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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/include/asm/local.h | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/local.h')
-rw-r--r-- | arch/x86/include/asm/local.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h new file mode 100644 index 000000000..349a47aca --- /dev/null +++ b/arch/x86/include/asm/local.h @@ -0,0 +1,162 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_LOCAL_H +#define _ASM_X86_LOCAL_H + +#include <linux/percpu.h> + +#include <linux/atomic.h> +#include <asm/asm.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)) + +static inline void local_inc(local_t *l) +{ + asm volatile(_ASM_INC "%0" + : "+m" (l->a.counter)); +} + +static inline void local_dec(local_t *l) +{ + asm volatile(_ASM_DEC "%0" + : "+m" (l->a.counter)); +} + +static inline void local_add(long i, local_t *l) +{ + asm volatile(_ASM_ADD "%1,%0" + : "+m" (l->a.counter) + : "ir" (i)); +} + +static inline void local_sub(long i, local_t *l) +{ + asm volatile(_ASM_SUB "%1,%0" + : "+m" (l->a.counter) + : "ir" (i)); +} + +/** + * local_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @l: pointer to type local_t + * + * Atomically subtracts @i from @l and returns + * true if the result is zero, or false for all + * other cases. + */ +static inline bool local_sub_and_test(long i, local_t *l) +{ + return GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, e, "er", i); +} + +/** + * local_dec_and_test - decrement and test + * @l: pointer to type local_t + * + * Atomically decrements @l by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +static inline bool local_dec_and_test(local_t *l) +{ + return GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, e); +} + +/** + * local_inc_and_test - increment and test + * @l: pointer to type local_t + * + * Atomically increments @l by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +static inline bool local_inc_and_test(local_t *l) +{ + return GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, e); +} + +/** + * local_add_negative - add and test if negative + * @i: integer value to add + * @l: pointer to type local_t + * + * Atomically adds @i to @l and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +static inline bool local_add_negative(long i, local_t *l) +{ + return GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, s, "er", i); +} + +/** + * local_add_return - add and return + * @i: integer value to add + * @l: pointer to type local_t + * + * Atomically adds @i to @l and returns @i + @l + */ +static inline long local_add_return(long i, local_t *l) +{ + long __i = i; + asm volatile(_ASM_XADD "%0, %1;" + : "+r" (i), "+m" (l->a.counter) + : : "memory"); + return i + __i; +} + +static inline long local_sub_return(long i, local_t *l) +{ + return local_add_return(-i, l); +} + +#define local_inc_return(l) (local_add_return(1, l)) +#define local_dec_return(l) (local_sub_return(1, l)) + +#define local_cmpxchg(l, o, n) \ + (cmpxchg_local(&((l)->a.counter), (o), (n))) +/* Always has a lock prefix */ +#define local_xchg(l, n) (xchg(&((l)->a.counter), (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)); \ + for (;;) { \ + if (unlikely(c == (u))) \ + break; \ + old = local_cmpxchg((l), c, c + (a)); \ + if (likely(old == c)) \ + break; \ + c = old; \ + } \ + c != (u); \ +}) +#define local_inc_not_zero(l) local_add_unless((l), 1, 0) + +/* On x86_32, these are no better than the atomic variants. + * On x86-64 these are better than the atomic variants on SMP kernels + * because they dont use a lock prefix. + */ +#define __local_inc(l) local_inc(l) +#define __local_dec(l) local_dec(l) +#define __local_add(i, l) local_add((i), (l)) +#define __local_sub(i, l) local_sub((i), (l)) + +#endif /* _ASM_X86_LOCAL_H */ |