|
Server IP : 128.199.20.84 / Your IP : 172.69.6.188 Web Server : Apache/2.4.41 (Ubuntu) System : Linux competent-maruti 5.4.0-128-generic #144-Ubuntu SMP Tue Sep 20 11:00:04 UTC 2022 x86_64 User : www-data ( 33) PHP Version : 8.0.20 Disable Function : pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_get_handler,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,pcntl_async_signals,pcntl_unshare, MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : OFF Directory (0755) : /usr/src/../src/linux-headers-5.4.0-128/include/vdso/ |
| [ Home ] | [ C0mmand ] | [ Upload File ] |
|---|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __VDSO_HELPERS_H
#define __VDSO_HELPERS_H
#ifndef __ASSEMBLY__
#include <vdso/datapage.h>
static __always_inline u32 vdso_read_begin(const struct vdso_data *vd)
{
u32 seq;
while ((seq = READ_ONCE(vd->seq)) & 1)
cpu_relax();
smp_rmb();
return seq;
}
static __always_inline u32 vdso_read_retry(const struct vdso_data *vd,
u32 start)
{
u32 seq;
smp_rmb();
seq = READ_ONCE(vd->seq);
return seq != start;
}
static __always_inline void vdso_write_begin(struct vdso_data *vd)
{
/*
* WRITE_ONCE it is required otherwise the compiler can validly tear
* updates to vd[x].seq and it is possible that the value seen by the
* reader it is inconsistent.
*/
WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1);
WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1);
smp_wmb();
}
static __always_inline void vdso_write_end(struct vdso_data *vd)
{
smp_wmb();
/*
* WRITE_ONCE it is required otherwise the compiler can validly tear
* updates to vd[x].seq and it is possible that the value seen by the
* reader it is inconsistent.
*/
WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1);
WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1);
}
#endif /* !__ASSEMBLY__ */
#endif /* __VDSO_HELPERS_H */