s390/time,vdso: convert to the new update_vsyscall interface

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>

8 files changed, 62 insertions, 45 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 314fced4fc14..5877e71901b3 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -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
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