Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski <[email protected]>, rework it for use in both arm and arm64, overlapping any optimizations for each architecture. But instead of landing it in arm64, land the result into lib/vdso and unify both implementations to simplify future maintenance.
Add a case for CLOCK_MONOTONIC_RAW to match up with support that is available in arm64's vdso. Signed-off-by: Mark Salyzyn <[email protected]> Cc: James Morse <[email protected]> Cc: Russell King <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: John Stultz <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Kees Cook <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Andy Gross <[email protected]> Cc: Kevin Brodsky <[email protected]> Cc: Andrew Pinski <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] v2: - split first CL into 6 of 7 pieces. v4: - Move out ARCH_CLOCK_FIXED_MASK to later adjustment. - update commit message to reflect overall reasoning. - replace typeof() with type vdso_raw_time_sec_t. - remove forced inline. --- arch/arm/include/asm/vdso_datapage.h | 11 +++++++++ arch/arm/kernel/vdso.c | 5 ++++ arch/arm/vdso/vgettimeofday.c | 44 ++++++++++++++++++++++++++++++++++++ 3 files changed, 60 insertions(+) diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h index 8dd7303db4ec..1c6e6a5d5d9d 100644 --- a/arch/arm/include/asm/vdso_datapage.h +++ b/arch/arm/include/asm/vdso_datapage.h @@ -34,6 +34,11 @@ typedef u32 vdso_wtm_clock_nsec_t; typedef u32 vdso_xtime_clock_sec_t; #endif +#ifndef _VDSO_RAW_TIME_SEC_T +#define _VDSO_RAW_TIME_SEC_T +typedef u32 vdso_raw_time_sec_t; +#endif + /* Try to be cache-friendly on systems that don't implement the * generic timer: fit the unconditionally updated fields in the first * 32 bytes. @@ -58,6 +63,12 @@ struct vdso_data { u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */ u32 tz_minuteswest; /* timezone info for gettimeofday(2) */ u32 tz_dsttime; + + /* Raw clocksource multipler */ + u32 cs_raw_mult; + /* Raw time */ + vdso_raw_time_sec_t raw_time_sec; + 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 3ae96d236e48..2b9fce92904e 100644 --- a/arch/arm/vdso/vgettimeofday.c +++ b/arch/arm/vdso/vgettimeofday.c @@ -189,6 +189,40 @@ static notrace int do_monotonic(const struct vdso_data *vd, struct timespec *ts) return 0; } +static notrace int do_monotonic_raw(const struct vdso_data *vd, + struct timespec *ts) +{ + u32 seq, mult, shift; + u64 nsec, cycle_last; + u64 mask; + vdso_raw_time_sec_t 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; + mask = vd->cs_mask; + + 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) @@ -201,6 +235,12 @@ 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) @@ -222,6 +262,10 @@ 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; } -- 2.15.0.rc2.357.g7e34df9404-goog
