__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 {
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);
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
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 */
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 = {
*/
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;
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
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
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 */
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 */
projects / mirror_ubuntu-artful-kernel.git / commitdiff