From f939890b6687e05c42361655fb6610fa08f5a601 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 22 Feb 2009 12:57:49 +0100 Subject: time: ntp: refactor and clean up ntp_update_offset() Impact: cleanup, no functionality changed - introduce the ntp_update_offset_fll() helper - clean up the flow and variable naming kernel/time/ntp.o: text data bss dec hex filename 2504 114 136 2754 ac2 ntp.o.before 2504 114 136 2754 ac2 ntp.o.after md5: 01f7b8e1a5472a3056f9e4ae84d46315 ntp.o.before.asm 01f7b8e1a5472a3056f9e4ae84d46315 ntp.o.after.asm Signed-off-by: Ingo Molnar --- kernel/time/ntp.c | 44 ++++++++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 14 deletions(-) (limited to 'kernel/time/ntp.c') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index f1abad73857..ee437e1445d 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -103,10 +103,27 @@ static void ntp_update_frequency(void) tick_length_base = new_base; } +static inline s64 ntp_update_offset_fll(s64 freq_adj, s64 offset64, long secs) +{ + time_status &= ~STA_MODE; + + if (secs < MINSEC) + return freq_adj; + + if (!(time_status & STA_FLL) && (secs <= MAXSEC)) + return freq_adj; + + freq_adj += div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs); + time_status |= STA_MODE; + + return freq_adj; +} + static void ntp_update_offset(long offset) { - long mtemp; s64 freq_adj; + s64 offset64; + long secs; if (!(time_status & STA_PLL)) return; @@ -127,22 +144,21 @@ static void ntp_update_offset(long offset) */ if (time_status & STA_FREQHOLD || time_reftime == 0) time_reftime = xtime.tv_sec; - mtemp = xtime.tv_sec - time_reftime; + + secs = xtime.tv_sec - time_reftime; time_reftime = xtime.tv_sec; - freq_adj = (s64)offset * mtemp; - freq_adj <<= NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant); - time_status &= ~STA_MODE; - if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) { - freq_adj += div_s64((s64)offset << (NTP_SCALE_SHIFT - SHIFT_FLL), - mtemp); - time_status |= STA_MODE; - } - freq_adj += time_freq; - freq_adj = min(freq_adj, MAXFREQ_SCALED); - time_freq = max(freq_adj, -MAXFREQ_SCALED); + offset64 = offset; + freq_adj = (offset64 * secs) << + (NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant)); + + freq_adj = ntp_update_offset_fll(freq_adj, offset64, secs); + + freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED); + + time_freq = max(freq_adj, -MAXFREQ_SCALED); - time_offset = div_s64((s64)offset << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ); + time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ); } /** -- cgit v1.2.3