public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
	Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
	linux-kernel@vger.kernel.org
Subject: Re: 2.6.23-rc4-mm1 compile error for ppc 32
Date: Thu, 13 Sep 2007 15:17:38 -0700	[thread overview]
Message-ID: <20070913151738.4462fdf2.akpm@linux-foundation.org> (raw)
In-Reply-To: <1189269730.5972.163.camel@localhost.localdomain>

On Sat, 08 Sep 2007 18:42:10 +0200
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

> 
> > > If so, the finger points at this:
> > >
> > > static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long
> > > *addr) {
> > > 	__asm__ __volatile__(LWSYNC_ON_SMP ::: "memory");
> > > 	__clear_bit(nr, addr);
> > > }
> > >
> > > which was added by Nick's powerpc-lock-bitops.patch.  I am suspecting that
> > > this isn't pp32 code?
> > 
> > Hmm, when LWSYNC_ON_SMP is a noop, it seems like it should probably
> > be an empty string instead of nothing? ("") That should make behaviour
> > more consistent I think.
> 
> The wormhole is arch/ppc's hack to get to include/asm-powerpc...
> 
> As for having LWSYNC_ON_SMP be "" ... that might be the best way but I'd
> rather not take chances right now and go for the quick fix of making
> __clear_bit_unlock() do
> 
> 	LWSYNC_ON_SMP ""
> 
> instead.
> 

Like this?

--- a/include/asm-powerpc/bitops.h~powerpc-lock-bitops-fix
+++ a/include/asm-powerpc/bitops.h
@@ -226,7 +226,7 @@ static __inline__ void set_bits(unsigned
 
 static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
 {
-	__asm__ __volatile__(LWSYNC_ON_SMP ::: "memory");
+	__asm__ __volatile__(LWSYNC_ON_SMP "" ::: "memory");
 	__clear_bit(nr, addr);
 }
 
_


  reply	other threads:[~2007-09-13 22:17 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-06 18:40 2.6.23-rc4-mm1 compile error for ppc 32 Mathieu Desnoyers
2007-09-06 23:00 ` Andrew Morton
2007-09-08  1:36   ` Nick Piggin
2007-09-08 16:42     ` Benjamin Herrenschmidt
2007-09-13 22:17       ` Andrew Morton [this message]
2007-09-15 13:32         ` Benjamin Herrenschmidt
2007-09-15 15:00           ` Mathieu Desnoyers
2007-09-17 20:31             ` Benjamin Herrenschmidt
2007-09-17 20:44               ` Balbir Singh

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=20070913151738.4462fdf2.akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=benh@kernel.crashing.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@polymtl.ca \
    --cc=nickpiggin@yahoo.com.au \
    /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