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Message-Id: <20171027222747.58391-1-salyzyn@android.com>
Date: Fri, 27 Oct 2017 15:27:37 -0700
From: Mark Salyzyn <salyzyn@...roid.com>
To: linux-kernel@...r.kernel.org
Cc: Mark Salyzyn <salyzyn@...roid.com>,
James Morse <james.morse@....com>,
Russell King <linux@...linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Andy Lutomirski <luto@...capital.net>,
Dmitry Safonov <dsafonov@...tuozzo.com>,
John Stultz <john.stultz@...aro.org>,
Mark Rutland <mark.rutland@....com>,
Laura Abbott <labbott@...hat.com>,
Kees Cook <keescook@...omium.org>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Andy Gross <andy.gross@...aro.org>,
Kevin Brodsky <kevin.brodsky@....com>,
Andrew Pinski <apinski@...ium.com>,
linux-arm-kernel@...ts.infradead.org,
Mark Salyzyn <salyzyn@...gle.com>
Subject: [PATCH v3 11/12] lib: vdso: Add support for CLOCK_BOOTTIME
Add a case for CLOCK_BOOTTIME as it is popular for measuring
relative time on systems expected to suspend() or hibernate().
Signed-off-by: Mark Salyzyn <salyzyn@...roid.com>
Cc: James Morse <james.morse@....com>
Cc: Russell King <linux@...linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dmitry Safonov <dsafonov@...tuozzo.com>
Cc: John Stultz <john.stultz@...aro.org>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Laura Abbott <labbott@...hat.com>
Cc: Kees Cook <keescook@...omium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc: Andy Gross <andy.gross@...aro.org>
Cc: Kevin Brodsky <kevin.brodsky@....com>
Cc: Andrew Pinski <apinski@...ium.com>
Cc: linux-kernel@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org
v2:
- rebased and changed from 3/3 to 10/10, fortified commit message.
v3:
- move arch/arm/vdso/vgettimeofday.c to lib/vdso/vgettimeofday.c
---
arch/arm/include/asm/vdso_datapage.h | 1 +
arch/arm/kernel/vdso.c | 1 +
arch/arm64/include/asm/vdso_datapage.h | 1 +
arch/arm64/kernel/vdso.c | 1 +
lib/vdso/vgettimeofday.c | 56 ++++++++++++++++++++++++++++++++++
5 files changed, 60 insertions(+)
diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h
index d57c296f7f52..d2c8e0807f06 100644
--- a/arch/arm/include/asm/vdso_datapage.h
+++ b/arch/arm/include/asm/vdso_datapage.h
@@ -47,6 +47,7 @@ struct vdso_data {
u32 tz_minuteswest; /* timezone info for gettimeofday(2) */
u32 tz_dsttime;
+ u64 btm_nsec; /* monotonic to boot time */
u32 cs_raw_mult; /* Raw clocksource multipler */
u32 raw_time_sec; /* Raw time */
u32 raw_time_nsec;
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 287424541f3a..9370ab4b2734 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -347,6 +347,7 @@ void update_vsyscall(struct timekeeper *tk)
/* tkr_mono.shift == tkr_raw.shift */
vdso_data->cs_shift = tk->tkr_mono.shift;
vdso_data->cs_mask = tk->tkr_mono.mask;
+ vdso_data->btm_nsec = ktime_to_ns(tk->offs_boot);
}
vdso_write_end(vdso_data);
diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h
index c9e30226cdbc..1e115b0f373d 100644
--- a/arch/arm64/include/asm/vdso_datapage.h
+++ b/arch/arm64/include/asm/vdso_datapage.h
@@ -30,6 +30,7 @@ struct vdso_data {
__u64 xtime_coarse_nsec;
__u64 wtm_clock_sec; /* Wall to monotonic time */
__u64 wtm_clock_nsec;
+ __u64 btm_nsec; /* monotonic to boot time */
__u32 tb_seq_count; /* Timebase sequence counter */
/* cs_* members must be adjacent and in this order (ldp accesses) */
__u32 cs_mono_mult; /* NTP-adjusted clocksource multiplier */
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 59f150c25889..0710edd8bedc 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -243,6 +243,7 @@ void update_vsyscall(struct timekeeper *tk)
vdso_data->cs_raw_mult = tk->tkr_raw.mult;
/* tkr_mono.shift == tkr_raw.shift */
vdso_data->cs_shift = tk->tkr_mono.shift;
+ vdso_data->btm_nsec = ktime_to_ns(tk->offs_boot);
}
smp_wmb();
diff --git a/lib/vdso/vgettimeofday.c b/lib/vdso/vgettimeofday.c
index 2cafd732c65f..0546ff12673d 100644
--- a/lib/vdso/vgettimeofday.c
+++ b/lib/vdso/vgettimeofday.c
@@ -248,6 +248,51 @@ static __always_inline notrace int do_monotonic_raw(const struct vdso_data *vd,
return 0;
}
+static __always_inline notrace int do_boottime(const struct vdso_data *vd,
+ struct timespec *ts)
+{
+ u32 seq, mult, shift;
+ u64 nsec, cycle_last, wtm_nsec;
+#ifdef ARCH_CLOCK_FIXED_MASK
+ static const u64 mask = ARCH_CLOCK_FIXED_MASK;
+#else
+ u64 mask;
+#endif
+
+ typeof(ts->tv_sec) sec;
+
+ do {
+ seq = vdso_read_begin(vd);
+
+ if (vd->use_syscall)
+ return -1;
+
+ cycle_last = vd->cs_cycle_last;
+
+ mult = vd->cs_mono_mult;
+ shift = vd->cs_shift;
+#ifndef ARCH_CLOCK_FIXED_MASK
+ mask = vd->cs_mask;
+#endif
+
+ sec = vd->xtime_clock_sec;
+ nsec = vd->xtime_clock_snsec;
+
+ sec += vd->wtm_clock_sec;
+ wtm_nsec = vd->wtm_clock_nsec + vd->btm_nsec;
+
+ } while (unlikely(vdso_read_retry(vd, seq)));
+
+ nsec += get_clock_shifted_nsec(cycle_last, mult, mask);
+ nsec >>= shift;
+ nsec += wtm_nsec;
+
+ ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec);
+ ts->tv_nsec = nsec;
+
+ return 0;
+}
+
#else /* ARCH_PROVIDES_TIMER */
static notrace int do_realtime(const struct vdso_data *vd, struct timespec *ts)
@@ -266,6 +311,12 @@ static notrace int do_monotonic_raw(const struct vdso_data *vd,
return -1;
}
+static notrace int do_boottime(const struct vdso_data *vd,
+ struct timespec *ts)
+{
+ return -1;
+}
+
#endif /* ARCH_PROVIDES_TIMER */
notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
@@ -291,6 +342,10 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
if (do_monotonic_raw(vd, ts))
goto fallback;
break;
+ case CLOCK_BOOTTIME:
+ if (do_boottime(vd, ts))
+ goto fallback;
+ break;
default:
goto fallback;
}
@@ -327,6 +382,7 @@ int __vdso_clock_getres(clockid_t clock_id, struct timespec *res)
typeof(res->tv_nsec) nsec;
if (clock_id == CLOCK_REALTIME ||
+ clock_id == CLOCK_BOOTTIME ||
clock_id == CLOCK_MONOTONIC ||
clock_id == CLOCK_MONOTONIC_RAW)
nsec = MONOTONIC_RES_NSEC;
--
2.15.0.rc2.357.g7e34df9404-goog
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