From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit 79c74ecbebf76732f91b82a62ce7fc8a88326962 upstream.
Switch to the improved update_vsyscall interface that provides
sub-nanosecond precision for gettimeofday and clock_gettime.
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
arch/s390/Kconfig | 2 +-
arch/s390/include/asm/vdso.h | 5 +++--
arch/s390/kernel/asm-offsets.c | 3 ++-
arch/s390/kernel/time.c | 27 ++++++++++++++++++---------
arch/s390/kernel/vdso32/clock_gettime.S | 30 ++++++++++++++++--------------
arch/s390/kernel/vdso32/gettimeofday.S | 9 +++++----
arch/s390/kernel/vdso64/clock_gettime.S | 22 ++++++++++++----------
arch/s390/kernel/vdso64/gettimeofday.S | 9 +++++----
8 files changed, 62 insertions(+), 45 deletions(-)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 7143793859fa..3e01afa21710 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -100,7 +100,7 @@ config S390
select GENERIC_CLOCKEVENTS
select GENERIC_CPU_DEVICES if !SMP
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
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index a73eb2e1e918..bc9746a7d47c 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -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 {
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 2416138ebd3e..496116cd65ec 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -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 */
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 064c3082ab33..60a508a9b981 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -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;
}
diff --git a/arch/s390/kernel/vdso32/clock_gettime.S b/arch/s390/kernel/vdso32/clock_gettime.S
index b2224e0b974c..5be8e472f57d 100644
--- a/arch/s390/kernel/vdso32/clock_gettime.S
+++ b/arch/s390/kernel/vdso32/clock_gettime.S
@@ -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
@@ -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
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S
index 2d3633175e3b..fd621a950f7c 100644
--- a/arch/s390/kernel/vdso32/gettimeofday.S
+++ b/arch/s390/kernel/vdso32/gettimeofday.S
@@ -35,15 +35,14 @@ __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
@@ -51,6 +50,8 @@ __kernel_gettimeofday:
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
diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S
index d46c95ed5f19..0add1072ba30 100644
--- a/arch/s390/kernel/vdso64/clock_gettime.S
+++ b/arch/s390/kernel/vdso64/clock_gettime.S
@@ -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
@@ -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
diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
index 36ee674722ec..d0860d1d0ccc 100644
--- a/arch/s390/kernel/vdso64/gettimeofday.S
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -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
--
1.9.0
--
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