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/*
* Copyright (c) 2006-2026 RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2026-04-21 rcitach init ver.
*/
#ifndef RT_VDSO_USER_INTERNAL_H
#define RT_VDSO_USER_INTERNAL_H
#include <errno.h>
#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <sys/types.h>
#include <vdso_data_page.h>
#include <vdso_arch.h>
#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)
#ifndef barrier
#define barrier() __asm__ __volatile__("" : : : "memory")
#endif
static inline void rt_vdso_read_once_size(const volatile void *ptr, void *dst, int size)
{
switch (size)
{
case 1:
*(uint8_t *)dst = *(const volatile uint8_t *)ptr;
break;
case 2:
*(uint16_t *)dst = *(const volatile uint16_t *)ptr;
break;
case 4:
*(uint32_t *)dst = *(const volatile uint32_t *)ptr;
break;
case 8:
*(uint64_t *)dst = *(const volatile uint64_t *)ptr;
break;
default:
barrier();
__builtin_memcpy(dst, (const void *)ptr, size);
barrier();
break;
}
}
#define READ_ONCE(x) \
({ \
union \
{ \
typeof(x) value; \
char bytes[sizeof(x)]; \
} once; \
rt_vdso_read_once_size(&(x), once.bytes, sizeof(x)); \
once.value; \
})
extern const struct rt_vdso_data_page __rt_vdso_data_page[] __attribute__((visibility("hidden")));
static inline const struct rt_vdso_data_page *rt_vdso_get_data_page(void)
{
return __rt_vdso_data_page;
}
static inline uint32_t rt_vdso_data_read_begin(const struct rt_vdso_data_page *data_page)
{
uint32_t seq;
while (unlikely((seq = READ_ONCE(data_page->seq_counter)) & 1U))
{
rt_vdso_arch_cpu_relax();
}
rt_vdso_arch_rmb();
return seq;
}
static inline uint32_t rt_vdso_data_read_retry(const struct rt_vdso_data_page *data_page,
uint32_t start)
{
rt_vdso_arch_rmb();
return READ_ONCE(data_page->seq_counter) != start;
}
static inline uint64_t rt_vdso_counter_delta_to_ns(uint64_t now, uint64_t last,
uint64_t freq)
{
if (freq == 0)
{
return 0;
}
return (now - last) * RT_VDSO_NSEC_PER_SEC / freq;
}
static inline void rt_vdso_timespec_add_nanoseconds(struct timespec *ts, uint64_t ns)
{
ts->tv_sec += (time_t)(ns / RT_VDSO_NSEC_PER_SEC);
ns = (uint64_t)ts->tv_nsec + (ns % RT_VDSO_NSEC_PER_SEC);
if (ns >= RT_VDSO_NSEC_PER_SEC)
{
ts->tv_sec += 1;
ns -= RT_VDSO_NSEC_PER_SEC;
}
ts->tv_nsec = (long)ns;
}
#endif /* RT_VDSO_USER_INTERNAL_H */
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