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Commit 2f82f577 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/time: STP sync clock correction 



The sync clock operation of the channel subsystem call for STP delivers
the TOD clock difference as a result. Use this TOD clock difference
instead of the difference between the TOD timestamps before and after
the sync clock operation.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 4e042af4

arch/s390/include/asm/cio.h

+1 −1
Original line number Diff line number Diff line
@@ -320,7 +320,7 @@ struct cio_iplinfo { 
extern int cio_get_iplinfo(struct cio_iplinfo *iplinfo);



/* Function from drivers/s390/cio/chsc.c */

int chsc_sstpc(void *page, unsigned int op, u16 ctrl);

int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta);

int chsc_sstpi(void *page, void *result, size_t size);



#endif

arch/s390/kernel/time.c

+5 −6
Original line number Diff line number Diff line
@@ -1455,7 +1455,7 @@ static void __init stp_reset(void) 
	int rc;



	stp_page = (void *) get_zeroed_page(GFP_ATOMIC);

	rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);

	rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);

	if (rc == 0)

		set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);

	else if (stp_online) {
@@ -1554,11 +1554,10 @@ static int stp_sync_clock(void *data) 
	    stp_info.todoff[2] || stp_info.todoff[3] ||

	    stp_info.tmd != 2) {

		old_clock = get_tod_clock();

		rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0);

		rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, &clock_delta);

		if (rc == 0) {

			new_clock = get_tod_clock();

			new_clock = old_clock + clock_delta;

			delta = adjust_time(old_clock, new_clock, 0);

			clock_delta = new_clock - old_clock;

			atomic_notifier_call_chain(&s390_epoch_delta_notifier,

						   0, &clock_delta);

			fixup_clock_comparator(delta);
@@ -1590,12 +1589,12 @@ static void stp_work_fn(struct work_struct *work) 
	mutex_lock(&stp_work_mutex);



	if (!stp_online) {

		chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);

		chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);

		del_timer_sync(&stp_timer);

		goto out_unlock;

	}



	rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);

	rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL);

	if (rc)

		goto out_unlock;

drivers/s390/cio/chsc.c

+6 −2
Original line number Diff line number Diff line
@@ -1176,7 +1176,7 @@ chsc_determine_css_characteristics(void) 
EXPORT_SYMBOL_GPL(css_general_characteristics);

EXPORT_SYMBOL_GPL(css_chsc_characteristics);



int chsc_sstpc(void *page, unsigned int op, u16 ctrl)

int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta)

{

	struct {

		struct chsc_header request;
@@ -1186,7 +1186,9 @@ int chsc_sstpc(void *page, unsigned int op, u16 ctrl) 
		unsigned int ctrl : 16;

		unsigned int rsvd2[5];

		struct chsc_header response;

		unsigned int rsvd3[7];

		unsigned int rsvd3[3];

		u64 clock_delta;

		unsigned int rsvd4[2];

	} __attribute__ ((packed)) *rr;

	int rc;
@@ -1200,6 +1202,8 @@ int chsc_sstpc(void *page, unsigned int op, u16 ctrl) 
	if (rc)

		return -EIO;

	rc = (rr->response.code == 0x0001) ? 0 : -EIO;

	if (clock_delta)

		*clock_delta = rr->clock_delta;

	return rc;

}