^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright 2019 ARM Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Generic implementation of update_vsyscall and update_vsyscall_tz.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Based on the x86 specific implementation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/hrtimer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/timekeeper_internal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <vdso/datapage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <vdso/helpers.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <vdso/vsyscall.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include "timekeeping_internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) static inline void update_vdso_data(struct vdso_data *vdata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) struct timekeeper *tk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct vdso_timestamp *vdso_ts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) u64 nsec, sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) vdata[CS_HRES_COARSE].cycle_last = tk->tkr_mono.cycle_last;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) vdata[CS_HRES_COARSE].mask = tk->tkr_mono.mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) vdata[CS_HRES_COARSE].mult = tk->tkr_mono.mult;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) vdata[CS_HRES_COARSE].shift = tk->tkr_mono.shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) vdata[CS_RAW].cycle_last = tk->tkr_raw.cycle_last;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) vdata[CS_RAW].mask = tk->tkr_raw.mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) vdata[CS_RAW].mult = tk->tkr_raw.mult;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) vdata[CS_RAW].shift = tk->tkr_raw.shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) /* CLOCK_MONOTONIC */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) nsec = tk->tkr_mono.xtime_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) vdso_ts->sec++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) vdso_ts->nsec = nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /* Copy MONOTONIC time for BOOTTIME */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) sec = vdso_ts->sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) /* Add the boot offset */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) sec += tk->monotonic_to_boot.tv_sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) nsec += (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) /* CLOCK_BOOTTIME */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) vdso_ts->sec = sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) vdso_ts->sec++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) vdso_ts->nsec = nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) /* CLOCK_MONOTONIC_RAW */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) vdso_ts->sec = tk->raw_sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /* CLOCK_TAI */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) void update_vsyscall(struct timekeeper *tk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct vdso_data *vdata = __arch_get_k_vdso_data();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) struct vdso_timestamp *vdso_ts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) s32 clock_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) u64 nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /* copy vsyscall data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) vdso_write_begin(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) vdata[CS_HRES_COARSE].clock_mode = clock_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) vdata[CS_RAW].clock_mode = clock_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) /* CLOCK_REALTIME also required for time() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) vdso_ts->sec = tk->xtime_sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) /* CLOCK_REALTIME_COARSE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) vdso_ts->sec = tk->xtime_sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /* CLOCK_MONOTONIC_COARSE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) nsec = nsec + tk->wall_to_monotonic.tv_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * Read without the seqlock held by clock_getres().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * Note: No need to have a second copy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * If the current clocksource is not VDSO capable, then spare the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * update of the high reolution parts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (clock_mode != VDSO_CLOCKMODE_NONE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) update_vdso_data(vdata, tk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) __arch_update_vsyscall(vdata, tk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) vdso_write_end(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) __arch_sync_vdso_data(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) void update_vsyscall_tz(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) struct vdso_data *vdata = __arch_get_k_vdso_data();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) __arch_sync_vdso_data(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * vdso_update_begin - Start of a VDSO update section
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * Allows architecture code to safely update the architecture specific VDSO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * data. Disables interrupts, acquires timekeeper lock to serialize against
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * concurrent updates from timekeeping and invalidates the VDSO data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * sequence counter to prevent concurrent readers from accessing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) * inconsistent data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * Returns: Saved interrupt flags which need to be handed in to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * vdso_update_end().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) unsigned long vdso_update_begin(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) struct vdso_data *vdata = __arch_get_k_vdso_data();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) raw_spin_lock_irqsave(&timekeeper_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) vdso_write_begin(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) return flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) * vdso_update_end - End of a VDSO update section
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * @flags: Interrupt flags as returned from vdso_update_begin()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * Pairs with vdso_update_begin(). Marks vdso data consistent, invokes data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) * synchronization if the architecture requires it, drops timekeeper lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * and restores interrupt flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) void vdso_update_end(unsigned long flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) struct vdso_data *vdata = __arch_get_k_vdso_data();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) vdso_write_end(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) __arch_sync_vdso_data(vdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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