[PATCH v3 06/12] arm: vdso: Add support for CLOCK_MONOTONIC_RAW
From: Mark Salyzyn <hidden>
Date: 2017-10-27 22:26:08
Also in:
lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
Add a case for CLOCK_MONOTONIC_RAW to match up with support that is available in arm64's vdso. Signed-off-by: Mark Salyzyn <redacted> Cc: James Morse <james.morse@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dmitry Safonov <redacted> Cc: John Stultz <redacted> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Laura Abbott <redacted> Cc: Kees Cook <redacted> Cc: Ard Biesheuvel <redacted> Cc: Andy Gross <redacted> Cc: Kevin Brodsky <redacted> Cc: Andrew Pinski <redacted> Cc: linux-kernel at vger.kernel.org Cc: linux-arm-kernel at lists.infradead.org v2: - split first CL into 6 of 7 pieces v3: - rebase (unchanged) --- arch/arm/include/asm/vdso_datapage.h | 4 +++ arch/arm/kernel/vdso.c | 5 ++++ arch/arm/vdso/vgettimeofday.c | 51 ++++++++++++++++++++++++++++++++++++ 3 files changed, 60 insertions(+)
diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h
index fa3e1856244d..d57c296f7f52 100644
--- a/arch/arm/include/asm/vdso_datapage.h
+++ b/arch/arm/include/asm/vdso_datapage.h@@ -46,6 +46,10 @@ struct vdso_data { u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */ u32 tz_minuteswest; /* timezone info for gettimeofday(2) */ u32 tz_dsttime; + + u32 cs_raw_mult; /* Raw clocksource multipler */ + u32 raw_time_sec; /* Raw time */ + u32 raw_time_nsec; }; union vdso_data_store {
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index aed84b659cc5..7377638a3b00 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c@@ -335,9 +335,14 @@ void update_vsyscall(struct timekeeper *tk) if (!vdso_data->use_syscall) { vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; + vdso_data->raw_time_sec = tk->raw_time.tv_sec; + vdso_data->raw_time_nsec = (tk->raw_time.tv_nsec << + tk->raw_time.shift) + + tk->tkr_raw.xtime_nsec; vdso_data->xtime_clock_sec = tk->xtime_sec; vdso_data->xtime_clock_snsec = tk->tkr_mono.xtime_nsec; vdso_data->cs_mono_mult = tk->tkr_mono.mult; + 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->cs_mask = tk->tkr_mono.mask;
diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index 7fcc8cfcb7df..b374c143d53e 100644
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c@@ -206,6 +206,47 @@ static __always_inline notrace int do_monotonic(const struct vdso_data *vd, return 0; } +static __always_inline notrace int do_monotonic_raw(const struct vdso_data *vd, + struct timespec *ts) +{ + u32 seq, mult, shift; + u64 nsec, cycle_last; +#ifdef ARCH_CLOCK_FIXED_MASK + static const u64 mask = ARCH_CLOCK_FIXED_MASK; +#else + u64 mask; +#endif + + typeof(((struct vdso_data *)vd)->raw_time_sec) sec; + + do { + seq = vdso_read_begin(vd); + + if (vd->use_syscall) + return -1; + + cycle_last = vd->cs_cycle_last; + + mult = vd->cs_raw_mult; + shift = vd->cs_shift; +#ifndef ARCH_CLOCK_FIXED_MASK + mask = vd->cs_mask; +#endif + + sec = vd->raw_time_sec; + nsec = vd->raw_time_nsec; + + } while (unlikely(vdso_read_retry(vd, seq))); + + nsec += get_clock_shifted_nsec(cycle_last, mult, mask); + nsec >>= shift; + /* open coding timespec_add_ns to save a ts->tv_nsec = 0 */ + ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); + ts->tv_nsec = nsec; + + return 0; +} + #else /* CONFIG_ARM_ARCH_TIMER */ static notrace int do_realtime(const struct vdso_data *vd, struct timespec *ts)
@@ -218,6 +259,12 @@ static notrace int do_monotonic(const struct vdso_data *vd, struct timespec *ts) return -1; } +static notrace int do_monotonic_raw(const struct vdso_data *vd, + struct timespec *ts) +{ + return -1; +} + #endif /* CONFIG_ARM_ARCH_TIMER */ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
@@ -239,6 +286,10 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) if (do_monotonic(vd, ts)) goto fallback; break; + case CLOCK_MONOTONIC_RAW: + if (do_monotonic_raw(vd, ts)) + goto fallback; + break; default: goto fallback; }
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2.15.0.rc2.357.g7e34df9404-goog