s390/cmpxchg: use symbolic names for inline assembly operands

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

Link: https://lore.kernel.org/r/Y2J7yzQYt/bjLQXY@osiris
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h
index 84c3f0d..56fb8aa 100644 (file)
--- 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;
        }