| #ifndef __ARCH_S390_ATOMIC__ |
| #define __ARCH_S390_ATOMIC__ |
| |
| /* |
| * include/asm-s390/atomic.h |
| * |
| * S390 version |
| * Copyright (C) 1999,2000 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; } __attribute__ ((aligned (4))) atomic_t; |
| #define ATOMIC_INIT(i) { (i) } |
| |
| #define atomic_eieio() __asm__ __volatile__ ("BCR 15,0") |
| |
| #define __CS_LOOP(old_val, new_val, ptr, op_val, op_string) \ |
| __asm__ __volatile__(" l %0,0(%2)\n" \ |
| "0: lr %1,%0\n" \ |
| op_string " %1,%3\n" \ |
| " cs %0,%1,0(%2)\n" \ |
| " jl 0b" \ |
| : "=&d" (old_val), "=&d" (new_val) \ |
| : "a" (ptr), "d" (op_val) : "cc" ); |
| |
| #define atomic_read(v) ((v)->counter) |
| #define atomic_set(v,i) (((v)->counter) = (i)) |
| |
| static __inline__ void atomic_add(int i, atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, i, "ar"); |
| } |
| |
| static __inline__ int atomic_add_return (int i, atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, i, "ar"); |
| return new_val; |
| } |
| |
| static __inline__ int atomic_add_negative(int i, atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, i, "ar"); |
| return new_val < 0; |
| } |
| |
| static __inline__ void atomic_sub(int i, atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, i, "sr"); |
| } |
| |
| static __inline__ void atomic_inc(volatile atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, 1, "ar"); |
| } |
| |
| static __inline__ int atomic_inc_return(volatile atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, 1, "ar"); |
| return new_val; |
| } |
| |
| static __inline__ int atomic_inc_and_test(volatile atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, 1, "ar"); |
| return new_val != 0; |
| } |
| |
| static __inline__ void atomic_dec(volatile atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, 1, "sr"); |
| } |
| |
| static __inline__ int atomic_dec_return(volatile atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, 1, "sr"); |
| return new_val; |
| } |
| |
| static __inline__ int atomic_dec_and_test(volatile atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, 1, "sr"); |
| return new_val == 0; |
| } |
| |
| static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, ~mask, "nr"); |
| } |
| |
| static __inline__ void atomic_set_mask(unsigned long mask, atomic_t *v) |
| { |
| int old_val, new_val; |
| __CS_LOOP(old_val, new_val, v, mask, "or"); |
| } |
| |
| /* |
| 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__( |
| " lr 0,%2\n" |
| " cs 0,%3,0(%1)\n" |
| " ipm %0\n" |
| " srl %0,28\n" |
| "0:" |
| : "=&d" (retval) |
| : "a" (v), "d" (expected_oldval) , "d" (new_val) |
| : "0", "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 0,%1\n" |
| " cs 0,%2,0(%0)\n" |
| " jl 0b\n" |
| : : "a" (v), "d" (expected_oldval) , "d" (new_val) |
| : "cc", "0" ); |
| } |
| |
| #define atomic_compare_and_swap_debug(where,from,to) \ |
| if (atomic_compare_and_swap ((from), (to), (where))) {\ |
| printk (KERN_WARNING"%s/%d atomic counter:%s couldn't be changed from %d(%s) to %d(%s), was %d\n",\ |
| __FILE__,__LINE__,#where,(from),#from,(to),#to,atomic_read (where));\ |
| atomic_set(where,(to));\ |
| } |
| |
| #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 /* __ARCH_S390_ATOMIC __ */ |
| |