From patchwork Mon Dec 23 14:31:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 11308409 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 B4F5A921 for ; Mon, 23 Dec 2019 14:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8990F2075B for ; Mon, 23 Dec 2019 14:31:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="cfApg9sH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726840AbfLWOby (ORCPT ); Mon, 23 Dec 2019 09:31:54 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:24560 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726777AbfLWObD (ORCPT ); Mon, 23 Dec 2019 09:31:03 -0500 Received: from localhost (mailhub1-ext [192.168.12.233]) by localhost (Postfix) with ESMTP id 47hMGS5T4sz9txjw; Mon, 23 Dec 2019 15:30:56 +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=cfApg9sH; 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 NGVhIXcP7bQ8; Mon, 23 Dec 2019 15:30:56 +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 47hMGS4B7Wz9txjv; Mon, 23 Dec 2019 15:30:56 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1577111456; bh=yVxuGmQR051J6pETL5q29uPkTsP81kEW/OmeuvlbY/k=; h=From:Subject:To:Cc:Date:From; b=cfApg9sH1a9HHa55YFyf8L755JhqvakH05NG+R/qHkWzE5LUPrg24rswTt4CXyRyC 2bhyW8BcRvrp/qnckgOME1s7wI6VFu8a2RSUlLqOrq/21c00ILlXV1sAzj+xe5fgf+ 5bND3VhxVxgMSsmr0NGgo6eGrLt7/vsuVuvx9Kh4= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id AD3658B7AB; Mon, 23 Dec 2019 15:31:01 +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 AbT8jpQZojIw; Mon, 23 Dec 2019 15:31:01 +0100 (CET) Received: from po16098vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.100]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 7C04C8B7A1; Mon, 23 Dec 2019 15:31:01 +0100 (CET) Received: by po16098vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 57F2B637D4; Mon, 23 Dec 2019 14:31:01 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [RFC PATCH v2 00/10] powerpc/32: switch VDSO to C implementation. 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, 23 Dec 2019 14:31:01 +0000 (UTC) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org This is a second tentative to switch powerpc/32 vdso to generic C implementation. It will likely not work on 64 bits or even build properly at the moment. powerpc is a bit special for VDSO as well as system calls in the way that it requires setting CR SO bit which cannot be done in C. Therefore, entry/exit and fallback needs to be performed in ASM. To allow that, the fallback calls are moved out of the common code and left to the arches. A few other changes in the common code have allowed performance improvement. The performance has improved since first RFC, but it is still lower than current assembly VDSO. On a powerpc8xx, with current powerpc/32 ASM VDSO: gettimeofday: vdso: 737 nsec/call clock-getres-realtime: vdso: 475 nsec/call clock-gettime-realtime: vdso: 892 nsec/call clock-getres-monotonic: vdso: 475 nsec/call clock-gettime-monotonic: vdso: 1014 nsec/call First try of C implementation: gettimeofday: vdso: 1533 nsec/call clock-getres-realtime: vdso: 853 nsec/call clock-gettime-realtime: vdso: 1570 nsec/call clock-getres-monotonic: vdso: 835 nsec/call clock-gettime-monotonic: vdso: 1605 nsec/call With this series: gettimeofday: vdso: 1016 nsec/call clock-getres-realtime: vdso: 560 nsec/call clock-gettime-realtime: vdso: 1192 nsec/call clock-getres-monotonic: vdso: 560 nsec/call clock-gettime-monotonic: vdso: 1192 nsec/call Changes made to other arches are untested, not even compiled. Christophe Leroy (10): lib: vdso: ensure all arches have 32bit fallback lib: vdso: move call to fallback out of common code. lib: vdso: Change __cvdso_clock_gettime/getres_common() to __cvdso_clock_gettime/getres() lib: vdso: get pointer to vdso data from the arch lib: vdso: inline do_hres() lib: vdso: make do_coarse() return 0 lib: vdso: don't use READ_ONCE() in __c_kernel_time() lib: vdso: Avoid duplication in __cvdso_clock_getres() powerpc/vdso32: inline __get_datapage() powerpc/32: Switch VDSO to C implementation. arch/arm/include/asm/vdso/gettimeofday.h | 26 +++ arch/arm/vdso/vgettimeofday.c | 32 ++- arch/arm64/include/asm/vdso/compat_gettimeofday.h | 2 - arch/arm64/include/asm/vdso/gettimeofday.h | 26 +++ arch/arm64/kernel/vdso/vgettimeofday.c | 24 +- arch/arm64/kernel/vdso32/vgettimeofday.c | 39 +++- arch/mips/include/asm/vdso/gettimeofday.h | 28 ++- arch/mips/vdso/vgettimeofday.c | 56 ++++- arch/powerpc/Kconfig | 2 + arch/powerpc/include/asm/vdso/gettimeofday.h | 45 ++++ arch/powerpc/include/asm/vdso/vsyscall.h | 27 +++ arch/powerpc/include/asm/vdso_datapage.h | 28 +-- arch/powerpc/kernel/asm-offsets.c | 23 +- arch/powerpc/kernel/time.c | 92 +------- arch/powerpc/kernel/vdso.c | 19 +- arch/powerpc/kernel/vdso32/Makefile | 19 +- arch/powerpc/kernel/vdso32/cacheflush.S | 9 +- arch/powerpc/kernel/vdso32/datapage.S | 28 +-- arch/powerpc/kernel/vdso32/gettimeofday.S | 265 +++------------------- arch/powerpc/kernel/vdso32/vgettimeofday.c | 32 +++ arch/x86/entry/vdso/vclock_gettime.c | 52 ++++- arch/x86/include/asm/vdso/gettimeofday.h | 28 ++- lib/vdso/gettimeofday.c | 100 +++----- 23 files changed, 505 insertions(+), 497 deletions(-) create mode 100644 arch/powerpc/include/asm/vdso/gettimeofday.h create mode 100644 arch/powerpc/include/asm/vdso/vsyscall.h create mode 100644 arch/powerpc/kernel/vdso32/vgettimeofday.c