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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2018-09-10 16:41:15 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-09-21 13:24:50 +0800 |
| commit | 2e5d2f33d1dbd551f14634483c7ea81e5119d689 (patch) | |
| tree | ea7b3f03c3af0d1e818d588ac2a8e99c391b0826 /arch/arm64/crypto/aes-modes.S | |
| parent | dd597fb33ff0d2a158d7dd098be6dc849b7c2bcc (diff) | |
| download | linux-2e5d2f33d1dbd551f14634483c7ea81e5119d689.tar.bz2 | |
crypto: arm64/aes-blk - improve XTS mask handling
The Crypto Extension instantiation of the aes-modes.S collection of
skciphers uses only 15 NEON registers for the round key array, whereas
the pure NEON flavor uses 16 NEON registers for the AES S-box.
This means we have a spare register available that we can use to hold
the XTS mask vector, removing the need to reload it at every iteration
of the inner loop.
Since the pure NEON version does not permit this optimization, tweak
the macros so we can factor out this functionality. Also, replace the
literal load with a short sequence to compose the mask vector.
On Cortex-A53, this results in a ~4% speedup.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm64/crypto/aes-modes.S')
| -rw-r--r-- | arch/arm64/crypto/aes-modes.S | 40 |
1 files changed, 21 insertions, 19 deletions
diff --git a/arch/arm64/crypto/aes-modes.S b/arch/arm64/crypto/aes-modes.S index 9697eda3b4d1..039738ae23f6 100644 --- a/arch/arm64/crypto/aes-modes.S +++ b/arch/arm64/crypto/aes-modes.S @@ -340,17 +340,19 @@ AES_ENDPROC(aes_ctr_encrypt) * int blocks, u8 const rk2[], u8 iv[], int first) */ - .macro next_tweak, out, in, const, tmp + .macro next_tweak, out, in, tmp sshr \tmp\().2d, \in\().2d, #63 - and \tmp\().16b, \tmp\().16b, \const\().16b + and \tmp\().16b, \tmp\().16b, xtsmask.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 ) + .macro xts_load_mask, tmp + movi xtsmask.2s, #0x1 + movi \tmp\().2s, #0x87 + uzp1 xtsmask.4s, xtsmask.4s, \tmp\().4s + .endm AES_ENTRY(aes_xts_encrypt) stp x29, x30, [sp, #-16]! @@ -362,24 +364,24 @@ AES_ENTRY(aes_xts_encrypt) 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 + xts_load_mask v8 b .LxtsencNx .Lxtsencnotfirst: enc_prepare w3, x2, x8 .LxtsencloopNx: - ldr q7, .Lxts_mul_x - next_tweak v4, v4, v7, v8 + xts_reload_mask v8 + next_tweak v4, v4, v8 .LxtsencNx: subs w4, w4, #4 bmi .Lxtsenc1x ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 pt blocks */ - next_tweak v5, v4, v7, v8 + next_tweak v5, v4, v8 eor v0.16b, v0.16b, v4.16b - next_tweak v6, v5, v7, v8 + next_tweak v6, v5, v8 eor v1.16b, v1.16b, v5.16b eor v2.16b, v2.16b, v6.16b - next_tweak v7, v6, v7, v8 + next_tweak v7, v6, v8 eor v3.16b, v3.16b, v7.16b bl aes_encrypt_block4x eor v3.16b, v3.16b, v7.16b @@ -401,7 +403,7 @@ AES_ENTRY(aes_xts_encrypt) st1 {v0.16b}, [x0], #16 subs w4, w4, #1 beq .Lxtsencout - next_tweak v4, v4, v7, v8 + next_tweak v4, v4, v8 b .Lxtsencloop .Lxtsencout: st1 {v4.16b}, [x6] @@ -420,24 +422,24 @@ AES_ENTRY(aes_xts_decrypt) enc_prepare w3, x5, x8 encrypt_block v4, w3, x5, x8, w7 /* first tweak */ dec_prepare w3, x2, x8 - ldr q7, .Lxts_mul_x + xts_load_mask v8 b .LxtsdecNx .Lxtsdecnotfirst: dec_prepare w3, x2, x8 .LxtsdecloopNx: - ldr q7, .Lxts_mul_x - next_tweak v4, v4, v7, v8 + xts_reload_mask v8 + next_tweak v4, v4, v8 .LxtsdecNx: subs w4, w4, #4 bmi .Lxtsdec1x ld1 {v0.16b-v3.16b}, [x1], #64 /* get 4 ct blocks */ - next_tweak v5, v4, v7, v8 + next_tweak v5, v4, v8 eor v0.16b, v0.16b, v4.16b - next_tweak v6, v5, v7, v8 + next_tweak v6, v5, v8 eor v1.16b, v1.16b, v5.16b eor v2.16b, v2.16b, v6.16b - next_tweak v7, v6, v7, v8 + next_tweak v7, v6, v8 eor v3.16b, v3.16b, v7.16b bl aes_decrypt_block4x eor v3.16b, v3.16b, v7.16b @@ -459,7 +461,7 @@ AES_ENTRY(aes_xts_decrypt) st1 {v0.16b}, [x0], #16 subs w4, w4, #1 beq .Lxtsdecout - next_tweak v4, v4, v7, v8 + next_tweak v4, v4, v8 b .Lxtsdecloop .Lxtsdecout: st1 {v4.16b}, [x6] |