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 X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2664AC4338F for ; Tue, 10 Aug 2021 08:33:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 041A6610A4 for ; Tue, 10 Aug 2021 08:33:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236694AbhHJIeG (ORCPT ); Tue, 10 Aug 2021 04:34:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229639AbhHJId6 (ORCPT ); Tue, 10 Aug 2021 04:33:58 -0400 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FC37C0613D3 for ; Tue, 10 Aug 2021 01:33:36 -0700 (PDT) Received: by mail-lf1-x12a.google.com with SMTP id t9so39875606lfc.6 for ; Tue, 10 Aug 2021 01:33:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=p2Fr5BJzhcYbE5uoZF3uMydSpmFYCPWUAIM4ZDQIAO8=; b=ZX9kpQH2G3eesgI+qHAHL1ZSUCALh+QYm9VkNA2ZVb4n/vvxRRGVrH2bWa1vk9TrG4 WxOt/pG3CQ1DojqpbuVR2VUvdEnpDh82SwV8LJ9fHWaqlMshBTghsuUy7R+K9Kq1I5EH eD5wvl1lFJ7sEiLKpGMZ84snliGClZ20x7TIZZvnTuJaGmti15gmHEEtLmmi9rpM/QYg mXzrXV1qeourKNTywlvA3jrQcO2M+coW+i0DxdbhOD676KkBDzhAk2zMfu5zHwUhRu/o Sp89C5VSXEQPSyKKGrBmI9gRUzAObj3Y29jcYXn/Cn617MSfFtEqsBJ7EoU54HxTwYBa d69g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=p2Fr5BJzhcYbE5uoZF3uMydSpmFYCPWUAIM4ZDQIAO8=; b=KCJ1jbQ5UJfN2lgwNNNvvXoT8QyF0fq/EKIEpfbgmjYOMWZt4dpKjHRgygzRqSkUT7 a+IWeEV2XUPCbpQmx8lUmFokGnOrPXEKa1YKwgKxBmlV4cpSLPR/zBmOwcA9DRLLkPL6 Rg+xK1XN6tOS3h93viU0j9JQqoOj6XILbhchTbLs06On8XeUcEHorAqNF+4yEJ3TEMLC GtZZPusyZt8o56i5kzw4a3/49m6fw8cqyynBMGWZbswVS+r+eTdK8yFV2aIpz5cbaeO4 algacHCsMRNup4zjmYMlT8dzdB7P9wO90AWELSXclAZoABuLwXQNsFj8cBylTsM414BJ QosQ== X-Gm-Message-State: AOAM530q1clS7xxcp6U5HvB3Jl79TxEWKnJzcMhrbJiVYtdP6uEbchSz VdZuDSNAba9E1o5LkNOsjZzyQw0+CrLj+v3kSGw= X-Google-Smtp-Source: ABdhPJyrI9dStbUFIFtHPxBjTNID3TeK9D5oT0XbVpIxhRowhuOAkAEEEqiEYMCwd5D31/PuAwcBbvCpSVEWo7Kufs4= X-Received: by 2002:a05:6512:53c:: with SMTP id o28mr21246802lfc.641.1628584414971; Tue, 10 Aug 2021 01:33:34 -0700 (PDT) MIME-Version: 1.0 References: <20210807010239.416055-1-sxwjean@me.com> <20210807010239.416055-2-sxwjean@me.com> <127de0c7-5e30-6797-1e72-6414d4a60119@csgroup.eu> In-Reply-To: <127de0c7-5e30-6797-1e72-6414d4a60119@csgroup.eu> From: Xiongwei Song Date: Tue, 10 Aug 2021 16:33:08 +0800 Message-ID: Subject: Re: [PATCH v2 1/4] powerpc: Optimize register usage for esr register To: Christophe Leroy Cc: Xiongwei Song , PowerPC , oleg@redhat.com, Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , npiggin@gmail.com, ravi.bangoria@linux.ibm.com, aneesh.kumar@linux.ibm.com, efremov@linux.com, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 7, 2021 at 2:57 PM Christophe Leroy wrote: > > > > Le 07/08/2021 =C3=A0 03:02, sxwjean@me.com a =C3=A9crit : > > From: Xiongwei Song > > > > Create an anonymous union for dsisr and esr regsiters, we can reference > > esr to get the exception detail when CONFIG_4xx=3Dy or CONFIG_BOOKE=3Dy= . > > Otherwise, reference dsisr. This makes code more clear. > > > > Signed-off-by: Xiongwei Song > > --- > > arch/powerpc/include/asm/ptrace.h | 5 ++++- > > arch/powerpc/kernel/process.c | 2 +- > > arch/powerpc/kernel/ptrace/ptrace.c | 2 ++ > > arch/powerpc/kernel/traps.c | 2 +- > > arch/powerpc/platforms/44x/machine_check.c | 4 ++-- > > arch/powerpc/platforms/4xx/machine_check.c | 2 +- > > 6 files changed, 11 insertions(+), 6 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/a= sm/ptrace.h > > index 3e5d470a6155..c252d04b1206 100644 > > --- a/arch/powerpc/include/asm/ptrace.h > > +++ b/arch/powerpc/include/asm/ptrace.h > > @@ -44,7 +44,10 @@ struct pt_regs > > #endif > > unsigned long trap; > > unsigned long dar; > > - unsigned long dsisr; > > + union { > > + unsigned long dsisr; > > + unsigned long esr; > > + }; > > unsigned long result; > > }; > > }; > > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/proces= s.c > > index 185beb290580..f74af8f9133c 100644 > > --- a/arch/powerpc/kernel/process.c > > +++ b/arch/powerpc/kernel/process.c > > @@ -1499,7 +1499,7 @@ static void __show_regs(struct pt_regs *regs) > > trap =3D=3D INTERRUPT_DATA_STORAGE || > > trap =3D=3D INTERRUPT_ALIGNMENT) { > > if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) > > - pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, reg= s->dsisr); > > + pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, reg= s->esr); > > else > > pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, re= gs->dsisr); > > } > > diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/= ptrace/ptrace.c > > index 0a0a33eb0d28..a222fd4d6334 100644 > > --- a/arch/powerpc/kernel/ptrace/ptrace.c > > +++ b/arch/powerpc/kernel/ptrace/ptrace.c > > @@ -375,6 +375,8 @@ void __init pt_regs_check(void) > > offsetof(struct user_pt_regs, dar)); > > BUILD_BUG_ON(offsetof(struct pt_regs, dsisr) !=3D > > offsetof(struct user_pt_regs, dsisr)); > > + BUILD_BUG_ON(offsetof(struct pt_regs, esr) !=3D > > + offsetof(struct user_pt_regs, dsisr)); > > esr and dsisr are the same, so checking the same thing a second time is p= ointless. Hmm...it's better to check if the changes on pt_regs structure is expected I think. Regards, Xiongwei > > > BUILD_BUG_ON(offsetof(struct pt_regs, result) !=3D > > offsetof(struct user_pt_regs, result)); > > > > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > > index dfbce527c98e..2164f5705a0b 100644 > > --- a/arch/powerpc/kernel/traps.c > > +++ b/arch/powerpc/kernel/traps.c > > @@ -562,7 +562,7 @@ static inline int check_io_access(struct pt_regs *r= egs) > > #ifdef CONFIG_PPC_ADV_DEBUG_REGS > > /* On 4xx, the reason for the machine check or program exception > > is in the ESR. */ > > -#define get_reason(regs) ((regs)->dsisr) > > +#define get_reason(regs) ((regs)->esr) > > #define REASON_FP ESR_FP > > #define REASON_ILLEGAL (ESR_PIL | ESR_PUO) > > #define REASON_PRIVILEGED ESR_PPR > > diff --git a/arch/powerpc/platforms/44x/machine_check.c b/arch/powerpc/= platforms/44x/machine_check.c > > index a5c898bb9bab..5d19daacd78a 100644 > > --- a/arch/powerpc/platforms/44x/machine_check.c > > +++ b/arch/powerpc/platforms/44x/machine_check.c > > @@ -11,7 +11,7 @@ > > > > int machine_check_440A(struct pt_regs *regs) > > { > > - unsigned long reason =3D regs->dsisr; > > + unsigned long reason =3D regs->esr; > > > > printk("Machine check in kernel mode.\n"); > > if (reason & ESR_IMCP){ > > @@ -48,7 +48,7 @@ int machine_check_440A(struct pt_regs *regs) > > #ifdef CONFIG_PPC_47x > > int machine_check_47x(struct pt_regs *regs) > > { > > - unsigned long reason =3D regs->dsisr; > > + unsigned long reason =3D regs->esr; > > u32 mcsr; > > > > printk(KERN_ERR "Machine check in kernel mode.\n"); > > diff --git a/arch/powerpc/platforms/4xx/machine_check.c b/arch/powerpc/= platforms/4xx/machine_check.c > > index a71c29892a91..a905da1d6f41 100644 > > --- a/arch/powerpc/platforms/4xx/machine_check.c > > +++ b/arch/powerpc/platforms/4xx/machine_check.c > > @@ -10,7 +10,7 @@ > > > > int machine_check_4xx(struct pt_regs *regs) > > { > > - unsigned long reason =3D regs->dsisr; > > + unsigned long reason =3D regs->esr; > > > > if (reason & ESR_IMCP) { > > printk("Instruction"); > >