From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 25EE023CE for ; Wed, 6 Aug 2025 02:49:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754448569; cv=none; b=gBI5Fzs7HyBhfGcZn7YamzMhDUczIzOlyZbGvjTkdgsJU+1/x3QK0QRxRKE0wmD9bIDP4YzRy3PtT2KUAbleMJA/GoHZQxSmmm4a/OC8PhaHS5RGWi7iofP065JVkBXKSC3HLA7YTTKQBMBwzRACLemeWx70pIglO2zeA2jXCxQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754448569; c=relaxed/simple; bh=0BmMkPKxthCidJu5e8ogZHf/bKGYor1BsxkiRpDVriQ=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=VYb2dugWeFH/vbtjrdksOIUP1Mvm1pHb+n5a3pmSLa+B3NY1EX8WjP6HJm3CqlQg7XI/8ugmLtMTrc5sYDeVMuLnG777KIGFPTJYMPYTWqXeFAWpt04jLm2H7KLq3QXB9Ykp4Yx92n/WCtppDbkiiruusaRTYwx3VFvVjiXxiNc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4bxZQV4lLmz14MLW; Wed, 6 Aug 2025 10:45:06 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 3E366180B54; Wed, 6 Aug 2025 10:49:23 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 6 Aug 2025 10:49:21 +0800 Message-ID: <6825c4c4-2c48-db3b-55e2-97922f25897f@huawei.com> Date: Wed, 6 Aug 2025 10:49:21 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH -next v7 2/7] arm64: entry: Refactor the entry and exit for exceptions from EL1 Content-Language: en-US To: Ada Couprie Diaz CC: , , , , , , , , , , , , , , , , , , References: <20250729015456.3411143-1-ruanjinjie@huawei.com> <20250729015456.3411143-3-ruanjinjie@huawei.com> From: Jinjie Ruan In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To dggpemf500011.china.huawei.com (7.185.36.131) On 2025/8/5 23:06, Ada Couprie Diaz wrote: > Hi, > > On 29/07/2025 02:54, Jinjie Ruan wrote: > >> The generic entry code uses irqentry_state_t to track lockdep and RCU >> state across exception entry and return. For historical reasons, arm64 >> embeds similar fields within its pt_regs structure. >> >> In preparation for moving arm64 over to the generic entry code, pull >> these fields out of arm64's pt_regs, and use a separate structure, >> matching the style of the generic entry code. >> >> No functional changes. > As far as I understand and checked, we used the two fields > in an exclusive fashion, so there is indeed no functional change. >> Suggested-by: Mark Rutland >> Signed-off-by: Jinjie Ruan >> --- >> [...] >> diff --git a/arch/arm64/kernel/entry-common.c >> b/arch/arm64/kernel/entry-common.c >> index 8e798f46ad28..97e0741abde1 100644 >> --- a/arch/arm64/kernel/entry-common.c >> +++ b/arch/arm64/kernel/entry-common.c >> [...] >> @@ -475,73 +497,81 @@ UNHANDLED(el1t, 64, error) >>   static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr) >>   { >>       unsigned long far = read_sysreg(far_el1); >> +    arm64_irqentry_state_t state; >>   -    enter_from_kernel_mode(regs); >> +    state = enter_from_kernel_mode(regs); > Nit: There is some inconsistencies with some functions splitting state's > definition > and declaration (like el1_abort here), while some others do it on the > same line > (el1_undef() below for example). > In some cases it is welcome as the entry function is called after some > other work, > but here for example it doesn't seem to be beneficial ? Both methods can keep the modifications to `enter_from_kernel_mode()` on the same line as the original code, which will facilitate code review. I think it is also fine to do it on the same line here, which can reduce one line code, which method is better may be a matter of personal opinion. >>       local_daif_inherit(regs); >>       do_mem_abort(far, esr, regs); >>       local_daif_mask(); >> -    exit_to_kernel_mode(regs); >> +    exit_to_kernel_mode(regs, state); >>   } >>     static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr) >>   { >>       unsigned long far = read_sysreg(far_el1); >> +    arm64_irqentry_state_t state; >>   -    enter_from_kernel_mode(regs); >> +    state = enter_from_kernel_mode(regs); >>       local_daif_inherit(regs); >>       do_sp_pc_abort(far, esr, regs); >>       local_daif_mask(); >> -    exit_to_kernel_mode(regs); >> +    exit_to_kernel_mode(regs, state); >>   } >>     static void noinstr el1_undef(struct pt_regs *regs, unsigned long >> esr) >>   { >> -    enter_from_kernel_mode(regs); >> +    arm64_irqentry_state_t state = enter_from_kernel_mode(regs); >> + >>       local_daif_inherit(regs); >>       do_el1_undef(regs, esr); >>       local_daif_mask(); >> -    exit_to_kernel_mode(regs); >> +    exit_to_kernel_mode(regs, state); >>   } >> >> [...] > Other than the small nit: > Reviewed-by: Ada Couprie Diaz > >