// SPDX-License-Identifier: GPL-2.0/* * Copyright 2019 ARM Ltd. * * Generic implementation of update_vsyscall and update_vsyscall_tz. * * Based on the x86 specific implementation. */ #include <linux/hrtimer.h>#include <linux/timekeeper_internal.h>#include <vdso/datapage.h>#include <vdso/helpers.h>#include <vdso/vsyscall.h> #include "timekeeping_internal.h" static inline void fill_clock_configuration(struct vdso_clock *vc, const struct tk_read_base *base){	vc->cycle_last	= base->cycle_last;#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT	vc->max_cycles	= base->clock->max_cycles;#endif	vc->mask	= base->mask;	vc->mult	= base->mult;	vc->shift	= base->shift;} static inline void update_vdso_time_data(struct vdso_time_data *vdata, struct timekeeper *tk){	struct vdso_clock *vc = vdata->clock_data;	struct vdso_timestamp *vdso_ts;	u64 nsec, sec; 	fill_clock_configuration(&vc[CS_HRES_COARSE],	&tk->tkr_mono);	fill_clock_configuration(&vc[CS_RAW],		&tk->tkr_raw); 	/* CLOCK_MONOTONIC */	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];	vdso_ts->sec	= tk->xtime_sec + tk->wall_to_monotonic.tv_sec; 	nsec = tk->tkr_mono.xtime_nsec;	nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);	while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {		nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);		vdso_ts->sec++;	}	vdso_ts->nsec	= nsec; 	/* Copy MONOTONIC time for BOOTTIME */	sec	= vdso_ts->sec;	/* Add the boot offset */	sec	+= tk->monotonic_to_boot.tv_sec;	nsec	+= (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift; 	/* CLOCK_BOOTTIME */	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];	vdso_ts->sec	= sec; 	while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {		nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);		vdso_ts->sec++;	}	vdso_ts->nsec	= nsec; 	/* CLOCK_MONOTONIC_RAW */	vdso_ts		= &vc[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];	vdso_ts->sec	= tk->raw_sec;	vdso_ts->nsec	= tk->tkr_raw.xtime_nsec; 	/* CLOCK_TAI */	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_TAI];	vdso_ts->sec	= tk->xtime_sec + (s64)tk->tai_offset;	vdso_ts->nsec	= tk->tkr_mono.xtime_nsec;} void update_vsyscall(struct timekeeper *tk){	struct vdso_time_data *vdata = vdso_k_time_data;	struct vdso_clock *vc = vdata->clock_data;	struct vdso_timestamp *vdso_ts;	s32 clock_mode;	u64 nsec; 	/* copy vsyscall data */	vdso_write_begin(vdata); 	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;	vc[CS_HRES_COARSE].clock_mode	= clock_mode;	vc[CS_RAW].clock_mode		= clock_mode; 	/* CLOCK_REALTIME also required for time() */	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME];	vdso_ts->sec	= tk->xtime_sec;	vdso_ts->nsec	= tk->tkr_mono.xtime_nsec; 	/* CLOCK_REALTIME_COARSE */	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];	vdso_ts->sec	= tk->xtime_sec;	vdso_ts->nsec	= tk->coarse_nsec; 	/* CLOCK_MONOTONIC_COARSE */	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];	vdso_ts->sec	= tk->xtime_sec + tk->wall_to_monotonic.tv_sec;	nsec		= tk->coarse_nsec;	nsec		= nsec + tk->wall_to_monotonic.tv_nsec;	vdso_ts->sec	+= __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec); 	/*	 * Read without the seqlock held by clock_getres().	 */	WRITE_ONCE(vdata->hrtimer_res, hrtimer_resolution); 	/*	 * If the current clocksource is not VDSO capable, then spare the	 * update of the high resolution parts.	 */	if (clock_mode != VDSO_CLOCKMODE_NONE)		update_vdso_time_data(vdata, tk); 	__arch_update_vdso_clock(&vc[CS_HRES_COARSE]);	__arch_update_vdso_clock(&vc[CS_RAW]); 	vdso_write_end(vdata); 	__arch_sync_vdso_time_data(vdata);} void update_vsyscall_tz(void){	struct vdso_time_data *vdata = vdso_k_time_data; 	vdata->tz_minuteswest = sys_tz.tz_minuteswest;	vdata->tz_dsttime = sys_tz.tz_dsttime; 	__arch_sync_vdso_time_data(vdata);} #ifdef CONFIG_POSIX_AUX_CLOCKSvoid vdso_time_update_aux(struct timekeeper *tk){	struct vdso_time_data *vdata = vdso_k_time_data;	struct vdso_timestamp *vdso_ts;	struct vdso_clock *vc;	s32 clock_mode;	u64 nsec; 	vc = &vdata->aux_clock_data[tk->id - TIMEKEEPER_AUX_FIRST];	vdso_ts = &vc->basetime[VDSO_BASE_AUX];	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;	if (!tk->clock_valid)		clock_mode = VDSO_CLOCKMODE_NONE; 	/* copy vsyscall data */	vdso_write_begin_clock(vc); 	vc->clock_mode = clock_mode; 	if (clock_mode != VDSO_CLOCKMODE_NONE) {		fill_clock_configuration(vc, &tk->tkr_mono); 		vdso_ts->sec = tk->xtime_sec + tk->monotonic_to_aux.tv_sec; 		nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;		nsec += tk->monotonic_to_aux.tv_nsec;		vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec);		nsec = nsec << tk->tkr_mono.shift;		vdso_ts->nsec = nsec;	} 	__arch_update_vdso_clock(vc); 	vdso_write_end_clock(vc); 	__arch_sync_vdso_time_data(vdata);}#endif /** * vdso_update_begin - Start of a VDSO update section * * Allows architecture code to safely update the architecture specific VDSO * data. Disables interrupts, acquires timekeeper lock to serialize against * concurrent updates from timekeeping and invalidates the VDSO data * sequence counter to prevent concurrent readers from accessing * inconsistent data. * * Returns: Saved interrupt flags which need to be handed in to * vdso_update_end(). */unsigned long vdso_update_begin(void){	struct vdso_time_data *vdata = vdso_k_time_data;	unsigned long flags = timekeeper_lock_irqsave(); 	vdso_write_begin(vdata);	return flags;} /** * vdso_update_end - End of a VDSO update section * @flags:	Interrupt flags as returned from vdso_update_begin() * * Pairs with vdso_update_begin(). Marks vdso data consistent, invokes data * synchronization if the architecture requires it, drops timekeeper lock * and restores interrupt flags. */void vdso_update_end(unsigned long flags){	struct vdso_time_data *vdata = vdso_k_time_data; 	vdso_write_end(vdata);	__arch_sync_vdso_time_data(vdata);	timekeeper_unlock_irqrestore(flags);}