From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4AB15ECE561 for ; Mon, 24 Sep 2018 10:50:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F295B206B5 for ; Mon, 24 Sep 2018 10:50:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F295B206B5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728562AbeIXQvn (ORCPT ); Mon, 24 Sep 2018 12:51:43 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:60372 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726154AbeIXQvn (ORCPT ); Mon, 24 Sep 2018 12:51:43 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AE22480D; Mon, 24 Sep 2018 03:50:15 -0700 (PDT) Received: from [10.4.13.92] (e112298-lin.Emea.Arm.com [10.4.13.92]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 32CB23F5B3; Mon, 24 Sep 2018 03:50:14 -0700 (PDT) Subject: Re: [PATCH 02/10] irqchip/gic-v3-its: Consolidate LPI_PENDBASE_SZ usage To: Suzuki K Poulose , Marc Zyngier , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Jeremy Linton , Jeffrey Hugo , Thomas Gleixner , Jason Cooper References: <20180921195954.21574-1-marc.zyngier@arm.com> <20180921195954.21574-3-marc.zyngier@arm.com> From: Julien Thierry Message-ID: Date: Mon, 24 Sep 2018 11:50:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 24/09/18 11:33, Suzuki K Poulose wrote: > Hi Marc, > > On 21/09/18 20:59, Marc Zyngier wrote: >> LPI_PENDING_SZ is always used in conjunction with a max(). Let's >> factor this in the definition of the macro, and simplify the rest >> of the code. >> >> Signed-off-by: Marc Zyngier >> --- >>   drivers/irqchip/irq-gic-v3-its.c | 12 ++++-------- >>   1 file changed, 4 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/irqchip/irq-gic-v3-its.c >> b/drivers/irqchip/irq-gic-v3-its.c >> index c2df341ff6fa..ed6aab11e019 100644 >> --- a/drivers/irqchip/irq-gic-v3-its.c >> +++ b/drivers/irqchip/irq-gic-v3-its.c >> @@ -62,7 +62,7 @@ static u32 lpi_id_bits; >>    */ >>   #define LPI_NRBITS        lpi_id_bits >>   #define LPI_PROPBASE_SZ        ALIGN(BIT(LPI_NRBITS), SZ_64K) >> -#define LPI_PENDBASE_SZ        ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K) >> +#define LPI_PENDBASE_SZ        max_t(u32, SZ_64K, >> ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)) > > minor nit: The ALIGN() already aligns the given value up to the required > alignment. So, if the LPI_NRBITS is guaranteed to be non-zero, > we could simply drop the max_t(). > Hmmm, Doesn't ALIGN only aligns down? So if "BIT(LPI_NR_BITS) / 8 < SZ_64K" (i.e. LPI_NRBITS < 20) The ALIGN(..., SZ_64K) would give 0. Thanks, > Rest looks good to me. > > Suzuki > >>   #define LPI_PROP_DEFAULT_PRIO    0xa0 >> @@ -1924,12 +1924,9 @@ static int its_alloc_collections(struct >> its_node *its) >>   static struct page *its_allocate_pending_table(gfp_t gfp_flags) >>   { >>       struct page *pend_page; >> -    /* >> -     * The pending pages have to be at least 64kB aligned, >> -     * hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below. >> -     */ >> + >>       pend_page = alloc_pages(gfp_flags | __GFP_ZERO, >> -                get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K))); >> +                get_order(LPI_PENDBASE_SZ)); >>       if (!pend_page) >>           return NULL; >> @@ -1941,8 +1938,7 @@ static struct page >> *its_allocate_pending_table(gfp_t gfp_flags) >>   static void its_free_pending_table(struct page *pt) >>   { >> -    free_pages((unsigned long)page_address(pt), >> -           get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K))); >> +    free_pages((unsigned long)page_address(pt), >> get_order(LPI_PENDBASE_SZ)); >>   } >>   static void its_cpu_init_lpis(void) >> -- Julien Thierry