linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Stafford Horne <shorne@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Openrisc <openrisc@lists.librecores.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Stafford Horne <shorne@gmail.com>,
	Jonas Bonn <jonas@southpole.se>,
	Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Subject: [PATCH] openrisc: Define memory barrier mb
Date: Sat, 15 May 2021 16:58:08 +0900	[thread overview]
Message-ID: <20210515075810.163206-1-shorne@gmail.com> (raw)

From: Peter Zijlstra <peterz@infradead.org>

This came up in the discussion of the requirements of qspinlock on an
architecture.  OpenRISC uses qspinlock, but it was noticed that the
memmory barrier was not defined.

Peter defined it in the mail thread writing:

    As near as I can tell this should do. The arch spec only lists
    this one instruction and the text makes it sound like a completion
    barrier.

This is correct so applying this patch.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
[shorne@gmail.com:Turned the mail into a patch]
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
I just applied the patch posted by Peter in the mail as is hence it is labeled
from peter.  This also required me to set the Signed-off-by to Peter.

If there is any issue with that let me know.  I tested this out on my single
processor setup and it all works fine, it will take me some time to get my SMP
setup up and running again to test the other patches, but I figured I would send
this patch first.

Also, I got delayed because I had to rebuild my main workstation after a
hardware failure.

 arch/openrisc/include/asm/barrier.h | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 arch/openrisc/include/asm/barrier.h

diff --git a/arch/openrisc/include/asm/barrier.h b/arch/openrisc/include/asm/barrier.h
new file mode 100644
index 000000000000..7538294721be
--- /dev/null
+++ b/arch/openrisc/include/asm/barrier.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_BARRIER_H
+#define __ASM_BARRIER_H
+
+#define mb() asm volatile ("l.msync" ::: "memory")
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASM_BARRIER_H */
-- 
2.31.1


             reply	other threads:[~2021-05-15  7:58 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-15  7:58 Stafford Horne [this message]
2021-05-15 12:51 ` [PATCH] openrisc: Define memory barrier mb Peter Zijlstra

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=20210515075810.163206-1-shorne@gmail.com \
    --to=shorne@gmail.com \
    --cc=jonas@southpole.se \
    --cc=linux-kernel@vger.kernel.org \
    --cc=openrisc@lists.librecores.org \
    --cc=peterz@infradead.org \
    --cc=stefan.kristiansson@saunalahti.fi \
    /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).