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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 DA34AC00306 for ; Thu, 5 Sep 2019 17:19:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B03A520828 for ; Thu, 5 Sep 2019 17:19:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B03A520828 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 34F626B0285; Thu, 5 Sep 2019 13:19:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D80A6B0287; Thu, 5 Sep 2019 13:19:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 179196B0288; Thu, 5 Sep 2019 13:19:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0049.hostedemail.com [216.40.44.49]) by kanga.kvack.org (Postfix) with ESMTP id E42996B0285 for ; Thu, 5 Sep 2019 13:19:45 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 85F65180AD7C3 for ; Thu, 5 Sep 2019 17:19:45 +0000 (UTC) X-FDA: 75901529130.05.grass87_8f46afb0dff57 X-HE-Tag: grass87_8f46afb0dff57 X-Filterd-Recvd-Size: 5477 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Sep 2019 17:19:44 +0000 (UTC) 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 52F09337; Thu, 5 Sep 2019 10:19:43 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5215C3F718; Thu, 5 Sep 2019 10:19:41 -0700 (PDT) Date: Thu, 5 Sep 2019 18:19:39 +0100 From: Catalin Marinas To: Nicolas Saenz Julienne Cc: hch@lst.de, wahrenst@gmx.net, marc.zyngier@arm.com, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, Will Deacon , f.fainelli@gmail.com, robin.murphy@arm.com, linux-kernel@vger.kernel.org, mbrugger@suse.com, linux-rpi-kernel@lists.infradead.org, phill@raspberrypi.org, m.szyprowski@samsung.com Subject: Re: [PATCH v3 3/4] arm64: use both ZONE_DMA and ZONE_DMA32 Message-ID: <20190905171939.GF31268@arrakis.emea.arm.com> References: <20190902141043.27210-1-nsaenzjulienne@suse.de> <20190902141043.27210-4-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190902141043.27210-4-nsaenzjulienne@suse.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Sep 02, 2019 at 04:10:41PM +0200, Nicolas Saenz Julienne wrote: > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 8956c22634dd..f02a4945aeac 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -50,6 +50,13 @@ > s64 memstart_addr __ro_after_init = -1; > EXPORT_SYMBOL(memstart_addr); > > +/* > + * We create both ZONE_DMA and ZONE_DMA32. ZONE_DMA covers the first 1G of > + * memory as some devices, namely the Raspberry Pi 4, have peripherals with > + * this limited view of the memory. ZONE_DMA32 will cover the rest of the 32 > + * bit addressable memory area. > + */ > +phys_addr_t arm64_dma_phys_limit __ro_after_init; > phys_addr_t arm64_dma32_phys_limit __ro_after_init; > > #ifdef CONFIG_KEXEC_CORE > @@ -164,9 +171,9 @@ static void __init reserve_elfcorehdr(void) > } > #endif /* CONFIG_CRASH_DUMP */ > /* > - * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32)). It > - * currently assumes that for memory starting above 4G, 32-bit devices will > - * use a DMA offset. > + * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32)) and > + * ZONE_DMA (DMA_BIT_MASK(30)) respectively. It currently assumes that for > + * memory starting above 4G, 32-bit devices will use a DMA offset. > */ > static phys_addr_t __init max_zone_dma32_phys(void) > { > @@ -174,12 +181,23 @@ static phys_addr_t __init max_zone_dma32_phys(void) > return min(offset + (1ULL << 32), memblock_end_of_DRAM()); > } > > +static phys_addr_t __init max_zone_dma_phys(void) > +{ > + phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32); > + > + return min(offset + (1ULL << ARCH_ZONE_DMA_BITS), > + memblock_end_of_DRAM()); > +} I think we could squash these two functions into a single one with a "bits" argument that is either 32 or ARCH_ZONE_DMA_BITS. > + > #ifdef CONFIG_NUMA > > static void __init zone_sizes_init(unsigned long min, unsigned long max) > { > unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; > > +#ifdef CONFIG_ZONE_DMA > + max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); > +#endif > #ifdef CONFIG_ZONE_DMA32 > max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit); > #endif > @@ -195,13 +213,17 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) > struct memblock_region *reg; > unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; > unsigned long max_dma32 = min; > + unsigned long max_dma = min; > > memset(zone_size, 0, sizeof(zone_size)); > > - /* 4GB maximum for 32-bit only capable devices */ > +#ifdef CONFIG_ZONE_DMA > + max_dma = PFN_DOWN(arm64_dma_phys_limit); > + zone_size[ZONE_DMA] = max_dma - min; > +#endif > #ifdef CONFIG_ZONE_DMA32 > max_dma32 = PFN_DOWN(arm64_dma32_phys_limit); > - zone_size[ZONE_DMA32] = max_dma32 - min; > + zone_size[ZONE_DMA32] = max_dma32 - max_dma; > #endif > zone_size[ZONE_NORMAL] = max - max_dma32; Does this still work if we have ZONE_DMA32 disabled but ZONE_DMA enabled? You could use a max(max_dma32, max_dma) or just update max_dma32 to max_dma in the CONFIG_ZONE_DMA block. > @@ -213,11 +235,17 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) > > if (start >= max) > continue; > - > +#ifdef CONFIG_ZONE_DMA > + if (start < max_dma) { > + unsigned long dma_end = min_not_zero(end, max_dma); > + zhole_size[ZONE_DMA] -= dma_end - start; > + } > +#endif > #ifdef CONFIG_ZONE_DMA32 > if (start < max_dma32) { > - unsigned long dma_end = min(end, max_dma32); > - zhole_size[ZONE_DMA32] -= dma_end - start; > + unsigned long dma32_end = min(end, max_dma32); > + unsigned long dma32_start = max(start, max_dma); > + zhole_size[ZONE_DMA32] -= dma32_end - dma32_start; > } > #endif > if (end > max_dma32) { Similar comment here. -- Catalin