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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 671A3CCA47B for ; Mon, 11 Jul 2022 09:50:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233738AbiGKJuI (ORCPT ); Mon, 11 Jul 2022 05:50:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233795AbiGKJtQ (ORCPT ); Mon, 11 Jul 2022 05:49:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B99FACEC5; Mon, 11 Jul 2022 02:23:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E63F261356; Mon, 11 Jul 2022 09:23:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC88CC34115; Mon, 11 Jul 2022 09:23:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657531438; bh=tOrTmnkvypOInQwBGOplI6UmHax23uF7QhIN1+eDHZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GkrkpNa3Wm9rpwDRuqOHZRfUgVAI00rvMT2ZTzmVhewUDTQAK/5+VhOAaj+mksWnU q70nvGMnO0sWeT9t6frL5VPh2p7PgHfO66QSvaRxFD6tPFBVDyO923rPnjHiPA1wy1 /N3YyFyzhhS+hujb37vTvoX8qV3tf1lfN/zCkeQI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Michael Ellerman , Sasha Levin Subject: [PATCH 5.15 106/230] powerpc/32: Dont use lmw/stmw for saving/restoring non volatile regs Date: Mon, 11 Jul 2022 11:06:02 +0200 Message-Id: <20220711090607.074732684@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090604.055883544@linuxfoundation.org> References: <20220711090604.055883544@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christophe Leroy [ Upstream commit a85c728cb5e12216c19ae5878980c2cbbbf8616d ] Instructions lmw/stmw are interesting for functions that are rarely used and not in the cache, because only one instruction is to be copied into the instruction cache instead of 19. However those instruction are less performant than 19x raw lwz/stw as they require synchronisation plus one additional cycle. SAVE_NVGPRS / REST_NVGPRS are used in only a few places which are mostly in interrupts entries/exits and in task switch so they are likely already in the cache. Using standard lwz improves null_syscall selftest by: - 10 cycles on mpc832x. - 2 cycles on mpc8xx. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/316c543b8906712c108985c8463eec09c8db577b.1629732542.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/ppc_asm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 1c538a9a11e0..7be24048b8d1 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -28,8 +28,8 @@ #else #define SAVE_GPR(n, base) stw n,GPR0+4*(n)(base) #define REST_GPR(n, base) lwz n,GPR0+4*(n)(base) -#define SAVE_NVGPRS(base) stmw 13, GPR0+4*13(base) -#define REST_NVGPRS(base) lmw 13, GPR0+4*13(base) +#define SAVE_NVGPRS(base) SAVE_GPR(13, base); SAVE_8GPRS(14, base); SAVE_10GPRS(22, base) +#define REST_NVGPRS(base) REST_GPR(13, base); REST_8GPRS(14, base); REST_10GPRS(22, base) #endif #define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base) -- 2.35.1