From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 22D702E9EB4; Thu, 14 Aug 2025 10:13:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755166433; cv=none; b=RyxmJgrioP65QmHzK5JKDDtgGtjZsqVQEb/9NUJs4PkT+SLF5T6lJc7QjKbMmC+hV+EA1dWKAMP5vK0H+W6d7ogNigSzsCdD7riYTY1dYvOqLWfzjQ2d4h9N86InzQO/JpdTrznSKDH5Sm85u9+47GKTmiYH860bnUXZLstKzhA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755166433; c=relaxed/simple; bh=Bg9AzY3Mn0AYL1nBIXFeDIoVS+u15WrCOpXgAgnHRFc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kCA1ZS2AT5Obnk/38GzlNsVyI9+ca4/1ibPJt9zsw9dbe3eotChwWbg7ngu3pGWedYMUAyRA2te8+i/ftnhbHXbX4umKkmZKOE+YirnHneOQCvNOJZUeE9Hg3+VeucEHr57v3XQWZe0vkUFjiF1X/HSmmy8NynKoFkW3wGb/Hcs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 43B7A1691; Thu, 14 Aug 2025 03:13:43 -0700 (PDT) Received: from [10.1.32.48] (e122027.cambridge.arm.com [10.1.32.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8A06E3F738; Thu, 14 Aug 2025 03:13:49 -0700 (PDT) Message-ID: <8e58b01b-772d-4ca7-a681-34f10baa07e6@arm.com> Date: Thu, 14 Aug 2025 11:13:47 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/4] clocksource/drivers/arm_arch_timer: Add standalone MMIO driver To: Marc Zyngier , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , "Rafael J. Wysocki" , Daniel Lezcano , Thomas Gleixner , Mark Rutland References: <20250807160243.1970533-1-maz@kernel.org> <20250807160243.1970533-3-maz@kernel.org> From: Steven Price Content-Language: en-GB In-Reply-To: <20250807160243.1970533-3-maz@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 07/08/2025 17:02, Marc Zyngier wrote: > Add a new driver for the MMIO side of the ARM architected timer. > Most of it has been lifted from the existing arch timer code, > massaged, and finally rewritten. > > It supports both DT and ACPI as firmware descriptions. > > Signed-off-by: Marc Zyngier > --- > MAINTAINERS | 1 + > drivers/clocksource/arm_arch_timer_mmio.c | 420 ++++++++++++++++++++++ > 2 files changed, 421 insertions(+) > create mode 100644 drivers/clocksource/arm_arch_timer_mmio.c > [...] > +static void arch_timer_mmio_setup(struct arch_timer *at, int irq) > +{ > + at->evt = (struct clock_event_device) { > + .features = (CLOCK_EVT_FEAT_ONESHOT | > + CLOCK_EVT_FEAT_DYNIRQ), > + .name = "arch_mem_timer", > + .rating = 400, > + .cpumask = cpu_possible_mask, > + .irq = irq, > + .set_next_event = arch_timer_mmio_set_next_event, > + .set_state_oneshot_stopped = arch_timer_mmio_shutdown, > + .set_state_shutdown = arch_timer_mmio_shutdown, > + }; > + > + at->evt.set_state_shutdown(&at->evt); > + > + clockevents_config_and_register(&at->evt, at->rate, 0xf, CLOCKSOURCE_MASK(56)); This doesn't work on 32 bit - clockevents_config_and_register()'s final argument is an unsigned long, and a 56 bit mask doesn't fit. This triggers a compiler warning: drivers/clocksource/arm_arch_timer_mmio.c: In function 'arch_timer_mmio_setup': ./include/linux/bits.h:47:9: error: conversion from 'long long unsigned int' to 'long unsigned int' changes value from '72057594037927935' to '4294967295' [-Werror=overflow] 47 | ((t)(GENMASK_INPUT_CHECK(h, l) + \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 48 | (type_max(t) << (l) & \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 49 | type_max(t) >> (BITS_PER_TYPE(t) - 1 - (h))))) | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/bits.h:52:33: note: in expansion of macro 'GENMASK_TYPE' 52 | #define GENMASK_ULL(h, l) GENMASK_TYPE(unsigned long long, h, l) | ^~~~~~~~~~~~ ./include/linux/clocksource.h:153:32: note: in expansion of macro 'GENMASK_ULL' 153 | #define CLOCKSOURCE_MASK(bits) GENMASK_ULL((bits) - 1, 0) | ^~~~~~~~~~~ drivers/clocksource/arm_arch_timer_mmio.c:255:66: note: in expansion of macro 'CLOCKSOURCE_MASK' 255 | clockevents_config_and_register(&at->evt, at->rate, 0xf, CLOCKSOURCE_MASK(56)); | ^~~~~~~~~~~~~~~~ Possible this should really be min(CLOCKSOURCE_MASK(56), ULONG_MAX)? But I'm not familiar enough with this code. Most likely it's dead code on a 32 bit platform. Thanks, Steve