patch-2.2.14 linux/include/asm-s390/atomic.h

• Lines: 192
• Date: Tue Jan 4 10:12:24 2000
• Orig file: v2.2.13/linux/include/asm-s390/atomic.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.2.13/linux/include/asm-s390/atomic.h linux/include/asm-s390/atomic.h
@@ -0,0 +1,191 @@
+#ifndef __ARCH_S390_ATOMIC__
+#define __ARCH_S390_ATOMIC__
+
+/*
+ *  include/asm-s390/atomic.h
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *               Denis Joseph Barrow
+ *
+ *  Derived from "include/asm-i386/bitops.h"
+ *    Copyright (C) 1992, Linus Torvalds
+ *
+ */
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ * S390 uses 'Compare And Swap' for atomicity in SMP enviroment
+ */
+
+typedef struct { volatile int counter; } atomic_t __attribute__ ((aligned (4)));
+#define ATOMIC_INIT(i)  { (i) }
+
+#define atomic_eieio()          __asm__ __volatile__ ("BCR 15,0")
+
+static __inline__ int atomic_read(atomic_t *v)
+{
+        int retval;
+        __asm__ __volatile("bcr      15,0\n\t"
+                           "l        %0,%1"
+                           : "=d" (retval) : "m" (*v) );
+        return retval;
+}
+
+static __inline__ void atomic_set(atomic_t *v, int i)
+{
+        __asm__ __volatile__("st  %1,%0\n\t"
+                             "bcr 15,0"
+                             : : "m" (*v), "d" (i) : "memory");
+}
+
+static __inline__ void atomic_add(int i, atomic_t *v)
+{
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    1,0\n"
+                             "   ar    1,%1\n"
+                             "   cs    0,1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v) : "d" (i) : "0", "1" );
+}
+
+static __inline__ void atomic_sub(int i, atomic_t *v)
+{
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    1,0\n"
+                             "   sr    1,%1\n"
+                             "   cs    0,1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v) : "d" (i) : "0", "1" );
+}
+
+static __inline__ void atomic_inc(volatile atomic_t *v)
+{
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    1,0\n"
+                             "   ahi   1,1\n"
+                             "   cs    0,1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v) : : "0", "1" );
+}
+
+static __inline__ int atomic_inc_return(volatile atomic_t *v)
+{
+        int i;
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    %1,0\n"
+                             "   ahi   %1,1\n"
+                             "   cs    0,%1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v), "=&d" (i) : : "0" );
+        return i;
+}
+
+static __inline__ void atomic_dec(volatile atomic_t *v)
+{
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    1,0\n"
+                             "   ahi   1,-1\n"
+                             "   cs    0,1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v) : : "0", "1" );
+}
+
+static __inline__ int atomic_dec_return(volatile atomic_t *v)
+{
+        int i;
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    %1,0\n"
+                             "   ahi   %1,-1\n"
+                             "   cs    0,%1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v), "=&d" (i) : : "0" );
+        return i;
+}
+
+static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
+{
+        int i;
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    %1,0\n"
+                             "   ahi   %1,-1\n"
+                             "   cs    0,%1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v), "=&d" (i) : : "0");
+        return i == 0;
+}
+
+static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t *v)
+{
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    1,0\n"
+                             "   nr    1,%1\n"
+                             "   cs    0,1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v) : "d" (~(mask)) : "0", "1" );
+}
+
+static __inline__ void atomic_set_mask(unsigned long mask, atomic_t *v)
+{
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    1,0\n"
+                             "   or    1,%1\n"
+                             "   cs    0,1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v) : "d" (mask) : "0", "1" );
+}
+
+/*
+  returns 0  if expected_oldval==value in *v ( swap was successful )
+  returns 1  if unsuccessful.
+*/
+static __inline__ int
+atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
+{
+        int retval;
+
+        __asm__ __volatile__(
+                "  cs   %2,%3,%1\n"
+                "  ipm  %0\n"
+                "  srl  %0,28\n"
+                "0:"
+                : "=&r" (retval), "+m" (*v)
+                : "d" (expected_oldval) , "d" (new_val)
+                : "memory", "cc");
+        return retval;
+}
+
+/*
+  Spin till *v = expected_oldval then swap with newval.
+ */
+static __inline__ void
+atomic_compare_and_swap_spin(int expected_oldval,int new_val,atomic_t *v)
+{
+        __asm__ __volatile__(
+                "0: lr  1,%1\n"
+                "   cs  1,%2,%0\n"
+                "   jl  0b\n"
+                : "+m" (*v)
+                : "d" (expected_oldval) , "d" (new_val)
+                : "memory", "cc", "1");
+}
+
+/*
+ * Increase and test if atomic counter > 0
+ */
+extern __inline__ int atomic_inc_and_test_greater_zero(volatile atomic_t *v)
+{
+        int i;
+        __asm__ __volatile__("   l     0,%0\n"
+                             "0: lr    %1,0\n"
+                             "   ahi   %1,1\n"
+                             "   cs    0,%1,%0\n"
+                             "   jl    0b"
+                             : "+m" (*v), "=&d" (i) : : "0" );
+        return i > 0;
+}
+
+#endif                                 /* __ARCH_S390_ATOMIC __            */
+