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Date: Fri, 23 Feb 2024 12:25:30 +0000
From: Will Deacon <will@kernel.org>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: linux-kernel@vger.kernel.org, kernel-team@android.com,
	iommu@lists.linux.dev, Christoph Hellwig <hch@lst.de>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Petr Tesarik <petr.tesarik1@huawei-partners.com>,
	Dexuan Cui <decui@microsoft.com>,
	Michael Kelley <mhklinux@outlook.com>
Subject: Re: [PATCH v4 0/5] Fix double allocation in swiotlb_alloc()
Message-ID: <20240223122529.GA10641@willie-the-truck>
References: <20240221113504.7161-1-will@kernel.org>
 <ZdiC4OpEMQHQjEtv@Asurada-Nvidia>
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On Fri, Feb 23, 2024 at 03:34:56AM -0800, Nicolin Chen wrote:
> On Wed, Feb 21, 2024 at 11:34:59AM +0000, Will Deacon wrote:
> > This is version four of the patches which I previously posted at:
> > 
> > v1: https://lore.kernel.org/r/20240126151956.10014-1-will@kernel.org
> > v2: https://lore.kernel.org/r/20240131122543.14791-1-will@kernel.org
> > v3: https://lore.kernel.org/r/20240205190127.20685-1-will@kernel.org
> > 
> > Thanks to Petr for his Reviewed-by tag on the first three.
> > 
> > Changes since v3 include:
> > 
> >   - Use umax() instead of max() to fix a build warning if the first
> >     patch is applied to older kernels which warn on signedness
> >     mismatches.
> > 
> >   - Add two new patches to the end of the series to resolve some
> >     additional issues with NVME and 64KiB pages, reported by Nicolin.
> >     I've added them to this series, as the first three patches make it
> >     easier to fix this problem in the SWIOTLB code.
> > 
> >   - Add Reviewed-by tags from Petr
> > 
> > Cheers,
> > 
> > Will
> > 
> > Cc: iommu@lists.linux.dev
> > Cc: Christoph Hellwig <hch@lst.de>
> > Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> > Cc: Robin Murphy <robin.murphy@arm.com>
> > Cc: Petr Tesarik <petr.tesarik1@huawei-partners.com>
> > Cc: Dexuan Cui <decui@microsoft.com>
> > Cc: Nicolin Chen <nicolinc@nvidia.com>
> 
> This fixes the bug with NVME on arm64/SMMU when PAGE_SIZE=64KiB.
> 
> Tested-by: Nicolin Chen <nicolinc@nvidia.com>

Thanks, Nicolin! Please can you also respond to Michael's observation on
your patch (5/5)? I didn't think we needed anything extra there, but since
it's your patch I'd prefer to hear your opinion.

https://lore.kernel.org/lkml/SN6PR02MB4157828120FB7D3408CEC991D4572@SN6PR02MB4157.namprd02.prod.outlook.com/

Cheers,

Will