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Date:   Wed, 2 Nov 2022 15:16:43 +0100
From:   Heiko Carstens <hca@linux.ibm.com>
To:     Heiko Carstens <hca@linux.ibm.com>
Cc:     Janis Schoetterl-Glausch <scgl@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        David Hildenbrand <david@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>, kvm@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org,
        Paolo Bonzini <pbonzini@redhat.com>,
        Shuah Khan <shuah@kernel.org>,
        Sven Schnelle <svens@linux.ibm.com>
Subject: [PATCH 1/5] s390/cmpxchg: use symbolic names for inline assembly
 operands
Message-ID: <Y2J7yzQYt/bjLQXY@osiris>
References: <20221012205609.2811294-1-scgl@linux.ibm.com>
 <20221012205609.2811294-2-scgl@linux.ibm.com>
 <Y2J61LWSV+HolIeT@osiris>
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Precedence: bulk

Make cmpxchg() inline assemblies more readable by using symbolic names
for operands.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 arch/s390/include/asm/cmpxchg.h | 76 ++++++++++++++++++---------------
 1 file changed, 42 insertions(+), 34 deletions(-)

diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h
index 84c3f0d576c5..56fb8aa08945 100644
--- a/arch/s390/include/asm/cmpxchg.h
+++ b/arch/s390/include/asm/cmpxchg.h
@@ -96,56 +96,64 @@ static __always_inline unsigned long __cmpxchg(unsigned long address,
 		shift = (3 ^ (address & 3)) << 3;
 		address ^= address & 3;
 		asm volatile(
-			"       l       %0,%2\n"
-			"0:     nr      %0,%5\n"
-			"       lr      %1,%0\n"
-			"       or      %0,%3\n"
-			"       or      %1,%4\n"
-			"       cs      %0,%1,%2\n"
-			"       jnl     1f\n"
-			"       xr      %1,%0\n"
-			"       nr      %1,%5\n"
-			"       jnz     0b\n"
+			"	l	%[prev],%[address]\n"
+			"0:	nr	%[prev],%[mask]\n"
+			"	lr	%[tmp],%[prev]\n"
+			"	or	%[prev],%[old]\n"
+			"	or	%[tmp],%[new]\n"
+			"	cs	%[prev],%[tmp],%[address]\n"
+			"	jnl	1f\n"
+			"	xr	%[tmp],%[prev]\n"
+			"	nr	%[tmp],%[mask]\n"
+			"	jnz	0b\n"
 			"1:"
-			: "=&d" (prev), "=&d" (tmp), "+Q" (*(int *) address)
-			: "d" ((old & 0xff) << shift),
-			  "d" ((new & 0xff) << shift),
-			  "d" (~(0xff << shift))
+			: [prev] "=&d" (prev),
+			  [tmp] "=&d" (tmp),
+			  [address] "+Q" (*(int *)address)
+			: [old] "d" ((old & 0xff) << shift),
+			  [new] "d" ((new & 0xff) << shift),
+			  [mask] "d" (~(0xff << shift))
 			: "memory", "cc");
 		return prev >> shift;
 	case 2:
 		shift = (2 ^ (address & 2)) << 3;
 		address ^= address & 2;
 		asm volatile(
-			"       l       %0,%2\n"
-			"0:     nr      %0,%5\n"
-			"       lr      %1,%0\n"
-			"       or      %0,%3\n"
-			"       or      %1,%4\n"
-			"       cs      %0,%1,%2\n"
-			"       jnl     1f\n"
-			"       xr      %1,%0\n"
-			"       nr      %1,%5\n"
-			"       jnz     0b\n"
+			"	l	%[prev],%[address]\n"
+			"0:	nr	%[prev],%[mask]\n"
+			"	lr	%[tmp],%[prev]\n"
+			"	or	%[prev],%[old]\n"
+			"	or	%[tmp],%[new]\n"
+			"	cs	%[prev],%[tmp],%[address]\n"
+			"	jnl	1f\n"
+			"	xr	%[tmp],%[prev]\n"
+			"	nr	%[tmp],%[mask]\n"
+			"	jnz	0b\n"
 			"1:"
-			: "=&d" (prev), "=&d" (tmp), "+Q" (*(int *) address)
-			: "d" ((old & 0xffff) << shift),
-			  "d" ((new & 0xffff) << shift),
-			  "d" (~(0xffff << shift))
+			: [prev] "=&d" (prev),
+			  [tmp] "=&d" (tmp),
+			  [address] "+Q" (*(int *)address)
+			: [old] "d" ((old & 0xffff) << shift),
+			  [new] "d" ((new & 0xffff) << shift),
+			  [mask] "d" (~(0xffff << shift))
 			: "memory", "cc");
 		return prev >> shift;
 	case 4:
 		asm volatile(
-			"       cs      %0,%3,%1\n"
-			: "=&d" (prev), "+Q" (*(int *) address)
-			: "0" (old), "d" (new)
+			"	cs	%[prev],%[new],%[address]\n"
+			: [prev] "=&d" (prev),
+			  [address] "+Q" (*(int *)address)
+			: "0" (old),
+			  [new] "d" (new)
 			: "memory", "cc");
 		return prev;
 	case 8:
 		asm volatile(
-			"       csg     %0,%3,%1\n"
-			: "=&d" (prev), "+QS" (*(long *) address)
-			: "0" (old), "d" (new)
+			"	csg	%[prev],%[new],%[address]\n"
+			: [prev] "=&d" (prev),
+			  [address] "+QS" (*(long *)address)
+			: "0" (old),
+			  [new] "d" (new)
 			: "memory", "cc");
 		return prev;
 	}
-- 
2.34.1