From patchwork Tue Aug 18 03:28:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: zhukeqian X-Patchwork-Id: 11719747 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 B13AC722 for ; Tue, 18 Aug 2020 03:33:39 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 832922053B for ; Tue, 18 Aug 2020 03:33:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="XOzZrXP+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 832922053B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Umz1MzxknY/oF9Hi5x1Lw3XtaeZdSHekF+/cfJP/Sro=; b=XOzZrXP+vKTVz0sHWJn5IjLpD HR4yzuiiAJ0gd0N2WreAxXQUu++fd+e0KK0WSr3cpcH9otCFSTNkAd6ucuJKbsguQ2vpdtGjEVbYL PWYhXR8TWENbVaMxRf6wpCf/fMuWwe1oYbgXha6CcEliQo436zqe63IN5MG/pQ34706gkj55yT1g6 AbwWxESUYQGWhXJ+IU5qcHKwHjZDHel4EoHNf0UB6PNxkFrxgyR6DrdEmC7XFdrAOOlSaeHXMPv+h eupcr7Ki655hVB0mvg4TwIMO+NZT21ePIsJX2pVqEE+ANJ8tqu3Som13ps2GGjgBcrmMfE6oks4v7 tTAfySbNQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k7sIf-0001dP-Q3; Tue, 18 Aug 2020 03:28:37 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k7sIY-0001az-Qg for linux-arm-kernel@lists.infradead.org; Tue, 18 Aug 2020 03:28:32 +0000 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 5E320A170C129F5B98F0; Tue, 18 Aug 2020 11:28:25 +0800 (CST) Received: from DESKTOP-5IS4806.china.huawei.com (10.174.187.22) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.487.0; Tue, 18 Aug 2020 11:28:18 +0800 From: Keqian Zhu To: , , , Subject: [PATCH v2 2/2] clocksource: arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI Date: Tue, 18 Aug 2020 11:28:14 +0800 Message-ID: <20200818032814.15968-3-zhukeqian1@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20200818032814.15968-1-zhukeqian1@huawei.com> References: <20200818032814.15968-1-zhukeqian1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.22] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200817_232831_183828_6C7242E4 X-CRM114-Status: GOOD ( 11.66 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 RCVD_IN_MSPIKE_H4 RBL: Very Good reputation (+4) [45.249.212.190 listed in wl.mailspike.net] -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.190 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Jones , Suzuki K Poulose , Marc Zyngier , Keqian Zhu , Steven Price , James Morse , Catalin Marinas , wanghaibin.wang@huawei.com, Will Deacon Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org ARM virtual counter supports event stream, it can only trigger an event when the trigger bit (the value of CNTKCTL_EL1.EVNTI) of CNTVCT_EL0 changes, so the actual period of event stream is 2^(cntkctl_evnti + 1). For example, when the trigger bit is 0, then virtual counter trigger an event for every two cycles. Fixes: 037f637767a8 ("drivers: clocksource: add support for ARM architected timer event stream") Suggested-by: Marc Zyngier Signed-off-by: Keqian Zhu --- drivers/clocksource/arm_arch_timer.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 777d38c..e3b2ee0 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -824,10 +824,14 @@ static void arch_timer_configure_evtstream(void) { int evt_stream_div, pos; - /* Find the closest power of two to the divisor */ - evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ; + /* + * Find the closest power of two to the divisor. As the event + * stream can at most be generated at half the frequency of the + * counter, use half the frequency when computing the divider. + */ + evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ / 2; pos = fls(evt_stream_div); - if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) + if ((pos == 1) || (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))) pos--; /* enable event stream */ arch_timer_evtstrm_enable(min(pos, 15));