From: Martin Schwidefsky Add a read_persistent_clock function that does not just return 0. Since timekeeping_init calls the function before time_init has been called move reset_tod_clock to early.c to make sure that the TOD clock is running when read_persistent_clock is invoked. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/timex.h | 5 +++++ arch/s390/kernel/early.c | 16 ++++++++++++++++ arch/s390/kernel/head.S | 7 +++++-- arch/s390/kernel/time.c | 28 +++++++++------------------- 4 files changed, 35 insertions(+), 21 deletions(-) Index: quilt-2.6/arch/s390/include/asm/timex.h =================================================================== --- quilt-2.6.orig/arch/s390/include/asm/timex.h +++ quilt-2.6/arch/s390/include/asm/timex.h @@ -11,6 +11,9 @@ #ifndef _ASM_S390_TIMEX_H #define _ASM_S390_TIMEX_H +/* The value of the TOD clock for 1.1.1970. */ +#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL + /* Inline functions for clock register access. */ static inline int set_clock(__u64 time) { @@ -85,4 +88,6 @@ int get_sync_clock(unsigned long long *c void init_cpu_timer(void); unsigned long long monotonic_clock(void); +extern u64 sched_clock_base_cc; + #endif Index: quilt-2.6/arch/s390/kernel/early.c =================================================================== --- quilt-2.6.orig/arch/s390/kernel/early.c +++ quilt-2.6/arch/s390/kernel/early.c @@ -38,6 +38,21 @@ static unsigned long machine_flags; static void __init setup_boot_command_line(void); +/* + * Get the TOD clock running. + */ +static void __init reset_tod_clock(void) +{ + u64 time; + + if (store_clock(&time) == 0) + return; + /* TOD clock not running. Set the clock to Unix Epoch. */ + if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0) + disabled_wait(0); + + sched_clock_base_cc = TOD_UNIX_EPOCH; +} #ifdef CONFIG_SHARED_KERNEL int __init savesys_ipl_nss(char *cmd, const int cmdlen); @@ -372,6 +387,7 @@ static void __init setup_boot_command_li */ void __init startup_init(void) { + reset_tod_clock(); ipl_save_parameters(); rescue_initrd(); clear_bss_section(); Index: quilt-2.6/arch/s390/kernel/head.S =================================================================== --- quilt-2.6.orig/arch/s390/kernel/head.S +++ quilt-2.6/arch/s390/kernel/head.S @@ -471,6 +471,8 @@ startup:basr %r13,0 # get base .LPG0: xc 0x200(256),0x200 # partially clear lowcore xc 0x300(256),0x300 + l %r1,5f-.LPG0(%r13) + stck 0(%r1) #ifndef CONFIG_MARCH_G5 # check processor version against MARCH_{G5,Z900,Z990,Z9_109,Z10} @@ -496,9 +498,10 @@ startup:basr %r13,0 # get base brct %r0,0b #endif - l %r13,0f-.LPG0(%r13) + l %r13,4f-.LPG0(%r13) b 0(%r13) -0: .long startup_continue +4: .long startup_continue +5: .long sched_clock_base_cc # # params at 10400 (setup.h) Index: quilt-2.6/arch/s390/kernel/time.c =================================================================== --- quilt-2.6.orig/arch/s390/kernel/time.c +++ quilt-2.6/arch/s390/kernel/time.c @@ -52,9 +52,6 @@ #define USECS_PER_JIFFY ((unsigned long) 1000000/HZ) #define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12) -/* The value of the TOD clock for 1.1.1970. */ -#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL - /* * Create a small time difference between the timer interrupts * on the different cpus to avoid lock contention. @@ -63,9 +60,10 @@ #define TICK_SIZE tick +u64 sched_clock_base_cc = -1; /* Force to data section. */ + static ext_int_info_t ext_int_info_cc; static ext_int_info_t ext_int_etr_cc; -static u64 sched_clock_base_cc; static DEFINE_PER_CPU(struct clock_event_device, comparators); @@ -195,22 +193,12 @@ static void timing_alert_interrupt(__u16 static void etr_reset(void); static void stp_reset(void); -/* - * Get the TOD clock running. - */ -static u64 __init reset_tod_clock(void) +unsigned long read_persistent_clock(void) { - u64 time; + struct timespec ts; - etr_reset(); - stp_reset(); - if (store_clock(&time) == 0) - return time; - /* TOD clock not running. Set the clock to Unix Epoch. */ - if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0) - panic("TOD clock not operational."); - - return TOD_UNIX_EPOCH; + tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, &ts); + return ts.tv_sec; } static cycle_t read_tod_clock(void) @@ -265,7 +253,9 @@ void update_vsyscall_tz(void) */ void __init time_init(void) { - sched_clock_base_cc = reset_tod_clock(); + /* Reset time synchronization interfaces. */ + etr_reset(); + stp_reset(); /* set xtime */ tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &xtime); -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/