From: Borislav Petkov <bp@alien8.de>
To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: linux-kernel@vger.kernel.org,
Ross Zwisler <ross.zwisler@linux.intel.com>,
"H . Peter Anvin" <hpa@linux.intel.com>,
Imre Deak <imre.deak@intel.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] x86: Add an explicit barrier() to clflushopt()
Date: Mon, 19 Oct 2015 13:25:26 +0200 [thread overview]
Message-ID: <20151019112526.GB20341@pd.tnic> (raw)
In-Reply-To: <20151019110529.GG27143@nuc-i3427.alporthouse.com>
On Mon, Oct 19, 2015 at 12:05:29PM +0100, Chris Wilson wrote:
> In order to add the clobbers, I had to adjust the macro slightly:
>
> +#define alternative_output(oldinstr, newinstr, feature, output) \
> + asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
> + : output : "i" (0) : "memory")
>
> and that also works. The concern I have here is that the asm does use
> "+m" as its output already, and the clflush() asm doesn't require the
> manual clobber.
Yeah, you could make the above
#define alternative_output(oldinstr, newinstr, feature, output, clobber...)
and use it to define clflushopt(). hpa might have a better idea, though...
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
next prev parent reply other threads:[~2015-10-19 11:25 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-19 9:58 Chris Wilson
2015-10-19 10:16 ` Borislav Petkov
2015-10-19 11:05 ` Chris Wilson
2015-10-19 11:25 ` Borislav Petkov [this message]
2015-10-19 18:29 ` Ross Zwisler
2016-01-07 10:16 ` Chris Wilson
2016-01-07 17:55 ` Andy Lutomirski
2016-01-07 19:44 ` Chris Wilson
2016-01-07 21:05 ` H. Peter Anvin
2016-01-07 21:54 ` Chris Wilson
2016-01-07 22:29 ` H. Peter Anvin
2016-01-07 22:32 ` H. Peter Anvin
2016-01-09 5:55 ` H. Peter Anvin
2016-01-09 8:01 ` Chris Wilson
2016-01-09 22:36 ` Andy Lutomirski
2016-01-11 11:28 ` Chris Wilson
2016-01-11 20:11 ` Linus Torvalds
2016-01-11 21:05 ` Chris Wilson
2016-01-12 16:37 ` Chris Wilson
2016-01-12 17:05 ` Linus Torvalds
2016-01-12 21:13 ` Chris Wilson
2016-01-12 22:07 ` Linus Torvalds
2016-01-13 0:55 ` Chris Wilson
2016-01-13 2:06 ` Linus Torvalds
2016-01-13 2:42 ` Andy Lutomirski
2016-01-13 4:39 ` Linus Torvalds
2016-01-13 12:34 ` Chris Wilson
2016-01-13 18:45 ` Linus Torvalds
2016-01-12 17:17 ` H. Peter Anvin
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