s390/time: refactor clock sync
Merge clock_sync_cpu into stp_sync_clock and split out the update of the global and per-CPU clock fields into clock_sync_global and clock_sync_local. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
Родитель
62ba6f85ee
Коммит
b1c0854d16
|
|
@ -52,11 +52,9 @@ static inline void store_clock_comparator(__u64 *time)
|
|||
|
||||
void clock_comparator_work(void);
|
||||
|
||||
void __init ptff_init(void);
|
||||
void __init time_early_init(void);
|
||||
|
||||
extern unsigned char ptff_function_mask[16];
|
||||
extern unsigned long lpar_offset;
|
||||
extern unsigned long initial_leap_seconds;
|
||||
|
||||
/* Function codes for the ptff instruction. */
|
||||
#define PTFF_QAF 0x00 /* query available functions */
|
||||
|
|
|
|||
|
|
@ -467,7 +467,7 @@ void __init startup_init(void)
|
|||
ipl_save_parameters();
|
||||
rescue_initrd();
|
||||
clear_bss_section();
|
||||
ptff_init();
|
||||
time_early_init();
|
||||
init_kernel_storage_key();
|
||||
lockdep_off();
|
||||
setup_lowcore_early();
|
||||
|
|
|
|||
|
|
@ -59,13 +59,14 @@ ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier);
|
|||
EXPORT_SYMBOL(s390_epoch_delta_notifier);
|
||||
|
||||
unsigned char ptff_function_mask[16];
|
||||
unsigned long lpar_offset;
|
||||
unsigned long initial_leap_seconds;
|
||||
|
||||
static unsigned long long lpar_offset;
|
||||
static unsigned long long initial_leap_seconds;
|
||||
|
||||
/*
|
||||
* Get time offsets with PTFF
|
||||
*/
|
||||
void __init ptff_init(void)
|
||||
void __init time_early_init(void)
|
||||
{
|
||||
struct ptff_qto qto;
|
||||
struct ptff_qui qui;
|
||||
|
|
@ -80,7 +81,7 @@ void __init ptff_init(void)
|
|||
|
||||
/* get initial leap seconds */
|
||||
if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0)
|
||||
initial_leap_seconds = (unsigned long)
|
||||
initial_leap_seconds = (unsigned long long)
|
||||
((long) qui.old_leap * 4096000000L);
|
||||
}
|
||||
|
||||
|
|
@ -123,18 +124,6 @@ void clock_comparator_work(void)
|
|||
cd->event_handler(cd);
|
||||
}
|
||||
|
||||
/*
|
||||
* Fixup the clock comparator.
|
||||
*/
|
||||
static void fixup_clock_comparator(unsigned long long delta)
|
||||
{
|
||||
/* If nobody is waiting there's nothing to fix. */
|
||||
if (S390_lowcore.clock_comparator == -1ULL)
|
||||
return;
|
||||
S390_lowcore.clock_comparator += delta;
|
||||
set_clock_comparator(S390_lowcore.clock_comparator);
|
||||
}
|
||||
|
||||
static int s390_next_event(unsigned long delta,
|
||||
struct clock_event_device *evt)
|
||||
{
|
||||
|
|
@ -384,6 +373,36 @@ static inline int check_sync_clock(void)
|
|||
return rc;
|
||||
}
|
||||
|
||||
/*
|
||||
* Apply clock delta to the global data structures.
|
||||
* This is called once on the CPU that performed the clock sync.
|
||||
*/
|
||||
static void clock_sync_global(unsigned long long delta)
|
||||
{
|
||||
struct ptff_qto qto;
|
||||
|
||||
/* Fixup the monotonic sched clock. */
|
||||
sched_clock_base_cc += delta;
|
||||
/* Update LPAR offset. */
|
||||
if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
|
||||
lpar_offset = qto.tod_epoch_difference;
|
||||
/* Call the TOD clock change notifier. */
|
||||
atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta);
|
||||
}
|
||||
|
||||
/*
|
||||
* Apply clock delta to the per-CPU data structures of this CPU.
|
||||
* This is called for each online CPU after the call to clock_sync_global.
|
||||
*/
|
||||
static void clock_sync_local(unsigned long long delta)
|
||||
{
|
||||
/* Add the delta to the clock comparator. */
|
||||
if (S390_lowcore.clock_comparator != -1ULL) {
|
||||
S390_lowcore.clock_comparator += delta;
|
||||
set_clock_comparator(S390_lowcore.clock_comparator);
|
||||
}
|
||||
}
|
||||
|
||||
/* Single threaded workqueue used for stp sync events */
|
||||
static struct workqueue_struct *time_sync_wq;
|
||||
|
||||
|
|
@ -397,31 +416,9 @@ static void __init time_init_wq(void)
|
|||
struct clock_sync_data {
|
||||
atomic_t cpus;
|
||||
int in_sync;
|
||||
unsigned long long fixup_cc;
|
||||
unsigned long long clock_delta;
|
||||
};
|
||||
|
||||
static void clock_sync_cpu(struct clock_sync_data *sync)
|
||||
{
|
||||
atomic_dec(&sync->cpus);
|
||||
enable_sync_clock();
|
||||
while (sync->in_sync == 0) {
|
||||
__udelay(1);
|
||||
/*
|
||||
* A different cpu changes *in_sync. Therefore use
|
||||
* barrier() to force memory access.
|
||||
*/
|
||||
barrier();
|
||||
}
|
||||
if (sync->in_sync != 1)
|
||||
/* Didn't work. Clear per-cpu in sync bit again. */
|
||||
disable_sync_clock(NULL);
|
||||
/*
|
||||
* This round of TOD syncing is done. Set the clock comparator
|
||||
* to the next tick and let the processor continue.
|
||||
*/
|
||||
fixup_clock_comparator(sync->fixup_cc);
|
||||
}
|
||||
|
||||
/*
|
||||
* Server Time Protocol (STP) code.
|
||||
*/
|
||||
|
|
@ -523,54 +520,46 @@ void stp_queue_work(void)
|
|||
|
||||
static int stp_sync_clock(void *data)
|
||||
{
|
||||
static int first;
|
||||
struct clock_sync_data *sync = data;
|
||||
unsigned long long clock_delta;
|
||||
struct clock_sync_data *stp_sync;
|
||||
struct ptff_qto qto;
|
||||
static int first;
|
||||
int rc;
|
||||
|
||||
stp_sync = data;
|
||||
|
||||
if (xchg(&first, 1) == 1) {
|
||||
/* Slave */
|
||||
clock_sync_cpu(stp_sync);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Wait until all other cpus entered the sync function. */
|
||||
while (atomic_read(&stp_sync->cpus) != 0)
|
||||
cpu_relax();
|
||||
|
||||
enable_sync_clock();
|
||||
|
||||
rc = 0;
|
||||
if (stp_info.todoff[0] || stp_info.todoff[1] ||
|
||||
stp_info.todoff[2] || stp_info.todoff[3] ||
|
||||
stp_info.tmd != 2) {
|
||||
rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, &clock_delta);
|
||||
if (rc == 0) {
|
||||
/* fixup the monotonic sched clock */
|
||||
sched_clock_base_cc += clock_delta;
|
||||
if (ptff_query(PTFF_QTO) &&
|
||||
ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
|
||||
/* Update LPAR offset */
|
||||
lpar_offset = qto.tod_epoch_difference;
|
||||
atomic_notifier_call_chain(&s390_epoch_delta_notifier,
|
||||
0, &clock_delta);
|
||||
stp_sync->fixup_cc = clock_delta;
|
||||
fixup_clock_comparator(clock_delta);
|
||||
rc = chsc_sstpi(stp_page, &stp_info,
|
||||
sizeof(struct stp_sstpi));
|
||||
if (rc == 0 && stp_info.tmd != 2)
|
||||
rc = -EAGAIN;
|
||||
if (xchg(&first, 1) == 0) {
|
||||
/* Wait until all other cpus entered the sync function. */
|
||||
while (atomic_read(&sync->cpus) != 0)
|
||||
cpu_relax();
|
||||
rc = 0;
|
||||
if (stp_info.todoff[0] || stp_info.todoff[1] ||
|
||||
stp_info.todoff[2] || stp_info.todoff[3] ||
|
||||
stp_info.tmd != 2) {
|
||||
rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0,
|
||||
&clock_delta);
|
||||
if (rc == 0) {
|
||||
sync->clock_delta = clock_delta;
|
||||
clock_sync_global(clock_delta);
|
||||
rc = chsc_sstpi(stp_page, &stp_info,
|
||||
sizeof(struct stp_sstpi));
|
||||
if (rc == 0 && stp_info.tmd != 2)
|
||||
rc = -EAGAIN;
|
||||
}
|
||||
}
|
||||
sync->in_sync = rc ? -EAGAIN : 1;
|
||||
xchg(&first, 0);
|
||||
} else {
|
||||
/* Slave */
|
||||
atomic_dec(&sync->cpus);
|
||||
/* Wait for in_sync to be set. */
|
||||
while (READ_ONCE(sync->in_sync) == 0)
|
||||
__udelay(1);
|
||||
}
|
||||
if (rc) {
|
||||
if (sync->in_sync != 1)
|
||||
/* Didn't work. Clear per-cpu in sync bit again. */
|
||||
disable_sync_clock(NULL);
|
||||
stp_sync->in_sync = -EAGAIN;
|
||||
} else
|
||||
stp_sync->in_sync = 1;
|
||||
xchg(&first, 0);
|
||||
/* Apply clock delta to per-CPU fields of this CPU. */
|
||||
clock_sync_local(sync->clock_delta);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче