From patchwork Mon Jan 13 17:08:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 11330577 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 231D992A for ; Mon, 13 Jan 2020 17:08:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBF962084D for ; Mon, 13 Jan 2020 17:08:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="VCsSI0Ym" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728558AbgAMRIl (ORCPT ); Mon, 13 Jan 2020 12:08:41 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:2142 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727323AbgAMRIl (ORCPT ); Mon, 13 Jan 2020 12:08:41 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 47xKmf0c4xz9txyr; Mon, 13 Jan 2020 18:08:34 +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=VCsSI0Ym; 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 YpE9yvHpzNph; Mon, 13 Jan 2020 18:08:34 +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 47xKmd6Vt6z9txyq; Mon, 13 Jan 2020 18:08:33 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1578935313; bh=HWz0NtVtGF6JzuFvn1IEu26bS25Q46p2uQtnUn88eHs=; h=From:Subject:To:Cc:Date:From; b=VCsSI0YmRfqt3jhfrCAg6RSUj1sPG5J+ypYkfjIgakQ3Ukz7AtoB6jArFcyzqYdsZ GlhNVPJmOaYwxRRlvFQOZdIwpAANt/SritBFT2Q6XoBOZFXYKGIL0rKzuczCydlRP5 jjqR1csQiqmNFtLuAyN1E7m3v17abUHCf230875A= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 3C3628B7C9; Mon, 13 Jan 2020 18:08:39 +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 8wXE7irLHIRC; Mon, 13 Jan 2020 18:08:39 +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 ECB1A8B7BE; Mon, 13 Jan 2020 18:08:38 +0100 (CET) Received: by localhost.localdomain (Postfix, from userid 0) id 8DBC464A1D; Mon, 13 Jan 2020 17:08:38 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [RFC PATCH v3 00/12] powerpc: 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, 13 Jan 2020 17:08:38 +0000 (UTC) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org This is a third tentative to switch powerpc VDSO to generic C implementation. This version should work on PPC64 (untested). VDSO32 for PPC64 is impossible to build and has been de-activated, because the powerpc ASM header files for C are not prepared to build 32 bits code with CONFIG_PPC64. 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 need to be performed in ASM. 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 The first patch adds VDSO generic C support without any changes to common code. Performance is as follows: gettimeofday: vdso: 1379 nsec/call clock-getres-realtime-coarse: vdso: 984 nsec/call clock-gettime-realtime-coarse: vdso: 868 nsec/call clock-getres-realtime: vdso: 922 nsec/call clock-gettime-realtime: vdso: 1511 nsec/call clock-getres-monotonic-raw: vdso: 968 nsec/call clock-gettime-monotonic-raw: vdso: 1576 nsec/call Then a few changes in the common code have allowed performance improvement. At the end of the series we have: gettimeofday: vdso: 899 nsec/call clock-getres-realtime-coarse: vdso: 546 nsec/call clock-gettime-realtime-coarse: vdso: 615 nsec/call clock-getres-realtime: vdso: 545 nsec/call clock-gettime-realtime: vdso: 1064 nsec/call clock-getres-monotonic-raw: vdso: 546 nsec/call clock-gettime-monotonic-raw: vdso: 1125 nsec/call Christophe Leroy (12): powerpc/64: Don't provide time functions in compat VDSO32 powerpc/vdso: Switch VDSO to generic C implementation. lib: vdso: mark __cvdso_clock_getres() as static lib: vdso: inline do_hres() and do_coarse() lib: vdso: Avoid duplication in __cvdso_clock_getres() lib: vdso: __iter_div_u64_rem() is suboptimal for 32 bit time powerpc/vdso: simplify __get_datapage() lib: vdso: allow arches to provide vdso data pointer powerpc/vdso: provide inline alternative to __get_datapage() powerpc/vdso: provide vdso data pointer from the ASM caller. lib: vdso: split clock verification out of __arch_get_hw_counter() powerpc/vdso: provide __arch_is_hw_counter_valid() arch/powerpc/Kconfig | 2 + arch/powerpc/include/asm/vdso/gettimeofday.h | 104 +++++++++++ arch/powerpc/include/asm/vdso/vsyscall.h | 25 +++ arch/powerpc/include/asm/vdso_datapage.h | 52 +++--- arch/powerpc/kernel/asm-offsets.c | 46 +---- arch/powerpc/kernel/time.c | 90 ---------- arch/powerpc/kernel/vdso.c | 58 ++---- arch/powerpc/kernel/vdso32/Makefile | 30 +++- arch/powerpc/kernel/vdso32/datapage.S | 10 +- arch/powerpc/kernel/vdso32/gettimeofday.S | 258 ++++----------------------- arch/powerpc/kernel/vdso32/vdso32.lds.S | 9 +- arch/powerpc/kernel/vdso32/vgettimeofday.c | 29 +++ arch/powerpc/kernel/vdso64/Makefile | 23 ++- arch/powerpc/kernel/vdso64/datapage.S | 13 +- arch/powerpc/kernel/vdso64/gettimeofday.S | 257 ++++---------------------- arch/powerpc/kernel/vdso64/vdso64.lds.S | 7 +- arch/powerpc/kernel/vdso64/vgettimeofday.c | 29 +++ lib/vdso/gettimeofday.c | 130 +++++++++++--- 18 files changed, 457 insertions(+), 715 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 create mode 100644 arch/powerpc/kernel/vdso64/vgettimeofday.c