143 lines
4.1 KiB
C
143 lines
4.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __VDSO_DATAPAGE_H
|
|
#define __VDSO_DATAPAGE_H
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <linux/compiler.h>
|
|
#include <uapi/linux/time.h>
|
|
#include <uapi/linux/types.h>
|
|
#include <uapi/asm-generic/errno-base.h>
|
|
|
|
#include <vdso/bits.h>
|
|
#include <vdso/clocksource.h>
|
|
#include <vdso/ktime.h>
|
|
#include <vdso/limits.h>
|
|
#include <vdso/math64.h>
|
|
#include <vdso/processor.h>
|
|
#include <vdso/time.h>
|
|
#include <vdso/time32.h>
|
|
#include <vdso/time64.h>
|
|
|
|
#ifdef CONFIG_ARCH_HAS_VDSO_DATA
|
|
#include <asm/vdso/data.h>
|
|
#else
|
|
struct arch_vdso_data {};
|
|
#endif
|
|
|
|
#define VDSO_BASES (CLOCK_TAI + 1)
|
|
#define VDSO_HRES (BIT(CLOCK_REALTIME) | \
|
|
BIT(CLOCK_MONOTONIC) | \
|
|
BIT(CLOCK_BOOTTIME) | \
|
|
BIT(CLOCK_TAI))
|
|
#define VDSO_COARSE (BIT(CLOCK_REALTIME_COARSE) | \
|
|
BIT(CLOCK_MONOTONIC_COARSE))
|
|
#define VDSO_RAW (BIT(CLOCK_MONOTONIC_RAW))
|
|
|
|
#define CS_HRES_COARSE 0
|
|
#define CS_RAW 1
|
|
#define CS_BASES (CS_RAW + 1)
|
|
|
|
/**
|
|
* struct vdso_timestamp - basetime per clock_id
|
|
* @sec: seconds
|
|
* @nsec: nanoseconds
|
|
*
|
|
* There is one vdso_timestamp object in vvar for each vDSO-accelerated
|
|
* clock_id. For high-resolution clocks, this encodes the time
|
|
* corresponding to vdso_data.cycle_last. For coarse clocks this encodes
|
|
* the actual time.
|
|
*
|
|
* To be noticed that for highres clocks nsec is left-shifted by
|
|
* vdso_data.cs[x].shift.
|
|
*/
|
|
struct vdso_timestamp {
|
|
u64 sec;
|
|
u64 nsec;
|
|
};
|
|
|
|
/**
|
|
* struct vdso_data - vdso datapage representation
|
|
* @seq: timebase sequence counter
|
|
* @clock_mode: clock mode
|
|
* @cycle_last: timebase at clocksource init
|
|
* @mask: clocksource mask
|
|
* @mult: clocksource multiplier
|
|
* @shift: clocksource shift
|
|
* @basetime[clock_id]: basetime per clock_id
|
|
* @offset[clock_id]: time namespace offset per clock_id
|
|
* @tz_minuteswest: minutes west of Greenwich
|
|
* @tz_dsttime: type of DST correction
|
|
* @hrtimer_res: hrtimer resolution
|
|
* @__unused: unused
|
|
* @arch_data: architecture specific data (optional, defaults
|
|
* to an empty struct)
|
|
*
|
|
* vdso_data will be accessed by 64 bit and compat code at the same time
|
|
* so we should be careful before modifying this structure.
|
|
*
|
|
* @basetime is used to store the base time for the system wide time getter
|
|
* VVAR page.
|
|
*
|
|
* @offset is used by the special time namespace VVAR pages which are
|
|
* installed instead of the real VVAR page. These namespace pages must set
|
|
* @seq to 1 and @clock_mode to VDSO_CLOCKMODE_TIMENS to force the code into
|
|
* the time namespace slow path. The namespace aware functions retrieve the
|
|
* real system wide VVAR page, read host time and add the per clock offset.
|
|
* For clocks which are not affected by time namespace adjustment the
|
|
* offset must be zero.
|
|
*/
|
|
struct vdso_data {
|
|
u32 seq;
|
|
|
|
s32 clock_mode;
|
|
u64 cycle_last;
|
|
u64 mask;
|
|
u32 mult;
|
|
u32 shift;
|
|
|
|
union {
|
|
struct vdso_timestamp basetime[VDSO_BASES];
|
|
struct timens_offset offset[VDSO_BASES];
|
|
};
|
|
|
|
s32 tz_minuteswest;
|
|
s32 tz_dsttime;
|
|
u32 hrtimer_res;
|
|
u32 __unused;
|
|
|
|
struct arch_vdso_data arch_data;
|
|
};
|
|
|
|
/*
|
|
* We use the hidden visibility to prevent the compiler from generating a GOT
|
|
* relocation. Not only is going through a GOT useless (the entry couldn't and
|
|
* must not be overridden by another library), it does not even work: the linker
|
|
* cannot generate an absolute address to the data page.
|
|
*
|
|
* With the hidden visibility, the compiler simply generates a PC-relative
|
|
* relocation, and this is what we need.
|
|
*/
|
|
extern struct vdso_data _vdso_data[CS_BASES] __attribute__((visibility("hidden")));
|
|
extern struct vdso_data _timens_data[CS_BASES] __attribute__((visibility("hidden")));
|
|
|
|
/*
|
|
* The generic vDSO implementation requires that gettimeofday.h
|
|
* provides:
|
|
* - __arch_get_vdso_data(): to get the vdso datapage.
|
|
* - __arch_get_hw_counter(): to get the hw counter based on the
|
|
* clock_mode.
|
|
* - gettimeofday_fallback(): fallback for gettimeofday.
|
|
* - clock_gettime_fallback(): fallback for clock_gettime.
|
|
* - clock_getres_fallback(): fallback for clock_getres.
|
|
*/
|
|
#ifdef ENABLE_COMPAT_VDSO
|
|
#include <asm/vdso/compat_gettimeofday.h>
|
|
#else
|
|
#include <asm/vdso/gettimeofday.h>
|
|
#endif /* ENABLE_COMPAT_VDSO */
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#endif /* __VDSO_DATAPAGE_H */
|