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Commit b6112ccb authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] add read_persistent_clock 



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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 5b409ed1

arch/s390/include/asm/timex.h

+5 −0
Original line number Diff line number Diff line
@@ -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 *clock); 
void init_cpu_timer(void);

unsigned long long monotonic_clock(void);



extern u64 sched_clock_base_cc;



#endif

arch/s390/kernel/early.c

+16 −0
Original line number Diff line number Diff line
@@ -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_line(void) 
 */

void __init startup_init(void)

{

	reset_tod_clock();

	ipl_save_parameters();

	rescue_initrd();

	clear_bss_section();

arch/s390/kernel/head.S

+5 −2
Original line number Diff line number Diff line
@@ -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)

arch/s390/kernel/time.c

+9 −19
Original line number Diff line number Diff line
@@ -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 code) 
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);