From: Kevin Hao <haokexin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Scott Wood <scottwood@freescale.com>, Paul Mackerras <paulus@samba.org>
Subject: [PATCH] powerpc64: use fixed lock token for !CONFIG_PPC_SPLPAR
Date: Sat, 7 Mar 2015 19:19:43 +0800 [thread overview]
Message-ID: <1425727183-30880-1-git-send-email-haokexin@gmail.com> (raw)
It makes no sense to use a variant lock token on a platform which
doesn't support for shared-processor logical partitions. Actually we
can eliminate a memory load by using a fixed lock token on these
platforms.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
arch/powerpc/include/asm/spinlock.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index 4dbe072eecbe..d303cdad2519 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -30,7 +30,7 @@
#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_PPC_SPLPAR
/* use 0x800000yy when locked, where yy == CPU number */
#ifdef __BIG_ENDIAN__
#define LOCK_TOKEN (*(u32 *)(&get_paca()->lock_token))
@@ -187,9 +187,13 @@ extern void arch_spin_unlock_wait(arch_spinlock_t *lock);
#ifdef CONFIG_PPC64
#define __DO_SIGN_EXTEND "extsw %0,%0\n"
-#define WRLOCK_TOKEN LOCK_TOKEN /* it's negative */
#else
#define __DO_SIGN_EXTEND
+#endif
+
+#ifdef CONFIG_PPC_SPLPAR
+#define WRLOCK_TOKEN LOCK_TOKEN /* it's negative */
+#else
#define WRLOCK_TOKEN (-1)
#endif
--
2.1.0
next reply other threads:[~2015-03-07 11:19 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-07 11:19 Kevin Hao [this message]
2015-03-09 6:53 ` [PATCH] powerpc64: use fixed lock token for !CONFIG_PPC_SPLPAR Benjamin Herrenschmidt
2015-03-10 0:15 ` Michael Ellerman
2015-03-10 12:32 ` Kevin Hao
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=1425727183-30880-1-git-send-email-haokexin@gmail.com \
--to=haokexin@gmail.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=paulus@samba.org \
--cc=scottwood@freescale.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;
as well as URLs for NNTP newsgroup(s).