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 9040F14F9FA; Fri, 31 May 2024 08:37:11 +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=1717144633; cv=none; b=MPJIM+ox5samKLKUJiE8tpYqbZLwh4/Oc/f4utFGDJmbKfCs71G6z2s3cfHE/3W9IRyU3PEepV89HMUh4/jqHgUpMdoJdkE8zkbOW9oOfqWCwAf7OIRx8fgeYDqVE6ay1Upq6h7m039/y2b1UA/MIyO5Hx0IXEGb34kp2PM3BxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717144633; c=relaxed/simple; bh=krRVD3UkRnE4YDx4vNs3xr7/v74++jw0AqyhDKkqFB4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oyU6TlzCcu/TVGwETXjswPwCb6KAcrMKUe+VW+Zf96rXbzgyqdygFSv2emYyyJPYUjB3yaPnfhbHo2skQBM2i+fNTgOZ+DlUOJAHyqYnRX8rSUKWjSeIMhpNzy+9rOer+3jxy5rUac4Lmxju3feZ8xfL+vSqyU6ylvNaP2SWbWk= 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 D9D6F113E; Fri, 31 May 2024 01:37:34 -0700 (PDT) Received: from [10.57.67.251] (unknown [10.57.67.251]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 481AB3F792; Fri, 31 May 2024 01:37:08 -0700 (PDT) Message-ID: Date: Fri, 31 May 2024 09:37:02 +0100 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/5] iommu: sun50i: allocate page tables from below 4 GiB To: Andre Przywara , Joerg Roedel , Will Deacon , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Krzysztof Kozlowski , Conor Dooley , Rob Herring Cc: Chris Morgan , Ryan Walklin , iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-arm-kernel@lists.infradead.org References: <20240530233800.27705-1-andre.przywara@arm.com> <20240530233800.27705-3-andre.przywara@arm.com> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20240530233800.27705-3-andre.przywara@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2024-05-31 12:37 am, Andre Przywara wrote: > The Allwinner IOMMU is a strict 32-bit device, with the page table root > pointer as well as both level's page tables and also the target addresses > all required to be below 4GB. > The Allwinner H6 SoC only supports 32-bit worth of physical addresses > anyway, so this isn't a problem so far, but the H616 and later SoCs extend > the PA space beyond 32 bit to accommodate more DRAM. > To make sure we stay within the 32-bit PA range required by the IOMMU, > force the memory for the page tables to come from below 4GB. by using > allocations with the DMA32 flag. Uh-oh... what about the output addresses in sun50i_mk_pte()? Limiting its own accesses is OK, but if the IOMMU isn't capable of *mapping* any valid PA for its clients, we can't easily support that. Thanks, Robin. > Signed-off-by: Andre Przywara > --- > drivers/iommu/sun50i-iommu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c > index dd3f07384624c..c3244db5ac02f 100644 > --- a/drivers/iommu/sun50i-iommu.c > +++ b/drivers/iommu/sun50i-iommu.c > @@ -682,7 +682,8 @@ sun50i_iommu_domain_alloc_paging(struct device *dev) > if (!sun50i_domain) > return NULL; > > - sun50i_domain->dt = iommu_alloc_pages(GFP_KERNEL, get_order(DT_SIZE)); > + sun50i_domain->dt = iommu_alloc_pages(GFP_KERNEL | GFP_DMA32, > + get_order(DT_SIZE)); > if (!sun50i_domain->dt) > goto err_free_domain; > > @@ -997,7 +998,7 @@ static int sun50i_iommu_probe(struct platform_device *pdev) > > iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev), > PT_SIZE, PT_SIZE, > - SLAB_HWCACHE_ALIGN, > + SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA32, > NULL); > if (!iommu->pt_pool) > return -ENOMEM; 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A020EC25B75 for ; Fri, 31 May 2024 08:37:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=QS/VhQM+8mJDHWsA4Bp9m3PznWS6l5YSb4ogzFXUiYc=; b=nRmCI49Yofr1+f UqYLuBulN90RBUcdov/6k+LW53k2Z9RM38tjRXTNCIn94Eo6AtmKjSJnETl1ZxzAmRo3NLvhT31Eh xNCmJyW2ERAwELOLDahMovc0L54rHu4V+9MHb3BvyYwxmM1csYFq88kLkPOTMY0uKh0YtWWWSPHEf KEISFNQpwdGllrTMQ1MqFmchfHwwch3RS5wldZF8w2Y8BVqj4NKuuCER0sSs93DgnSIF8RYYvccPq 5EfTX8Y1W1zUuk+1tM7Zwi8D+Ylu+nwbBiKtkgyess/qE+mMAKpVkdW5EayPK5XAtnMCyoRJ6Ufvf Y+5MPzU+sgFjcrzIEZdQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sCxlD-00000009dgG-0uGL; Fri, 31 May 2024 08:37:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sCxlB-00000009df0-09B8 for linux-arm-kernel@lists.infradead.org; Fri, 31 May 2024 08:37:14 +0000 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 D9D6F113E; Fri, 31 May 2024 01:37:34 -0700 (PDT) Received: from [10.57.67.251] (unknown [10.57.67.251]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 481AB3F792; Fri, 31 May 2024 01:37:08 -0700 (PDT) Message-ID: Date: Fri, 31 May 2024 09:37:02 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/5] iommu: sun50i: allocate page tables from below 4 GiB To: Andre Przywara , Joerg Roedel , Will Deacon , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Krzysztof Kozlowski , Conor Dooley , Rob Herring Cc: Chris Morgan , Ryan Walklin , iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-arm-kernel@lists.infradead.org References: <20240530233800.27705-1-andre.przywara@arm.com> <20240530233800.27705-3-andre.przywara@arm.com> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20240530233800.27705-3-andre.przywara@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240531_013713_182578_87924ADD X-CRM114-Status: GOOD ( 18.24 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2024-05-31 12:37 am, Andre Przywara wrote: > The Allwinner IOMMU is a strict 32-bit device, with the page table root > pointer as well as both level's page tables and also the target addresses > all required to be below 4GB. > The Allwinner H6 SoC only supports 32-bit worth of physical addresses > anyway, so this isn't a problem so far, but the H616 and later SoCs extend > the PA space beyond 32 bit to accommodate more DRAM. > To make sure we stay within the 32-bit PA range required by the IOMMU, > force the memory for the page tables to come from below 4GB. by using > allocations with the DMA32 flag. Uh-oh... what about the output addresses in sun50i_mk_pte()? Limiting its own accesses is OK, but if the IOMMU isn't capable of *mapping* any valid PA for its clients, we can't easily support that. Thanks, Robin. > Signed-off-by: Andre Przywara > --- > drivers/iommu/sun50i-iommu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c > index dd3f07384624c..c3244db5ac02f 100644 > --- a/drivers/iommu/sun50i-iommu.c > +++ b/drivers/iommu/sun50i-iommu.c > @@ -682,7 +682,8 @@ sun50i_iommu_domain_alloc_paging(struct device *dev) > if (!sun50i_domain) > return NULL; > > - sun50i_domain->dt = iommu_alloc_pages(GFP_KERNEL, get_order(DT_SIZE)); > + sun50i_domain->dt = iommu_alloc_pages(GFP_KERNEL | GFP_DMA32, > + get_order(DT_SIZE)); > if (!sun50i_domain->dt) > goto err_free_domain; > > @@ -997,7 +998,7 @@ static int sun50i_iommu_probe(struct platform_device *pdev) > > iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev), > PT_SIZE, PT_SIZE, > - SLAB_HWCACHE_ALIGN, > + SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA32, > NULL); > if (!iommu->pt_pool) > return -ENOMEM; _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel