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kernel: add APIs for atomic os on pointers

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The existing APIs are insufficient on 64-bit systems as atomic_t
is 32-bits wide.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit is contained in:
Andrew Boie 2020-02-20 13:57:11 -08:00 • committed by Anas Nashif
commit 9f0acd44a4
4 changed files with 196 additions and 0 deletions
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94
include/sys/atomic.h
View file

@ -11,6 +11,7 @@
#include <stdbool.h>
#include <toolchain.h>
#include <stddef.h>
#include <zephyr/types.h>
@ -20,6 +21,7 @@ extern "C" {
typedef int atomic_t;
typedef atomic_t atomic_val_t;
typedef void *atomic_ptr_t;
/**
* @defgroup atomic_apis Atomic Services APIs
@ -57,6 +59,35 @@ extern bool atomic_cas(atomic_t *target, atomic_val_t old_value,
atomic_val_t new_value);
#endif
/**
* @brief Atomic compare-and-set with pointer values
*
* 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_ptr_cas(atomic_ptr_t *target, void *old_value,
void *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 bool atomic_ptr_cas(atomic_ptr_t *target, void *old_value,
void *new_value);
#else
extern bool atomic_ptr_cas(atomic_ptr_t *target, void *old_value,
void *new_value);
#endif
/**
*
* @brief Atomic addition.
@ -158,6 +189,25 @@ static inline atomic_val_t atomic_get(const atomic_t *target)
extern atomic_val_t atomic_get(const atomic_t *target);
#endif
/**
*
* @brief Atomic get a pointer value
*
* This routine performs an atomic read on @a target.
*
* @param target Address of pointer variable.
*
* @return Value of @a target.
*/
#ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN
static inline void *atomic_ptr_get(const atomic_ptr_t *target)
{
return __atomic_load_n(target, __ATOMIC_SEQ_CST);
}
#else
extern void *atomic_ptr_get(const atomic_ptr_t *target);
#endif
/**
*
* @brief Atomic get-and-set.
@ -185,6 +235,29 @@ __syscall atomic_val_t atomic_set(atomic_t *target, atomic_val_t value);
extern atomic_val_t atomic_set(atomic_t *target, atomic_val_t value);
#endif
/**
*
* @brief Atomic get-and-set for pointer values
*
* 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 void *atomic_ptr_set(atomic_ptr_t *target, void *value)
{
return __atomic_exchange_n(target, value, __ATOMIC_SEQ_CST);
}
#elif defined(CONFIG_ATOMIC_OPERATIONS_C)
__syscall void *atomic_ptr_set(atomic_ptr_t *target, void *value);
#else
extern void *atomic_ptr_set(atomic_ptr_t *target, void *value);
#endif
/**
*
* @brief Atomic clear.
@ -205,6 +278,27 @@ static inline atomic_val_t atomic_clear(atomic_t *target)
extern atomic_val_t atomic_clear(atomic_t *target);
#endif
/**
*
* @brief Atomic clear of a pointer value
*
* 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 void *atomic_ptr_clear(atomic_ptr_t *target)
{
return atomic_ptr_set(target, NULL);
}
#else
extern void *atomic_ptr_clear(atomic_ptr_t *target);
#endif
/**
*
* @brief Atomic bitwise inclusive OR.