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Diffstat (limited to '')
-rw-r--r-- | arch/loongarch/include/asm/local.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/local.h b/arch/loongarch/include/asm/local.h new file mode 100644 index 000000000..65fbbae9f --- /dev/null +++ b/arch/loongarch/include/asm/local.h @@ -0,0 +1,137 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ +#ifndef _ARCH_LOONGARCH_LOCAL_H +#define _ARCH_LOONGARCH_LOCAL_H + +#include <linux/percpu.h> +#include <linux/bitops.h> +#include <linux/atomic.h> +#include <asm/cmpxchg.h> + +typedef struct { + atomic_long_t a; +} local_t; + +#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } + +#define local_read(l) atomic_long_read(&(l)->a) +#define local_set(l, i) atomic_long_set(&(l)->a, (i)) + +#define local_add(i, l) atomic_long_add((i), (&(l)->a)) +#define local_sub(i, l) atomic_long_sub((i), (&(l)->a)) +#define local_inc(l) atomic_long_inc(&(l)->a) +#define local_dec(l) atomic_long_dec(&(l)->a) + +/* + * Same as above, but return the result value + */ +static inline long local_add_return(long i, local_t *l) +{ + unsigned long result; + + __asm__ __volatile__( + " " __AMADD " %1, %2, %0 \n" + : "+ZB" (l->a.counter), "=&r" (result) + : "r" (i) + : "memory"); + result = result + i; + + return result; +} + +static inline long local_sub_return(long i, local_t *l) +{ + unsigned long result; + + __asm__ __volatile__( + " " __AMADD "%1, %2, %0 \n" + : "+ZB" (l->a.counter), "=&r" (result) + : "r" (-i) + : "memory"); + + result = result - i; + + return result; +} + +#define local_cmpxchg(l, o, n) \ + ((long)cmpxchg_local(&((l)->a.counter), (o), (n))) +#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n))) + +/** + * local_add_unless - add unless the number is a given value + * @l: pointer of type local_t + * @a: the amount to add to l... + * @u: ...unless l is equal to u. + * + * Atomically adds @a to @l, so long as it was not @u. + * Returns non-zero if @l was not @u, and zero otherwise. + */ +#define local_add_unless(l, a, u) \ +({ \ + long c, old; \ + c = local_read(l); \ + while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define local_inc_not_zero(l) local_add_unless((l), 1, 0) + +#define local_dec_return(l) local_sub_return(1, (l)) +#define local_inc_return(l) local_add_return(1, (l)) + +/* + * local_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @l: pointer of type local_t + * + * Atomically subtracts @i from @l and returns + * true if the result is zero, or false for all + * other cases. + */ +#define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0) + +/* + * local_inc_and_test - increment and test + * @l: pointer of type local_t + * + * Atomically increments @l by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +#define local_inc_and_test(l) (local_inc_return(l) == 0) + +/* + * local_dec_and_test - decrement by 1 and test + * @l: pointer of type local_t + * + * Atomically decrements @l by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0) + +/* + * local_add_negative - add and test if negative + * @l: pointer of type local_t + * @i: integer value to add + * + * Atomically adds @i to @l and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +#define local_add_negative(i, l) (local_add_return(i, (l)) < 0) + +/* Use these for per-cpu local_t variables: on some archs they are + * much more efficient than these naive implementations. Note they take + * a variable, not an address. + */ + +#define __local_inc(l) ((l)->a.counter++) +#define __local_dec(l) ((l)->a.counter++) +#define __local_add(i, l) ((l)->a.counter += (i)) +#define __local_sub(i, l) ((l)->a.counter -= (i)) + +#endif /* _ARCH_LOONGARCH_LOCAL_H */ |