[RFC/NOT FOR MERGING] HACK: add global/private timers for A9

[balbi@ti.com (Felipe Balbi)]

On Thu, Jun 04, 2015 at 03:20:57PM -0700, Stephen Boyd wrote:
> On 06/04, Felipe Balbi wrote:
> > On Thu, Jun 04, 2015 at 03:18:25PM -0500, Felipe Balbi wrote:
> > > On Thu, Jun 04, 2015 at 03:08:50PM -0500, Felipe Balbi wrote:
> > > > Hi,
> > > > 
> > > > On Thu, Jun 04, 2015 at 11:46:59AM +0200, Mason wrote:
> > > > > Also, check /proc/timer_list for a "Broadcast device". If you don't
> > > > > define one, the TWD timers are set to periodic mode, with hrtimers
> > > > > disabled.
> > > > 
> > > > Did you manage to turn global timer into Broadcast device ?
> > > 
> > > arm_global_timer is marked PERCPU, so it will never be chosen as
> > > broadcast.
> > 
> > Perhaps this is acceptable ?
> > 
> > diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
> > index e6833771a716..8c0170ac367d 100644
> > --- a/drivers/clocksource/arm_global_timer.c
> > +++ b/drivers/clocksource/arm_global_timer.c
> > @@ -169,8 +169,9 @@ static int gt_clockevents_init(struct clock_event_device *clk)
> >  	int cpu = smp_processor_id();
> >  
> >  	clk->name = "arm_global_timer";
> > -	clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
> > -		CLOCK_EVT_FEAT_PERCPU;
> > +	clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
> > +	if (is_smp() || setup_max_cpus)
> > +		clk->features |= CLOCK_EVT_FEAT_PERCPU;
> >  	clk->set_mode = gt_clockevent_set_mode;
> >  	clk->set_next_event = gt_clockevent_set_next_event;
> >  	clk->cpumask = cpumask_of(cpu);
> > 
> 
> What is this doing? Allowing the global timer to become the
> broadcast timer? Can you share all the clockevents that are being

yeah, as long as have single CPU.

> registered in the system and what ratings and features they have?

Timer List Version: v0.7
HRTIMER_MAX_CLOCK_BASES: 4
now at 126645624877 nsecs

cpu: 0
 clock 0:
  .base:       eeec36b8
  .index:      0
  .resolution: 1 nsecs
  .get_time:   ktime_get
  .offset:     0 nsecs
active timers:
 #0: <eeec3970>, tick_sched_timer, S:01
 # expires at 126646000000-126646000000 nsecs [in 375123 to 375123 nsecs]
 #1: def_rt_bandwidth, sched_rt_period_timer, S:01
 # expires at 127000000000-127000000000 nsecs [in 354375123 to 354375123 nsecs]
 #2: <ed07ff28>, hrtimer_wakeup, S:01
 # expires at 135190356958-135190406958 nsecs [in 8544732081 to 8544782081 nsecs]
 #3: <ed17bb40>, timerfd_tmrproc, S:01
 # expires at 136961414000-136961414000 nsecs [in 10315789123 to 10315789123 nsecs]
 #4: <ed17bcc0>, timerfd_tmrproc, S:01
 # expires at 156961414000-156961414000 nsecs [in 30315789123 to 30315789123 nsecs]
 #5: <ed1fde40>, timerfd_tmrproc, S:01
 # expires at 157211414000-157211414000 nsecs [in 30565789123 to 30565789123 nsecs]
 #6: <ed143c00>, timerfd_tmrproc, S:01
 # expires at 180211414000-180211414000 nsecs [in 53565789123 to 53565789123 nsecs]
 #7: <ee43d0c0>, timerfd_tmrproc, S:01
 # expires at 305461414000-305461414000 nsecs [in 178815789123 to 178815789123 nsecs]
 #8: <ed11fae0>, hrtimer_wakeup, S:01
 # expires at 606265898975-606365898975 nsecs [in 479620274098 to 479720274098 nsecs]
 #9: sched_clock_timer, sched_clock_poll, S:01
 # expires at 1924145348608-1924145348608 nsecs [in 1797499723731 to 1797499723731 nsecs]
 clock 1:
  .base:       eeec36f8
  .index:      1
  .resolution: 1 nsecs
  .get_time:   ktime_get_real
  .offset:     1433450686592811401 nsecs
active timers:
 #0: <ee43cc00>, timerfd_tmrproc, S:01
 # expires at 2147483647000000000-2147483647000000000 nsecs [in 2147483520354375123 to 2147483520354375123 nsecs]
 clock 2:
  .base:       eeec3738
  .index:      2
  .resolution: 1 nsecs
  .get_time:   ktime_get_boottime
  .offset:     0 nsecs
active timers:
 clock 3:
  .base:       eeec3778
  .index:      3
  .resolution: 1 nsecs
  .get_time:   ktime_get_clocktai
  .offset:     1433450686592811401 nsecs
active timers:
  .expires_next   : 126646000000 nsecs
  .hres_active    : 1
  .nr_events      : 6888
  .nr_retries     : 0
  .nr_hangs       : 0
  .max_hang_time  : 0 nsecs
  .nohz_mode      : 2
  .last_tick      : 126639000000 nsecs
  .tick_stopped   : 0
  .idle_jiffies   : 4294793935
  .idle_calls     : 3733
  .idle_sleeps    : 1759
  .idle_entrytime : 126644701595 nsecs
  .idle_waketime  : 126640000808 nsecs
  .idle_exittime  : 126640012942 nsecs
  .idle_sleeptime : 121454496379 nsecs
  .iowait_sleeptime: 23896349 nsecs
  .last_jiffies   : 4294793940
  .next_jiffies   : 4294793941
  .idle_expires   : 126640000000 nsecs
jiffies: 4294793941

Tick Device: mode:     1
Broadcast device
Clock Event Device: arm_global_timer
 max_delta_ns:   4294967295
 min_delta_ns:   1000
 mult:           2147483648
 shift:          31
 mode:           1
 next_event:     9223372036854775807 nsecs
 set_next_event: gt_clockevent_set_next_event
 set_mode:       gt_clockevent_set_mode
 event_handler:  tick_handle_oneshot_broadcast
 retries:        0

tick_broadcast_mask: 00000000
tick_broadcast_oneshot_mask: 00000000

Tick Device: mode:     1
Per CPU device: 0
Clock Event Device: local_timer
 max_delta_ns:   4294967295
 min_delta_ns:   1000
 mult:           2147483648
 shift:          31
 mode:           3
 next_event:     126646000000 nsecs
 set_next_event: twd_set_next_event
 set_mode:       twd_set_mode
 event_handler:  hrtimer_interrupt
 retries:        0

-- 
balbi
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