From patchwork Mon Jan 13 17:08:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 11330591 X-Patchwork-Delegate: paulburton@kernel.org Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A615C14B4 for ; Mon, 13 Jan 2020 17:09:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8400324656 for ; Mon, 13 Jan 2020 17:09:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="UjWNw3Qp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728851AbgAMRIv (ORCPT ); Mon, 13 Jan 2020 12:08:51 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:40965 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728829AbgAMRIu (ORCPT ); Mon, 13 Jan 2020 12:08:50 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 47xKmq18QMz9v0DP; Mon, 13 Jan 2020 18:08:43 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=UjWNw3Qp; dkim-adsp=pass; dkim-atps=neutral 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 B9T6ObAEkSau; Mon, 13 Jan 2020 18:08:43 +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 47xKmp6WlNz9tyXf; Mon, 13 Jan 2020 18:08:42 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1578935322; bh=8NMCNHuubcE6t4e17wk7DBu9YLriy2ZDehAsOAuF4AM=; h=In-Reply-To:References:From:Subject:To:Cc:Date:From; b=UjWNw3QpjSpsFOvUaUM8OtpncTUsaDVW9fyOtxPvIgOjuPt21K4VGlFLKAZvHGAtg DX/ABsxBaXP3v+YseN/kLMMmCMS6KlqlBycosWAZM50e9rJLMJtj+tUVoQ8kLmhZf0 0+1xi5QWHkWEUZO1UnR9hyZyBn2sJlPTBiymcRl4= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 3CA3A8B7C9; Mon, 13 Jan 2020 18:08:48 +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 MOJBmvXIlLvR; Mon, 13 Jan 2020 18:08:48 +0100 (CET) Received: from po14934vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 05B648B7BE; Mon, 13 Jan 2020 18:08:48 +0100 (CET) Received: by localhost.localdomain (Postfix, from userid 0) id CF0AD64A1D; Mon, 13 Jan 2020 17:08:47 +0000 (UTC) Message-Id: In-Reply-To: References: From: Christophe Leroy Subject: [RFC PATCH v3 09/12] powerpc/vdso: provide inline alternative to __get_datapage() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , arnd@arndb.de, tglx@linutronix.de, vincenzo.frascino@arm.com, luto@kernel.org Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, x86@kernel.org Date: Mon, 13 Jan 2020 17:08:47 +0000 (UTC) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org __get_datapage() is only a few instructions to retrieve the address of the page where the kernel stores data to the VDSO. By inlining this function into its users, a bl/blr pair and a mflr/mtlr pair is avoided, plus a few reg moves. The improvement is noticeable (about 55 nsec/call on an 8xx) With current __get_datapage() function: gettimeofday: vdso: 731 nsec/call clock-gettime-realtime-coarse: vdso: 668 nsec/call clock-gettime-monotonic-coarse: vdso: 745 nsec/call Using the __get_datapage macro provided by this patch: gettimeofday: vdso: 677 nsec/call clock-gettime-realtime-coarse: vdso: 613 nsec/call clock-gettime-monotonic-coarse: vdso: 690 nsec/call Signed-off-by: Christophe Leroy --- arch/powerpc/include/asm/vdso_datapage.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h index 4d7965bf369e..7342cc0c1ae4 100644 --- a/arch/powerpc/include/asm/vdso_datapage.h +++ b/arch/powerpc/include/asm/vdso_datapage.h @@ -105,6 +105,17 @@ struct vdso_arch_data { extern struct vdso_arch_data *vdso_data; +#else /* __ASSEMBLY__ */ + +.macro get_datapage ptr, offset=0 + bcl 20, 31, .+4 + mflr \ptr +#if CONFIG_PPC_PAGE_SHIFT > 14 + addis \ptr, \ptr, (_vdso_datapage + \offset - (.-4))@ha +#endif + addi \ptr, \ptr, (_vdso_datapage + \offset - (.-4))@l +.endm + #endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */