linux/arch/arm64/crypto/aes-modes.S
Ard Biesheuvel 6833817472 crypto: arm64/aes-blk - move kernel mode neon en/disable into loop
When kernel mode NEON was first introduced on arm64, the preserve and
restore of the userland NEON state was completely unoptimized, and
involved saving all registers on each call to kernel_neon_begin(),
and restoring them on each call to kernel_neon_end(). For this reason,
the NEON crypto code that was introduced at the time keeps the NEON
enabled throughout the execution of the crypto API methods, which may
include calls back into the crypto API that could result in memory
allocation or other actions that we should avoid when running with
preemption disabled.

Since then, we have optimized the kernel mode NEON handling, which now
restores lazily (upon return to userland), and so the preserve action
is only costly the first time it is called after entering the kernel.

So let's put the kernel_neon_begin() and kernel_neon_end() calls around
the actual invocations of the NEON crypto code, and run the remainder of
the code with kernel mode NEON disabled (and preemption enabled)

Note that this requires some reshuffling of the registers in the asm
code, because the XTS routines can no longer rely on the registers to
retain their contents between invocations.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-16 23:35:54 +08:00

555 lines
12 KiB
ArmAsm

/*
* linux/arch/arm64/crypto/aes-modes.S - chaining mode wrappers for AES
*
* Copyright (C) 2013 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/* included by aes-ce.S and aes-neon.S */
.text
.align 4
/*
* There are several ways to instantiate this code:
* - no interleave, all inline
* - 2-way interleave, 2x calls out of line (-DINTERLEAVE=2)
* - 2-way interleave, all inline (-DINTERLEAVE=2 -DINTERLEAVE_INLINE)
* - 4-way interleave, 4x calls out of line (-DINTERLEAVE=4)
* - 4-way interleave, all inline (-DINTERLEAVE=4 -DINTERLEAVE_INLINE)
*
* Macros imported by this code:
* - enc_prepare - setup NEON registers for encryption
* - dec_prepare - setup NEON registers for decryption
* - enc_switch_key - change to new key after having prepared for encryption
* - encrypt_block - encrypt a single block
* - decrypt block - decrypt a single block
* - encrypt_block2x - encrypt 2 blocks in parallel (if INTERLEAVE == 2)
* - decrypt_block2x - decrypt 2 blocks in parallel (if INTERLEAVE == 2)
* - encrypt_block4x - encrypt 4 blocks in parallel (if INTERLEAVE == 4)
* - decrypt_block4x - decrypt 4 blocks in parallel (if INTERLEAVE == 4)
*/
#if defined(INTERLEAVE) && !defined(INTERLEAVE_INLINE)
#define FRAME_PUSH stp x29, x30, [sp,#-16]! ; mov x29, sp
#define FRAME_POP ldp x29, x30, [sp],#16
#if INTERLEAVE == 2
aes_encrypt_block2x:
encrypt_block2x v0, v1, w3, x2, x8, w7
ret
ENDPROC(aes_encrypt_block2x)
aes_decrypt_block2x:
decrypt_block2x v0, v1, w3, x2, x8, w7
ret
ENDPROC(aes_decrypt_block2x)
#elif INTERLEAVE == 4
aes_encrypt_block4x:
encrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
ret
ENDPROC(aes_encrypt_block4x)
aes_decrypt_block4x:
decrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
ret
ENDPROC(aes_decrypt_block4x)
#else
#error INTERLEAVE should equal 2 or 4
#endif
.macro do_encrypt_block2x
bl aes_encrypt_block2x
.endm
.macro do_decrypt_block2x
bl aes_decrypt_block2x
.endm
.macro do_encrypt_block4x
bl aes_encrypt_block4x
.endm
.macro do_decrypt_block4x
bl aes_decrypt_block4x
.endm
#else
#define FRAME_PUSH
#define FRAME_POP
.macro do_encrypt_block2x
encrypt_block2x v0, v1, w3, x2, x8, w7
.endm
.macro do_decrypt_block2x
decrypt_block2x v0, v1, w3, x2, x8, w7
.endm
.macro do_encrypt_block4x
encrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
.endm
.macro do_decrypt_block4x
decrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
.endm
#endif
/*
* aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks)
* aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks)
*/
AES_ENTRY(aes_ecb_encrypt)
FRAME_PUSH
enc_prepare w3, x2, x5
.LecbencloopNx:
#if INTERLEAVE >= 2
subs w4, w4, #INTERLEAVE
bmi .Lecbenc1x
#if INTERLEAVE == 2
ld1 {v0.16b-v1.16b}, [x1], #32 /* get 2 pt blocks */
do_encrypt_block2x
st1 {v0.16b-v1.16b}, [x0], #32
#else
ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 pt blocks */
do_encrypt_block4x
st1 {v0.16b-v3.16b}, [x0], #64
#endif
b .LecbencloopNx
.Lecbenc1x:
adds w4, w4, #INTERLEAVE
beq .Lecbencout
#endif
.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
bne .Lecbencloop
.Lecbencout:
FRAME_POP
ret
AES_ENDPROC(aes_ecb_encrypt)
AES_ENTRY(aes_ecb_decrypt)
FRAME_PUSH
dec_prepare w3, x2, x5
.LecbdecloopNx:
#if INTERLEAVE >= 2
subs w4, w4, #INTERLEAVE
bmi .Lecbdec1x
#if INTERLEAVE == 2
ld1 {v0.16b-v1.16b}, [x1], #32 /* get 2 ct blocks */
do_decrypt_block2x
st1 {v0.16b-v1.16b}, [x0], #32
#else
ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */
do_decrypt_block4x
st1 {v0.16b-v3.16b}, [x0], #64
#endif
b .LecbdecloopNx
.Lecbdec1x:
adds w4, w4, #INTERLEAVE
beq .Lecbdecout
#endif
.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
bne .Lecbdecloop
.Lecbdecout:
FRAME_POP
ret
AES_ENDPROC(aes_ecb_decrypt)
/*
* aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 iv[])
* aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 iv[])
*/
AES_ENTRY(aes_cbc_encrypt)
ld1 {v0.16b}, [x5] /* get iv */
enc_prepare w3, x2, x6
.Lcbcencloop:
ld1 {v1.16b}, [x1], #16 /* get next pt block */
eor v0.16b, v0.16b, v1.16b /* ..and xor with iv */
encrypt_block v0, w3, x2, x6, w7
st1 {v0.16b}, [x0], #16
subs w4, w4, #1
bne .Lcbcencloop
st1 {v0.16b}, [x5] /* return iv */
ret
AES_ENDPROC(aes_cbc_encrypt)
AES_ENTRY(aes_cbc_decrypt)
FRAME_PUSH
ld1 {v7.16b}, [x5] /* get iv */
dec_prepare w3, x2, x6
.LcbcdecloopNx:
#if INTERLEAVE >= 2
subs w4, w4, #INTERLEAVE
bmi .Lcbcdec1x
#if INTERLEAVE == 2
ld1 {v0.16b-v1.16b}, [x1], #32 /* get 2 ct blocks */
mov v2.16b, v0.16b
mov v3.16b, v1.16b
do_decrypt_block2x
eor v0.16b, v0.16b, v7.16b
eor v1.16b, v1.16b, v2.16b
mov v7.16b, v3.16b
st1 {v0.16b-v1.16b}, [x0], #32
#else
ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */
mov v4.16b, v0.16b
mov v5.16b, v1.16b
mov v6.16b, v2.16b
do_decrypt_block4x
sub x1, x1, #16
eor v0.16b, v0.16b, v7.16b
eor v1.16b, v1.16b, v4.16b
ld1 {v7.16b}, [x1], #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
#endif
b .LcbcdecloopNx
.Lcbcdec1x:
adds w4, w4, #INTERLEAVE
beq .Lcbcdecout
#endif
.Lcbcdecloop:
ld1 {v1.16b}, [x1], #16 /* get next ct block */
mov v0.16b, v1.16b /* ...and copy to v0 */
decrypt_block v0, w3, x2, 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
bne .Lcbcdecloop
.Lcbcdecout:
FRAME_POP
st1 {v7.16b}, [x5] /* return iv */
ret
AES_ENDPROC(aes_cbc_decrypt)
/*
* aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 ctr[])
*/
AES_ENTRY(aes_ctr_encrypt)
FRAME_PUSH
enc_prepare w3, x2, x6
ld1 {v4.16b}, [x5]
umov x6, v4.d[1] /* keep swabbed ctr in reg */
rev x6, x6
#if INTERLEAVE >= 2
cmn w6, w4 /* 32 bit overflow? */
bcs .Lctrloop
.LctrloopNx:
subs w4, w4, #INTERLEAVE
bmi .Lctr1x
#if INTERLEAVE == 2
mov v0.8b, v4.8b
mov v1.8b, v4.8b
rev x7, x6
add x6, x6, #1
ins v0.d[1], x7
rev x7, x6
add x6, x6, #1
ins v1.d[1], x7
ld1 {v2.16b-v3.16b}, [x1], #32 /* get 2 input blocks */
do_encrypt_block2x
eor v0.16b, v0.16b, v2.16b
eor v1.16b, v1.16b, v3.16b
st1 {v0.16b-v1.16b}, [x0], #32
#else
ldr q8, =0x30000000200000001 /* addends 1,2,3[,0] */
dup v7.4s, w6
mov v0.16b, v4.16b
add v7.4s, v7.4s, v8.4s
mov v1.16b, v4.16b
rev32 v8.16b, v7.16b
mov v2.16b, v4.16b
mov v3.16b, v4.16b
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 */
do_encrypt_block4x
eor v0.16b, v5.16b, v0.16b
ld1 {v5.16b}, [x1], #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
add x6, x6, #INTERLEAVE
#endif
rev x7, x6
ins v4.d[1], x7
cbz w4, .Lctrout
b .LctrloopNx
.Lctr1x:
adds w4, w4, #INTERLEAVE
beq .Lctrout
#endif
.Lctrloop:
mov v0.16b, v4.16b
encrypt_block v0, w3, x2, x8, w7
adds x6, x6, #1 /* increment BE ctr */
rev x7, x6
ins v4.d[1], x7
bcs .Lctrcarry /* overflow? */
.Lctrcarrydone:
subs w4, w4, #1
bmi .Lctrtailblock /* blocks <0 means tail block */
ld1 {v3.16b}, [x1], #16
eor v3.16b, v0.16b, v3.16b
st1 {v3.16b}, [x0], #16
bne .Lctrloop
.Lctrout:
st1 {v4.16b}, [x5] /* return next CTR value */
FRAME_POP
ret
.Lctrtailblock:
st1 {v0.16b}, [x0]
FRAME_POP
ret
.Lctrcarry:
umov x7, v4.d[0] /* load upper word of ctr */
rev x7, x7 /* ... to handle the carry */
add x7, x7, #1
rev x7, x7
ins v4.d[0], x7
b .Lctrcarrydone
AES_ENDPROC(aes_ctr_encrypt)
.ltorg
/*
* aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
* int blocks, u8 const rk2[], u8 iv[], int first)
* aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
* int blocks, u8 const rk2[], u8 iv[], int first)
*/
.macro next_tweak, out, in, const, tmp
sshr \tmp\().2d, \in\().2d, #63
and \tmp\().16b, \tmp\().16b, \const\().16b
add \out\().2d, \in\().2d, \in\().2d
ext \tmp\().16b, \tmp\().16b, \tmp\().16b, #8
eor \out\().16b, \out\().16b, \tmp\().16b
.endm
.Lxts_mul_x:
CPU_LE( .quad 1, 0x87 )
CPU_BE( .quad 0x87, 1 )
AES_ENTRY(aes_xts_encrypt)
FRAME_PUSH
ld1 {v4.16b}, [x6]
cbz w7, .Lxtsencnotfirst
enc_prepare w3, x5, x8
encrypt_block v4, w3, x5, x8, w7 /* first tweak */
enc_switch_key w3, x2, x8
ldr q7, .Lxts_mul_x
b .LxtsencNx
.Lxtsencnotfirst:
enc_prepare w3, x2, x8
.LxtsencloopNx:
ldr q7, .Lxts_mul_x
next_tweak v4, v4, v7, v8
.LxtsencNx:
#if INTERLEAVE >= 2
subs w4, w4, #INTERLEAVE
bmi .Lxtsenc1x
#if INTERLEAVE == 2
ld1 {v0.16b-v1.16b}, [x1], #32 /* get 2 pt blocks */
next_tweak v5, v4, v7, v8
eor v0.16b, v0.16b, v4.16b
eor v1.16b, v1.16b, v5.16b
do_encrypt_block2x
eor v0.16b, v0.16b, v4.16b
eor v1.16b, v1.16b, v5.16b
st1 {v0.16b-v1.16b}, [x0], #32
cbz w4, .LxtsencoutNx
next_tweak v4, v5, v7, v8
b .LxtsencNx
.LxtsencoutNx:
mov v4.16b, v5.16b
b .Lxtsencout
#else
ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 pt blocks */
next_tweak v5, v4, v7, v8
eor v0.16b, v0.16b, v4.16b
next_tweak v6, v5, v7, v8
eor v1.16b, v1.16b, v5.16b
eor v2.16b, v2.16b, v6.16b
next_tweak v7, v6, v7, v8
eor v3.16b, v3.16b, v7.16b
do_encrypt_block4x
eor v3.16b, v3.16b, v7.16b
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
mov v4.16b, v7.16b
cbz w4, .Lxtsencout
b .LxtsencloopNx
#endif
.Lxtsenc1x:
adds w4, w4, #INTERLEAVE
beq .Lxtsencout
#endif
.Lxtsencloop:
ld1 {v1.16b}, [x1], #16
eor v0.16b, v1.16b, v4.16b
encrypt_block v0, w3, x2, x8, w7
eor v0.16b, v0.16b, v4.16b
st1 {v0.16b}, [x0], #16
subs w4, w4, #1
beq .Lxtsencout
next_tweak v4, v4, v7, v8
b .Lxtsencloop
.Lxtsencout:
st1 {v4.16b}, [x6]
FRAME_POP
ret
AES_ENDPROC(aes_xts_encrypt)
AES_ENTRY(aes_xts_decrypt)
FRAME_PUSH
ld1 {v4.16b}, [x6]
cbz w7, .Lxtsdecnotfirst
enc_prepare w3, x5, x8
encrypt_block v4, w3, x5, x8, w7 /* first tweak */
dec_prepare w3, x2, x8
ldr q7, .Lxts_mul_x
b .LxtsdecNx
.Lxtsdecnotfirst:
dec_prepare w3, x2, x8
.LxtsdecloopNx:
ldr q7, .Lxts_mul_x
next_tweak v4, v4, v7, v8
.LxtsdecNx:
#if INTERLEAVE >= 2
subs w4, w4, #INTERLEAVE
bmi .Lxtsdec1x
#if INTERLEAVE == 2
ld1 {v0.16b-v1.16b}, [x1], #32 /* get 2 ct blocks */
next_tweak v5, v4, v7, v8
eor v0.16b, v0.16b, v4.16b
eor v1.16b, v1.16b, v5.16b
do_decrypt_block2x
eor v0.16b, v0.16b, v4.16b
eor v1.16b, v1.16b, v5.16b
st1 {v0.16b-v1.16b}, [x0], #32
cbz w4, .LxtsdecoutNx
next_tweak v4, v5, v7, v8
b .LxtsdecNx
.LxtsdecoutNx:
mov v4.16b, v5.16b
b .Lxtsdecout
#else
ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */
next_tweak v5, v4, v7, v8
eor v0.16b, v0.16b, v4.16b
next_tweak v6, v5, v7, v8
eor v1.16b, v1.16b, v5.16b
eor v2.16b, v2.16b, v6.16b
next_tweak v7, v6, v7, v8
eor v3.16b, v3.16b, v7.16b
do_decrypt_block4x
eor v3.16b, v3.16b, v7.16b
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
mov v4.16b, v7.16b
cbz w4, .Lxtsdecout
b .LxtsdecloopNx
#endif
.Lxtsdec1x:
adds w4, w4, #INTERLEAVE
beq .Lxtsdecout
#endif
.Lxtsdecloop:
ld1 {v1.16b}, [x1], #16
eor v0.16b, v1.16b, v4.16b
decrypt_block v0, w3, x2, x8, w7
eor v0.16b, v0.16b, v4.16b
st1 {v0.16b}, [x0], #16
subs w4, w4, #1
beq .Lxtsdecout
next_tweak v4, v4, v7, v8
b .Lxtsdecloop
.Lxtsdecout:
st1 {v4.16b}, [x6]
FRAME_POP
ret
AES_ENDPROC(aes_xts_decrypt)
/*
* aes_mac_update(u8 const in[], u32 const rk[], int rounds,
* int blocks, u8 dg[], int enc_before, int enc_after)
*/
AES_ENTRY(aes_mac_update)
ld1 {v0.16b}, [x4] /* get dg */
enc_prepare w2, x1, x7
cbnz w5, .Lmacenc
.Lmacloop:
cbz w3, .Lmacout
ld1 {v1.16b}, [x0], #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
cbz w5, .Lmacout
.Lmacenc:
encrypt_block v0, w2, x1, x7, w8
b .Lmacloop
.Lmacout:
st1 {v0.16b}, [x4] /* return dg */
ret
AES_ENDPROC(aes_mac_update)