linux-mips.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sven Eckelmann <sven@narfation.org>
To: linux-mips@linux-mips.org, Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paul.burton@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>,
	James Hogan <james.hogan@imgtec.com>,
	Joshua Kinard <kumba@gentoo.org>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	linux-kernel@vger.kernel.org,
	"Maciej W. Rozycki" <macro@codesourcery.com>,
	Markos Chandras <markos.chandras@imgtec.com>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	David Bauer <mail@david-bauer.net>
Subject: Re: [PATCH 1/2] MIPS: Add barriers between dcache & icache flushes
Date: Mon, 06 Mar 2023 11:28:15 +0100	[thread overview]
Message-ID: <4818332.31r3eYUQgx@ripper> (raw)
In-Reply-To: <1456164585-26910-1-git-send-email-paul.burton@imgtec.com>

[-- Attachment #1: Type: text/plain, Size: 1133 bytes --]

On Monday, 22 February 2016 19:09:44 CET Paul Burton wrote:
> Index-based cache operations may be arbitrarily reordered by out of
> order CPUs. Thus code which writes back the dcache & then invalidates
> the icache using indexed cache ops must include a barrier between
> operating on the 2 caches in order to prevent the scenario in which:
> 
>   - icache invalidation occurs.
> 
>   - icache fetch occurs, due to speculation.
> 
>   - dcache writeback occurs.
> 
> If the above were allowed to happen then the icache would contain stale
> data. Forcing the dcache writeback to complete before the icache
> invalidation avoids this.
> 
> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> Cc: James Hogan <james.hogan@imgtec.com>
> ---

What happened to this patch? Because it seems like it is required for some 
74kc devices to get them booting (instead of being stuck in an endless
tlbmiss_handler_setup_pgd loop):

* https://github.com/freifunk-gluon/gluon/issues/2784
* https://github.com/openwrt/openwrt/commit/ea6fb9c16dfb9763ea681803db65644b68bae873
* https://github.com/freifunk-gluon/gluon/pull/2810

Kind regards,
	Sven

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

      parent reply	other threads:[~2023-03-06 10:45 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-22 18:09 [PATCH 1/2] MIPS: Add barriers between dcache & icache flushes Paul Burton
2016-02-22 18:09 ` Paul Burton
2016-02-22 18:09 ` [PATCH 2/2] MIPS: Flush highmem pages from dcache in __flush_icache_page Paul Burton
2016-02-22 18:09   ` Paul Burton
2016-02-24  8:02   ` Lars Persson
2016-02-24  8:02     ` Lars Persson
2016-02-22 23:39 ` [PATCH 1/2] MIPS: Add barriers between dcache & icache flushes Joshua Kinard
2016-03-01  2:23   ` Paul Burton
2016-03-01  2:23     ` Paul Burton
2016-02-23  0:02 ` Florian Fainelli
2016-03-01  2:27   ` Paul Burton
2016-03-01  2:27     ` Paul Burton
2023-03-06 10:28 ` Sven Eckelmann [this message]

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=4818332.31r3eYUQgx@ripper \
    --to=sven@narfation.org \
    --cc=james.hogan@imgtec.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=kumba@gentoo.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@linux-mips.org \
    --cc=macro@codesourcery.com \
    --cc=mail@david-bauer.net \
    --cc=markos.chandras@imgtec.com \
    --cc=paul.burton@imgtec.com \
    --cc=paul.gortmaker@windriver.com \
    --cc=ralf@linux-mips.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).