diff options
| -rw-r--r-- | arch/s390/include/asm/vdso.h | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/asm-offsets.c | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/time.c | 41 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso32/clock_gettime.S | 23 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso32/gettimeofday.S | 23 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso64/clock_gettime.S | 11 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso64/gettimeofday.S | 11 |
7 files changed, 106 insertions, 7 deletions
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h index d0a2dbf2433d..88bdc477a843 100644 --- a/arch/s390/include/asm/vdso.h +++ b/arch/s390/include/asm/vdso.h @@ -33,6 +33,8 @@ struct vdso_data { __u32 ectg_available; /* ECTG instruction present 0x58 */ __u32 tk_mult; /* Mult. used for xtime_nsec 0x5c */ __u32 tk_shift; /* Shift used for xtime_nsec 0x60 */ + __u32 ts_dir; /* TOD steering direction 0x64 */ + __u64 ts_end; /* TOD steering end 0x68 */ }; struct vdso_per_cpu_data { diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index f3df9e0a5dec..ec16cec6bcd4 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -79,6 +79,8 @@ int main(void) OFFSET(__VDSO_ECTG_OK, vdso_data, ectg_available); OFFSET(__VDSO_TK_MULT, vdso_data, tk_mult); OFFSET(__VDSO_TK_SHIFT, vdso_data, tk_shift); + OFFSET(__VDSO_TS_DIR, vdso_data, ts_dir); + OFFSET(__VDSO_TS_END, vdso_data, ts_end); OFFSET(__VDSO_ECTG_BASE, vdso_per_cpu_data, ectg_timer_base); OFFSET(__VDSO_ECTG_USER, vdso_per_cpu_data, ectg_user_time); OFFSET(__VDSO_CPU_NR, vdso_per_cpu_data, cpu_nr); diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 5ba6c67ddd99..33082f6cbb5d 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -62,6 +62,8 @@ unsigned char ptff_function_mask[16]; static unsigned long long lpar_offset; static unsigned long long initial_leap_seconds; +static unsigned long long tod_steering_end; +static unsigned long long tod_steering_delta; /* * Get time offsets with PTFF @@ -71,8 +73,13 @@ void __init time_early_init(void) struct ptff_qto qto; struct ptff_qui qui; + /* Initialize TOD steering parameters */ + tod_steering_end = sched_clock_base_cc; + vdso_data->ts_end = tod_steering_end; + if (!test_facility(28)) return; + ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF); /* get LPAR offset */ @@ -204,7 +211,22 @@ void read_boot_clock64(struct timespec64 *ts) static cycle_t read_tod_clock(struct clocksource *cs) { - return get_tod_clock(); + unsigned long long now, adj; + + preempt_disable(); /* protect from changes to steering parameters */ + now = get_tod_clock(); + adj = tod_steering_end - now; + if (unlikely((s64) adj >= 0)) + /* + * manually steer by 1 cycle every 2^16 cycles. This + * corresponds to shifting the tod delta by 15. 1s is + * therefore steered in ~9h. The adjust will decrease + * over time, until it finally reaches 0. + */ + now += ((s64) tod_steering_delta < 0) ? + (adj >> 15) : -(adj >> 15); + preempt_enable(); + return now; } static struct clocksource clocksource_tod = { @@ -379,10 +401,27 @@ static inline int check_sync_clock(void) */ static void clock_sync_global(unsigned long long delta) { + unsigned long now, adj; struct ptff_qto qto; /* Fixup the monotonic sched clock. */ sched_clock_base_cc += delta; + /* Adjust TOD steering parameters. */ + vdso_data->tb_update_count++; + now = get_tod_clock(); + adj = tod_steering_end - now; + if (unlikely((s64) adj >= 0)) + /* Calculate how much of the old adjustment is left. */ + tod_steering_delta = ((s64) tod_steering_delta < 0) ? + -(adj >> 15) : (adj >> 15); + tod_steering_delta += delta; + if ((abs(tod_steering_delta) >> 48) != 0) + panic("TOD clock sync offset %lli is too large to drift\n", + tod_steering_delta); + tod_steering_end = now + (abs(tod_steering_delta) << 15); + vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1; + vdso_data->ts_end = tod_steering_end; + vdso_data->tb_update_count++; /* Update LPAR offset. */ if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) lpar_offset = qto.tod_epoch_difference; diff --git a/arch/s390/kernel/vdso32/clock_gettime.S b/arch/s390/kernel/vdso32/clock_gettime.S index 5eec9afbb5b5..a5769b83d90e 100644 --- a/arch/s390/kernel/vdso32/clock_gettime.S +++ b/arch/s390/kernel/vdso32/clock_gettime.S @@ -99,8 +99,27 @@ __kernel_clock_gettime: tml %r4,0x0001 /* pending update ? loop */ jnz 11b stcke 0(%r15) /* Store TOD clock */ - lm %r0,%r1,1(%r15) - s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + lm %r0,%r1,__VDSO_TS_END(%r5) /* TOD steering end time */ + s %r0,1(%r15) /* no - ts_steering_end */ + sl %r1,5(%r15) + brc 3,22f + ahi %r0,-1 +22: ltr %r0,%r0 /* past end of steering? */ + jm 24f + srdl %r0,15 /* 1 per 2^16 */ + tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ + jz 23f + lcr %r0,%r0 /* negative TOD offset */ + lcr %r1,%r1 + je 23f + ahi %r0,-1 +23: a %r0,1(%r15) /* add TOD timestamp */ + al %r1,5(%r15) + brc 12,25f + ahi %r0,1 + j 25f +24: lm %r0,%r1,1(%r15) /* load TOD timestamp */ +25: s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ sl %r1,__VDSO_XTIME_STAMP+4(%r5) brc 3,12f ahi %r0,-1 diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S index 719de6186b20..63b86dceb0bf 100644 --- a/arch/s390/kernel/vdso32/gettimeofday.S +++ b/arch/s390/kernel/vdso32/gettimeofday.S @@ -31,8 +31,27 @@ __kernel_gettimeofday: tml %r4,0x0001 /* pending update ? loop */ jnz 1b stcke 0(%r15) /* Store TOD clock */ - lm %r0,%r1,1(%r15) - s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + lm %r0,%r1,__VDSO_TS_END(%r5) /* TOD steering end time */ + s %r0,1(%r15) + sl %r1,5(%r15) + brc 3,14f + ahi %r0,-1 +14: ltr %r0,%r0 /* past end of steering? */ + jm 16f + srdl %r0,15 /* 1 per 2^16 */ + tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ + jz 15f + lcr %r0,%r0 /* negative TOD offset */ + lcr %r1,%r1 + je 15f + ahi %r0,-1 +15: a %r0,1(%r15) /* add TOD timestamp */ + al %r1,5(%r15) + brc 12,17f + ahi %r0,1 + j 17f +16: lm %r0,%r1,1(%r15) /* load TOD timestamp */ +17: s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ sl %r1,__VDSO_XTIME_STAMP+4(%r5) brc 3,3f ahi %r0,-1 diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S index 61541fb93dc6..9c3b12626dba 100644 --- a/arch/s390/kernel/vdso64/clock_gettime.S +++ b/arch/s390/kernel/vdso64/clock_gettime.S @@ -83,8 +83,17 @@ __kernel_clock_gettime: tmll %r4,0x0001 /* pending update ? loop */ jnz 5b stcke 0(%r15) /* Store TOD clock */ - lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ lg %r1,1(%r15) + lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */ + slgr %r0,%r1 /* now - ts_steering_end */ + ltgr %r0,%r0 /* past end of steering ? */ + jm 17f + srlg %r0,%r0,15 /* 1 per 2^16 */ + tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ + jz 18f + lcgr %r0,%r0 /* negative TOD offset */ +18: algr %r1,%r0 /* add steering offset */ +17: lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S index 6ce46707663c..b02e62f3bc12 100644 --- a/arch/s390/kernel/vdso64/gettimeofday.S +++ b/arch/s390/kernel/vdso64/gettimeofday.S @@ -31,7 +31,16 @@ __kernel_gettimeofday: jnz 0b stcke 0(%r15) /* Store TOD clock */ lg %r1,1(%r15) - sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */ + slgr %r0,%r1 /* now - ts_steering_end */ + ltgr %r0,%r0 /* past end of steering ? */ + jm 6f + srlg %r0,%r0,15 /* 1 per 2^16 */ + tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ + jz 7f + lcgr %r0,%r0 /* negative TOD offset */ +7: algr %r1,%r0 /* add steering offset */ +6: sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */ |