From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932805AbcLUGrh (ORCPT ); Wed, 21 Dec 2016 01:47:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:32846 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932646AbcLUGrd (ORCPT ); Wed, 21 Dec 2016 01:47:33 -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 Cc: linux-arm-kernel@lists.infradead.org, linaro-acpi@lists.linaro.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rruigrok@codeaurora.org, harba@codeaurora.org, cov@codeaurora.org, timur@codeaurora.org, graeme.gregory@linaro.org, al.stone@linaro.org, jcm@redhat.com, wei@redhat.com, arnd@arndb.de, catalin.marinas@arm.com, will.deacon@arm.com, Suravee.Suthikulpanit@amd.com, leo.duran@amd.com, wim@iguana.be, linux@roeck-us.net, linux-watchdog@vger.kernel.org, tn@semihalf.com, christoffer.dall@linaro.org, julien.grall@arm.com, Fu Wei Subject: [PATCH v19 06/15] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Date: Wed, 21 Dec 2016 14:45:54 +0800 Message-Id: <20161221064603.11830-7-fu.wei@linaro.org> In-Reply-To: <20161221064603.11830-1-fu.wei@linaro.org> References: <20161221064603.11830-1-fu.wei@linaro.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 21 Dec 2016 06:47:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Tested-by: Xiongfeng Wang --- 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 c7b4482..9a1f138 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -488,27 +488,31 @@ 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"); } @@ -886,7 +890,9 @@ 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"); @@ -994,7 +1000,14 @@ 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; @@ -1056,7 +1069,7 @@ 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]) { -- 2.9.3