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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 97D6AC433E1 for ; Fri, 10 Jul 2020 18:51:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7836E20720 for ; Fri, 10 Jul 2020 18:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727989AbgGJSvt (ORCPT ); Fri, 10 Jul 2020 14:51:49 -0400 Received: from foss.arm.com ([217.140.110.172]:34440 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726872AbgGJSvs (ORCPT ); Fri, 10 Jul 2020 14:51:48 -0400 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 1E18E31B; Fri, 10 Jul 2020 11:51:48 -0700 (PDT) Received: from [192.168.122.166] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A175B3FA00; Fri, 10 Jul 2020 11:51:47 -0700 (PDT) Subject: Re: [PATCH] dma-pool: Only allocate from CMA when in same memory zone To: Nicolas Saenz Julienne , hch@lst.de, Marek Szyprowski , Robin Murphy , David Rientjes Cc: linux-rpi-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20200710141016.15495-1-nsaenzjulienne@suse.de> From: Jeremy Linton Message-ID: Date: Fri, 10 Jul 2020 13:51:36 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200710141016.15495-1-nsaenzjulienne@suse.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I have merged this to a 5.8 tree along with "dma-pool: Fix atomic pool selection" and tested it in various ACPI/DT combinations, particularly on the RPI4. It seems to be working fine. So thanks for your time and effort clearing this up! tested-by: Jeremy Linton On 7/10/20 9:10 AM, Nicolas Saenz Julienne wrote: > There is no guarantee to CMA's placement, so allocating a zone specific > atomic pool from CMA might return memory from a completely different > memory zone. To get around this double check CMA's placement before > allocating from it. > > Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask") > Reported-by: Jeremy Linton > Signed-off-by: Nicolas Saenz Julienne > --- > > This is a code intensive alternative to "dma-pool: Do not allocate pool > memory from CMA"[1]. > > [1] https://lkml.org/lkml/2020/7/8/1108 > > kernel/dma/pool.c | 36 +++++++++++++++++++++++++++++++++++- > 1 file changed, 35 insertions(+), 1 deletion(-) > > diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c > index 8cfa01243ed2..ccf3eeb77e00 100644 > --- a/kernel/dma/pool.c > +++ b/kernel/dma/pool.c > @@ -3,6 +3,7 @@ > * Copyright (C) 2012 ARM Ltd. > * Copyright (C) 2020 Google LLC > */ > +#include > #include > #include > #include > @@ -56,6 +57,39 @@ static void dma_atomic_pool_size_add(gfp_t gfp, size_t size) > pool_size_kernel += size; > } > > +static bool cma_in_zone(gfp_t gfp) > +{ > + u64 zone_dma_end, zone_dma32_end; > + phys_addr_t base, end; > + unsigned long size; > + struct cma *cma; > + > + cma = dev_get_cma_area(NULL); > + if (!cma) > + return false; > + > + size = cma_get_size(cma); > + if (!size) > + return false; > + base = cma_get_base(cma) - memblock_start_of_DRAM(); > + end = base + size - 1; > + > + zone_dma_end = IS_ENABLED(CONFIG_ZONE_DMA) ? DMA_BIT_MASK(zone_dma_bits) : 0; > + zone_dma32_end = IS_ENABLED(CONFIG_ZONE_DMA32) ? DMA_BIT_MASK(32) : 0; > + > + /* CMA can't cross zone boundaries, see cma_activate_area() */ > + if (IS_ENABLED(CONFIG_ZONE_DMA) && gfp & GFP_DMA && > + end <= zone_dma_end) > + return true; > + else if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp & GFP_DMA32 && > + base > zone_dma_end && end <= zone_dma32_end) > + return true; > + else if (base > zone_dma32_end) > + return true; > + > + return false; > +} > + > static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size, > gfp_t gfp) > { > @@ -70,7 +104,7 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size, > do { > pool_size = 1 << (PAGE_SHIFT + order); > > - if (dev_get_cma_area(NULL)) > + if (cma_in_zone(gfp)) > page = dma_alloc_from_contiguous(NULL, 1 << order, > order, false); > else >