+ encrypt_block4x v0, v1, v2, v3, w22, x21, x8, w7
ret
ENDPROC(aes_encrypt_block4x)

aes_decrypt_block4x:
- decrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
+ decrypt_block4x v0, v1, v2, v3, w22, x21, x8, w7
ret
ENDPROC(aes_decrypt_block4x)

@@ -31,57 +31,71 @@ ENDPROC(aes_decrypt_block4x)
*/

AES_ENTRY(aes_ecb_encrypt)
- stp x29, x30, [sp, #-16]!
- mov x29, sp
+ frame_push 5

- enc_prepare w3, x2, x5
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+
+.Lecbencrestart:
+ enc_prepare w22, x21, x5

.LecbencloopNx:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lecbenc1x
- ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 pt blocks */
+ ld1 {v0.16b-v3.16b}, [x20], #64 /* get 4 pt blocks */
bl aes_encrypt_block4x
- st1 {v0.16b-v3.16b}, [x0], #64
+ st1 {v0.16b-v3.16b}, [x19], #64
+ cond_yield_neon .Lecbencrestart
b .LecbencloopNx
.Lecbenc1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lecbencout
.Lecbencloop:
- ld1 {v0.16b}, [x1], #16 /* get next pt block */
- encrypt_block v0, w3, x2, x5, w6
- st1 {v0.16b}, [x0], #16
- subs w4, w4, #1
+ ld1 {v0.16b}, [x20], #16 /* get next pt block */
+ encrypt_block v0, w22, x21, x5, w6
+ st1 {v0.16b}, [x19], #16
+ subs w23, w23, #1
bne .Lecbencloop
.Lecbencout:
- ldp x29, x30, [sp], #16
+ frame_pop
ret
AES_ENDPROC(aes_ecb_encrypt)


AES_ENTRY(aes_ecb_decrypt)
- stp x29, x30, [sp, #-16]!
- mov x29, sp
+ frame_push 5
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4

- dec_prepare w3, x2, x5
+.Lecbdecrestart:
+ dec_prepare w22, x21, x5

.LecbdecloopNx:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lecbdec1x
- ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */
+ ld1 {v0.16b-v3.16b}, [x20], #64 /* get 4 ct blocks */
bl aes_decrypt_block4x
- st1 {v0.16b-v3.16b}, [x0], #64
+ st1 {v0.16b-v3.16b}, [x19], #64
+ cond_yield_neon .Lecbdecrestart
b .LecbdecloopNx
.Lecbdec1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lecbdecout
.Lecbdecloop:
- ld1 {v0.16b}, [x1], #16 /* get next ct block */
- decrypt_block v0, w3, x2, x5, w6
- st1 {v0.16b}, [x0], #16
- subs w4, w4, #1
+ ld1 {v0.16b}, [x20], #16 /* get next ct block */
+ decrypt_block v0, w22, x21, x5, w6
+ st1 {v0.16b}, [x19], #16
+ subs w23, w23, #1
bne .Lecbdecloop
.Lecbdecout:
- ldp x29, x30, [sp], #16
+ frame_pop
ret
AES_ENDPROC(aes_ecb_decrypt)

@@ -94,78 +108,100 @@ AES_ENDPROC(aes_ecb_decrypt)
*/

AES_ENTRY(aes_cbc_encrypt)
- ld1 {v4.16b}, [x5] /* get iv */
- enc_prepare w3, x2, x6
+ frame_push 6
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x5
+
+.Lcbcencrestart:
+ ld1 {v4.16b}, [x24] /* get iv */
+ enc_prepare w22, x21, x6

.Lcbcencloop4x:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lcbcenc1x
- ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 pt blocks */
+ ld1 {v0.16b-v3.16b}, [x20], #64 /* get 4 pt blocks */
eor v0.16b, v0.16b, v4.16b /* ..and xor with iv */
- encrypt_block v0, w3, x2, x6, w7
+ encrypt_block v0, w22, x21, x6, w7
eor v1.16b, v1.16b, v0.16b
- encrypt_block v1, w3, x2, x6, w7
+ encrypt_block v1, w22, x21, x6, w7
eor v2.16b, v2.16b, v1.16b
- encrypt_block v2, w3, x2, x6, w7
+ encrypt_block v2, w22, x21, x6, w7
eor v3.16b, v3.16b, v2.16b
- encrypt_block v3, w3, x2, x6, w7
- st1 {v0.16b-v3.16b}, [x0], #64
+ encrypt_block v3, w22, x21, x6, w7
+ st1 {v0.16b-v3.16b}, [x19], #64
mov v4.16b, v3.16b
+ st1 {v4.16b}, [x24] /* return iv */
+ cond_yield_neon .Lcbcencrestart
b .Lcbcencloop4x
.Lcbcenc1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lcbcencout
.Lcbcencloop:
- ld1 {v0.16b}, [x1], #16 /* get next pt block */
+ ld1 {v0.16b}, [x20], #16 /* get next pt block */
eor v4.16b, v4.16b, v0.16b /* ..and xor with iv */
- encrypt_block v4, w3, x2, x6, w7
- st1 {v4.16b}, [x0], #16
- subs w4, w4, #1
+ encrypt_block v4, w22, x21, x6, w7
+ st1 {v4.16b}, [x19], #16
+ subs w23, w23, #1
bne .Lcbcencloop
.Lcbcencout:
- st1 {v4.16b}, [x5] /* return iv */
+ st1 {v4.16b}, [x24] /* return iv */
+ frame_pop
ret
AES_ENDPROC(aes_cbc_encrypt)


AES_ENTRY(aes_cbc_decrypt)
- stp x29, x30, [sp, #-16]!
- mov x29, sp
+ frame_push 6
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x5

- ld1 {v7.16b}, [x5] /* get iv */
- dec_prepare w3, x2, x6
+.Lcbcdecrestart:
+ ld1 {v7.16b}, [x24] /* get iv */
+ dec_prepare w22, x21, x6

.LcbcdecloopNx:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lcbcdec1x
- ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */
+ ld1 {v0.16b-v3.16b}, [x20], #64 /* get 4 ct blocks */
mov v4.16b, v0.16b
mov v5.16b, v1.16b
mov v6.16b, v2.16b
bl aes_decrypt_block4x
- sub x1, x1, #16
+ sub x20, x20, #16
eor v0.16b, v0.16b, v7.16b
eor v1.16b, v1.16b, v4.16b
- ld1 {v7.16b}, [x1], #16 /* reload 1 ct block */
+ ld1 {v7.16b}, [x20], #16 /* reload 1 ct block */
eor v2.16b, v2.16b, v5.16b
eor v3.16b, v3.16b, v6.16b
- st1 {v0.16b-v3.16b}, [x0], #64
+ st1 {v0.16b-v3.16b}, [x19], #64
+ st1 {v7.16b}, [x24] /* return iv */
+ cond_yield_neon .Lcbcdecrestart
b .LcbcdecloopNx
.Lcbcdec1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lcbcdecout
.Lcbcdecloop:
- ld1 {v1.16b}, [x1], #16 /* get next ct block */
+ ld1 {v1.16b}, [x20], #16 /* get next ct block */
mov v0.16b, v1.16b /* ...and copy to v0 */
- decrypt_block v0, w3, x2, x6, w7
+ decrypt_block v0, w22, x21, x6, w7
eor v0.16b, v0.16b, v7.16b /* xor with iv => pt */
mov v7.16b, v1.16b /* ct is next iv */
- st1 {v0.16b}, [x0], #16
- subs w4, w4, #1
+ st1 {v0.16b}, [x19], #16
+ subs w23, w23, #1
bne .Lcbcdecloop
.Lcbcdecout:
- st1 {v7.16b}, [x5] /* return iv */
- ldp x29, x30, [sp], #16
+ st1 {v7.16b}, [x24] /* return iv */
+ frame_pop
ret
AES_ENDPROC(aes_cbc_decrypt)

@@ -176,19 +212,26 @@ AES_ENDPROC(aes_cbc_decrypt)
*/

AES_ENTRY(aes_ctr_encrypt)
- stp x29, x30, [sp, #-16]!
- mov x29, sp
+ frame_push 6

- enc_prepare w3, x2, x6
- ld1 {v4.16b}, [x5]
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x5
+
+.Lctrrestart:
+ enc_prepare w22, x21, x6
+ ld1 {v4.16b}, [x24]

umov x6, v4.d[1] /* keep swabbed ctr in reg */
rev x6, x6
- cmn w6, w4 /* 32 bit overflow? */
- bcs .Lctrloop
.LctrloopNx:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lctr1x
+ cmn w6, #4 /* 32 bit overflow? */
+ bcs .Lctr1x
ldr q8, =0x30000000200000001 /* addends 1,2,3[,0] */
dup v7.4s, w6
mov v0.16b, v4.16b
@@ -200,25 +243,27 @@ AES_ENTRY(aes_ctr_encrypt)
mov v1.s[3], v8.s[0]
mov v2.s[3], v8.s[1]
mov v3.s[3], v8.s[2]
- ld1 {v5.16b-v7.16b}, [x1], #48 /* get 3 input blocks */
+ ld1 {v5.16b-v7.16b}, [x20], #48 /* get 3 input blocks */
bl aes_encrypt_block4x
eor v0.16b, v5.16b, v0.16b
- ld1 {v5.16b}, [x1], #16 /* get 1 input block */
+ ld1 {v5.16b}, [x20], #16 /* get 1 input block */
eor v1.16b, v6.16b, v1.16b
eor v2.16b, v7.16b, v2.16b
eor v3.16b, v5.16b, v3.16b
- st1 {v0.16b-v3.16b}, [x0], #64
+ st1 {v0.16b-v3.16b}, [x19], #64
add x6, x6, #4
rev x7, x6
ins v4.d[1], x7
- cbz w4, .Lctrout
+ cbz w23, .Lctrout
+ st1 {v4.16b}, [x24] /* return next CTR value */
+ cond_yield_neon .Lctrrestart
b .LctrloopNx
.Lctr1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lctrout
.Lctrloop:
mov v0.16b, v4.16b
- encrypt_block v0, w3, x2, x8, w7
+ encrypt_block v0, w22, x21, x8, w7

adds x6, x6, #1 /* increment BE ctr */
rev x7, x6
@@ -226,22 +271,22 @@ AES_ENTRY(aes_ctr_encrypt)
bcs .Lctrcarry /* overflow? */

.Lctrcarrydone:
- subs w4, w4, #1
+ subs w23, w23, #1
bmi .Lctrtailblock /* blocks <0 means tail block */
- ld1 {v3.16b}, [x1], #16
+ ld1 {v3.16b}, [x20], #16
eor v3.16b, v0.16b, v3.16b
- st1 {v3.16b}, [x0], #16
+ st1 {v3.16b}, [x19], #16
bne .Lctrloop

.Lctrout:
- st1 {v4.16b}, [x5] /* return next CTR value */
- ldp x29, x30, [sp], #16
+ st1 {v4.16b}, [x24] /* return next CTR value */
+.Lctrret:
+ frame_pop
ret

.Lctrtailblock:
- st1 {v0.16b}, [x0]
- ldp x29, x30, [sp], #16
- ret
+ st1 {v0.16b}, [x19]
+ b .Lctrret

.Lctrcarry:
umov x7, v4.d[0] /* load upper word of ctr */
@@ -274,10 +319,16 @@ CPU_LE( .quad 1, 0x87 )
CPU_BE( .quad 0x87, 1 )

AES_ENTRY(aes_xts_encrypt)
- stp x29, x30, [sp, #-16]!
- mov x29, sp
+ frame_push 6
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x6

- ld1 {v4.16b}, [x6]
+ ld1 {v4.16b}, [x24]
cbz w7, .Lxtsencnotfirst

enc_prepare w3, x5, x8
@@ -286,15 +337,17 @@ AES_ENTRY(aes_xts_encrypt)
ldr q7, .Lxts_mul_x
b .LxtsencNx

+.Lxtsencrestart:
+ ld1 {v4.16b}, [x24]
.Lxtsencnotfirst:
- enc_prepare w3, x2, x8
+ enc_prepare w22, x21, x8
.LxtsencloopNx:
ldr q7, .Lxts_mul_x
next_tweak v4, v4, v7, v8
.LxtsencNx:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lxtsenc1x
- ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 pt blocks */
+ ld1 {v0.16b-v3.16b}, [x20], #64 /* get 4 pt blocks */
next_tweak v5, v4, v7, v8
eor v0.16b, v0.16b, v4.16b
next_tweak v6, v5, v7, v8
@@ -307,35 +360,43 @@ AES_ENTRY(aes_xts_encrypt)
eor v0.16b, v0.16b, v4.16b
eor v1.16b, v1.16b, v5.16b
eor v2.16b, v2.16b, v6.16b
- st1 {v0.16b-v3.16b}, [x0], #64
+ st1 {v0.16b-v3.16b}, [x19], #64
mov v4.16b, v7.16b
- cbz w4, .Lxtsencout
+ cbz w23, .Lxtsencout
+ st1 {v4.16b}, [x24]
+ cond_yield_neon .Lxtsencrestart
b .LxtsencloopNx
.Lxtsenc1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lxtsencout
.Lxtsencloop:
- ld1 {v1.16b}, [x1], #16
+ ld1 {v1.16b}, [x20], #16
eor v0.16b, v1.16b, v4.16b
- encrypt_block v0, w3, x2, x8, w7
+ encrypt_block v0, w22, x21, x8, w7
eor v0.16b, v0.16b, v4.16b
- st1 {v0.16b}, [x0], #16
- subs w4, w4, #1
+ st1 {v0.16b}, [x19], #16
+ subs w23, w23, #1
beq .Lxtsencout
next_tweak v4, v4, v7, v8
b .Lxtsencloop
.Lxtsencout:
- st1 {v4.16b}, [x6]
- ldp x29, x30, [sp], #16
+ st1 {v4.16b}, [x24]
+ frame_pop
ret
AES_ENDPROC(aes_xts_encrypt)


AES_ENTRY(aes_xts_decrypt)
- stp x29, x30, [sp, #-16]!
- mov x29, sp
+ frame_push 6

- ld1 {v4.16b}, [x6]
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x6
+
+ ld1 {v4.16b}, [x24]
cbz w7, .Lxtsdecnotfirst

enc_prepare w3, x5, x8
@@ -344,15 +405,17 @@ AES_ENTRY(aes_xts_decrypt)
ldr q7, .Lxts_mul_x
b .LxtsdecNx

+.Lxtsdecrestart:
+ ld1 {v4.16b}, [x24]
.Lxtsdecnotfirst:
- dec_prepare w3, x2, x8
+ dec_prepare w22, x21, x8
.LxtsdecloopNx:
ldr q7, .Lxts_mul_x
next_tweak v4, v4, v7, v8
.LxtsdecNx:
- subs w4, w4, #4
+ subs w23, w23, #4
bmi .Lxtsdec1x
- ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */
+ ld1 {v0.16b-v3.16b}, [x20], #64 /* get 4 ct blocks */
next_tweak v5, v4, v7, v8
eor v0.16b, v0.16b, v4.16b
next_tweak v6, v5, v7, v8
@@ -365,26 +428,28 @@ AES_ENTRY(aes_xts_decrypt)
eor v0.16b, v0.16b, v4.16b
eor v1.16b, v1.16b, v5.16b
eor v2.16b, v2.16b, v6.16b
- st1 {v0.16b-v3.16b}, [x0], #64
+ st1 {v0.16b-v3.16b}, [x19], #64
mov v4.16b, v7.16b
- cbz w4, .Lxtsdecout
+ cbz w23, .Lxtsdecout
+ st1 {v4.16b}, [x24]
+ cond_yield_neon .Lxtsdecrestart
b .LxtsdecloopNx
.Lxtsdec1x:
- adds w4, w4, #4
+ adds w23, w23, #4
beq .Lxtsdecout
.Lxtsdecloop:
- ld1 {v1.16b}, [x1], #16
+ ld1 {v1.16b}, [x20], #16
eor v0.16b, v1.16b, v4.16b
- decrypt_block v0, w3, x2, x8, w7
+ decrypt_block v0, w22, x21, x8, w7
eor v0.16b, v0.16b, v4.16b
- st1 {v0.16b}, [x0], #16
- subs w4, w4, #1
+ st1 {v0.16b}, [x19], #16
+ subs w23, w23, #1
beq .Lxtsdecout
next_tweak v4, v4, v7, v8
b .Lxtsdecloop
.Lxtsdecout:
- st1 {v4.16b}, [x6]
- ldp x29, x30, [sp], #16
+ st1 {v4.16b}, [x24]
+ frame_pop
ret
AES_ENDPROC(aes_xts_decrypt)

@@ -393,43 +458,61 @@ AES_ENDPROC(aes_xts_decrypt)
* int blocks, u8 dg[], int enc_before, int enc_after)
*/
AES_ENTRY(aes_mac_update)
- ld1 {v0.16b}, [x4] /* get dg */
+ frame_push 6
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x6
+
+ ld1 {v0.16b}, [x23] /* get dg */
enc_prepare w2, x1, x7
cbz w5, .Lmacloop4x

encrypt_block v0, w2, x1, x7, w8

.Lmacloop4x:
- subs w3, w3, #4
+ subs w22, w22, #4
bmi .Lmac1x
- ld1 {v1.16b-v4.16b}, [x0], #64 /* get next pt block */
+ ld1 {v1.16b-v4.16b}, [x19], #64 /* get next pt block */
eor v0.16b, v0.16b, v1.16b /* ..and xor with dg */
- encrypt_block v0, w2, x1, x7, w8
+ encrypt_block v0, w21, x20, x7, w8
eor v0.16b, v0.16b, v2.16b
- encrypt_block v0, w2, x1, x7, w8
+ encrypt_block v0, w21, x20, x7, w8
eor v0.16b, v0.16b, v3.16b
- encrypt_block v0, w2, x1, x7, w8
+ encrypt_block v0, w21, x20, x7, w8
eor v0.16b, v0.16b, v4.16b
- cmp w3, wzr
- csinv x5, x6, xzr, eq
+ cmp w22, wzr
+ csinv x5, x24, xzr, eq
cbz w5, .Lmacout
- encrypt_block v0, w2, x1, x7, w8
+ encrypt_block v0, w21, x20, x7, w8
+ st1 {v0.16b}, [x23] /* return dg */
+ cond_yield_neon .Lmacrestart
b .Lmacloop4x
.Lmac1x:
- add w3, w3, #4
+ add w22, w22, #4
.Lmacloop:
- cbz w3, .Lmacout
- ld1 {v1.16b}, [x0], #16 /* get next pt block */
+ cbz w22, .Lmacout
+ ld1 {v1.16b}, [x19], #16 /* get next pt block */
eor v0.16b, v0.16b, v1.16b /* ..and xor with dg */

- subs w3, w3, #1
- csinv x5, x6, xzr, eq
+ subs w22, w22, #1
+ csinv x5, x24, xzr, eq
cbz w5, .Lmacout

- encrypt_block v0, w2, x1, x7, w8
+.Lmacenc:
+ encrypt_block v0, w21, x20, x7, w8
b .Lmacloop

.Lmacout:
- st1 {v0.16b}, [x4] /* return dg */
+ st1 {v0.16b}, [x23] /* return dg */
+ frame_pop
ret
+
+.Lmacrestart:
+ ld1 {v0.16b}, [x23] /* get dg */
+ enc_prepare w21, x20, x0
+ b .Lmacloop4x
AES_ENDPROC(aes_mac_update)
--
2.11.0