Received-SPF: pass (google.com: domain of linux-kernel+bounces-150310-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Thu, 18 Apr 2024 15:28:40 +0100
From: Matthew Wilcox <willy@infradead.org>
To: mhklinux@outlook.com
Cc: robin.murphy@arm.com, joro@8bytes.org, will@kernel.org, hch@lst.de,
	m.szyprowski@samsung.com, corbet@lwn.net, iommu@lists.linux.dev,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	petr@tesarici.cz, roberto.sassu@huaweicloud.com
Subject: Re: [PATCH 1/1] Documentation/core-api: Add swiotlb documentation
Message-ID: <ZiEuGIoa-FCE0p4X@casper.infradead.org>
References: <20240418135213.426671-1-mhklinux@outlook.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240418135213.426671-1-mhklinux@outlook.com>

On Thu, Apr 18, 2024 at 06:52:13AM -0700, mhkelley58@gmail.com wrote:
> There's currently no documentation for the swiotlb. Add documentation
> describing usage scenarios, the key APIs, and implementation details.
> Group the new documentation with other DMA-related documentation.

This is really well written.  Thank you.  One minor nit below.

> +Usage Scenarios
> +---------------
> +The swiotlb was originally created to handle DMA for devices
> +with addressing limitations. As physical memory sizes grew
> +beyond 4 Gbytes, some devices could only provide 32-bit DMA
> +addresses. By allocating bounce buffer memory below the 4 Gbyte

I'd prefer GiB to Gbytes; we might also prefer GB, Gigabyte or Gibibyte,
but Gbytes seems wrong.

You've written a lot here, and I'm not an expert on swiommu, but nothing
else leapt out at me.