All of lore.kernel.org
 help / color / mirror / Atom feed
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
	linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	Jonathan Corbet <corbet@lwn.net>,
	opendmb@gmail.com, "Paul E. McKenney" <paulmck@kernel.org>,
	Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	"open list:SWIOTLB SUBSYSTEM" <iommu@lists.linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] swiotlb: Add swiotlb=off to disable SWIOTLB
Date: Thu, 18 Mar 2021 22:34:25 -0400	[thread overview]
Message-ID: <YFQNsaisCvYksA4A@Konrads-MacBook-Pro.local> (raw)
In-Reply-To: <a7a858e9-d6e6-cd06-85fc-8826e45d460e@gmail.com>

> > 
> > In fact I should have looked more closely at that myself - checking
> > debugfs on my 4GB arm64 board actually shows io_tlb_nslabs = 0, and
> > indeed we are bypassing initialisation completely and (ab)using
> > SWIOTLB_NO_FORCE to cover it up, so I guess it probably *is* safe now
> > for the noforce option to do the same for itself and save even that one
> > page.
> 
> OK, I can submit a patch that does that. 5.12-rc3 works correctly for me
> here as well and only allocates SWIOTLB when needed which in our case is
> either:
> 
> - we have DRAM at PA >= 4GB
> - we have limited peripherals (Raspberry Pi 4 derivative) that can only
> address the lower 1GB
> 
> Now let's see if we can get ARM 32-bit to match :)

Whatever patch you come up with, if it is against SWIOTLB please base it on top of
devel/for-linus-5.12 in https://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git/

Thx
> -- 
> Florian

WARNING: multiple messages have this Message-ID (diff)
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: opendmb@gmail.com, "Paul E. McKenney" <paulmck@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
	linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	"open list:SWIOTLB SUBSYSTEM" <iommu@lists.linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	Mike Kravetz <mike.kravetz@oracle.com>
Subject: Re: [PATCH] swiotlb: Add swiotlb=off to disable SWIOTLB
Date: Thu, 18 Mar 2021 22:34:25 -0400	[thread overview]
Message-ID: <YFQNsaisCvYksA4A@Konrads-MacBook-Pro.local> (raw)
In-Reply-To: <a7a858e9-d6e6-cd06-85fc-8826e45d460e@gmail.com>

> > 
> > In fact I should have looked more closely at that myself - checking
> > debugfs on my 4GB arm64 board actually shows io_tlb_nslabs = 0, and
> > indeed we are bypassing initialisation completely and (ab)using
> > SWIOTLB_NO_FORCE to cover it up, so I guess it probably *is* safe now
> > for the noforce option to do the same for itself and save even that one
> > page.
> 
> OK, I can submit a patch that does that. 5.12-rc3 works correctly for me
> here as well and only allocates SWIOTLB when needed which in our case is
> either:
> 
> - we have DRAM at PA >= 4GB
> - we have limited peripherals (Raspberry Pi 4 derivative) that can only
> address the lower 1GB
> 
> Now let's see if we can get ARM 32-bit to match :)

Whatever patch you come up with, if it is against SWIOTLB please base it on top of
devel/for-linus-5.12 in https://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git/

Thx
> -- 
> Florian
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2021-03-19  2:40 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-18 19:18 [PATCH] swiotlb: Add swiotlb=off to disable SWIOTLB Florian Fainelli
2021-03-18 19:18 ` Florian Fainelli
2021-03-18 19:22 ` Florian Fainelli
2021-03-18 19:22   ` Florian Fainelli
2021-03-18 19:34   ` Robin Murphy
2021-03-18 19:34     ` Robin Murphy
2021-03-18 19:43     ` Florian Fainelli
2021-03-18 19:43       ` Florian Fainelli
2021-03-18 19:53       ` Robin Murphy
2021-03-18 19:53         ` Robin Murphy
2021-03-18 21:31         ` Florian Fainelli
2021-03-18 21:31           ` Florian Fainelli
2021-03-18 23:35           ` Robin Murphy
2021-03-18 23:35             ` Robin Murphy
2021-03-19  0:48             ` Florian Fainelli
2021-03-19  0:48               ` Florian Fainelli
2021-03-19  2:34               ` Konrad Rzeszutek Wilk [this message]
2021-03-19  2:34                 ` Konrad Rzeszutek Wilk
2021-03-19  4:00 ` [PATCH] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation Florian Fainelli
2021-03-19  4:00   ` Florian Fainelli
2021-03-19  5:01   ` Konrad Rzeszutek Wilk
2021-03-19  5:01     ` Konrad Rzeszutek Wilk
2021-03-21  3:37   ` [PATCH v2] " Florian Fainelli
2021-03-21  3:37     ` Florian Fainelli
2021-03-22  7:46     ` Christoph Hellwig
2021-03-22  7:46       ` Christoph Hellwig
2021-03-23  1:53     ` [PATCH v3] " Florian Fainelli
2021-03-23  1:53       ` Florian Fainelli
2021-03-24  8:42       ` Christoph Hellwig
2021-03-24  8:42         ` Christoph Hellwig
2021-04-09  3:13         ` Florian Fainelli
2021-04-09  3:13           ` Florian Fainelli
2021-04-09 19:32           ` Konrad Rzeszutek Wilk
2021-04-09 19:32             ` Konrad Rzeszutek Wilk
2021-04-09 20:33             ` Florian Fainelli
2021-04-09 20:33               ` Florian Fainelli

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=YFQNsaisCvYksA4A@Konrads-MacBook-Pro.local \
    --to=konrad.wilk@oracle.com \
    --cc=akpm@linux-foundation.org \
    --cc=corbet@lwn.net \
    --cc=f.fainelli@gmail.com \
    --cc=hch@lst.de \
    --cc=iommu@lists.linux-foundation.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mchehab+huawei@kernel.org \
    --cc=mike.kravetz@oracle.com \
    --cc=opendmb@gmail.com \
    --cc=paulmck@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rdunlap@infradead.org \
    --cc=robin.murphy@arm.com \
    --cc=tglx@linutronix.de \
    --cc=viresh.kumar@linaro.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.