kernel: add APIs for atomic os on pointers

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

View file

@ -22,8 +22,11 @@
*/
.global atomic_clear
.type atomic_clear,@function
.global atomic_ptr_clear
.type atomic_ptr_clear,@function
.align 4
atomic_clear:
atomic_ptr_clear:
ENTRY(48)
movi a4, 0
.L_LoopClear:
@ -54,8 +57,11 @@ atomic_clear:
*/
.global atomic_set
.type atomic_set,@function
.global atomic_ptr_set
.type atomic_ptr_set,@function
.align 4
atomic_set:
atomic_ptr_set:
ENTRY(48)
.L_LoopSet:
l32ai a4, a2, 0
@ -81,8 +87,11 @@ atomic_set:
*/
.global atomic_get
.type atomic_get,@function
.global atomic_ptr_get
.type atomic_ptr_get,@function
.align 4
atomic_get:
atomic_ptr_get:
ENTRY(48)
l32ai a2, a2, 0
RET(48)
@ -388,8 +397,11 @@ atomic_xor:
*/
.global atomic_cas
.type atomic_cas,@function
.global atomic_ptr_cas
.type atomic_ptr_cas,@function
.align 4
atomic_cas:
atomic_ptr_cas:
ENTRY(48)
l32ai a5, a2, 0
beq a5, a3, 2f

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.

View file

@ -106,6 +106,35 @@ bool z_vrfy_atomic_cas(atomic_t *target, atomic_val_t old_value,
#include <syscalls/atomic_cas_mrsh.c>
#endif /* CONFIG_USERSPACE */
bool z_impl_atomic_ptr_cas(atomic_ptr_t *target, void *old_value,
void *new_value)
{
k_spinlock_key_t key;
int ret = false;
key = k_spin_lock(&lock);
if (*target == old_value) {
*target = new_value;
ret = true;
}
k_spin_unlock(&lock, key);
return ret;
}
#ifdef CONFIG_USERSPACE
static inline bool z_vrfy_atomic_ptr_cas(atomic_ptr_t *target, void *old_value,
void *new_value)
{
Z_OOPS(Z_SYSCALL_MEMORY_WRITE(target, sizeof(atomic_ptr_t)));
return z_impl_atomic_ptr_cas(target, old_value, new_value);
}
#include <syscalls/atomic_ptr_cas_mrsh.c>
#endif /* CONFIG_USERSPACE */
/**
*
* @brief Atomic addition primitive
@ -183,6 +212,11 @@ atomic_val_t atomic_get(const atomic_t *target)
return *target;
}
void *atomic_ptr_get(const atomic_ptr_t *target)
{
return *target;
}
/**
*
* @brief Atomic get-and-set primitive
@ -212,6 +246,31 @@ atomic_val_t z_impl_atomic_set(atomic_t *target, atomic_val_t value)
ATOMIC_SYSCALL_HANDLER_TARGET_VALUE(atomic_set);
void *z_impl_atomic_ptr_set(atomic_ptr_t *target, void *value)
{
k_spinlock_key_t key;
void *ret;
key = k_spin_lock(&lock);
ret = *target;
*target = value;
k_spin_unlock(&lock, key);
return ret;
}
#ifdef CONFIG_USERSPACE
static inline void *z_vrfy_atomic_ptr_set(atomic_ptr_t *target, void *value)
{
Z_OOPS(Z_SYSCALL_MEMORY_WRITE(target, sizeof(atomic_ptr_t)));
return z_impl_atomic_ptr_set(target, value);
}
#include <syscalls/atomic_ptr_set_mrsh.c>
#endif /* CONFIG_USERSPACE */
/**
*
* @brief Atomic bitwise inclusive OR primitive

View file

@ -26,8 +26,10 @@ void test_atomic(void)
int i;
atomic_t target, orig;
atomic_ptr_t ptr_target;
atomic_val_t value;
atomic_val_t oldvalue;
void *ptr_value, *old_ptr_value;
target = 4;
value = 5;
@ -39,6 +41,17 @@ void test_atomic(void)
zassert_true(atomic_cas(&target, oldvalue, value), "atomic_cas");
zassert_true((target == value), "atomic_cas");
/* atomic_ptr_cas() */
ptr_target = (atomic_ptr_t)4;
ptr_value = (void *)5;
old_ptr_value = (void *)6;
zassert_false(atomic_ptr_cas(&ptr_target, old_ptr_value, ptr_value),
"atomic_ptr_cas");
ptr_target = (void *)6;
zassert_true(atomic_ptr_cas(&ptr_target, old_ptr_value, ptr_value),
"atomic_ptr_cas");
zassert_true((ptr_target == ptr_value), "atomic_ptr_cas");
/* atomic_add() */
target = 1;
value = 2;
@ -65,17 +78,35 @@ void test_atomic(void)
target = 50;
zassert_true((atomic_get(&target) == 50), "atomic_get");
/* atomic_ptr_get() */
ptr_target = (atomic_ptr_t)50;
zassert_true((atomic_ptr_get(&ptr_target) == (void *)50),
"atomic_ptr_get");
/* atomic_set() */
target = 42;
value = 77;
zassert_true((atomic_set(&target, value) == 42), "atomic_set");
zassert_true((target == value), "atomic_set");
/* atomic_ptr_set() */
ptr_target = (atomic_ptr_t)42;
ptr_value = (void *)77;
zassert_true((atomic_ptr_set(&ptr_target, ptr_value) == (void *)42),
"atomic_ptr_set");
zassert_true((ptr_target == ptr_value), "atomic_ptr_set");
/* atomic_clear() */
target = 100;
zassert_true((atomic_clear(&target) == 100), "atomic_clear");
zassert_true((target == 0), "atomic_clear");
/* atomic_ptr_clear() */
ptr_target = (atomic_ptr_t)100;
zassert_true((atomic_ptr_clear(&ptr_target) == (void *)100),
"atomic_ptr_clear");
zassert_true((ptr_target == NULL), "atomic_ptr_clear");
/* atomic_or() */
target = 0xFF00;
value = 0x0F0F;