From: Anton Blanchard <anton@samba.org>
To: benh@kernel.crashing.org, paulus@samba.org
Cc: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 4/4] powerpc: No need to preserve count register across system call
Date: Thu, 5 Apr 2012 14:26:39 +1000 [thread overview]
Message-ID: <20120405142639.237dde63@kryten> (raw)
In-Reply-To: <20120405142327.6038bbb4@kryten>
The count register is volatile so we don't need to preserve it.
Store zero to the entry in the exception frame.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: linux-build/arch/powerpc/kernel/entry_64.S
===================================================================
--- linux-build.orig/arch/powerpc/kernel/entry_64.S 2012-03-22 22:47:15.023504471 +1100
+++ linux-build/arch/powerpc/kernel/entry_64.S 2012-03-22 22:47:17.899556262 +1100
@@ -77,6 +77,7 @@ system_call_common:
std r11,GPR11(r1)
std r11,GPR12(r1)
std r11,_XER(r1)
+ std r11,_CTR(r1)
std r9,GPR13(r1)
mflr r10
li r11,0xc01
@@ -87,8 +88,6 @@ system_call_common:
rlwinm r2,r2,0,4,2
std r10,_LINK(r1)
std r11,_TRAP(r1)
- mfctr r10
- std r10,_CTR(r1)
std r3,ORIG_GPR3(r1)
std r2,_CCR(r1)
ld r2,PACATOC(r13)
prev parent reply other threads:[~2012-04-05 4:26 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-05 4:23 [PATCH 1/4] powerpc: Hide some system call labels from profile tools Anton Blanchard
2012-04-05 4:24 ` [PATCH 2/4] powerpc: No need to save XER in a system call Anton Blanchard
2012-04-05 4:25 ` [PATCH 3/4] powerpc: Better scheduling of CR save code in system call path Anton Blanchard
2012-04-05 13:44 ` [PATCH 3/4 v2] " Anton Blanchard
2012-04-05 4:26 ` Anton Blanchard [this message]
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=20120405142639.237dde63@kryten \
--to=anton@samba.org \
--cc=benh@kernel.crashing.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=paulus@samba.org \
/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).