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Commit ca64f639 authored by David Hildenbrand's avatar David Hildenbrand Committed by Martin Schwidefsky
Browse files

s390/time: cleanup etr leftovers 



There are still some etr leftovers and wrong comments, let's clean that up.

Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 41ad0220

arch/s390/kernel/time.c

+9 −21
Original line number Diff line number Diff line
@@ -318,10 +318,8 @@ static DEFINE_PER_CPU(atomic_t, clock_sync_word); 
static DEFINE_MUTEX(clock_sync_mutex);

static unsigned long clock_sync_flags;



#define CLOCK_SYNC_HAS_ETR	0

#define CLOCK_SYNC_HAS_STP	1

#define CLOCK_SYNC_ETR		2

#define CLOCK_SYNC_STP		3

#define CLOCK_SYNC_HAS_STP	0

#define CLOCK_SYNC_STP		1



/*

 * The get_clock function for the physical clock. It will get the current
@@ -343,34 +341,32 @@ int get_phys_clock(unsigned long long *clock) 
	if (sw0 == sw1 && (sw0 & 0x80000000U))

		/* Success: time is in sync. */

		return 0;

	if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags) &&

	    !test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))

	if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))

		return -EOPNOTSUPP;

	if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) &&

	    !test_bit(CLOCK_SYNC_STP, &clock_sync_flags))

	if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))

		return -EACCES;

	return -EAGAIN;

}

EXPORT_SYMBOL(get_phys_clock);



/*

 * Make get_sync_clock return -EAGAIN.

 * Make get_phys_clock() return -EAGAIN.

 */

static void disable_sync_clock(void *dummy)

{

	atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);

	/*

	 * Clear the in-sync bit 2^31. All get_sync_clock calls will

	 * Clear the in-sync bit 2^31. All get_phys_clock calls will

	 * fail until the sync bit is turned back on. In addition

	 * increase the "sequence" counter to avoid the race of an

	 * etr event and the complete recovery against get_sync_clock.

	 * stp event and the complete recovery against get_phys_clock.

	 */

	atomic_andnot(0x80000000, sw_ptr);

	atomic_inc(sw_ptr);

}



/*

 * Make get_sync_clock return 0 again.

 * Make get_phys_clock() return 0 again.

 * Needs to be called from a context disabled for preemption.

 */

static void enable_sync_clock(void)
@@ -393,7 +389,7 @@ static inline int check_sync_clock(void) 
	return rc;

}



/* Single threaded workqueue used for etr and stp sync events */

/* Single threaded workqueue used for stp sync events */

static struct workqueue_struct *time_sync_wq;



static void __init time_init_wq(void)
@@ -407,20 +403,12 @@ struct clock_sync_data { 
	atomic_t cpus;

	int in_sync;

	unsigned long long fixup_cc;

	int etr_port;

	struct etr_aib *etr_aib;

};



static void clock_sync_cpu(struct clock_sync_data *sync)

{

	atomic_dec(&sync->cpus);

	enable_sync_clock();

	/*

	 * This looks like a busy wait loop but it isn't. etr_sync_cpus

	 * is called on all other cpus while the TOD clocks is stopped.

	 * __udelay will stop the cpu on an enabled wait psw until the

	 * TOD is running again.

	 */

	while (sync->in_sync == 0) {

		__udelay(1);

		/*