From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E77DAC3ABA5 for ; Tue, 29 Apr 2025 21:08:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u9sAu-0000UA-2w; Tue, 29 Apr 2025 17:07:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u9sAZ-0000L5-M2 for qemu-devel@nongnu.org; Tue, 29 Apr 2025 17:07:11 -0400 Received: from mail-pf1-x42b.google.com ([2607:f8b0:4864:20::42b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1u9sAW-0003zN-Qi for qemu-devel@nongnu.org; Tue, 29 Apr 2025 17:07:11 -0400 Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-736c062b1f5so5602884b3a.0 for ; Tue, 29 Apr 2025 14:07:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1745960825; x=1746565625; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=J0R7aQy+3GY23ZMFehDXTfzL4PuUym9QxuFfe3VQUYA=; b=F0WO2x/uPF5ERNLWJVAwilfmz2Uc/GF7a3iKCY1zKZptxXeYKXSQ/NJQnetlvQ/4r/ mRfJtB7kw+N44Vg2dQ9CF+dFJ6BL8u4Tl0fIIJHxFZTAxqUMT+Z0QhELLRFwvKbBamYa Bj95fXBwN5JctNXeqG3YmbdYwAbktfLzkRiF2FZJ6OKpSDyH6HjLvQ+P9cv5kPG2m5En iRugD9pvivDWk5vgEqfFfRy9mz9R5v+HB9jmrkSCFcCY+SytST4r1AHF6+npH5ZSg9jI kqw/yoOtD+EyB7nJaAJM41sMm6kU9cdkoNZnX1nPkZ0YbQHp+SE31rkG93FSIZ2Ok/8h FXmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745960825; x=1746565625; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=J0R7aQy+3GY23ZMFehDXTfzL4PuUym9QxuFfe3VQUYA=; b=lA4awQRBiZUdT4HNtuvzfhxdSxTo04A2uPOdV3WCQWyrH+0vd4H9wp05YOVdOyblbh X+GXFZe94VAXbBL5Ap+ue7XzfL8rkXG4m0fqLFLG12NVBwr2qOa5gAipfFRYX4UDc2aB iPQNnMBK8l4eHwn5GYlc+/oSmVWLdkZjrWOR0CqMAFKWZ7V/6W5exrZw1jEhOQMWPDFY rv0CcyWgrn9VSjcjuMFufbelbGV5AMvH3/rSKSxLOtcXSJ7tONxwgF+oAAWeb6QkPXUn JUinMize+lXWk9N37zIfuOGAjUnt3YPsjhD/ylu5Ndlx7/R+3+zqRJkkzE9G2VhGhgWD 6LkA== X-Gm-Message-State: AOJu0Yzo7gO9RqGYCp0gg2ILwrT599tO7qg3IteyfIXtH5XyHEKQdNdz bnqvjhS/T21SdJWjWEVZsbRHRU59+ukAgDVfnVJRZ4GJqvZWSU4Tg80oJevN4NI= X-Gm-Gg: ASbGnct3XKxRfJiuWLb+E0SFvKFeQNk42eMDg5kghbVYAwRIM68wMadEK7OXKw1WpHa geY6HHw3Fpn7idYLGJ1GwxJLr+MTmvh/uMhA8Yng+ww7sO47uEIOKRe62i/IXZjgQU+0T935fDF NYGHlbjw4esRnODtJ7hA5hHs4jlbJyoWJn2AxMPmJ3DlCbdcS6opLDwzOC86bdks1NKNEzDxTFB 4nKBwo+NMi4AYu+e3h6yBMJxeKHnpxYK0bN2xv/j0/xHq9wT1LquxAkXmkiV5s+3w6xBob1TGKI FrYT+TOXS7SC7i9QbRSDtIU5lTrLK2j9CZ1/1iH9SqLnMyF3ci0Jyg== X-Google-Smtp-Source: AGHT+IH32wV8hOys1/FlSKA99ZrcKLdxQ/jVjCKspBhTfIoQlbisbUoYD7FByxZw5MrxgeqxouXjtA== X-Received: by 2002:a05:6a00:10ce:b0:739:56c2:b661 with SMTP id d2e1a72fcca58-740389b795bmr898455b3a.12.1745960824759; Tue, 29 Apr 2025 14:07:04 -0700 (PDT) Received: from [192.168.1.87] ([38.41.223.211]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-74039a5c36bsm146946b3a.132.2025.04.29.14.07.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 29 Apr 2025 14:07:04 -0700 (PDT) Message-ID: <6e628189-f497-4d95-a6ac-c3cc726be2ad@linaro.org> Date: Tue, 29 Apr 2025 14:07:03 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 09/13] target/arm/cpu: get endianness from cpu state To: Anton Johansson Cc: qemu-devel@nongnu.org, Peter Maydell , kvm@vger.kernel.org, alex.bennee@linaro.org, Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , qemu-arm@nongnu.org, richard.henderson@linaro.org References: <20250429050010.971128-1-pierrick.bouvier@linaro.org> <20250429050010.971128-10-pierrick.bouvier@linaro.org> From: Pierrick Bouvier Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::42b; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pf1-x42b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 4/29/25 5:26 AM, Anton Johansson wrote: > On 29/04/25, Pierrick Bouvier wrote: >> Remove TARGET_BIG_ENDIAN dependency. >> >> Signed-off-by: Pierrick Bouvier >> --- >> target/arm/cpu.c | 22 +++++++++++----------- >> 1 file changed, 11 insertions(+), 11 deletions(-) >> >> diff --git a/target/arm/cpu.c b/target/arm/cpu.c >> index e7a15ade8b4..85e886944f6 100644 >> --- a/target/arm/cpu.c >> +++ b/target/arm/cpu.c >> @@ -67,6 +67,15 @@ static void arm_cpu_set_pc(CPUState *cs, vaddr value) >> } >> } >> >> +static bool arm_cpu_is_big_endian(CPUState *cs) >> +{ >> + ARMCPU *cpu = ARM_CPU(cs); >> + CPUARMState *env = &cpu->env; >> + >> + cpu_synchronize_state(cs); >> + return arm_cpu_data_is_big_endian(env); >> +} >> + >> static vaddr arm_cpu_get_pc(CPUState *cs) >> { >> ARMCPU *cpu = ARM_CPU(cs); >> @@ -1130,15 +1139,6 @@ static void arm_cpu_kvm_set_irq(void *opaque, int irq, int level) >> #endif >> } >> >> -static bool arm_cpu_virtio_is_big_endian(CPUState *cs) >> -{ >> - ARMCPU *cpu = ARM_CPU(cs); >> - CPUARMState *env = &cpu->env; >> - >> - cpu_synchronize_state(cs); >> - return arm_cpu_data_is_big_endian(env); >> -} >> - >> #ifdef CONFIG_TCG >> bool arm_cpu_exec_halt(CPUState *cs) >> { >> @@ -1203,7 +1203,7 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info) >> >> info->endian = BFD_ENDIAN_LITTLE; >> if (bswap_code(sctlr_b)) { >> - info->endian = TARGET_BIG_ENDIAN ? BFD_ENDIAN_LITTLE : BFD_ENDIAN_BIG; >> + info->endian = arm_cpu_is_big_endian(cpu) ? BFD_ENDIAN_LITTLE : BFD_ENDIAN_BIG; >> } > > I'm not the most familiar with arm but as far as I can tell these are > not equivalent. My understanding is that arm_cpu_is_big_endian() models > data endianness, and TARGET_BIG_ENDIAN instruction endianness. > > Also, for user mode where this branch is relevant, bswap_code() still > depends on TARGET_BIG_ENDIAN anyway and the above branch would reduce to > (on arm32) > > if (TARGET_BIG_ENDIAN ^ sctlr_b) { > info->endian = sctlr_b ? BFD_ENDIAN_LITTLE : BFD_ENDIAN_BIG; > } > > giving the opposite result to the original code. > Ooops, that's a good point, I missed it was calling arm_cpu_data_is_big_endian under the hoods. I'll stick to target_big_endian(). Thanks, Pierrick