linux-kernel - [PATCH 3/8] s390/entry: shorten OUTSIDE macro

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Message-Id: <20220511120532.2228616-4-hca@linux.ibm.com>
Date:   Wed, 11 May 2022 14:05:27 +0200
From:   Heiko Carstens <hca@...ux.ibm.com>
To:     Vasily Gorbik <gor@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Jonas Paulsson <paulsson@...ux.vnet.ibm.com>,
        Ulrich Weigand <ulrich.weigand@...ibm.com>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Alexander Egorenkov <egorenar@...ux.ibm.com>
Cc:     Sven Schnelle <svens@...ux.ibm.com>,
        Andreas Krebbel <krebbel@...ux.ibm.com>,
        Nathan Chancellor <natechancellor@...il.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        linux-kernel@...r.kernel.org, linux-s390@...r.kernel.org
Subject: [PATCH 3/8] s390/entry: shorten OUTSIDE macro

Since the minimum architecture level has been raised to z10 a shorter
instruction sequence can be used to implement the OUTSIDE macro. This
also reduces the number of used registers within that macro to one.

Signed-off-by: Heiko Carstens <hca@...ux.ibm.com>
---
 arch/s390/kernel/entry.S | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index a6b45eaa3450..e1664b45090f 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -169,11 +169,9 @@ _LPP_OFFSET	= __LC_LPP
 	 * @outside_label: jump here if @reg is outside of [@start..@end)
 	 */
 	.macro OUTSIDE reg,start,end,outside_label
-	lgr	%r14,\reg
-	larl	%r13,\start
-	slgr	%r14,%r13
-	lghi	%r13,\end - \start
-	clgr	%r14,%r13
+	larl	%r14,\start
+	slgrk	%r14,\reg,%r14
+	clgfi	%r14,\end - \start
 	jhe	\outside_label
 	.endm
 
-- 
2.32.0