Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/include/asm-s390/atomic.h b/include/asm-s390/atomic.h
new file mode 100644
index 0000000..d5a05cf
--- /dev/null
+++ b/include/asm-s390/atomic.h
@@ -0,0 +1,207 @@
+#ifndef __ARCH_S390_ATOMIC__
+#define __ARCH_S390_ATOMIC__
+
+/*
+ * include/asm-s390/atomic.h
+ *
+ * S390 version
+ * Copyright (C) 1999-2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ * Denis Joseph Barrow,
+ * Arnd Bergmann (arndb@de.ibm.com)
+ *
+ * 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;
+} __attribute__ ((aligned (4))) atomic_t;
+#define ATOMIC_INIT(i) { (i) }
+
+#ifdef __KERNEL__
+
+#define __CS_LOOP(ptr, op_val, op_string) ({ \
+ typeof(ptr->counter) old_val, new_val; \
+ __asm__ __volatile__(" l %0,0(%3)\n" \
+ "0: lr %1,%0\n" \
+ op_string " %1,%4\n" \
+ " cs %0,%1,0(%3)\n" \
+ " jl 0b" \
+ : "=&d" (old_val), "=&d" (new_val), \
+ "=m" (((atomic_t *)(ptr))->counter) \
+ : "a" (ptr), "d" (op_val), \
+ "m" (((atomic_t *)(ptr))->counter) \
+ : "cc", "memory" ); \
+ new_val; \
+})
+#define atomic_read(v) ((v)->counter)
+#define atomic_set(v,i) (((v)->counter) = (i))
+
+static __inline__ void atomic_add(int i, atomic_t * v)
+{
+ __CS_LOOP(v, i, "ar");
+}
+static __inline__ int atomic_add_return(int i, atomic_t * v)
+{
+ return __CS_LOOP(v, i, "ar");
+}
+static __inline__ int atomic_add_negative(int i, atomic_t * v)
+{
+ return __CS_LOOP(v, i, "ar") < 0;
+}
+static __inline__ void atomic_sub(int i, atomic_t * v)
+{
+ __CS_LOOP(v, i, "sr");
+}
+static __inline__ int atomic_sub_return(int i, atomic_t * v)
+{
+ return __CS_LOOP(v, i, "sr");
+}
+static __inline__ void atomic_inc(volatile atomic_t * v)
+{
+ __CS_LOOP(v, 1, "ar");
+}
+static __inline__ int atomic_inc_return(volatile atomic_t * v)
+{
+ return __CS_LOOP(v, 1, "ar");
+}
+
+static __inline__ int atomic_inc_and_test(volatile atomic_t * v)
+{
+ return __CS_LOOP(v, 1, "ar") == 0;
+}
+static __inline__ void atomic_dec(volatile atomic_t * v)
+{
+ __CS_LOOP(v, 1, "sr");
+}
+static __inline__ int atomic_dec_return(volatile atomic_t * v)
+{
+ return __CS_LOOP(v, 1, "sr");
+}
+static __inline__ int atomic_dec_and_test(volatile atomic_t * v)
+{
+ return __CS_LOOP(v, 1, "sr") == 0;
+}
+static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
+{
+ __CS_LOOP(v, ~mask, "nr");
+}
+static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
+{
+ __CS_LOOP(v, mask, "or");
+}
+#undef __CS_LOOP
+
+#ifdef __s390x__
+typedef struct {
+ volatile long long counter;
+} __attribute__ ((aligned (8))) atomic64_t;
+#define ATOMIC64_INIT(i) { (i) }
+
+#define __CSG_LOOP(ptr, op_val, op_string) ({ \
+ typeof(ptr->counter) old_val, new_val; \
+ __asm__ __volatile__(" lg %0,0(%3)\n" \
+ "0: lgr %1,%0\n" \
+ op_string " %1,%4\n" \
+ " csg %0,%1,0(%3)\n" \
+ " jl 0b" \
+ : "=&d" (old_val), "=&d" (new_val), \
+ "=m" (((atomic_t *)(ptr))->counter) \
+ : "a" (ptr), "d" (op_val), \
+ "m" (((atomic_t *)(ptr))->counter) \
+ : "cc", "memory" ); \
+ new_val; \
+})
+#define atomic64_read(v) ((v)->counter)
+#define atomic64_set(v,i) (((v)->counter) = (i))
+
+static __inline__ void atomic64_add(int i, atomic64_t * v)
+{
+ __CSG_LOOP(v, i, "agr");
+}
+static __inline__ long long atomic64_add_return(int i, atomic64_t * v)
+{
+ return __CSG_LOOP(v, i, "agr");
+}
+static __inline__ long long atomic64_add_negative(int i, atomic64_t * v)
+{
+ return __CSG_LOOP(v, i, "agr") < 0;
+}
+static __inline__ void atomic64_sub(int i, atomic64_t * v)
+{
+ __CSG_LOOP(v, i, "sgr");
+}
+static __inline__ void atomic64_inc(volatile atomic64_t * v)
+{
+ __CSG_LOOP(v, 1, "agr");
+}
+static __inline__ long long atomic64_inc_return(volatile atomic64_t * v)
+{
+ return __CSG_LOOP(v, 1, "agr");
+}
+static __inline__ long long atomic64_inc_and_test(volatile atomic64_t * v)
+{
+ return __CSG_LOOP(v, 1, "agr") == 0;
+}
+static __inline__ void atomic64_dec(volatile atomic64_t * v)
+{
+ __CSG_LOOP(v, 1, "sgr");
+}
+static __inline__ long long atomic64_dec_return(volatile atomic64_t * v)
+{
+ return __CSG_LOOP(v, 1, "sgr");
+}
+static __inline__ long long atomic64_dec_and_test(volatile atomic64_t * v)
+{
+ return __CSG_LOOP(v, 1, "sgr") == 0;
+}
+static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
+{
+ __CSG_LOOP(v, ~mask, "ngr");
+}
+static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
+{
+ __CSG_LOOP(v, mask, "ogr");
+}
+
+#undef __CSG_LOOP
+#endif
+
+/*
+ returns 0 if expected_oldval==value in *v ( swap was successful )
+ returns 1 if unsuccessful.
+
+ This is non-portable, use bitops or spinlocks instead!
+*/
+static __inline__ int
+atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
+{
+ int retval;
+
+ __asm__ __volatile__(
+ " lr %0,%3\n"
+ " cs %0,%4,0(%2)\n"
+ " ipm %0\n"
+ " srl %0,28\n"
+ "0:"
+ : "=&d" (retval), "=m" (v->counter)
+ : "a" (v), "d" (expected_oldval) , "d" (new_val),
+ "m" (v->counter) : "cc", "memory" );
+ return retval;
+}
+
+#define smp_mb__before_atomic_dec() smp_mb()
+#define smp_mb__after_atomic_dec() smp_mb()
+#define smp_mb__before_atomic_inc() smp_mb()
+#define smp_mb__after_atomic_inc() smp_mb()
+
+#endif /* __KERNEL__ */
+#endif /* __ARCH_S390_ATOMIC__ */