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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 4CD5FC433E0 for ; Mon, 1 Jun 2020 07:27:53 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 53828206C3 for ; Mon, 1 Jun 2020 07:27:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 53828206C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49b6Fx63FfzDqT6 for ; Mon, 1 Jun 2020 17:27:49 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49b6D56wvBzDq9d for ; Mon, 1 Jun 2020 17:26:08 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 49b6Cm45Yyz9v6by; Mon, 1 Jun 2020 09:25:56 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id E9SZ1vd2xmBG; Mon, 1 Jun 2020 09:25:56 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 49b6Cm3G3hz9v6bx; Mon, 1 Jun 2020 09:25:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 962078B7E5; Mon, 1 Jun 2020 09:26:02 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id Jg1AWcYZRYSe; Mon, 1 Jun 2020 09:26:02 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 918388B7E1; Mon, 1 Jun 2020 09:26:01 +0200 (CEST) Subject: Re: [PATCH v5] powerpc/irq: inline call_do_irq() and call_do_softirq() on PPC32 To: Michael Ellerman References: <72a6cd86137b2a7ab835213cf5c74df6ed2f6ea7.1575739197.git.christophe.leroy@c-s.fr> From: Christophe Leroy Message-ID: Date: Mon, 1 Jun 2020 09:26:00 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: <72a6cd86137b2a7ab835213cf5c74df6ed2f6ea7.1575739197.git.christophe.leroy@c-s.fr> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Michael, Le 07/12/2019 à 18:20, Christophe Leroy a écrit : > call_do_irq() and call_do_softirq() are simple enough to be > worth inlining. > > Inlining them avoids an mflr/mtlr pair plus a save/reload on stack. > It also allows GCC to keep the saved ksp_limit in an nonvolatile reg. > > This is inspired from S390 arch. Several other arches do more or > less the same. The way sparc arch does seems odd thought. > > Signed-off-by: Christophe Leroy > Reviewed-by: Segher Boessenkool Anything more I need to do for this patch to get merged ? Thanks Christophe > > --- > v2: no change. > v3: no change. > v4: > - comment reminding the purpose of the inline asm block. > - added r2 as clobbered reg > v5: > - Limiting the change to PPC32 for now. > - removed r2 from the clobbered regs list (on PPC32 r2 points to current all the time) > - Removed patch 1 and merged ksp_limit handling in here. > --- > arch/powerpc/include/asm/irq.h | 2 ++ > arch/powerpc/kernel/irq.c | 48 ++++++++++++++++++++++++++++++++++++++++++ > arch/powerpc/kernel/misc_32.S | 39 ---------------------------------- > 3 files changed, 50 insertions(+), 39 deletions(-) > > diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h > index 814dfab7e392..e4a92f0b4ad4 100644 > --- a/arch/powerpc/include/asm/irq.h > +++ b/arch/powerpc/include/asm/irq.h > @@ -56,8 +56,10 @@ extern void *mcheckirq_ctx[NR_CPUS]; > extern void *hardirq_ctx[NR_CPUS]; > extern void *softirq_ctx[NR_CPUS]; > > +#ifdef CONFIG_PPC64 > void call_do_softirq(void *sp); > void call_do_irq(struct pt_regs *regs, void *sp); > +#endif > extern void do_IRQ(struct pt_regs *regs); > extern void __init init_IRQ(void); > extern void __do_irq(struct pt_regs *regs); > diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c > index 5645bc9cbc09..240eca12c71d 100644 > --- a/arch/powerpc/kernel/irq.c > +++ b/arch/powerpc/kernel/irq.c > @@ -611,6 +611,54 @@ static inline void check_stack_overflow(void) > #endif > } > > +#ifdef CONFIG_PPC32 > +static inline void call_do_softirq(const void *sp) > +{ > + register unsigned long ret asm("r3"); > + unsigned long limit = current->thread.ksp_limit; > + > + /* Adjust the stack limit */ > + current->thread.ksp_limit = (unsigned long)sp; > + > + /* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */ > + asm volatile( > + " "PPC_STLU" 1, %2(%1);\n" > + " mr 1, %1;\n" > + " bl %3;\n" > + " "PPC_LL" 1, 0(1);\n" : > + "=r"(ret) : > + "b"(sp), "i"(THREAD_SIZE - STACK_FRAME_OVERHEAD), "i"(__do_softirq) : > + "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", "cr7", > + "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12"); > + > + /* Restore stack limit */ > + current->thread.ksp_limit = limit; > +} > + > +static inline void call_do_irq(struct pt_regs *regs, void *sp) > +{ > + register unsigned long r3 asm("r3") = (unsigned long)regs; > + unsigned long limit = current->thread.ksp_limit; > + > + /* Adjust the stack limit */ > + current->thread.ksp_limit = (unsigned long)sp; > + > + /* Temporarily switch r1 to sp, call __do_irq() then restore r1 */ > + asm volatile( > + " "PPC_STLU" 1, %2(%1);\n" > + " mr 1, %1;\n" > + " bl %3;\n" > + " "PPC_LL" 1, 0(1);\n" : > + "+r"(r3) : > + "b"(sp), "i"(THREAD_SIZE - STACK_FRAME_OVERHEAD), "i"(__do_irq) : > + "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", "cr7", > + "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12"); > + > + /* Restore stack limit */ > + current->thread.ksp_limit = limit; > +} > +#endif > + > void __do_irq(struct pt_regs *regs) > { > unsigned int irq; > diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S > index d80212be8698..341a3cd199cb 100644 > --- a/arch/powerpc/kernel/misc_32.S > +++ b/arch/powerpc/kernel/misc_32.S > @@ -28,45 +28,6 @@ > .text > > /* > - * We store the saved ksp_limit in the unused part > - * of the STACK_FRAME_OVERHEAD > - */ > -_GLOBAL(call_do_softirq) > - mflr r0 > - stw r0,4(r1) > - lwz r10,THREAD+KSP_LIMIT(r2) > - stw r3, THREAD+KSP_LIMIT(r2) > - stwu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3) > - mr r1,r3 > - stw r10,8(r1) > - bl __do_softirq > - lwz r10,8(r1) > - lwz r1,0(r1) > - lwz r0,4(r1) > - stw r10,THREAD+KSP_LIMIT(r2) > - mtlr r0 > - blr > - > -/* > - * void call_do_irq(struct pt_regs *regs, void *sp); > - */ > -_GLOBAL(call_do_irq) > - mflr r0 > - stw r0,4(r1) > - lwz r10,THREAD+KSP_LIMIT(r2) > - stw r4, THREAD+KSP_LIMIT(r2) > - stwu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4) > - mr r1,r4 > - stw r10,8(r1) > - bl __do_irq > - lwz r10,8(r1) > - lwz r1,0(r1) > - lwz r0,4(r1) > - stw r10,THREAD+KSP_LIMIT(r2) > - mtlr r0 > - blr > - > -/* > * This returns the high 64 bits of the product of two 64-bit numbers. > */ > _GLOBAL(mulhdu) >