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s390/time,vdso: convert to the new update_vsyscall interface
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Switch to the improved update_vsyscall interface that provides
sub-nanosecond precision for gettimeofday and clock_gettime.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky committed Nov 25, 2013
1 parent 71a86ef commit 79c74ec
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Showing 8 changed files with 62 additions and 45 deletions.
2 changes: 1 addition & 1 deletion arch/s390/Kconfig
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Expand Up @@ -101,7 +101,7 @@ config S390
select GENERIC_CPU_DEVICES if !SMP
select GENERIC_FIND_FIRST_BIT
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL_OLD
select GENERIC_TIME_VSYSCALL
select HAVE_ALIGNED_STRUCT_PAGE if SLUB
select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
select HAVE_ARCH_SECCOMP_FILTER
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5 changes: 3 additions & 2 deletions arch/s390/include/asm/vdso.h
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Expand Up @@ -26,8 +26,9 @@ struct vdso_data {
__u64 wtom_clock_nsec; /* 0x28 */
__u32 tz_minuteswest; /* Minutes west of Greenwich 0x30 */
__u32 tz_dsttime; /* Type of dst correction 0x34 */
__u32 ectg_available;
__u32 ntp_mult; /* NTP adjusted multiplier 0x3C */
__u32 ectg_available; /* ECTG instruction present 0x38 */
__u32 tk_mult; /* Mult. used for xtime_nsec 0x3c */
__u32 tk_shift; /* Shift used for xtime_nsec 0x40 */
};

struct vdso_per_cpu_data {
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3 changes: 2 additions & 1 deletion arch/s390/kernel/asm-offsets.c
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Expand Up @@ -65,7 +65,8 @@ int main(void)
DEFINE(__VDSO_WTOM_NSEC, offsetof(struct vdso_data, wtom_clock_nsec));
DEFINE(__VDSO_TIMEZONE, offsetof(struct vdso_data, tz_minuteswest));
DEFINE(__VDSO_ECTG_OK, offsetof(struct vdso_data, ectg_available));
DEFINE(__VDSO_NTP_MULT, offsetof(struct vdso_data, ntp_mult));
DEFINE(__VDSO_TK_MULT, offsetof(struct vdso_data, tk_mult));
DEFINE(__VDSO_TK_SHIFT, offsetof(struct vdso_data, tk_shift));
DEFINE(__VDSO_ECTG_BASE, offsetof(struct vdso_per_cpu_data, ectg_timer_base));
DEFINE(__VDSO_ECTG_USER, offsetof(struct vdso_per_cpu_data, ectg_user_time));
/* constants used by the vdso */
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27 changes: 18 additions & 9 deletions arch/s390/kernel/time.c
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Expand Up @@ -221,21 +221,30 @@ struct clocksource * __init clocksource_default_clock(void)
return &clocksource_tod;
}

void update_vsyscall_old(struct timespec *wall_time, struct timespec *wtm,
struct clocksource *clock, u32 mult)
void update_vsyscall(struct timekeeper *tk)
{
if (clock != &clocksource_tod)
u64 nsecps;

if (tk->clock != &clocksource_tod)
return;

/* Make userspace gettimeofday spin until we're done. */
++vdso_data->tb_update_count;
smp_wmb();
vdso_data->xtime_tod_stamp = clock->cycle_last;
vdso_data->xtime_clock_sec = wall_time->tv_sec;
vdso_data->xtime_clock_nsec = wall_time->tv_nsec;
vdso_data->wtom_clock_sec = wtm->tv_sec;
vdso_data->wtom_clock_nsec = wtm->tv_nsec;
vdso_data->ntp_mult = mult;
vdso_data->xtime_tod_stamp = tk->clock->cycle_last;
vdso_data->xtime_clock_sec = tk->xtime_sec;
vdso_data->xtime_clock_nsec = tk->xtime_nsec;
vdso_data->wtom_clock_sec =
tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = tk->xtime_nsec +
+ (tk->wall_to_monotonic.tv_nsec << tk->shift);
nsecps = (u64) NSEC_PER_SEC << tk->shift;
while (vdso_data->wtom_clock_nsec >= nsecps) {
vdso_data->wtom_clock_nsec -= nsecps;
vdso_data->wtom_clock_sec++;
}
vdso_data->tk_mult = tk->mult;
vdso_data->tk_shift = tk->shift;
smp_wmb();
++vdso_data->tb_update_count;
}
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30 changes: 16 additions & 14 deletions arch/s390/kernel/vdso32/clock_gettime.S
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Expand Up @@ -38,25 +38,26 @@ __kernel_clock_gettime:
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,2f
ahi %r0,-1
2: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */
2: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
lr %r2,%r0
l %r0,__VDSO_NTP_MULT(%r5)
l %r0,__VDSO_TK_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 3f
a %r0,__VDSO_NTP_MULT(%r5)
a %r0,__VDSO_TK_MULT(%r5)
3: alr %r0,%r2
srdl %r0,12
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
al %r0,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
al %r1,__VDSO_XTIME_NSEC+4(%r5)
brc 12,4f
ahi %r0,1
4: l %r2,__VDSO_XTIME_SEC+4(%r5)
al %r0,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic */
4: al %r0,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic.nsec */
al %r1,__VDSO_WTOM_NSEC+4(%r5)
brc 12,5f
ahi %r0,1
5: al %r2,__VDSO_WTOM_SEC+4(%r5)
5: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
srdl %r0,0(%r2) /* >> tk->shift */
l %r2,__VDSO_XTIME_SEC+4(%r5)
al %r2,__VDSO_WTOM_SEC+4(%r5)
cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
jne 1b
basr %r5,0
Expand Down Expand Up @@ -86,20 +87,21 @@ __kernel_clock_gettime:
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,12f
ahi %r0,-1
12: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */
12: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
lr %r2,%r0
l %r0,__VDSO_NTP_MULT(%r5)
l %r0,__VDSO_TK_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 13f
a %r0,__VDSO_NTP_MULT(%r5)
a %r0,__VDSO_TK_MULT(%r5)
13: alr %r0,%r2
srdl %r0,12
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
al %r0,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
al %r1,__VDSO_XTIME_NSEC+4(%r5)
brc 12,14f
ahi %r0,1
14: l %r2,__VDSO_XTIME_SEC+4(%r5)
14: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
srdl %r0,0(%r2) /* >> tk->shift */
l %r2,__VDSO_XTIME_SEC+4(%r5)
cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
jne 11b
basr %r5,0
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9 changes: 5 additions & 4 deletions arch/s390/kernel/vdso32/gettimeofday.S
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Original file line number Diff line number Diff line change
Expand Up @@ -35,22 +35,23 @@ __kernel_gettimeofday:
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,3f
ahi %r0,-1
3: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */
3: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
st %r0,24(%r15)
l %r0,__VDSO_NTP_MULT(%r5)
l %r0,__VDSO_TK_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 4f
a %r0,__VDSO_NTP_MULT(%r5)
a %r0,__VDSO_TK_MULT(%r5)
4: al %r0,24(%r15)
srdl %r0,12
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
al %r1,__VDSO_XTIME_NSEC+4(%r5)
brc 12,5f
ahi %r0,1
5: mvc 24(4,%r15),__VDSO_XTIME_SEC+4(%r5)
cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
jne 1b
l %r4,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
srdl %r0,0(%r4) /* >> tk->shift */
l %r4,24(%r15) /* get tv_sec from stack */
basr %r5,0
6: ltr %r0,%r0
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22 changes: 12 additions & 10 deletions arch/s390/kernel/vdso64/clock_gettime.S
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Original file line number Diff line number Diff line change
Expand Up @@ -34,14 +34,15 @@ __kernel_clock_gettime:
tmll %r4,0x0001 /* pending update ? loop */
jnz 0b
stck 48(%r15) /* Store TOD clock */
lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */
alg %r0,__VDSO_WTOM_SEC(%r5) /* + wall_to_monotonic.sec */
lg %r1,48(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */
srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */
lg %r0,__VDSO_XTIME_SEC(%r5)
alg %r1,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic */
alg %r0,__VDSO_WTOM_SEC(%r5)
msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
alg %r1,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic.nsec */
srlg %r1,%r1,0(%r2) /* >> tk->shift */
clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
jne 0b
larl %r5,13f
Expand All @@ -62,12 +63,13 @@ __kernel_clock_gettime:
tmll %r4,0x0001 /* pending update ? loop */
jnz 5b
stck 48(%r15) /* Store TOD clock */
lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
lg %r1,48(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */
srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */
lg %r0,__VDSO_XTIME_SEC(%r5)
msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
srlg %r1,%r1,0(%r2) /* >> tk->shift */
lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */
clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
jne 5b
larl %r5,13f
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9 changes: 5 additions & 4 deletions arch/s390/kernel/vdso64/gettimeofday.S
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Original file line number Diff line number Diff line change
Expand Up @@ -31,12 +31,13 @@ __kernel_gettimeofday:
stck 48(%r15) /* Store TOD clock */
lg %r1,48(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */
srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime.tv_nsec */
lg %r0,__VDSO_XTIME_SEC(%r5) /* xtime.tv_sec */
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 */
clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
jne 0b
lgf %r5,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
srlg %r1,%r1,0(%r5) /* >> tk->shift */
larl %r5,5f
2: clg %r1,0(%r5)
jl 3f
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