From patchwork Fri Nov 25 08:46:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: fu.wei@linaro.org X-Patchwork-Id: 9446839 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7EC3960779 for ; Fri, 25 Nov 2016 08:56:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D33F28047 for ; Fri, 25 Nov 2016 08:56:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 61B232756B; Fri, 25 Nov 2016 08:56:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0255928047 for ; Fri, 25 Nov 2016 08:56:52 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1cACGz-0001Rp-RL; Fri, 25 Nov 2016 08:54:21 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1cACAy-0004Iv-Ae for linux-arm-kernel@lists.infradead.org; Fri, 25 Nov 2016 08:48:11 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 51EBC4E047; Fri, 25 Nov 2016 08:47:49 +0000 (UTC) Received: from Rei-Ayanami.localdomain (vpn1-7-161.pek2.redhat.com [10.72.7.161]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uAP8kYdP023998; Fri, 25 Nov 2016 03:47:39 -0500 From: fu.wei@linaro.org To: rjw@rjwysocki.net, lenb@kernel.org, daniel.lezcano@linaro.org, tglx@linutronix.de, marc.zyngier@arm.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com, hanjun.guo@linaro.org Subject: [PATCH v17 06/15] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Date: Fri, 25 Nov 2016 16:46:14 +0800 Message-Id: <20161125084623.22515-7-fu.wei@linaro.org> In-Reply-To: <20161125084623.22515-1-fu.wei@linaro.org> References: <20161125084623.22515-1-fu.wei@linaro.org> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 25 Nov 2016 08:47:49 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161125_004808_727453_6C21AB2B X-CRM114-Status: GOOD ( 16.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linaro-acpi@lists.linaro.org, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, wim@iguana.be, Fu Wei , wei@redhat.com, al.stone@linaro.org, tn@semihalf.com, timur@codeaurora.org, linux-acpi@vger.kernel.org, linux@roeck-us.net, harba@codeaurora.org, julien.grall@arm.com, linux-watchdog@vger.kernel.org, arnd@arndb.de, jcm@redhat.com, cov@codeaurora.org, linux-arm-kernel@lists.infradead.org, graeme.gregory@linaro.org, rruigrok@codeaurora.org, leo.duran@amd.com, Suravee.Suthikulpanit@amd.com, christoffer.dall@linaro.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Fu Wei Currently, the counter frequency detection call(arch_timer_detect_rate) combines all the ways to get counter frequency: device-tree property, system coprocessor register, MMIO timer. But in the most of use cases, we don't need all the ways to try: For example, reading device-tree property will be needed only when system boot with device-tree, getting frequency from MMIO timer register will beneeded only when we init MMIO timer. This patch separates paths to determine frequency: Separate out device-tree code, keep them in device-tree init function. Separate out the MMIO frequency and the sysreg frequency detection call, and use the appropriate one for the counter. Signed-off-by: Fu Wei --- drivers/clocksource/arm_arch_timer.c | 49 +++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 18 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index e43be0a..e554081 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -487,27 +487,31 @@ static int arch_timer_starting_cpu(unsigned int cpu) return 0; } -static void -arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) +static void arch_timer_detect_rate(void) { - /* Who has more than one independent system counter? */ - if (arch_timer_rate) - return; + /* + * Try to get the timer frequency from + * cntfrq_el0(system coprocessor register). + */ + if (!arch_timer_rate) + arch_timer_rate = arch_timer_get_cntfrq(); + + /* Check the timer frequency. */ + if (!arch_timer_rate) + pr_warn("frequency not available\n"); +} +static void arch_timer_mem_detect_rate(void __iomem *cntbase) +{ /* - * Try to determine the frequency from the device tree or CNTFRQ, - * if ACPI is enabled, get the frequency from CNTFRQ ONLY. + * Try to determine the frequency from + * CNTFRQ in memory-mapped timer. */ - if (!acpi_disabled || - of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) { - if (cntbase) - arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); - else - arch_timer_rate = arch_timer_get_cntfrq(); - } + if (!arch_timer_rate) + arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); /* Check the timer frequency. */ - if (arch_timer_rate == 0) + if (!arch_timer_rate) pr_warn("frequency not available\n"); } @@ -883,7 +887,9 @@ static int __init arch_timer_of_init(struct device_node *np) for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++) arch_timer_ppi[i] = irq_of_parse_and_map(np, i); - arch_timer_detect_rate(NULL, np); + if (!arch_timer_rate && + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_detect_rate(); arch_timer_c3stop = !of_property_read_bool(np, "always-on"); @@ -986,7 +992,14 @@ static int __init arch_timer_mem_init(struct device_node *np) goto out; } - arch_timer_detect_rate(base, np); + /* + * Try to determine the frequency from the device tree, + * if fail, get the frequency from CNTFRQ. + */ + if (!arch_timer_rate && + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_mem_detect_rate(base); + ret = arch_timer_mem_register(base, irq); if (ret) goto out; @@ -1048,7 +1061,7 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) gtdt->non_secure_el2_flags); /* Get the frequency from CNTFRQ */ - arch_timer_detect_rate(NULL, NULL); + arch_timer_detect_rate(); arch_timer_uses_ppi = arch_timer_select_ppi(); if (!arch_timer_ppi[arch_timer_uses_ppi]) {