From patchwork Wed Jun 5 23:54:44 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 2676441 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork2.kernel.org (Postfix) with ESMTP id 00F19DF264 for ; Wed, 5 Jun 2013 23:57:09 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UkNYZ-00030I-V2; Wed, 05 Jun 2013 23:55:56 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UkNYG-0002Gd-D5; Wed, 05 Jun 2013 23:55:36 +0000 Received: from smtp.codeaurora.org ([198.145.11.231]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UkNXp-0002DR-KW for linux-arm-kernel@lists.infradead.org; Wed, 05 Jun 2013 23:55:13 +0000 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 27A3E13F104; Wed, 5 Jun 2013 23:54:49 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 1780F13F108; Wed, 5 Jun 2013 23:54:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-caf-smtp.dmz.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=ham version=3.3.1 Received: from sboyd-linux.qualcomm.com (i-global252.qualcomm.com [199.106.103.252]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: sboyd@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 7569313F104; Wed, 5 Jun 2013 23:54:48 +0000 (UTC) From: Stephen Boyd To: John Stultz Subject: [PATCHv3 2/3] ARM: arch_timer: Move to generic sched_clock framework Date: Wed, 5 Jun 2013 16:54:44 -0700 Message-Id: <1370476485-468-3-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.8.3.rc3.8.g5e49f30.dirty In-Reply-To: <1370476485-468-1-git-send-email-sboyd@codeaurora.org> References: <1370476485-468-1-git-send-email-sboyd@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130605_195510_034823_E8FF12F7 X-CRM114-Status: GOOD ( 17.38 ) X-Spam-Score: -2.4 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.4 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Russell King , linux-arm-msm@vger.kernel.org, Will Deacon , linux-kernel@vger.kernel.org, arm@kernel.org, Christopher Covington , Catalin Marinas , Thomas Gleixner , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Register with the generic sched_clock framework now that it supports 64 bits. This fixes two problems with the current sched_clock support for machines using the architected timers. First off, we don't subtract the start value from subsequent sched_clock calls so we can potentially start off with sched_clock returning gigantic numbers. Second, there is no support for suspend/resume handling so problems such as discussed in 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during suspend, 2012-10-23) can happen without this patch. Signed-off-by: Stephen Boyd --- arch/arm/kernel/arch_timer.c | 14 ++------------ include/linux/sched_clock.h | 2 -- kernel/time/sched_clock.c | 13 ++++--------- 3 files changed, 6 insertions(+), 23 deletions(-) diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 221f07b..2966288 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -22,13 +22,6 @@ static unsigned long arch_timer_read_counter_long(void) return arch_timer_read_counter(); } -static u32 sched_clock_mult __read_mostly; - -static unsigned long long notrace arch_timer_sched_clock(void) -{ - return arch_timer_read_counter() * sched_clock_mult; -} - static struct delay_timer arch_delay_timer; static void __init arch_timer_delay_timer_register(void) @@ -48,11 +41,8 @@ int __init arch_timer_arch_init(void) arch_timer_delay_timer_register(); - /* Cache the sched_clock multiplier to save a divide in the hot path. */ - sched_clock_mult = NSEC_PER_SEC / arch_timer_rate; - sched_clock_func = arch_timer_sched_clock; - pr_info("sched_clock: ARM arch timer >56 bits at %ukHz, resolution %uns\n", - arch_timer_rate / 1000, sched_clock_mult); + /* 56 bits minimum, so we assume worst case rollover */ + sched_clock_setup(arch_timer_read_counter, 56, arch_timer_rate); return 0; } diff --git a/include/linux/sched_clock.h b/include/linux/sched_clock.h index 81baaef..04cee83 100644 --- a/include/linux/sched_clock.h +++ b/include/linux/sched_clock.h @@ -17,6 +17,4 @@ static inline void sched_clock_postinit(void) { } extern void setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate); extern void sched_clock_setup(u64 (*read)(void), int bits, unsigned long rate); -extern unsigned long long (*sched_clock_func)(void); - #endif diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c index 3478b6d..f69addf 100644 --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -173,20 +173,15 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) sched_clock_setup(read_sched_clock_32_wrapper, bits, rate); } -static unsigned long long notrace sched_clock_32(void) -{ - u64 cyc = read_sched_clock(); - return cyc_to_sched_clock(cyc, sched_clock_mask); -} - -unsigned long long __read_mostly (*sched_clock_func)(void) = sched_clock_32; - unsigned long long notrace sched_clock(void) { + u64 cyc; + if (cd.suspended) return cd.epoch_ns; - return sched_clock_func(); + cyc = read_sched_clock(); + return cyc_to_sched_clock(cyc, sched_clock_mask); } void __init sched_clock_postinit(void)