From patchwork Fri Apr 14 18:40:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fu Wei Fu X-Patchwork-Id: 97440 Delivered-To: patch@linaro.org Received: by 10.140.109.52 with SMTP id k49csp404103qgf; Fri, 14 Apr 2017 11:41:01 -0700 (PDT) X-Received: by 10.84.238.22 with SMTP id u22mr10608822plk.137.1492195261742; Fri, 14 Apr 2017 11:41:01 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 189si3107759pfg.334.2017.04.14.11.41.01 for ; Fri, 14 Apr 2017 11:41:01 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-watchdog-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-watchdog-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-watchdog-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754340AbdDNSlB (ORCPT ); Fri, 14 Apr 2017 14:41:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751687AbdDNSk7 (ORCPT ); Fri, 14 Apr 2017 14:40:59 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 03AEEC04BD37; Fri, 14 Apr 2017 18:40:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 03AEEC04BD37 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=fu.wei@linaro.org DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 03AEEC04BD37 Received: from Rei-Ayanami.localdomain.com (ovpn-8-47.pek2.redhat.com [10.72.8.47]) by smtp.corp.redhat.com (Postfix) with ESMTP id BC6FE174B0; Fri, 14 Apr 2017 18:40:45 +0000 (UTC) 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 v24 01/11] clocksource: arm_arch_timer: split dt-only rate handling Date: Sat, 15 Apr 2017 02:40:04 +0800 Message-Id: <20170414184014.8524-2-fu.wei@linaro.org> In-Reply-To: <20170414184014.8524-1-fu.wei@linaro.org> References: <20170414184014.8524-1-fu.wei@linaro.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 14 Apr 2017 18:40:58 +0000 (UTC) Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Fu Wei For historical reasons, rate detection when probing via DT is somewhat convoluted. We tried to package this up in arch_timer_detect_rate(), but with the addition of ACPI worse, and gets in the way of stringent rate checking when ACPI is used. This patch makes arch_timer_detect_rate() specific to DT, ripping out ACPI logic. In preparation for rework of the MMIO timer probing, the reading of the relevant CNTFRQ register is factored out to callers. The function is then renamed to arch_timer_of_configure_rate(), which better represents its new place in the world. Comments are added in the DT and ACPI probe paths to explain this. Signed-off-by: Fu Wei [Mark: reword commit message, TODO: rework comments] Signed-off-by: Mark Rutland --- drivers/clocksource/arm_arch_timer.c | 41 ++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 18 deletions(-) -- 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 94de018..0138b0c 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -818,24 +818,19 @@ static int arch_timer_starting_cpu(unsigned int cpu) return 0; } -static void -arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) +/* + * For historical reasons, when probing with DT we use whichever (non-zero) + * rate was probed first, and don't verify that others match. If the first node + * probed has a clock-frequency property, this overrides the HW register. + */ +static void arch_timer_of_configure_rate(u32 rate, struct device_node *np) { /* Who has more than one independent system counter? */ if (arch_timer_rate) return; - /* - * Try to determine the frequency from the device tree or CNTFRQ, - * if ACPI is enabled, get the frequency from CNTFRQ ONLY. - */ - 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 (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_rate = rate; /* Check the timer frequency. */ if (arch_timer_rate == 0) @@ -1166,6 +1161,7 @@ static int __init arch_timer_init(void) static int __init arch_timer_of_init(struct device_node *np) { int i; + u32 rate; if (arch_timers_present & ARCH_TIMER_TYPE_CP15) { pr_warn("multiple nodes in dt, skipping\n"); @@ -1176,7 +1172,8 @@ 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); + rate = arch_timer_get_cntfrq(); + arch_timer_of_configure_rate(rate, np); arch_timer_c3stop = !of_property_read_bool(np, "always-on"); @@ -1212,7 +1209,7 @@ static int __init arch_timer_mem_init(struct device_node *np) struct device_node *frame, *best_frame = NULL; void __iomem *cntctlbase, *base; unsigned int irq, ret = -EINVAL; - u32 cnttidr; + u32 cnttidr, rate; arch_timers_present |= ARCH_TIMER_TYPE_MEM; cntctlbase = of_iomap(np, 0); @@ -1278,7 +1275,8 @@ static int __init arch_timer_mem_init(struct device_node *np) goto out; } - arch_timer_detect_rate(base, np); + rate = readl(base + CNTFRQ); + arch_timer_of_configure_rate(rate, np); ret = arch_timer_mem_register(base, irq); if (ret) goto out; @@ -1339,8 +1337,15 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt, gtdt->non_secure_el2_flags); - /* Get the frequency from CNTFRQ */ - arch_timer_detect_rate(NULL, NULL); + /* + * When probing via ACPI, we have no mechanism to override the sysreg + * CNTFRQ value. This *must* be correct. + */ + arch_timer_rate = arch_timer_get_cntfrq(); + if (!arch_timer_rate) { + pr_err(FW_BUG "frequency not available.\n"); + return -EINVAL; + } arch_timer_uses_ppi = arch_timer_select_ppi(); if (!arch_timer_ppi[arch_timer_uses_ppi]) {