local.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ALPHA_LOCAL_H
  3#define _ALPHA_LOCAL_H
  4
  5#include <linux/percpu.h>
  6#include <linux/atomic.h>
  7
  8typedef struct
  9{
 10	atomic_long_t a;
 11} local_t;
 12
 13#define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
 14#define local_read(l)	atomic_long_read(&(l)->a)
 15#define local_set(l,i)	atomic_long_set(&(l)->a, (i))
 16#define local_inc(l)	atomic_long_inc(&(l)->a)
 17#define local_dec(l)	atomic_long_dec(&(l)->a)
 18#define local_add(i,l)	atomic_long_add((i),(&(l)->a))
 19#define local_sub(i,l)	atomic_long_sub((i),(&(l)->a))
 20
 21static __inline__ long local_add_return(long i, local_t * l)
 22{
 23	long temp, result;
 24	__asm__ __volatile__(
 25	"1:	ldq_l %0,%1\n"
 26	"	addq %0,%3,%2\n"
 27	"	addq %0,%3,%0\n"
 28	"	stq_c %0,%1\n"
 29	"	beq %0,2f\n"
 30	".subsection 2\n"
 31	"2:	br 1b\n"
 32	".previous"
 33	:"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
 34	:"Ir" (i), "m" (l->a.counter) : "memory");
 35	return result;
 36}
 37
 38static __inline__ long local_sub_return(long i, local_t * l)
 39{
 40	long temp, result;
 41	__asm__ __volatile__(
 42	"1:	ldq_l %0,%1\n"
 43	"	subq %0,%3,%2\n"
 44	"	subq %0,%3,%0\n"
 45	"	stq_c %0,%1\n"
 46	"	beq %0,2f\n"
 47	".subsection 2\n"
 48	"2:	br 1b\n"
 49	".previous"
 50	:"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
 51	:"Ir" (i), "m" (l->a.counter) : "memory");
 52	return result;
 53}
 54
 55static __inline__ long local_cmpxchg(local_t *l, long old, long new)
 56{
 57	return cmpxchg_local(&l->a.counter, old, new);
 58}
 59
 60static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
 61{
 62	return try_cmpxchg_local(&l->a.counter, (s64 *)old, new);
 63}
 64
 65#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
 66
 67/**
 68 * local_add_unless - add unless the number is already a given value
 69 * @l: pointer of type local_t
 70 * @a: the amount to add to l...
 71 * @u: ...unless l is equal to u.
 72 *
 73 * Atomically adds @a to @l, if @v was not already @u.
 74 * Returns true if the addition was done.
 75 */
 76static __inline__ bool
 77local_add_unless(local_t *l, long a, long u)
 78{
 79	long c = local_read(l);
 80
 81	do {
 82		if (unlikely(c == u))
 83			return false;
 84	} while (!local_try_cmpxchg(l, &c, c + a));
 85
 86	return true;
 87}
 88
 89#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 90
 91#define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
 92
 93#define local_dec_return(l) local_sub_return(1,(l))
 94
 95#define local_inc_return(l) local_add_return(1,(l))
 96
 97#define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
 98
 99#define local_inc_and_test(l) (local_add_return(1, (l)) == 0)
100
101#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
102
103/* Verify if faster than atomic ops */
104#define __local_inc(l)		((l)->a.counter++)
105#define __local_dec(l)		((l)->a.counter++)
106#define __local_add(i,l)	((l)->a.counter+=(i))
107#define __local_sub(i,l)	((l)->a.counter-=(i))
108
109#endif /* _ALPHA_LOCAL_H */