From: Christoph Hellwig <hch@lst.de>
To: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: stefan.wahren@i2se.com, f.fainelli@gmail.com,
catalin.marinas@arm.com, phil@raspberrypi.org,
Robin Murphy <robin.murphy@arm.com>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
Jisheng.Zhang@synaptics.com, mbrugger@suse.com, will@kernel.org,
Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [RFC 3/4] dma-direct: add dma_direct_min_mask
Date: Thu, 18 Jul 2019 11:15:26 +0200 [thread overview]
Message-ID: <20190718091526.GA25321@lst.de> (raw)
In-Reply-To: <20190717153135.15507-4-nsaenzjulienne@suse.de>
On Wed, Jul 17, 2019 at 05:31:34PM +0200, Nicolas Saenz Julienne wrote:
> Historically devices with ZONE_DMA32 have been assumed to be able to
> address at least the lower 4GB of ram for DMA. This is still the defualt
> behavior yet the Raspberry Pi 4 is limited to the first GB of memory.
> This has been observed to trigger failures in dma_direct_supported() as
> the 'min_mask' isn't properly set.
>
> We create 'dma_direct_min_mask' in order for the arch init code to be
> able to fine-tune dma direct's 'min_dma' mask.
Normally we use ZONE_DMA for that case.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-07-18 9:15 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-17 15:31 [RFC 0/4] Raspberry Pi 4 DMA addressing support Nicolas Saenz Julienne
2019-07-17 15:31 ` [RFC 1/4] arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys() Nicolas Saenz Julienne
2019-07-17 15:31 ` [RFC 2/4] arm64: mm: parse dma-ranges in order to better estimate arm64_dma_phys_limit Nicolas Saenz Julienne
2019-07-24 13:54 ` Catalin Marinas
2019-07-17 15:31 ` [RFC 3/4] dma-direct: add dma_direct_min_mask Nicolas Saenz Julienne
2019-07-18 9:15 ` Christoph Hellwig [this message]
2019-07-18 11:18 ` Nicolas Saenz Julienne
2019-07-19 13:08 ` Nicolas Saenz Julienne
2019-07-24 13:51 ` Catalin Marinas
2019-07-24 13:56 ` Christoph Hellwig
2019-07-24 14:27 ` Nicolas Saenz Julienne
2019-07-17 15:31 ` [RFC 4/4] arm64: mm: set direct_dma_min_mask according to dma-ranges Nicolas Saenz Julienne
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190718091526.GA25321@lst.de \
--to=hch@lst.de \
--cc=Jisheng.Zhang@synaptics.com \
--cc=catalin.marinas@arm.com \
--cc=f.fainelli@gmail.com \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=mbrugger@suse.com \
--cc=nsaenzjulienne@suse.de \
--cc=phil@raspberrypi.org \
--cc=robin.murphy@arm.com \
--cc=stefan.wahren@i2se.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).