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 B65DDC4338F for ; Fri, 6 Aug 2021 03:17:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 926EB61165 for ; Fri, 6 Aug 2021 03:17:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242072AbhHFDRi (ORCPT ); Thu, 5 Aug 2021 23:17:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231429AbhHFDRh (ORCPT ); Thu, 5 Aug 2021 23:17:37 -0400 Received: from mail-lj1-x230.google.com (mail-lj1-x230.google.com [IPv6:2a00:1450:4864:20::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 164CFC061798 for ; Thu, 5 Aug 2021 20:17:22 -0700 (PDT) Received: by mail-lj1-x230.google.com with SMTP id u13so9927150lje.5 for ; Thu, 05 Aug 2021 20:17:22 -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=zj33fEFxiHh9L7Od2CChfLnX3PMn/v2vhh53C69leEc=; b=WhJOF6lEfMQ7PQ2Dm44rut4BwLCIYnh9rETAXNH5YTGCKRwlkP1XvNoa92JL0ffDms NiEFnBw+QmXNL8dXPXTHqiBQcfHOrsE966ffYqT5ty1kGZfzAQV4Al6p0trJzTT+kdgK vy4Gk11erETBeoWtOJt4AebhLFddQQiA6tSlEuRNmYfcLawEaT1izurTpwCqy/SLwVmL TDamTFmrotMv/2tjzYLxYi3VXu9Jz/YLxhqzObYt+JYVI+7ku7748W8nmQwrWtBgxvI4 L28kwCjCaRgI/2Jn3wPpaBYWcxjepmUawi3xLktc/5CbJqH6EWMxmiCh3P7lixxjvB5C iZbw== 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=zj33fEFxiHh9L7Od2CChfLnX3PMn/v2vhh53C69leEc=; b=SxTw0EuX3IeWTjOAw+hx4BHBbmLHD4VeVYVB9zEhsoBawpWtPGFbVsYYBxTM9NXXec M+YTwl/lIuosQ9dShOPRIEyypFDYWZPPinyTFDabk2qM/NAjH47NrniLfhwQ1GEeyUqt /Cxn+JqqH4wWQ2ZYUVHJ0lnt0lF2yB+fIhvlL/u+JRpnZqXUkQBthQCX8Z0sknjEejJ3 CR96Ls6T8KeQOwEHawqYOx5S1gcRI2E1nLT51hxBamqtv+WBnJRqwqCruEsl8fbmZ1jz NisZnR5LYedWVi0qsSXXkptsRyPZr1/L6622j6+dIBDTsOWRP3e9haDSkWGZIPVOa+ay qZbw== X-Gm-Message-State: AOAM53272l6+byCXMQffxEft/9ty17C2teA64lJ/ip84UPjeha0JUi9w HKPLkOed1gc4nakyAbFXo/4wfRujEHC4e1W+tDE= X-Google-Smtp-Source: ABdhPJyuuwxWUKFdUjxHxsIpU5QiCpC61h0PQQO10OgYsJ21Jq7XYltBMp1TAtD21Z5CMnGJqfLkXM41gflbVGwHShg= X-Received: by 2002:a2e:3312:: with SMTP id d18mr5169021ljc.297.1628219839913; Thu, 05 Aug 2021 20:17:19 -0700 (PDT) MIME-Version: 1.0 References: <20210726143053.532839-1-sxwjean@me.com> <20210726143053.532839-3-sxwjean@me.com> <56d9e3ce-f303-fd41-bd16-5655d9dc5e52@csgroup.eu> In-Reply-To: <56d9e3ce-f303-fd41-bd16-5655d9dc5e52@csgroup.eu> From: Xiongwei Song Date: Fri, 6 Aug 2021 11:16:53 +0800 Message-ID: Subject: Re: [RFC PATCH 3/4] powerpc: Optimize register usage for dear register To: Christophe Leroy Cc: Xiongwei Song , PowerPC , oleg@redhat.com, Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , ravi.bangoria@linux.ibm.com, npiggin@gmail.com, aneesh.kumar@linux.ibm.com, sandipan@linux.ibm.com, efremov@linux.com, peterx@redhat.com, akpm@linux-foundation.org, 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 Thu, Aug 5, 2021 at 6:09 PM Christophe Leroy wrote: > > > > Le 26/07/2021 =C3=A0 16:30, sxwjean@me.com a =C3=A9crit : > > From: Xiongwei Song > > > > Create an anonymous union for dar and dear regsiters, we can reference > > dear to get the effective address when CONFIG_4xx=3Dy or CONFIG_BOOKE= =3Dy. > > Otherwise, reference dar. This makes code more clear. > > Same comment here as for patch 1. Same reply for the patch 1. Thank you. > > > > > > Signed-off-by: Xiongwei Song > > --- > > arch/powerpc/include/asm/ptrace.h | 5 ++++- > > arch/powerpc/include/uapi/asm/ptrace.h | 5 ++++- > > arch/powerpc/kernel/process.c | 2 +- > > arch/powerpc/kernel/ptrace/ptrace.c | 2 ++ > > arch/powerpc/kernel/traps.c | 5 ++++- > > arch/powerpc/mm/fault.c | 2 +- > > 6 files changed, 16 insertions(+), 5 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/a= sm/ptrace.h > > index c252d04b1206..fa725e3238c2 100644 > > --- a/arch/powerpc/include/asm/ptrace.h > > +++ b/arch/powerpc/include/asm/ptrace.h > > @@ -43,7 +43,10 @@ struct pt_regs > > unsigned long mq; > > #endif > > unsigned long trap; > > - unsigned long dar; > > + union { > > + unsigned long dar; > > + unsigned long dear; > > + }; > > union { > > unsigned long dsisr; > > unsigned long esr; > > diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/incl= ude/uapi/asm/ptrace.h > > index e357288b5f34..9ae150fb4c4b 100644 > > --- a/arch/powerpc/include/uapi/asm/ptrace.h > > +++ b/arch/powerpc/include/uapi/asm/ptrace.h > > @@ -52,7 +52,10 @@ struct pt_regs > > unsigned long trap; /* Reason for being here */ > > /* N.B. for critical exceptions on 4xx, the dar and dsisr > > fields are overloaded to hold srr0 and srr1. */ > > - unsigned long dar; /* Fault registers */ > > + union { > > + unsigned long dar; /* Fault registers */ > > + unsigned long dear; > > + }; > > union { > > unsigned long dsisr; /* on Book-S used for DSI= SR */ > > unsigned long esr; /* on 4xx/Book-E used for= ESR */ > > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/proces= s.c > > index f74af8f9133c..50436b52c213 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->esr); > > + pr_cont("DEAR: "REG" ESR: "REG" ", regs->dear, re= gs->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 00789ad2c4a3..969dca8b0718 100644 > > --- a/arch/powerpc/kernel/ptrace/ptrace.c > > +++ b/arch/powerpc/kernel/ptrace/ptrace.c > > @@ -373,6 +373,8 @@ void __init pt_regs_check(void) > > offsetof(struct user_pt_regs, trap)); > > BUILD_BUG_ON(offsetof(struct pt_regs, dar) !=3D > > offsetof(struct user_pt_regs, dar)); > > + BUILD_BUG_ON(offsetof(struct pt_regs, dear) !=3D > > + offsetof(struct user_pt_regs, dear)); > > BUILD_BUG_ON(offsetof(struct pt_regs, dsisr) !=3D > > offsetof(struct user_pt_regs, dsisr)); > > BUILD_BUG_ON(offsetof(struct pt_regs, esr) !=3D > > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > > index 2164f5705a0b..0796630d3d23 100644 > > --- a/arch/powerpc/kernel/traps.c > > +++ b/arch/powerpc/kernel/traps.c > > @@ -1609,7 +1609,10 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception) > > } > > bad: > > if (user_mode(regs)) > > - _exception(sig, regs, code, regs->dar); > > + if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) > > + _exception(sig, regs, code, regs->dear); > > + else > > + _exception(sig, regs, code, regs->dar); > > else > > bad_page_fault(regs, sig); > > } > > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > > index 62953d4e7c93..3db6b39a1178 100644 > > --- a/arch/powerpc/mm/fault.c > > +++ b/arch/powerpc/mm/fault.c > > @@ -542,7 +542,7 @@ static __always_inline void __do_page_fault(struct = pt_regs *regs) > > long err; > > > > if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) > > - err =3D ___do_page_fault(regs, regs->dar, regs->esr); > > + err =3D ___do_page_fault(regs, regs->dear, regs->esr); > > else > > err =3D ___do_page_fault(regs, regs->dar, regs->dsisr); > > > >