| /* atomic operations */ |
| |
| /* |
| * Copyright (c) 1997-2015, Wind River Systems, Inc. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #ifndef ZEPHYR_INCLUDE_ATOMIC_H_ |
| #define ZEPHYR_INCLUDE_ATOMIC_H_ |
| |
| #include <stdbool.h> |
| #include <toolchain.h> |
| |
| #include <zephyr/types.h> |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef int atomic_t; |
| typedef atomic_t atomic_val_t; |
| |
| /** |
| * @defgroup atomic_apis Atomic Services APIs |
| * @ingroup kernel_apis |
| * @{ |
| */ |
| |
| /** |
| * @brief Atomic compare-and-set. |
| * |
| * This routine performs an atomic compare-and-set on @a target. If the current |
| * value of @a target equals @a old_value, @a target is set to @a new_value. |
| * If the current value of @a target does not equal @a old_value, @a target |
| * is left unchanged. |
| * |
| * @param target Address of atomic variable. |
| * @param old_value Original value to compare against. |
| * @param new_value New value to store. |
| * @return true if @a new_value is written, false otherwise. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline bool atomic_cas(atomic_t *target, atomic_val_t old_value, |
| atomic_val_t new_value) |
| { |
| return __atomic_compare_exchange_n(target, &old_value, new_value, |
| 0, __ATOMIC_SEQ_CST, |
| __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall int atomic_cas(atomic_t *target, atomic_val_t old_value, |
| atomic_val_t new_value); |
| |
| #else |
| extern int atomic_cas(atomic_t *target, atomic_val_t old_value, |
| atomic_val_t new_value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic addition. |
| * |
| * This routine performs an atomic addition on @a target. |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to add. |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_add(atomic_t *target, atomic_val_t value) |
| { |
| return __atomic_fetch_add(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_add(atomic_t *target, atomic_val_t value); |
| #else |
| extern atomic_val_t atomic_add(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic subtraction. |
| * |
| * This routine performs an atomic subtraction on @a target. |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to subtract. |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_sub(atomic_t *target, atomic_val_t value) |
| { |
| return __atomic_fetch_sub(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_sub(atomic_t *target, atomic_val_t value); |
| #else |
| extern atomic_val_t atomic_sub(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic increment. |
| * |
| * This routine performs an atomic increment by 1 on @a target. |
| * |
| * @param target Address of atomic variable. |
| * |
| * @return Previous value of @a target. |
| */ |
| #if defined(CONFIG_ATOMIC_OPERATIONS_BUILTIN) || defined (CONFIG_ATOMIC_OPERATIONS_C) |
| static inline atomic_val_t atomic_inc(atomic_t *target) |
| { |
| return atomic_add(target, 1); |
| } |
| #else |
| extern atomic_val_t atomic_inc(atomic_t *target); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic decrement. |
| * |
| * This routine performs an atomic decrement by 1 on @a target. |
| * |
| * @param target Address of atomic variable. |
| * |
| * @return Previous value of @a target. |
| */ |
| #if defined(CONFIG_ATOMIC_OPERATIONS_BUILTIN) || defined (CONFIG_ATOMIC_OPERATIONS_C) |
| static inline atomic_val_t atomic_dec(atomic_t *target) |
| { |
| return atomic_sub(target, 1); |
| } |
| #else |
| extern atomic_val_t atomic_dec(atomic_t *target); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic get. |
| * |
| * This routine performs an atomic read on @a target. |
| * |
| * @param target Address of atomic variable. |
| * |
| * @return Value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_get(const atomic_t *target) |
| { |
| return __atomic_load_n(target, __ATOMIC_SEQ_CST); |
| } |
| #else |
| extern atomic_val_t atomic_get(const atomic_t *target); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic get-and-set. |
| * |
| * This routine atomically sets @a target to @a value and returns |
| * the previous value of @a target. |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to write to @a target. |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_set(atomic_t *target, atomic_val_t value) |
| { |
| /* This builtin, as described by Intel, is not a traditional |
| * test-and-set operation, but rather an atomic exchange operation. It |
| * writes value into *ptr, and returns the previous contents of *ptr. |
| */ |
| return __atomic_exchange_n(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_set(atomic_t *target, atomic_val_t value); |
| #else |
| extern atomic_val_t atomic_set(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic clear. |
| * |
| * This routine atomically sets @a target to zero and returns its previous |
| * value. (Hence, it is equivalent to atomic_set(target, 0).) |
| * |
| * @param target Address of atomic variable. |
| * |
| * @return Previous value of @a target. |
| */ |
| #if defined(CONFIG_ATOMIC_OPERATIONS_BUILTIN) || defined (CONFIG_ATOMIC_OPERATIONS_C) |
| static inline atomic_val_t atomic_clear(atomic_t *target) |
| { |
| return atomic_set(target, 0); |
| } |
| #else |
| extern atomic_val_t atomic_clear(atomic_t *target); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic bitwise inclusive OR. |
| * |
| * This routine atomically sets @a target to the bitwise inclusive OR of |
| * @a target and @a value. |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to OR. |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_or(atomic_t *target, atomic_val_t value) |
| { |
| return __atomic_fetch_or(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_or(atomic_t *target, atomic_val_t value); |
| |
| #else |
| extern atomic_val_t atomic_or(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic bitwise exclusive OR (XOR). |
| * |
| * This routine atomically sets @a target to the bitwise exclusive OR (XOR) of |
| * @a target and @a value. |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to XOR |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_xor(atomic_t *target, atomic_val_t value) |
| { |
| return __atomic_fetch_xor(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_xor(atomic_t *target, atomic_val_t value); |
| #else |
| extern atomic_val_t atomic_xor(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic bitwise AND. |
| * |
| * This routine atomically sets @a target to the bitwise AND of @a target |
| * and @a value. |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to AND. |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_and(atomic_t *target, atomic_val_t value) |
| { |
| return __atomic_fetch_and(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_and(atomic_t *target, atomic_val_t value); |
| #else |
| extern atomic_val_t atomic_and(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| /** |
| * |
| * @brief Atomic bitwise NAND. |
| * |
| * This routine atomically sets @a target to the bitwise NAND of @a target |
| * and @a value. (This operation is equivalent to target = ~(target & value).) |
| * |
| * @param target Address of atomic variable. |
| * @param value Value to NAND. |
| * |
| * @return Previous value of @a target. |
| */ |
| #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN |
| static inline atomic_val_t atomic_nand(atomic_t *target, atomic_val_t value) |
| { |
| return __atomic_fetch_nand(target, value, __ATOMIC_SEQ_CST); |
| } |
| #elif defined(CONFIG_ATOMIC_OPERATIONS_C) |
| __syscall atomic_val_t atomic_nand(atomic_t *target, atomic_val_t value); |
| #else |
| extern atomic_val_t atomic_nand(atomic_t *target, atomic_val_t value); |
| #endif |
| |
| |
| /** |
| * @brief Initialize an atomic variable. |
| * |
| * This macro can be used to initialize an atomic variable. For example, |
| * @code atomic_t my_var = ATOMIC_INIT(75); @endcode |
| * |
| * @param i Value to assign to atomic variable. |
| */ |
| #define ATOMIC_INIT(i) (i) |
| |
| /** |
| * @cond INTERNAL_HIDDEN |
| */ |
| |
| #define ATOMIC_BITS (sizeof(atomic_val_t) * 8) |
| #define ATOMIC_MASK(bit) (1 << ((u32_t)(bit) & (ATOMIC_BITS - 1))) |
| #define ATOMIC_ELEM(addr, bit) ((addr) + ((bit) / ATOMIC_BITS)) |
| |
| /** |
| * INTERNAL_HIDDEN @endcond |
| */ |
| |
| /** |
| * @brief Define an array of atomic variables. |
| * |
| * This macro defines an array of atomic variables containing at least |
| * @a num_bits bits. |
| * |
| * @note |
| * If used from file scope, the bits of the array are initialized to zero; |
| * if used from within a function, the bits are left uninitialized. |
| * |
| * @param name Name of array of atomic variables. |
| * @param num_bits Number of bits needed. |
| */ |
| #define ATOMIC_DEFINE(name, num_bits) \ |
| atomic_t name[1 + ((num_bits) - 1) / ATOMIC_BITS] |
| |
| /** |
| * @brief Atomically test a bit. |
| * |
| * This routine tests whether bit number @a bit of @a target is set or not. |
| * The target may be a single atomic variable or an array of them. |
| * |
| * @param target Address of atomic variable or array. |
| * @param bit Bit number (starting from 0). |
| * |
| * @return true if the bit was set, false if it wasn't. |
| */ |
| static inline bool atomic_test_bit(const atomic_t *target, int bit) |
| { |
| atomic_val_t val = atomic_get(ATOMIC_ELEM(target, bit)); |
| |
| return (1 & (val >> (bit & (ATOMIC_BITS - 1)))) != 0; |
| } |
| |
| /** |
| * @brief Atomically test and clear a bit. |
| * |
| * Atomically clear bit number @a bit of @a target and return its old value. |
| * The target may be a single atomic variable or an array of them. |
| * |
| * @param target Address of atomic variable or array. |
| * @param bit Bit number (starting from 0). |
| * |
| * @return true if the bit was set, false if it wasn't. |
| */ |
| static inline bool atomic_test_and_clear_bit(atomic_t *target, int bit) |
| { |
| atomic_val_t mask = ATOMIC_MASK(bit); |
| atomic_val_t old; |
| |
| old = atomic_and(ATOMIC_ELEM(target, bit), ~mask); |
| |
| return (old & mask) != 0; |
| } |
| |
| /** |
| * @brief Atomically set a bit. |
| * |
| * Atomically set bit number @a bit of @a target and return its old value. |
| * The target may be a single atomic variable or an array of them. |
| * |
| * @param target Address of atomic variable or array. |
| * @param bit Bit number (starting from 0). |
| * |
| * @return true if the bit was set, false if it wasn't. |
| */ |
| static inline bool atomic_test_and_set_bit(atomic_t *target, int bit) |
| { |
| atomic_val_t mask = ATOMIC_MASK(bit); |
| atomic_val_t old; |
| |
| old = atomic_or(ATOMIC_ELEM(target, bit), mask); |
| |
| return (old & mask) != 0; |
| } |
| |
| /** |
| * @brief Atomically clear a bit. |
| * |
| * Atomically clear bit number @a bit of @a target. |
| * The target may be a single atomic variable or an array of them. |
| * |
| * @param target Address of atomic variable or array. |
| * @param bit Bit number (starting from 0). |
| * |
| * @return N/A |
| */ |
| static inline void atomic_clear_bit(atomic_t *target, int bit) |
| { |
| atomic_val_t mask = ATOMIC_MASK(bit); |
| |
| (void)atomic_and(ATOMIC_ELEM(target, bit), ~mask); |
| } |
| |
| /** |
| * @brief Atomically set a bit. |
| * |
| * Atomically set bit number @a bit of @a target. |
| * The target may be a single atomic variable or an array of them. |
| * |
| * @param target Address of atomic variable or array. |
| * @param bit Bit number (starting from 0). |
| * |
| * @return N/A |
| */ |
| static inline void atomic_set_bit(atomic_t *target, int bit) |
| { |
| atomic_val_t mask = ATOMIC_MASK(bit); |
| |
| (void)atomic_or(ATOMIC_ELEM(target, bit), mask); |
| } |
| |
| /** |
| * @brief Atomically set a bit to a given value. |
| * |
| * Atomically set bit number @a bit of @a target to value @a val. |
| * The target may be a single atomic variable or an array of them. |
| * |
| * @param target Address of atomic variable or array. |
| * @param bit Bit number (starting from 0). |
| * @param val true for 1, false for 0. |
| * |
| * @return N/A |
| */ |
| static inline void atomic_set_bit_to(atomic_t *target, int bit, bool val) |
| { |
| atomic_val_t mask = ATOMIC_MASK(bit); |
| |
| if (val) { |
| (void)atomic_or(ATOMIC_ELEM(target, bit), mask); |
| } else { |
| (void)atomic_and(ATOMIC_ELEM(target, bit), ~mask); |
| } |
| } |
| |
| #ifdef CONFIG_ATOMIC_OPERATIONS_C |
| #include <syscalls/atomic.h> |
| #endif |
| /** |
| * @} |
| */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* ZEPHYR_INCLUDE_ATOMIC_H_ */ |