From patchwork Mon Apr 15 13:04:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 789485 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87CF3129E8D for ; Mon, 15 Apr 2024 13:04:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713186281; cv=none; b=hPwjDmzi5++BxdyyK36dFG6f/nsaxfXSKI2M5WNz6t/fvO2R0fdNprDnyXZFzxBw/rD81yWWK9RaS+GfarxuYT3hRWoDnUUJUO5L2Wk0gCTNf1F0ZhpXejXw3Wjj+VPkYvc8uUbWNoT6wWPTYgw9xbeyIS+ydDiTh+Dus9UcZlc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713186281; c=relaxed/simple; bh=gv6RCyRiLzF5sYTSCR6UVKd1nRYO7POKsvCFzmBm6GQ=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=VDXzNMO3iJr2/H1G1mkUO3v19Phx9gKsiF32Pz+QTaMrvvv1dh8kS5Hc4pa82qmEfNW9UPH6pYn0K1MQP9lqWIrwAT6uQcKZddX7mhTWFMauAsSGDf7ugPT46ZjorCk4Ah+eox3ecggj7BZn1cALnsw8NPMstq9wW9mSd6MQr6Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=0pW1jrtH; arc=none smtp.client-ip=209.85.219.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="0pW1jrtH" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-ddaf165a8d9so4981882276.1 for ; Mon, 15 Apr 2024 06:04:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1713186275; x=1713791075; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=vTHIfbeWCqDn/6Ak6Nz73ChYB9sKU9j2WCGb9z4UFhA=; b=0pW1jrtHuomGo9WxZCOqdFcps5t5cNCdA9wuR4/N/wrJnqbBJ2JWDalUviOd7PH28w yXSaSXmJec2VBMf/4EzyEGzwbOU9a6o2bFN7frbuB7c/LxQD9bOM+aCP7IG/npoYpIq6 TxM4ftQXrbtwrEZdtMd4WoNkHnqCRiNbMn8HYlku9WKc+QUqNokK7YNqlSXDbREiZuiL JacWuxqz9PvaN9jJqMjpShty/KlyH4X9R9lphDw8TEd2sk+BpoUS7IcHFI35f/VsVr9k UuxpwN8gTLpmVM+qadq1zt6NiHKAF6RWSy8WZerocFnT45iBnxuvJql5DFwWIQOT+UUa 5LfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713186275; x=1713791075; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=vTHIfbeWCqDn/6Ak6Nz73ChYB9sKU9j2WCGb9z4UFhA=; b=XPb/XRvpKwXkg2nP/zURaFPkxXMz0ql+WfZeX4/LsOk5nMA9mk9F8qpAvSt7G2EIG9 d/XTpA7lsz+deT1rj/AkyIlFkqg9Zcmo4XVwvc5M0rgG2fXyetaByuaqfa3qrksoEONU l8VVMR3hBDoTbF4g3UNkAsXl4Dou/AuBopyqutg0r7XTkDFGNLmiMIzERILBcq1On8hu DRXah2jjKVWGRSQYZ3Hcchs6cPnhHHRmBIdxGpjNog3f+UYtKRbmkhLfUs2h16nEKmy/ JtFi8RFKqKLqIqjXrn6nqSBpHxOl+GtLdJDgz5yn+NEVLNKFw9stFQcFPTmLnw7RTq2F u4oQ== X-Gm-Message-State: AOJu0Ywnax3M+H0ccZ45Fzwv+qNKo+701K/5AS8Qugugbm/mLb8nZhse Uagb/ivJg/Q3yjjJDGZXFB3kBPJICknxwmhEw3w6+K4pwvTHdu7DKWWConoBv1ek77WNwOpf+0n 3t4PhlKxgLBPMA5Av7gl8eIXHIUxIueeOLH6wiBnsKZ5vkrk1r99+DnEkFYR/JNYO+f8RJ0dsBh jW/iMU9Dzoa122rBmOcV2CLWMCxQ5S7Q== X-Google-Smtp-Source: AGHT+IFEdrqSXbUhZqSFHBk+4NqWPvmeUHUoY/Nxmh2Y1T9lVTxCO3Puwe2+YIH2+BX87pkwvjg+fjAN X-Received: from palermo.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:118a]) (user=ardb job=sendgmr) by 2002:a05:6902:114c:b0:dcc:8be2:7cb0 with SMTP id p12-20020a056902114c00b00dcc8be27cb0mr1166461ybu.0.1713186275497; Mon, 15 Apr 2024 06:04:35 -0700 (PDT) Date: Mon, 15 Apr 2024 15:04:26 +0200 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=5404; i=ardb@kernel.org; h=from:subject; bh=W2X44H1A80cEEvDrTguBqJCXGG730nuz2bjOWwRC0QA=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIU1W9eYuAcfy7KI19RJWFmZTWQUmzv59NM/2Cc9JD54nT revKpzuKGVhEONgkBVTZBGY/ffdztMTpWqdZ8nCzGFlAhnCwMUpABM5U8fIsD+kab7B1embi5b8 9ZFMcY0MY9ZnX8TobrGiYNkbrjIXUUaGmVmFpm+vBrIXhWeLZ3PsLTHIY/r18tv3b+1lsRaPGZd wAAA= X-Mailer: git-send-email 2.44.0.683.g7961c838ac-goog Message-ID: <20240415130425.2414653-2-ardb+git@google.com> Subject: [PATCH] crypto: arm64/aes-ce - Simplify round key load sequence From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Cc: herbert@gondor.apana.org.au, ebiggers@kernel.org, Ard Biesheuvel From: Ard Biesheuvel Tweak the round key logic so that they can be loaded using a single branchless sequence using overlapping loads. This is shorter and simpler, and puts the conditional branches based on the key size further apart, which might benefit microarchitectures that cannot record taken branches at every instruction. For these branches, use test-bit-branch instructions that don't clobber the condition flags. Note that none of this has any impact on performance, positive or otherwise (and the branch prediction benefit would only benefit AES-192 which nobody uses). It does make for nicer code, though. While at it, use \@ to generate the labels inside the macros, which is more robust than using fixed numbers, which could clash inadvertently. Also, bring aes-neon.S in line with these changes, including the switch to test-and-branch instructions, to avoid surprises in the future when we might start relying on the condition flags being preserved in the chaining mode wrappers in aes-modes.S Signed-off-by: Ard Biesheuvel --- arch/arm64/crypto/aes-ce.S | 34 ++++++++++++++-------------------- arch/arm64/crypto/aes-neon.S | 20 ++++++++++---------- 2 files changed, 24 insertions(+), 30 deletions(-) diff --git a/arch/arm64/crypto/aes-ce.S b/arch/arm64/crypto/aes-ce.S index 1dc5bbbfeed2..b262eaa9170c 100644 --- a/arch/arm64/crypto/aes-ce.S +++ b/arch/arm64/crypto/aes-ce.S @@ -25,33 +25,28 @@ .endm /* preload all round keys */ - .macro load_round_keys, rounds, rk - cmp \rounds, #12 - blo 2222f /* 128 bits */ - beq 1111f /* 192 bits */ - ld1 {v17.4s-v18.4s}, [\rk], #32 -1111: ld1 {v19.4s-v20.4s}, [\rk], #32 -2222: ld1 {v21.4s-v24.4s}, [\rk], #64 - ld1 {v25.4s-v28.4s}, [\rk], #64 - ld1 {v29.4s-v31.4s}, [\rk] + .macro load_round_keys, rk, nr, tmp + add \tmp, \rk, \nr, sxtw #4 + sub \tmp, \tmp, #160 + ld1 {v17.4s-v20.4s}, [\rk] + ld1 {v21.4s-v24.4s}, [\tmp], #64 + ld1 {v25.4s-v28.4s}, [\tmp], #64 + ld1 {v29.4s-v31.4s}, [\tmp] .endm /* prepare for encryption with key in rk[] */ .macro enc_prepare, rounds, rk, temp - mov \temp, \rk - load_round_keys \rounds, \temp + load_round_keys \rk, \rounds, \temp .endm /* prepare for encryption (again) but with new key in rk[] */ .macro enc_switch_key, rounds, rk, temp - mov \temp, \rk - load_round_keys \rounds, \temp + load_round_keys \rk, \rounds, \temp .endm /* prepare for decryption with key in rk[] */ .macro dec_prepare, rounds, rk, temp - mov \temp, \rk - load_round_keys \rounds, \temp + load_round_keys \rk, \rounds, \temp .endm .macro do_enc_Nx, de, mc, k, i0, i1, i2, i3, i4 @@ -110,14 +105,13 @@ /* up to 5 interleaved blocks */ .macro do_block_Nx, enc, rounds, i0, i1, i2, i3, i4 - cmp \rounds, #12 - blo 2222f /* 128 bits */ - beq 1111f /* 192 bits */ + tbz \rounds, #2, .L\@ /* 128 bits */ round_Nx \enc, v17, \i0, \i1, \i2, \i3, \i4 round_Nx \enc, v18, \i0, \i1, \i2, \i3, \i4 -1111: round_Nx \enc, v19, \i0, \i1, \i2, \i3, \i4 + tbz \rounds, #1, .L\@ /* 192 bits */ + round_Nx \enc, v19, \i0, \i1, \i2, \i3, \i4 round_Nx \enc, v20, \i0, \i1, \i2, \i3, \i4 -2222: .irp key, v21, v22, v23, v24, v25, v26, v27, v28, v29 +.L\@: .irp key, v21, v22, v23, v24, v25, v26, v27, v28, v29 round_Nx \enc, \key, \i0, \i1, \i2, \i3, \i4 .endr fin_round_Nx \enc, v30, v31, \i0, \i1, \i2, \i3, \i4 diff --git a/arch/arm64/crypto/aes-neon.S b/arch/arm64/crypto/aes-neon.S index 9de7fbc797af..3a8961b6ea51 100644 --- a/arch/arm64/crypto/aes-neon.S +++ b/arch/arm64/crypto/aes-neon.S @@ -99,16 +99,16 @@ ld1 {v15.4s}, [\rk] add \rkp, \rk, #16 mov \i, \rounds -1111: eor \in\().16b, \in\().16b, v15.16b /* ^round key */ +.La\@: eor \in\().16b, \in\().16b, v15.16b /* ^round key */ movi v15.16b, #0x40 tbl \in\().16b, {\in\().16b}, v13.16b /* ShiftRows */ sub_bytes \in - subs \i, \i, #1 + sub \i, \i, #1 ld1 {v15.4s}, [\rkp], #16 - beq 2222f + cbz \i, .Lb\@ mix_columns \in, \enc - b 1111b -2222: eor \in\().16b, \in\().16b, v15.16b /* ^round key */ + b .La\@ +.Lb\@: eor \in\().16b, \in\().16b, v15.16b /* ^round key */ .endm .macro encrypt_block, in, rounds, rk, rkp, i @@ -206,7 +206,7 @@ ld1 {v15.4s}, [\rk] add \rkp, \rk, #16 mov \i, \rounds -1111: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */ +.La\@: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */ eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */ eor \in2\().16b, \in2\().16b, v15.16b /* ^round key */ eor \in3\().16b, \in3\().16b, v15.16b /* ^round key */ @@ -216,13 +216,13 @@ tbl \in2\().16b, {\in2\().16b}, v13.16b /* ShiftRows */ tbl \in3\().16b, {\in3\().16b}, v13.16b /* ShiftRows */ sub_bytes_4x \in0, \in1, \in2, \in3 - subs \i, \i, #1 + sub \i, \i, #1 ld1 {v15.4s}, [\rkp], #16 - beq 2222f + cbz \i, .Lb\@ mix_columns_2x \in0, \in1, \enc mix_columns_2x \in2, \in3, \enc - b 1111b -2222: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */ + b .La\@ +.Lb\@: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */ eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */ eor \in2\().16b, \in2\().16b, v15.16b /* ^round key */ eor \in3\().16b, \in3\().16b, v15.16b /* ^round key */