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authorHendrik Brueckner <brueckner@linux.vnet.ibm.com>2010-04-22 17:17:06 +0200
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-04-22 17:17:19 +0200
commit157a1a27d5921fc94db8c14e0d01363d13de99b5 (patch)
tree4906607e35a4bee0e84e42d59985af645c1564a2
parent8821d24cd261aede9b0436cd3252b17a60ccc33a (diff)
[S390] vdso: use ntp adjusted clock multiplier
Commit "timekeeping: Fix clock_gettime vsyscall time warp" (0696b711e) introduced the new parameter "mult" to update_vsyscall(). This parameter contains the internal NTP adjusted clock multiplier. The s390x vdso did not use this adjusted multiplier. Instead, it used the constant clock multiplier for gettimeofday() and clock_gettime() variants. This may result in observable time warps as explained in commit 0696b711e. Make the NTP adjusted clock multiplier available to the s390x vdso implementation and use it for time calculations. Cc: <stable@kernel.org> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/include/asm/vdso.h1
-rw-r--r--arch/s390/kernel/asm-offsets.c1
-rw-r--r--arch/s390/kernel/time.c1
-rw-r--r--arch/s390/kernel/vdso32/clock_gettime.S12
-rw-r--r--arch/s390/kernel/vdso32/gettimeofday.S6
-rw-r--r--arch/s390/kernel/vdso64/clock_gettime.S4
-rw-r--r--arch/s390/kernel/vdso64/gettimeofday.S2
7 files changed, 15 insertions, 12 deletions
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index 4a76d9480cc..533f35751ae 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -29,6 +29,7 @@ struct vdso_data {
__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 */
};
struct vdso_per_cpu_data {
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 08db736dded..a09408952ed 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -61,6 +61,7 @@ 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_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 fba6dec156b..d906bf19c14 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -221,6 +221,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock,
vdso_data->xtime_clock_nsec = wall_time->tv_nsec;
vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
+ vdso_data->ntp_mult = mult;
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 4a98909a831..96964395427 100644
--- a/arch/s390/kernel/vdso32/clock_gettime.S
+++ b/arch/s390/kernel/vdso32/clock_gettime.S
@@ -38,13 +38,13 @@ __kernel_clock_gettime:
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,2f
ahi %r0,-1
-2: mhi %r0,1000 /* cyc2ns(clock,cycle_delta) */
+2: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */
lr %r2,%r0
- lhi %r0,1000
+ l %r0,__VDSO_NTP_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 3f
- ahi %r0,1000
+ a %r0,__VDSO_NTP_MULT(%r5)
3: alr %r0,%r2
srdl %r0,12
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
@@ -86,13 +86,13 @@ __kernel_clock_gettime:
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,12f
ahi %r0,-1
-12: mhi %r0,1000 /* cyc2ns(clock,cycle_delta) */
+12: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */
lr %r2,%r0
- lhi %r0,1000
+ l %r0,__VDSO_NTP_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 13f
- ahi %r0,1000
+ a %r0,__VDSO_NTP_MULT(%r5)
13: alr %r0,%r2
srdl %r0,12
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S
index ad8acfc949f..2d3633175e3 100644
--- a/arch/s390/kernel/vdso32/gettimeofday.S
+++ b/arch/s390/kernel/vdso32/gettimeofday.S
@@ -35,13 +35,13 @@ __kernel_gettimeofday:
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,3f
ahi %r0,-1
-3: mhi %r0,1000 /* cyc2ns(clock,cycle_delta) */
+3: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */
st %r0,24(%r15)
- lhi %r0,1000
+ l %r0,__VDSO_NTP_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 4f
- ahi %r0,1000
+ a %r0,__VDSO_NTP_MULT(%r5)
4: al %r0,24(%r15)
srdl %r0,12
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S
index 49106c6e6f8..f40467884a0 100644
--- a/arch/s390/kernel/vdso64/clock_gettime.S
+++ b/arch/s390/kernel/vdso64/clock_gettime.S
@@ -36,7 +36,7 @@ __kernel_clock_gettime:
stck 48(%r15) /* Store TOD clock */
lg %r1,48(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
- mghi %r1,1000
+ 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)
@@ -64,7 +64,7 @@ __kernel_clock_gettime:
stck 48(%r15) /* Store TOD clock */
lg %r1,48(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
- mghi %r1,1000
+ 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)
diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
index f873e75634e..36ee674722e 100644
--- a/arch/s390/kernel/vdso64/gettimeofday.S
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -31,7 +31,7 @@ __kernel_gettimeofday:
stck 48(%r15) /* Store TOD clock */
lg %r1,48(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
- mghi %r1,1000
+ 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 */