From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754588AbaI2AYY (ORCPT ); Sun, 28 Sep 2014 20:24:24 -0400 Received: from mail-we0-f169.google.com ([74.125.82.169]:35342 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753951AbaI2AYD (ORCPT ); Sun, 28 Sep 2014 20:24:03 -0400 From: Daniel Lezcano To: tglx@linutronix.de, mingo@kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 11/13] clocksource: arm_arch_timer: Change clocksource name if CP15 unavailable Date: Mon, 29 Sep 2014 02:23:44 +0200 Message-Id: <1411950226-21598-11-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1411950226-21598-1-git-send-email-daniel.lezcano@linaro.org> References: <5428A559.5050908@linaro.org> <1411950226-21598-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nathan Lynch The arm and arm64 VDSOs need CP15 access to the architected counter. If this is unavailable (which is allowed by ARM v7), indicate this by changing the clocksource name to "arch_mem_counter" before registering the clocksource. Suggested by Stephen Boyd. Signed-off-by: Nathan Lynch Reviewed-by: Stephen Boyd Signed-off-by: Daniel Lezcano Acked-by: Will Deacon --- drivers/clocksource/arm_arch_timer.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 7e267e3..e0e7729 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -429,11 +429,19 @@ static void __init arch_counter_register(unsigned type) u64 start_count; /* Register the CP15 based counter if we have one */ - if (type & ARCH_CP15_TIMER) + if (type & ARCH_CP15_TIMER) { arch_timer_read_counter = arch_counter_get_cntvct; - else + } else { arch_timer_read_counter = arch_counter_get_cntvct_mem; + /* If the clocksource name is "arch_sys_counter" the + * VDSO will attempt to read the CP15-based counter. + * Ensure this does not happen when CP15-based + * counter is not available. + */ + clocksource_counter.name = "arch_mem_counter"; + } + start_count = arch_timer_read_counter(); clocksource_register_hz(&clocksource_counter, arch_timer_rate); cyclecounter.mult = clocksource_counter.mult; -- 1.9.1