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| -rw-r--r-- | arch/x86/crypto/aes-xts-avx-x86_64.S | 845 |
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diff --git a/arch/x86/crypto/aes-xts-avx-x86_64.S b/arch/x86/crypto/aes-xts-avx-x86_64.S new file mode 100644 index 0000000000..48f97b79f7 --- /dev/null +++ b/arch/x86/crypto/aes-xts-avx-x86_64.S @@ -0,0 +1,845 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * AES-XTS for modern x86_64 CPUs + * + * Copyright 2024 Google LLC + * + * Author: Eric Biggers <ebiggers@google.com> + */ + +/* + * This file implements AES-XTS for modern x86_64 CPUs. To handle the + * complexities of coding for x86 SIMD, e.g. where every vector length needs + * different code, it uses a macro to generate several implementations that + * share similar source code but are targeted at different CPUs, listed below: + * + * AES-NI + AVX + * - 128-bit vectors (1 AES block per vector) + * - VEX-coded instructions + * - xmm0-xmm15 + * - This is for older CPUs that lack VAES but do have AVX. + * + * VAES + VPCLMULQDQ + AVX2 + * - 256-bit vectors (2 AES blocks per vector) + * - VEX-coded instructions + * - ymm0-ymm15 + * - This is for CPUs that have VAES but lack AVX512 or AVX10, + * e.g. Intel's Alder Lake and AMD's Zen 3. + * + * VAES + VPCLMULQDQ + AVX10/256 + BMI2 + * - 256-bit vectors (2 AES blocks per vector) + * - EVEX-coded instructions + * - ymm0-ymm31 + * - This is for CPUs that have AVX512 but where using zmm registers causes + * downclocking, and for CPUs that have AVX10/256 but not AVX10/512. + * - By "AVX10/256" we really mean (AVX512BW + AVX512VL) || AVX10/256. + * To avoid confusion with 512-bit, we just write AVX10/256. + * + * VAES + VPCLMULQDQ + AVX10/512 + BMI2 + * - Same as the previous one, but upgrades to 512-bit vectors + * (4 AES blocks per vector) in zmm0-zmm31. + * - This is for CPUs that have good AVX512 or AVX10/512 support. + * + * This file doesn't have an implementation for AES-NI alone (without AVX), as + * the lack of VEX would make all the assembly code different. + * + * When we use VAES, we also use VPCLMULQDQ to parallelize the computation of + * the XTS tweaks. This avoids a bottleneck. Currently there don't seem to be + * any CPUs that support VAES but not VPCLMULQDQ. If that changes, we might + * need to start also providing an implementation using VAES alone. + * + * The AES-XTS implementations in this file support everything required by the + * crypto API, including support for arbitrary input lengths and multi-part + * processing. However, they are most heavily optimized for the common case of + * power-of-2 length inputs that are processed in a single part (disk sectors). + */ + +#include <linux/linkage.h> +#include <linux/cfi_types.h> + +.section .rodata +.p2align 4 +.Lgf_poly: + // The low 64 bits of this value represent the polynomial x^7 + x^2 + x + // + 1. It is the value that must be XOR'd into the low 64 bits of the + // tweak each time a 1 is carried out of the high 64 bits. + // + // The high 64 bits of this value is just the internal carry bit that + // exists when there's a carry out of the low 64 bits of the tweak. + .quad 0x87, 1 + + // This table contains constants for vpshufb and vpblendvb, used to + // handle variable byte shifts and blending during ciphertext stealing + // on CPUs that don't support AVX10-style masking. +.Lcts_permute_table: + .byte 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80 + .byte 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80 + .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 + .byte 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f + .byte 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80 + .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 to 7th-from-last round key +.set SRC, %rsi // Pointer to next source data +.set DST, %rdx // Pointer to next destination data +.set LEN, %ecx // Remaining length in bytes +.set LEN8, %cl +.set LEN64, %rcx +.set TWEAK, %r8 // Pointer to next tweak + +// %rax holds the AES key length in bytes. +.set KEYLEN, %eax +.set KEYLEN64, %rax + +// %r9-r11 are available as temporaries. + +.macro _define_Vi i +.if VL == 16 + .set V\i, %xmm\i +.elseif VL == 32 + .set V\i, %ymm\i +.elseif VL == 64 + .set V\i, %zmm\i +.else + .error "Unsupported Vector Length (VL)" +.endif +.endm + +.macro _define_aliases + // Define register aliases V0-V15, or V0-V31 if all 32 SIMD registers + // are available, that map to the xmm, ymm, or zmm registers according + // to the selected Vector Length (VL). + _define_Vi 0 + _define_Vi 1 + _define_Vi 2 + _define_Vi 3 + _define_Vi 4 + _define_Vi 5 + _define_Vi 6 + _define_Vi 7 + _define_Vi 8 + _define_Vi 9 + _define_Vi 10 + _define_Vi 11 + _define_Vi 12 + _define_Vi 13 + _define_Vi 14 + _define_Vi 15 +.if USE_AVX10 + _define_Vi 16 + _define_Vi 17 + _define_Vi 18 + _define_Vi 19 + _define_Vi 20 + _define_Vi 21 + _define_Vi 22 + _define_Vi 23 + _define_Vi 24 + _define_Vi 25 + _define_Vi 26 + _define_Vi 27 + _define_Vi 28 + _define_Vi 29 + _define_Vi 30 + _define_Vi 31 +.endif + + // V0-V3 hold the data blocks during the main loop, or temporary values + // otherwise. V4-V5 hold temporary values. + + // V6-V9 hold XTS tweaks. Each 128-bit lane holds one tweak. + .set TWEAK0_XMM, %xmm6 + .set TWEAK0, V6 + .set TWEAK1_XMM, %xmm7 + .set TWEAK1, V7 + .set TWEAK2, V8 + .set TWEAK3, V9 + + // V10-V13 are used for computing the next values of TWEAK[0-3]. + .set NEXT_TWEAK0, V10 + .set NEXT_TWEAK1, V11 + .set NEXT_TWEAK2, V12 + .set NEXT_TWEAK3, V13 + + // V14 holds the constant from .Lgf_poly, copied to all 128-bit lanes. + .set GF_POLY_XMM, %xmm14 + .set GF_POLY, V14 + + // V15 holds the key for AES "round 0", copied to all 128-bit lanes. + .set KEY0_XMM, %xmm15 + .set KEY0, V15 + + // If 32 SIMD registers are available, then V16-V29 hold the remaining + // AES round keys, copied to all 128-bit lanes. + // + // AES-128, AES-192, and AES-256 use different numbers of round keys. + // To allow handling all three variants efficiently, we align the round + // keys to the *end* of this register range. I.e., AES-128 uses + // KEY5-KEY14, AES-192 uses KEY3-KEY14, and AES-256 uses KEY1-KEY14. + // (All also use KEY0 for the XOR-only "round" at the beginning.) +.if USE_AVX10 + .set KEY1_XMM, %xmm16 + .set KEY1, V16 + .set KEY2_XMM, %xmm17 + .set KEY2, V17 + .set KEY3_XMM, %xmm18 + .set KEY3, V18 + .set KEY4_XMM, %xmm19 + .set KEY4, V19 + .set KEY5_XMM, %xmm20 + .set KEY5, V20 + .set KEY6_XMM, %xmm21 + .set KEY6, V21 + .set KEY7_XMM, %xmm22 + .set KEY7, V22 + .set KEY8_XMM, %xmm23 + .set KEY8, V23 + .set KEY9_XMM, %xmm24 + .set KEY9, V24 + .set KEY10_XMM, %xmm25 + .set KEY10, V25 + .set KEY11_XMM, %xmm26 + .set KEY11, V26 + .set KEY12_XMM, %xmm27 + .set KEY12, V27 + .set KEY13_XMM, %xmm28 + .set KEY13, V28 + .set KEY14_XMM, %xmm29 + .set KEY14, V29 +.endif + // V30-V31 are currently unused. +.endm + +// Move a vector between memory and a register. +.macro _vmovdqu src, dst +.if VL < 64 + vmovdqu \src, \dst +.else + vmovdqu8 \src, \dst +.endif +.endm + +// Broadcast a 128-bit value into a vector. +.macro _vbroadcast128 src, dst +.if VL == 16 && !USE_AVX10 + vmovdqu \src, \dst +.elseif VL == 32 && !USE_AVX10 + vbroadcasti128 \src, \dst +.else + vbroadcasti32x4 \src, \dst +.endif +.endm + +// XOR two vectors together. +.macro _vpxor src1, src2, dst +.if USE_AVX10 + vpxord \src1, \src2, \dst +.else + vpxor \src1, \src2, \dst +.endif +.endm + +// XOR three vectors together. +.macro _xor3 src1, src2, src3_and_dst +.if USE_AVX10 + // vpternlogd with immediate 0x96 is a three-argument XOR. + vpternlogd $0x96, \src1, \src2, \src3_and_dst +.else + vpxor \src1, \src3_and_dst, \src3_and_dst + vpxor \src2, \src3_and_dst, \src3_and_dst +.endif +.endm + +// Given a 128-bit XTS tweak in the xmm register \src, compute the next tweak +// (by multiplying by the polynomial 'x') and write it to \dst. +.macro _next_tweak src, tmp, dst + vpshufd $0x13, \src, \tmp + vpaddq \src, \src, \dst + vpsrad $31, \tmp, \tmp + vpand GF_POLY_XMM, \tmp, \tmp + vpxor \tmp, \dst, \dst +.endm + +// Given the XTS tweak(s) in the vector \src, compute the next vector of +// tweak(s) (by multiplying by the polynomial 'x^(VL/16)') and write it to \dst. +// +// If VL > 16, then there are multiple tweaks, and we use vpclmulqdq to compute +// all tweaks in the vector in parallel. If VL=16, we just do the regular +// computation without vpclmulqdq, as it's the faster method for a single tweak. +.macro _next_tweakvec src, tmp1, tmp2, dst +.if VL == 16 + _next_tweak \src, \tmp1, \dst +.else + vpsrlq $64 - VL/16, \src, \tmp1 + vpclmulqdq $0x01, GF_POLY, \tmp1, \tmp2 + vpslldq $8, \tmp1, \tmp1 + vpsllq $VL/16, \src, \dst + _xor3 \tmp1, \tmp2, \dst +.endif +.endm + +// Given the first XTS tweak at (TWEAK), compute the first set of tweaks and +// store them in the vector registers TWEAK0-TWEAK3. Clobbers V0-V5. +.macro _compute_first_set_of_tweaks + vmovdqu (TWEAK), TWEAK0_XMM + _vbroadcast128 .Lgf_poly(%rip), GF_POLY +.if VL == 16 + // With VL=16, multiplying by x serially is fastest. + _next_tweak TWEAK0, %xmm0, TWEAK1 + _next_tweak TWEAK1, %xmm0, TWEAK2 + _next_tweak TWEAK2, %xmm0, TWEAK3 +.else +.if VL == 32 + // Compute the second block of TWEAK0. + _next_tweak TWEAK0_XMM, %xmm0, %xmm1 + vinserti128 $1, %xmm1, TWEAK0, TWEAK0 +.elseif VL == 64 + // Compute the remaining blocks of TWEAK0. + _next_tweak TWEAK0_XMM, %xmm0, %xmm1 + _next_tweak %xmm1, %xmm0, %xmm2 + _next_tweak %xmm2, %xmm0, %xmm3 + vinserti32x4 $1, %xmm1, TWEAK0, TWEAK0 + vinserti32x4 $2, %xmm2, TWEAK0, TWEAK0 + vinserti32x4 $3, %xmm3, TWEAK0, TWEAK0 +.endif + // Compute TWEAK[1-3] from TWEAK0. + vpsrlq $64 - 1*VL/16, TWEAK0, V0 + vpsrlq $64 - 2*VL/16, TWEAK0, V2 + vpsrlq $64 - 3*VL/16, TWEAK0, V4 + vpclmulqdq $0x01, GF_POLY, V0, V1 + vpclmulqdq $0x01, GF_POLY, V2, V3 + vpclmulqdq $0x01, GF_POLY, V4, V5 + vpslldq $8, V0, V0 + vpslldq $8, V2, V2 + vpslldq $8, V4, V4 + vpsllq $1*VL/16, TWEAK0, TWEAK1 + vpsllq $2*VL/16, TWEAK0, TWEAK2 + vpsllq $3*VL/16, TWEAK0, TWEAK3 +.if USE_AVX10 + vpternlogd $0x96, V0, V1, TWEAK1 + vpternlogd $0x96, V2, V3, TWEAK2 + vpternlogd $0x96, V4, V5, TWEAK3 +.else + vpxor V0, TWEAK1, TWEAK1 + vpxor V2, TWEAK2, TWEAK2 + vpxor V4, TWEAK3, TWEAK3 + vpxor V1, TWEAK1, TWEAK1 + vpxor V3, TWEAK2, TWEAK2 + vpxor V5, TWEAK3, TWEAK3 +.endif +.endif +.endm + +// Do one step in computing the next set of tweaks using the method of just +// multiplying by x repeatedly (the same method _next_tweak uses). +.macro _tweak_step_mulx i +.if \i == 0 + .set PREV_TWEAK, TWEAK3 + .set NEXT_TWEAK, NEXT_TWEAK0 +.elseif \i == 5 + .set PREV_TWEAK, NEXT_TWEAK0 + .set NEXT_TWEAK, NEXT_TWEAK1 +.elseif \i == 10 + .set PREV_TWEAK, NEXT_TWEAK1 + .set NEXT_TWEAK, NEXT_TWEAK2 +.elseif \i == 15 + .set PREV_TWEAK, NEXT_TWEAK2 + .set NEXT_TWEAK, NEXT_TWEAK3 +.endif +.if \i >= 0 && \i < 20 && \i % 5 == 0 + vpshufd $0x13, PREV_TWEAK, V5 +.elseif \i >= 0 && \i < 20 && \i % 5 == 1 + vpaddq PREV_TWEAK, PREV_TWEAK, NEXT_TWEAK +.elseif \i >= 0 && \i < 20 && \i % 5 == 2 + vpsrad $31, V5, V5 +.elseif \i >= 0 && \i < 20 && \i % 5 == 3 + vpand GF_POLY, V5, V5 +.elseif \i >= 0 && \i < 20 && \i % 5 == 4 + vpxor V5, NEXT_TWEAK, NEXT_TWEAK +.elseif \i == 1000 + vmovdqa NEXT_TWEAK0, TWEAK0 + vmovdqa NEXT_TWEAK1, TWEAK1 + vmovdqa NEXT_TWEAK2, TWEAK2 + vmovdqa NEXT_TWEAK3, TWEAK3 +.endif +.endm + +// Do one step in computing the next set of tweaks using the VPCLMULQDQ method +// (the same method _next_tweakvec uses for VL > 16). This means multiplying +// each tweak by x^(4*VL/16) independently. Since 4*VL/16 is a multiple of 8 +// when VL > 16 (which it is here), the needed shift amounts are byte-aligned, +// which allows the use of vpsrldq and vpslldq to do 128-bit wide shifts. +.macro _tweak_step_pclmul i +.if \i == 0 + vpsrldq $(128 - 4*VL/16) / 8, TWEAK0, NEXT_TWEAK0 +.elseif \i == 2 + vpsrldq $(128 - 4*VL/16) / 8, TWEAK1, NEXT_TWEAK1 +.elseif \i == 4 + vpsrldq $(128 - 4*VL/16) / 8, TWEAK2, NEXT_TWEAK2 +.elseif \i == 6 + vpsrldq $(128 - 4*VL/16) / 8, TWEAK3, NEXT_TWEAK3 +.elseif \i == 8 + vpclmulqdq $0x00, GF_POLY, NEXT_TWEAK0, NEXT_TWEAK0 +.elseif \i == 10 + vpclmulqdq $0x00, GF_POLY, NEXT_TWEAK1, NEXT_TWEAK1 +.elseif \i == 12 + vpclmulqdq $0x00, GF_POLY, NEXT_TWEAK2, NEXT_TWEAK2 +.elseif \i == 14 + vpclmulqdq $0x00, GF_POLY, NEXT_TWEAK3, NEXT_TWEAK3 +.elseif \i == 1000 + vpslldq $(4*VL/16) / 8, TWEAK0, TWEAK0 + vpslldq $(4*VL/16) / 8, TWEAK1, TWEAK1 + vpslldq $(4*VL/16) / 8, TWEAK2, TWEAK2 + vpslldq $(4*VL/16) / 8, TWEAK3, TWEAK3 + _vpxor NEXT_TWEAK0, TWEAK0, TWEAK0 + _vpxor NEXT_TWEAK1, TWEAK1, TWEAK1 + _vpxor NEXT_TWEAK2, TWEAK2, TWEAK2 + _vpxor NEXT_TWEAK3, TWEAK3, TWEAK3 +.endif +.endm + +// _tweak_step does one step of the computation of the next set of tweaks from +// TWEAK[0-3]. To complete all steps, this is invoked with increasing values of +// \i that include at least 0 through 19, then 1000 which signals the last step. +// +// This is used to interleave the computation of the next set of tweaks with the +// AES en/decryptions, which increases performance in some cases. +.macro _tweak_step i +.if VL == 16 + _tweak_step_mulx \i +.else + _tweak_step_pclmul \i +.endif +.endm + +.macro _setup_round_keys enc + + // Select either the encryption round keys or the decryption round keys. +.if \enc + .set OFFS, 0 +.else + .set OFFS, 240 +.endif + + // Load the round key for "round 0". + _vbroadcast128 OFFS(KEY), KEY0 + + // Increment KEY to make it so that 7*16(KEY) is the last round key. + // For AES-128, increment by 3*16, resulting in the 10 round keys (not + // counting the zero-th round key which was just loaded into KEY0) being + // -2*16(KEY) through 7*16(KEY). For AES-192, increment by 5*16 and use + // 12 round keys -4*16(KEY) through 7*16(KEY). For AES-256, increment + // by 7*16 and use 14 round keys -6*16(KEY) through 7*16(KEY). + // + // This rebasing provides two benefits. First, it makes the offset to + // any round key be in the range [-96, 112], fitting in a signed byte. + // This shortens VEX-encoded instructions that access the later round + // keys which otherwise would need 4-byte offsets. Second, it makes it + // easy to do AES-128 and AES-192 by skipping irrelevant rounds at the + // beginning. Skipping rounds at the end doesn't work as well because + // the last round needs different instructions. + // + // An alternative approach would be to roll up all the round loops. We + // don't do that because it isn't compatible with caching the round keys + // in registers which we do when possible (see below), and also because + // it seems unwise to rely *too* heavily on the CPU's branch predictor. + lea OFFS-16(KEY, KEYLEN64, 4), KEY + + // If all 32 SIMD registers are available, cache all the round keys. +.if USE_AVX10 + cmp $24, KEYLEN + jl .Laes128\@ + je .Laes192\@ + _vbroadcast128 -6*16(KEY), KEY1 + _vbroadcast128 -5*16(KEY), KEY2 +.Laes192\@: + _vbroadcast128 -4*16(KEY), KEY3 + _vbroadcast128 -3*16(KEY), KEY4 +.Laes128\@: + _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 + _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 +// determines the number of AES blocks en/decrypted. +.macro _vaes enc, last, key, data +.if \enc +.if \last + vaesenclast \key, \data, \data +.else + vaesenc \key, \data, \data +.endif +.else +.if \last + vaesdeclast \key, \data, \data +.else + vaesdec \key, \data, \data +.endif +.endif +.endm + +// Do a single round of AES en/decryption on the block(s) in \data, using the +// same key for all block(s). The round key is loaded from the appropriate +// register or memory location for round \i. May clobber V4. +.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-7)*16(KEY), \data +.else + _vbroadcast128 (\i-7)*16(KEY), V4 + _vaes \enc, \last, V4, \data +.endif +.endif +.endm + +// Do a single round of AES en/decryption on the blocks in registers V0-V3, +// using the same key for all blocks. The round key is loaded from the +// appropriate register or memory location for round \i. In addition, does two +// steps of the computation of the next set of tweaks. May clobber V4. +.macro _vaes_4x enc, last, i +.if USE_AVX10 + _tweak_step (2*(\i-5)) + _vaes \enc, \last, KEY\i, V0 + _vaes \enc, \last, KEY\i, V1 + _tweak_step (2*(\i-5) + 1) + _vaes \enc, \last, KEY\i, V2 + _vaes \enc, \last, KEY\i, V3 +.else + _vbroadcast128 (\i-7)*16(KEY), V4 + _tweak_step (2*(\i-5)) + _vaes \enc, \last, V4, V0 + _vaes \enc, \last, V4, V1 + _tweak_step (2*(\i-5) + 1) + _vaes \enc, \last, V4, V2 + _vaes \enc, \last, V4, V3 +.endif +.endm + +// Do tweaked AES en/decryption (i.e., XOR with \tweak, then AES en/decrypt, +// then XOR with \tweak again) of the block(s) in \data. To process a single +// block, use xmm registers and set \xmm_suffix=_XMM. To process a vector of +// length VL, use V* registers and leave \xmm_suffix empty. May clobber V4. +.macro _aes_crypt enc, xmm_suffix, tweak, data + _xor3 KEY0\xmm_suffix, \tweak, \data + cmp $24, KEYLEN + jl .Laes128\@ + je .Laes192\@ + _vaes_1x \enc, 0, 1, \xmm_suffix, \data + _vaes_1x \enc, 0, 2, \xmm_suffix, \data +.Laes192\@: + _vaes_1x \enc, 0, 3, \xmm_suffix, \data + _vaes_1x \enc, 0, 4, \xmm_suffix, \data +.Laes128\@: + _vaes_1x \enc, 0, 5, \xmm_suffix, \data + _vaes_1x \enc, 0, 6, \xmm_suffix, \data + _vaes_1x \enc, 0, 7, \xmm_suffix, \data + _vaes_1x \enc, 0, 8, \xmm_suffix, \data + _vaes_1x \enc, 0, 9, \xmm_suffix, \data + _vaes_1x \enc, 0, 10, \xmm_suffix, \data + _vaes_1x \enc, 0, 11, \xmm_suffix, \data + _vaes_1x \enc, 0, 12, \xmm_suffix, \data + _vaes_1x \enc, 0, 13, \xmm_suffix, \data + _vaes_1x \enc, 1, 14, \xmm_suffix, \data + _vpxor \tweak, \data, \data +.endm + +.macro _aes_xts_crypt enc + _define_aliases + +.if !\enc + // When decrypting a message whose length isn't a multiple of the AES + // block length, exclude the last full block from the main loop by + // subtracting 16 from LEN. This is needed because ciphertext stealing + // decryption uses the last two tweaks in reverse order. We'll handle + // the last full block and the partial block specially at the end. + lea -16(LEN), %eax + test $15, LEN8 + cmovnz %eax, LEN +.endif + + // Load the AES key length: 16 (AES-128), 24 (AES-192), or 32 (AES-256). + movl 480(KEY), KEYLEN + + // Setup the pointer to the round keys and cache as many as possible. + _setup_round_keys \enc + + // Compute the first set of tweaks TWEAK[0-3]. + _compute_first_set_of_tweaks + + sub $4*VL, LEN + jl .Lhandle_remainder\@ + +.Lmain_loop\@: + // This is the main loop, en/decrypting 4*VL bytes per iteration. + + // XOR each source block with its tweak and the zero-th round key. +.if USE_AVX10 + vmovdqu8 0*VL(SRC), V0 + vmovdqu8 1*VL(SRC), V1 + vmovdqu8 2*VL(SRC), V2 + vmovdqu8 3*VL(SRC), V3 + vpternlogd $0x96, TWEAK0, KEY0, V0 + vpternlogd $0x96, TWEAK1, KEY0, V1 + vpternlogd $0x96, TWEAK2, KEY0, V2 + vpternlogd $0x96, TWEAK3, KEY0, V3 +.else + vpxor 0*VL(SRC), KEY0, V0 + vpxor 1*VL(SRC), KEY0, V1 + vpxor 2*VL(SRC), KEY0, V2 + vpxor 3*VL(SRC), KEY0, V3 + vpxor TWEAK0, V0, V0 + vpxor TWEAK1, V1, V1 + vpxor TWEAK2, V2, V2 + vpxor TWEAK3, V3, V3 +.endif + cmp $24, KEYLEN + jl .Laes128\@ + je .Laes192\@ + // Do all the AES rounds on the data blocks, interleaved with + // the computation of the next set of tweaks. + _vaes_4x \enc, 0, 1 + _vaes_4x \enc, 0, 2 +.Laes192\@: + _vaes_4x \enc, 0, 3 + _vaes_4x \enc, 0, 4 +.Laes128\@: + _vaes_4x \enc, 0, 5 + _vaes_4x \enc, 0, 6 + _vaes_4x \enc, 0, 7 + _vaes_4x \enc, 0, 8 + _vaes_4x \enc, 0, 9 + _vaes_4x \enc, 0, 10 + _vaes_4x \enc, 0, 11 + _vaes_4x \enc, 0, 12 + _vaes_4x \enc, 0, 13 + _vaes_4x \enc, 1, 14 + + // XOR in the tweaks again. + _vpxor TWEAK0, V0, V0 + _vpxor TWEAK1, V1, V1 + _vpxor TWEAK2, V2, V2 + _vpxor TWEAK3, V3, V3 + + // Store the destination blocks. + _vmovdqu V0, 0*VL(DST) + _vmovdqu V1, 1*VL(DST) + _vmovdqu V2, 2*VL(DST) + _vmovdqu V3, 3*VL(DST) + + // Finish computing the next set of tweaks. + _tweak_step 1000 + + add $4*VL, SRC + add $4*VL, DST + sub $4*VL, LEN + jge .Lmain_loop\@ + + // Check for the uncommon case where the data length isn't a multiple of + // 4*VL. Handle it out-of-line in order to optimize for the common + // case. In the common case, just fall through to the ret. + test $4*VL-1, LEN8 + jnz .Lhandle_remainder\@ +.Ldone\@: + // Store the next tweak back to *TWEAK to support continuation calls. + vmovdqu TWEAK0_XMM, (TWEAK) +.if VL > 16 + vzeroupper +.endif + RET + +.Lhandle_remainder\@: + + // En/decrypt any remaining full blocks, one vector at a time. +.if VL > 16 + add $3*VL, LEN // Undo extra sub of 4*VL, then sub VL. + jl .Lvec_at_a_time_done\@ +.Lvec_at_a_time\@: + _vmovdqu (SRC), V0 + _aes_crypt \enc, , TWEAK0, V0 + _vmovdqu V0, (DST) + _next_tweakvec TWEAK0, V0, V1, TWEAK0 + add $VL, SRC + add $VL, DST + sub $VL, LEN + jge .Lvec_at_a_time\@ +.Lvec_at_a_time_done\@: + add $VL-16, LEN // Undo extra sub of VL, then sub 16. +.else + add $4*VL-16, LEN // Undo extra sub of 4*VL, then sub 16. +.endif + + // En/decrypt any remaining full blocks, one at a time. + jl .Lblock_at_a_time_done\@ +.Lblock_at_a_time\@: + vmovdqu (SRC), %xmm0 + _aes_crypt \enc, _XMM, TWEAK0_XMM, %xmm0 + vmovdqu %xmm0, (DST) + _next_tweak TWEAK0_XMM, %xmm0, TWEAK0_XMM + add $16, SRC + add $16, DST + sub $16, LEN + jge .Lblock_at_a_time\@ +.Lblock_at_a_time_done\@: + add $16, LEN // Undo the extra sub of 16. + // Now 0 <= LEN <= 15. If LEN is zero, we're done. + jz .Ldone\@ + + // Otherwise 1 <= LEN <= 15, but the real remaining length is 16 + LEN. + // Do ciphertext stealing to process the last 16 + LEN bytes. + +.if \enc + // If encrypting, the main loop already encrypted the last full block to + // create the CTS intermediate ciphertext. Prepare for the rest of CTS + // by rewinding the pointers and loading the intermediate ciphertext. + sub $16, SRC + sub $16, DST + vmovdqu (DST), %xmm0 +.else + // If decrypting, the main loop didn't decrypt the last full block + // because CTS decryption uses the last two tweaks in reverse order. + // Do it now by advancing the tweak and decrypting the last full block. + _next_tweak TWEAK0_XMM, %xmm0, TWEAK1_XMM + vmovdqu (SRC), %xmm0 + _aes_crypt \enc, _XMM, TWEAK1_XMM, %xmm0 +.endif + +.if USE_AVX10 + // Create a mask that has the first LEN bits set. + mov $-1, %r9d + bzhi LEN, %r9d, %r9d + kmovd %r9d, %k1 + + // Swap the first LEN bytes of the en/decryption of the last full block + // with the partial block. Note that to support in-place en/decryption, + // the load from the src partial block must happen before the store to + // the dst partial block. + vmovdqa %xmm0, %xmm1 + vmovdqu8 16(SRC), %xmm0{%k1} + vmovdqu8 %xmm1, 16(DST){%k1} +.else + lea .Lcts_permute_table(%rip), %r9 + + // Load the src partial block, left-aligned. Note that to support + // in-place en/decryption, this must happen before the store to the dst + // partial block. + vmovdqu (SRC, LEN64, 1), %xmm1 + + // Shift the first LEN bytes of the en/decryption of the last full block + // to the end of a register, then store it to DST+LEN. This stores the + // dst partial block. It also writes to the second part of the dst last + // full block, but that part is overwritten later. + vpshufb (%r9, LEN64, 1), %xmm0, %xmm2 + vmovdqu %xmm2, (DST, LEN64, 1) + + // Make xmm3 contain [16-LEN,16-LEN+1,...,14,15,0x80,0x80,...]. + sub LEN64, %r9 + vmovdqu 32(%r9), %xmm3 + + // Shift the src partial block to the beginning of its register. + vpshufb %xmm3, %xmm1, %xmm1 + + // Do a blend to generate the src partial block followed by the second + // part of the en/decryption of the last full block. + vpblendvb %xmm3, %xmm0, %xmm1, %xmm0 +.endif + // En/decrypt again and store the last full block. + _aes_crypt \enc, _XMM, TWEAK0_XMM, %xmm0 + vmovdqu %xmm0, (DST) + jmp .Ldone\@ +.endm + +// 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 (%rdi), %xmm0, %xmm0 + movl 480(%rdi), %eax // AES key length + lea -16(%rdi, %rax, 4), %rdi + cmp $24, %eax + jl .Lencrypt_iv_aes128 + je .Lencrypt_iv_aes192 + vaesenc -6*16(%rdi), %xmm0, %xmm0 + vaesenc -5*16(%rdi), %xmm0, %xmm0 +.Lencrypt_iv_aes192: + vaesenc -4*16(%rdi), %xmm0, %xmm0 + vaesenc -3*16(%rdi), %xmm0, %xmm0 +.Lencrypt_iv_aes128: + 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 + vaesenc 3*16(%rdi), %xmm0, %xmm0 + vaesenc 4*16(%rdi), %xmm0, %xmm0 + vaesenc 5*16(%rdi), %xmm0, %xmm0 + vaesenc 6*16(%rdi), %xmm0, %xmm0 + vaesenclast 7*16(%rdi), %xmm0, %xmm0 + vmovdqu %xmm0, (%rsi) + RET +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: +// +// void (*xts_asm_func)(const struct crypto_aes_ctx *key, +// const u8 *src, u8 *dst, unsigned int len, +// u8 tweak[AES_BLOCK_SIZE]); +// +// |key| is the data key. |tweak| contains the next tweak; the encryption of +// the original IV with the tweak key was already done. This function supports +// incremental computation, but |len| must always be >= 16 (AES_BLOCK_SIZE), and +// |len| must be a multiple of 16 except on the last call. If |len| is a +// multiple of 16, then this function updates |tweak| to contain the next tweak. + +.set VL, 16 +.set USE_AVX10, 0 +SYM_TYPED_FUNC_START(aes_xts_encrypt_aesni_avx) + _aes_xts_crypt 1 +SYM_FUNC_END(aes_xts_encrypt_aesni_avx) +SYM_TYPED_FUNC_START(aes_xts_decrypt_aesni_avx) + _aes_xts_crypt 0 +SYM_FUNC_END(aes_xts_decrypt_aesni_avx) + +#if defined(CONFIG_AS_VAES) && defined(CONFIG_AS_VPCLMULQDQ) +.set VL, 32 +.set USE_AVX10, 0 +SYM_TYPED_FUNC_START(aes_xts_encrypt_vaes_avx2) + _aes_xts_crypt 1 +SYM_FUNC_END(aes_xts_encrypt_vaes_avx2) +SYM_TYPED_FUNC_START(aes_xts_decrypt_vaes_avx2) + _aes_xts_crypt 0 +SYM_FUNC_END(aes_xts_decrypt_vaes_avx2) + +.set VL, 32 +.set USE_AVX10, 1 +SYM_TYPED_FUNC_START(aes_xts_encrypt_vaes_avx10_256) + _aes_xts_crypt 1 +SYM_FUNC_END(aes_xts_encrypt_vaes_avx10_256) +SYM_TYPED_FUNC_START(aes_xts_decrypt_vaes_avx10_256) + _aes_xts_crypt 0 +SYM_FUNC_END(aes_xts_decrypt_vaes_avx10_256) + +.set VL, 64 +.set USE_AVX10, 1 +SYM_TYPED_FUNC_START(aes_xts_encrypt_vaes_avx10_512) + _aes_xts_crypt 1 +SYM_FUNC_END(aes_xts_encrypt_vaes_avx10_512) +SYM_TYPED_FUNC_START(aes_xts_decrypt_vaes_avx10_512) + _aes_xts_crypt 0 +SYM_FUNC_END(aes_xts_decrypt_vaes_avx10_512) +#endif /* CONFIG_AS_VAES && CONFIG_AS_VPCLMULQDQ */ |