From: Eric Biggers <ebiggers@xxxxxxxxxx> Access the AES round keys using offsets -7*16 through 7*16, instead of 0*16 through 14*16. This allows VEX-encoded instructions to address all round keys using 1-byte offsets, whereas before some needed 4-byte offsets. This decreases the code size of aes-xts-avx-x86_64.o by 4.2%. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- arch/x86/crypto/aes-xts-avx-x86_64.S | 81 +++++++++++++++------------- 1 file changed, 44 insertions(+), 37 deletions(-) diff --git a/arch/x86/crypto/aes-xts-avx-x86_64.S b/arch/x86/crypto/aes-xts-avx-x86_64.S index fcaf64a2f8c6..95e412e7601d 100644 --- a/arch/x86/crypto/aes-xts-avx-x86_64.S +++ b/arch/x86/crypto/aes-xts-avx-x86_64.S @@ -80,11 +80,11 @@ .byte 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80 .text // Function parameters .set KEY, %rdi // Initially points to crypto_aes_ctx, then is - // advanced to point directly to the round keys + // advanced to point directly to 7th round key .set SRC, %rsi // Pointer to next source data .set DST, %rdx // Pointer to next destination data .set LEN, %rcx // Remaining length in bytes .set TWEAK, %r8 // Pointer to next tweak @@ -406,28 +406,28 @@ .endif .endm // Load the round keys: just the first one if !USE_AVX10, otherwise all of them. .macro _load_round_keys - _vbroadcast128 0*16(KEY), KEY0 + _vbroadcast128 -7*16(KEY), KEY0 .if USE_AVX10 - _vbroadcast128 1*16(KEY), KEY1 - _vbroadcast128 2*16(KEY), KEY2 - _vbroadcast128 3*16(KEY), KEY3 - _vbroadcast128 4*16(KEY), KEY4 - _vbroadcast128 5*16(KEY), KEY5 - _vbroadcast128 6*16(KEY), KEY6 - _vbroadcast128 7*16(KEY), KEY7 - _vbroadcast128 8*16(KEY), KEY8 - _vbroadcast128 9*16(KEY), KEY9 - _vbroadcast128 10*16(KEY), KEY10 + _vbroadcast128 -6*16(KEY), KEY1 + _vbroadcast128 -5*16(KEY), KEY2 + _vbroadcast128 -4*16(KEY), KEY3 + _vbroadcast128 -3*16(KEY), KEY4 + _vbroadcast128 -2*16(KEY), KEY5 + _vbroadcast128 -1*16(KEY), KEY6 + _vbroadcast128 0*16(KEY), KEY7 + _vbroadcast128 1*16(KEY), KEY8 + _vbroadcast128 2*16(KEY), KEY9 + _vbroadcast128 3*16(KEY), KEY10 // Note: if it's AES-128 or AES-192, the last several round keys won't // be used. We do the loads anyway to save a conditional jump. - _vbroadcast128 11*16(KEY), KEY11 - _vbroadcast128 12*16(KEY), KEY12 - _vbroadcast128 13*16(KEY), KEY13 - _vbroadcast128 14*16(KEY), KEY14 + _vbroadcast128 4*16(KEY), KEY11 + _vbroadcast128 5*16(KEY), KEY12 + _vbroadcast128 6*16(KEY), KEY13 + _vbroadcast128 7*16(KEY), KEY14 .endif .endm // Do a single round of AES encryption (if \enc==1) or decryption (if \enc==0) // on the block(s) in \data using the round key(s) in \key. The register length @@ -454,13 +454,13 @@ .macro _vaes_1x enc, last, i, xmm_suffix, data .if USE_AVX10 _vaes \enc, \last, KEY\i\xmm_suffix, \data .else .ifnb \xmm_suffix - _vaes \enc, \last, \i*16(KEY), \data + _vaes \enc, \last, (\i-7)*16(KEY), \data .else - _vbroadcast128 \i*16(KEY), V4 + _vbroadcast128 (\i-7)*16(KEY), V4 _vaes \enc, \last, V4, \data .endif .endif .endm @@ -475,11 +475,11 @@ _vaes \enc, \last, KEY\i, V1 _tweak_step (2*(\i-1) + 1) _vaes \enc, \last, KEY\i, V2 _vaes \enc, \last, KEY\i, V3 .else - _vbroadcast128 \i*16(KEY), V4 + _vbroadcast128 (\i-7)*16(KEY), V4 _tweak_step (2*(\i-1)) _vaes \enc, \last, V4, V0 _vaes \enc, \last, V4, V1 _tweak_step (2*(\i-1) + 1) _vaes \enc, \last, V4, V2 @@ -526,13 +526,19 @@ _define_aliases // Load the AES key length: 16 (AES-128), 24 (AES-192), or 32 (AES-256). movl 480(KEY), KEYLEN - // If decrypting, advance KEY to the decryption round keys. -.if !\enc - add $240, KEY + // Advance KEY to point to the 7th encryption round key (if encrypting) + // or the 7th decryption round key (if decrypting). This makes the + // offset to any round key be in the range [-112, 112], fitting in a + // signed byte. This shortens VEX-encoded instructions that access the + // 8th and later round keys which otherwise would need 4-byte offsets. +.if \enc + add $7*16, KEY +.else + add $(15+7)*16, KEY .endif // Check whether the data length is a multiple of the AES block length. test $15, LEN jnz .Lneed_cts\@ @@ -751,40 +757,41 @@ // void aes_xts_encrypt_iv(const struct crypto_aes_ctx *tweak_key, // u8 iv[AES_BLOCK_SIZE]); SYM_TYPED_FUNC_START(aes_xts_encrypt_iv) vmovdqu (%rsi), %xmm0 - vpxor 0*16(%rdi), %xmm0, %xmm0 + add $7*16, %rdi + vpxor -7*16(%rdi), %xmm0, %xmm0 + vaesenc -6*16(%rdi), %xmm0, %xmm0 + vaesenc -5*16(%rdi), %xmm0, %xmm0 + vaesenc -4*16(%rdi), %xmm0, %xmm0 + vaesenc -3*16(%rdi), %xmm0, %xmm0 + vaesenc -2*16(%rdi), %xmm0, %xmm0 + vaesenc -1*16(%rdi), %xmm0, %xmm0 + vaesenc 0*16(%rdi), %xmm0, %xmm0 vaesenc 1*16(%rdi), %xmm0, %xmm0 vaesenc 2*16(%rdi), %xmm0, %xmm0 + cmpl $24, 480-(7*16)(%rdi) + jle .Lencrypt_iv_aes_128_or_192 vaesenc 3*16(%rdi), %xmm0, %xmm0 vaesenc 4*16(%rdi), %xmm0, %xmm0 vaesenc 5*16(%rdi), %xmm0, %xmm0 vaesenc 6*16(%rdi), %xmm0, %xmm0 - vaesenc 7*16(%rdi), %xmm0, %xmm0 - vaesenc 8*16(%rdi), %xmm0, %xmm0 - vaesenc 9*16(%rdi), %xmm0, %xmm0 - cmpl $24, 480(%rdi) - jle .Lencrypt_iv_aes_128_or_192 - vaesenc 10*16(%rdi), %xmm0, %xmm0 - vaesenc 11*16(%rdi), %xmm0, %xmm0 - vaesenc 12*16(%rdi), %xmm0, %xmm0 - vaesenc 13*16(%rdi), %xmm0, %xmm0 - vaesenclast 14*16(%rdi), %xmm0, %xmm0 + vaesenclast 7*16(%rdi), %xmm0, %xmm0 .Lencrypt_iv_done: vmovdqu %xmm0, (%rsi) RET // Out-of-line handling of AES-128 and AES-192 .Lencrypt_iv_aes_128_or_192: jz .Lencrypt_iv_aes_192 - vaesenclast 10*16(%rdi), %xmm0, %xmm0 + vaesenclast 3*16(%rdi), %xmm0, %xmm0 jmp .Lencrypt_iv_done .Lencrypt_iv_aes_192: - vaesenc 10*16(%rdi), %xmm0, %xmm0 - vaesenc 11*16(%rdi), %xmm0, %xmm0 - vaesenclast 12*16(%rdi), %xmm0, %xmm0 + vaesenc 3*16(%rdi), %xmm0, %xmm0 + vaesenc 4*16(%rdi), %xmm0, %xmm0 + vaesenclast 5*16(%rdi), %xmm0, %xmm0 jmp .Lencrypt_iv_done SYM_FUNC_END(aes_xts_encrypt_iv) // Below are the actual AES-XTS encryption and decryption functions, // instantiated from the above macro. They all have the following prototype: base-commit: 4ad27a8be9dbefd4820da0f60da879d512b2f659 prerequisite-patch-id: 8d09ed747039f5e718ac7267e2a15e22504aa7f3 -- 2.44.0
