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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 61C9CC41514 for ; Wed, 31 Jul 2019 15:48:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EDC9208E4 for ; Wed, 31 Jul 2019 15:48:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729448AbfGaPsV (ORCPT ); Wed, 31 Jul 2019 11:48:21 -0400 Received: from mx2.suse.de ([195.135.220.15]:50350 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730264AbfGaPsM (ORCPT ); Wed, 31 Jul 2019 11:48:12 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1CBAEB05E; Wed, 31 Jul 2019 15:48:11 +0000 (UTC) From: Nicolas Saenz Julienne To: catalin.marinas@arm.com, hch@lst.de, wahrenst@gmx.net, marc.zyngier@arm.com, Robin Murphy , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, iommu@lists.linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: phill@raspberryi.org, f.fainelli@gmail.com, will@kernel.org, robh+dt@kernel.org, eric@anholt.net, mbrugger@suse.com, nsaenzjulienne@suse.de, akpm@linux-foundation.org, frowand.list@gmail.com, m.szyprowski@samsung.com, linux-rpi-kernel@lists.infradead.org Subject: [PATCH 8/8] mm: comment arm64's usage of 'enum zone_type' Date: Wed, 31 Jul 2019 17:47:51 +0200 Message-Id: <20190731154752.16557-9-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190731154752.16557-1-nsaenzjulienne@suse.de> References: <20190731154752.16557-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org arm64 uses both ZONE_DMA and ZONE_DMA32 for the same reasons x86_64 does: peripherals with different DMA addressing limitations. This updates both ZONE_DMAs comments to inform about the usage. Signed-off-by: Nicolas Saenz Julienne --- include/linux/mmzone.h | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index d77d717c620c..8fa6bcf72e7c 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -365,23 +365,24 @@ enum zone_type { * * Some examples * - * Architecture Limit - * --------------------------- - * parisc, ia64, sparc <4G - * s390, powerpc <2G - * arm Various - * alpha Unlimited or 0-16MB. + * Architecture Limit + * ---------------------------------- + * parisc, ia64, sparc, arm64 <4G + * s390, powerpc <2G + * arm Various + * alpha Unlimited or 0-16MB. * * i386, x86_64 and multiple other arches - * <16M. + * <16M. */ ZONE_DMA, #endif #ifdef CONFIG_ZONE_DMA32 /* - * x86_64 needs two ZONE_DMAs because it supports devices that are - * only able to do DMA to the lower 16M but also 32 bit devices that - * can only do DMA areas below 4G. + * x86_64 and arm64 need two ZONE_DMAs because they support devices + * that are only able to DMA a fraction of the 32 bit addressable + * memory area, but also devices that are limited to that whole 32 bit + * area. */ ZONE_DMA32, #endif -- 2.22.0