From patchwork Mon Apr 1 20:58:32 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rob Herring X-Patchwork-Id: 2372781 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id ADCCA40214 for ; Mon, 1 Apr 2013 21:02:12 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UMloa-0005oh-S3; Mon, 01 Apr 2013 20:58:52 +0000 Received: from mail-ve0-f174.google.com ([209.85.128.174]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UMloW-0005o3-AZ for linux-arm-kernel@lists.infradead.org; Mon, 01 Apr 2013 20:58:49 +0000 Received: by mail-ve0-f174.google.com with SMTP id jz10so3012290veb.5 for ; Mon, 01 Apr 2013 13:58:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=a3QWFRlkKYlzL/PXlkQ40A+7XK+5Hd/NnR0sVJZZHSY=; b=tb3MY92zSgct7CCFLsjEBAge0V7rUAJMiStDVhispQHeSZg8fdl9NcAXIyrn2tOu0a wic/8fus+DhFulgKwbzluTAoN5NrJhxALup6u2xWiHhmj0EQUiHeSoRFxKwMRhmT4/Xn B3XWdjK7iYScrARKfZLcxP3+Q70RY9NnPfvlosqsofEfsTwU3PbimSS73a2QCksDEhXh WgXKq8QH9L6AUNXA2hdrrMBEBXUiKIuNBHpDW2TAJJrYC+uXfzISJjMr0sJi3JA/cMkN qRKpQB/uhwapByf8piWdTFcUP6XiXnnqlFcgMJCTxXxsZoKSMMeu0wgSKheFTqmCm5hR tk7A== X-Received: by 10.52.68.116 with SMTP id v20mr8786423vdt.126.1364849926969; Mon, 01 Apr 2013 13:58:46 -0700 (PDT) Received: from rob-laptop.calxeda.com ([173.226.190.126]) by mx.google.com with ESMTPS id l18sm15810836vdh.10.2013.04.01.13.58.45 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 01 Apr 2013 13:58:46 -0700 (PDT) From: Rob Herring To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 1/3] ARM: sched_clock: allow changing to higher frequency counter Date: Mon, 1 Apr 2013 15:58:32 -0500 Message-Id: <1364849914-26420-2-git-send-email-robherring2@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1364849914-26420-1-git-send-email-robherring2@gmail.com> References: <1364849914-26420-1-git-send-email-robherring2@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130401_165848_423460_02D1AC6A X-CRM114-Status: GOOD ( 11.58 ) X-Spam-Score: -2.5 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (robherring2[at]gmail.com) -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.128.174 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (robherring2[at]gmail.com) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Cc: Mark Rutland , Russell King , Rob Herring , arm@kernel.org, John Stultz , Thomas Gleixner 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 From: Rob Herring Allow multiple calls to setup_sched_clock and switch to the new counter if it is higher frequency. Signed-off-by: Rob Herring --- arch/arm/kernel/sched_clock.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index bd6f56b..040168e 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -20,6 +20,7 @@ struct clock_data { u64 epoch_ns; u32 epoch_cyc; u32 epoch_cyc_copy; + unsigned long rate; u32 mult; u32 shift; bool suspended; @@ -113,11 +114,14 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) u64 res, wrap; char r_unit; + if (cd.rate > rate) + return; + BUG_ON(bits > 32); WARN_ON(!irqs_disabled()); - WARN_ON(read_sched_clock != jiffy_sched_clock_read); read_sched_clock = read; sched_clock_mask = (1 << bits) - 1; + cd.rate = rate; /* calculate the mult/shift to convert counter ticks to ns. */ clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0);