Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Will Deacon <will@kernel.org>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: axboe@kernel.dk, Richard.Earnshaw@arm.com, rabinv@axis.com,
	catalin.marinas@arm.com, vincent.whitchurch@axis.com,
	linux@armlinux.org.uk, linux-kernel@vger.kernel.org,
	torvalds@linux-foundation.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] buffer: Fix I/O error due to ARM read-after-read hazard
Date: Thu, 21 Nov 2019 16:53:35 +0000	[thread overview]
Message-ID: <20191121165334.GB4905@willie-the-truck> (raw)
In-Reply-To: <20191121012533.3h6akm4oczswj7zr@gondor.apana.org.au>

On Thu, Nov 21, 2019 at 09:25:33AM +0800, Herbert Xu wrote:
> On Wed, Nov 20, 2019 at 07:18:40PM +0000, Will Deacon wrote:
> >
> > > The Alpha barrier matters for pointers, how could it make a
> > > difference for individual bits?
> > 
> > I guess you could use the result of test_bit to index into an array or
> > something?
> 
> Can Alpha Assembly even do this without using a branch?

Don't see why not: you can add the base address to the scaled result
of test_bit and use that as the address register into a load instruction.

Will

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2019-11-21 16:53 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-12 13:02 [PATCH v2] buffer: Fix I/O error due to ARM read-after-read hazard Vincent Whitchurch
2019-11-12 16:08 ` Catalin Marinas
2019-11-12 17:54   ` Linus Torvalds
2019-11-12 18:00   ` Will Deacon
2019-11-12 18:22     ` Catalin Marinas
2019-11-12 18:39       ` Linus Torvalds
2019-11-13 10:23         ` Will Deacon
2019-11-13 10:31           ` Russell King - ARM Linux admin
2019-11-13 10:49             ` Will Deacon
2019-11-14 13:28               ` Herbert Xu
2019-11-20 19:18                 ` Will Deacon
2019-11-21  1:25                   ` Herbert Xu
2019-11-21 16:53                     ` Will Deacon [this message]
2019-11-13 16:36           ` Linus Torvalds
2019-11-13 16:40             ` Linus Torvalds

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=20191121165334.GB4905@willie-the-truck \
    --to=will@kernel.org \
    --cc=Richard.Earnshaw@arm.com \
    --cc=axboe@kernel.dk \
    --cc=catalin.marinas@arm.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=rabinv@axis.com \
    --cc=torvalds@linux-foundation.org \
    --cc=vincent.whitchurch@axis.com \
    /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