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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6DB0EC433E6 for ; Mon, 8 Feb 2021 16:27:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1500864D87 for ; Mon, 8 Feb 2021 16:27:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234016AbhBHQ1i (ORCPT ); Mon, 8 Feb 2021 11:27:38 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:7054 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233150AbhBHPLL (ORCPT ); Mon, 8 Feb 2021 10:11:11 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4DZ8bG4kdjz9vBnC; Mon, 8 Feb 2021 16:10:18 +0100 (CET) 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 C7rjuJzjDpqL; Mon, 8 Feb 2021 16:10:18 +0100 (CET) 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 4DZ8bG3zSvz9vBn3; Mon, 8 Feb 2021 16:10:18 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C624D8B7B3; Mon, 8 Feb 2021 16:10:23 +0100 (CET) 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 VNxVEJ7nY3Ry; Mon, 8 Feb 2021 16:10:23 +0100 (CET) Received: from po16121vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.103]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8AD4A8B7B2; Mon, 8 Feb 2021 16:10:23 +0100 (CET) Received: by po16121vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 800A56733E; Mon, 8 Feb 2021 15:10:23 +0000 (UTC) Message-Id: <8fa13a59f73647e058c95fc7e1c7a98f316bd20a.1612796617.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v5 04/22] powerpc/32: Reorder instructions to avoid using CTR in syscall entry To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , npiggin@gmail.com, msuchanek@suse.de Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Mon, 8 Feb 2021 15:10:23 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that we are using rfi instead of mtmsr to reactivate MMU, it is possible to reorder instructions and avoid the need to use CTR for stashing SRR0. null_syscall on 8xx is reduced by 3 cycles (283 => 280 cycles). Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/head_32.h | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 4029c51dce5d..24dc326e0d56 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -116,30 +116,28 @@ .endm .macro SYSCALL_ENTRY trapno - mfspr r12,SPRN_SPRG_THREAD mfspr r9, SPRN_SRR1 - mfspr r11, SPRN_SRR0 - mtctr r11 + mfspr r10, SPRN_SRR0 andi. r11, r9, MSR_PR + beq- 99f + LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */ + lis r12, 1f@h + ori r12, r12, 1f@l + mtspr SPRN_SRR1, r11 + mtspr SPRN_SRR0, r12 + mfspr r12,SPRN_SPRG_THREAD mr r11, r1 lwz r1,TASK_STACK-THREAD(r12) - beq- 99f + tovirt(r12, r12) addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE - LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) /* can take exceptions */ - mtspr SPRN_SRR1, r10 - lis r10, 1f@h - ori r10, r10, 1f@l - mtspr SPRN_SRR0, r10 rfi 1: - tovirt(r12, r12) stw r11,GPR1(r1) stw r11,0(r1) mr r11, r1 + stw r10,_NIP(r11) mflr r10 stw r10, _LINK(r11) - mfctr r10 - stw r10,_NIP(r11) mfcr r10 rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */ stw r10,_CCR(r11) /* save registers */ -- 2.25.0 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=-13.8 required=3.0 tests=BAYES_00, 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 54C70C433E6 for ; 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Tue, 9 Feb 2021 02:10:27 +1100 (AEDT) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4DZ8bG4kdjz9vBnC; Mon, 8 Feb 2021 16:10:18 +0100 (CET) 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 C7rjuJzjDpqL; Mon, 8 Feb 2021 16:10:18 +0100 (CET) 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 4DZ8bG3zSvz9vBn3; Mon, 8 Feb 2021 16:10:18 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C624D8B7B3; Mon, 8 Feb 2021 16:10:23 +0100 (CET) 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 VNxVEJ7nY3Ry; Mon, 8 Feb 2021 16:10:23 +0100 (CET) Received: from po16121vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.103]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8AD4A8B7B2; Mon, 8 Feb 2021 16:10:23 +0100 (CET) Received: by po16121vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 800A56733E; Mon, 8 Feb 2021 15:10:23 +0000 (UTC) Message-Id: <8fa13a59f73647e058c95fc7e1c7a98f316bd20a.1612796617.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v5 04/22] powerpc/32: Reorder instructions to avoid using CTR in syscall entry To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , npiggin@gmail.com, msuchanek@suse.de Date: Mon, 8 Feb 2021 15:10:23 +0000 (UTC) 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: 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" Now that we are using rfi instead of mtmsr to reactivate MMU, it is possible to reorder instructions and avoid the need to use CTR for stashing SRR0. null_syscall on 8xx is reduced by 3 cycles (283 => 280 cycles). Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/head_32.h | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 4029c51dce5d..24dc326e0d56 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -116,30 +116,28 @@ .endm .macro SYSCALL_ENTRY trapno - mfspr r12,SPRN_SPRG_THREAD mfspr r9, SPRN_SRR1 - mfspr r11, SPRN_SRR0 - mtctr r11 + mfspr r10, SPRN_SRR0 andi. r11, r9, MSR_PR + beq- 99f + LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */ + lis r12, 1f@h + ori r12, r12, 1f@l + mtspr SPRN_SRR1, r11 + mtspr SPRN_SRR0, r12 + mfspr r12,SPRN_SPRG_THREAD mr r11, r1 lwz r1,TASK_STACK-THREAD(r12) - beq- 99f + tovirt(r12, r12) addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE - LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) /* can take exceptions */ - mtspr SPRN_SRR1, r10 - lis r10, 1f@h - ori r10, r10, 1f@l - mtspr SPRN_SRR0, r10 rfi 1: - tovirt(r12, r12) stw r11,GPR1(r1) stw r11,0(r1) mr r11, r1 + stw r10,_NIP(r11) mflr r10 stw r10, _LINK(r11) - mfctr r10 - stw r10,_NIP(r11) mfcr r10 rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */ stw r10,_CCR(r11) /* save registers */ -- 2.25.0