* [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer
@ 2018-10-01 23:01 Anton Blanchard
2018-10-01 23:01 ` [PATCH 2/2] powerpc/time: Add set_state_oneshot_stopped decrementer callback Anton Blanchard
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Anton Blanchard @ 2018-10-01 23:01 UTC (permalink / raw)
To: benh, paulus, mpe, npiggin, mikey, oohall; +Cc: linuxppc-dev
We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.
Signed-off-by: Anton Blanchard <anton@ozlabs.org>
---
arch/powerpc/kernel/time.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 70f145e02487..6a1f0a084ca3 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -984,10 +984,10 @@ static void register_decrementer_clockevent(int cpu)
*dec = decrementer_clockevent;
dec->cpumask = cpumask_of(cpu);
+ clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max);
+
printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
dec->name, dec->mult, dec->shift, cpu);
-
- clockevents_register_device(dec);
}
static void enable_large_decrementer(void)
@@ -1035,18 +1035,7 @@ static void __init set_decrementer_max(void)
static void __init init_decrementer_clockevent(void)
{
- int cpu = smp_processor_id();
-
- clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
-
- decrementer_clockevent.max_delta_ns =
- clockevent_delta2ns(decrementer_max, &decrementer_clockevent);
- decrementer_clockevent.max_delta_ticks = decrementer_max;
- decrementer_clockevent.min_delta_ns =
- clockevent_delta2ns(2, &decrementer_clockevent);
- decrementer_clockevent.min_delta_ticks = 2;
-
- register_decrementer_clockevent(cpu);
+ register_decrementer_clockevent(smp_processor_id());
}
void secondary_cpu_time_init(void)
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] powerpc/time: Add set_state_oneshot_stopped decrementer callback
2018-10-01 23:01 [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Anton Blanchard
@ 2018-10-01 23:01 ` Anton Blanchard
2018-10-11 8:35 ` [1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Michael Ellerman
2018-10-14 12:39 ` [PATCH 1/2] " Michael Ellerman
2 siblings, 0 replies; 5+ messages in thread
From: Anton Blanchard @ 2018-10-01 23:01 UTC (permalink / raw)
To: benh, paulus, mpe, npiggin, mikey, oohall; +Cc: linuxppc-dev
If CONFIG_PPC_WATCHDOG is enabled we always cap the decrementer to
0x7fffffff:
if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
set_dec(0x7fffffff);
else
set_dec(decrementer_max);
If there are no future events, we don't reprogram the decrementer
after this and we end up with 0x7fffffff even on a large decrementer
capable system.
As suggested by Nick, add a set_state_oneshot_stopped callback
so we program the decrementer with decrementer_max if there are
no future events.
Signed-off-by: Anton Blanchard <anton@ozlabs.org>
---
arch/powerpc/kernel/time.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 6a1f0a084ca3..40868f3ee113 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -111,6 +111,7 @@ struct clock_event_device decrementer_clockevent = {
.rating = 200,
.irq = 0,
.set_next_event = decrementer_set_next_event,
+ .set_state_oneshot_stopped = decrementer_shutdown,
.set_state_shutdown = decrementer_shutdown,
.tick_resume = decrementer_shutdown,
.features = CLOCK_EVT_FEAT_ONESHOT |
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer
2018-10-01 23:01 [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Anton Blanchard
2018-10-01 23:01 ` [PATCH 2/2] powerpc/time: Add set_state_oneshot_stopped decrementer callback Anton Blanchard
@ 2018-10-11 8:35 ` Michael Ellerman
2018-10-14 12:39 ` [PATCH 1/2] " Michael Ellerman
2 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2018-10-11 8:35 UTC (permalink / raw)
To: Anton Blanchard, benh, paulus, npiggin, mikey, oohall; +Cc: linuxppc-dev
On Mon, 2018-10-01 at 23:01:04 UTC, Anton Blanchard wrote:
> We currently cap the decrementer clockevent at 4 seconds, even on systems
> with large decrementer support. Fix this by converting the code to use
> clockevents_register_device() which calculates the upper bound based on
> the max_delta passed in.
>
> Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Series applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/8b78fdb045de60a4eb35460092bbd3
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer
2018-10-01 23:01 [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Anton Blanchard
2018-10-01 23:01 ` [PATCH 2/2] powerpc/time: Add set_state_oneshot_stopped decrementer callback Anton Blanchard
2018-10-11 8:35 ` [1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Michael Ellerman
@ 2018-10-14 12:39 ` Michael Ellerman
2 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2018-10-14 12:39 UTC (permalink / raw)
To: Anton Blanchard, benh, paulus, npiggin, mikey, oohall; +Cc: linuxppc-dev
Anton Blanchard <anton@ozlabs.org> writes:
> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> index 70f145e02487..6a1f0a084ca3 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -1035,18 +1035,7 @@ static void __init set_decrementer_max(void)
>
> static void __init init_decrementer_clockevent(void)
> {
> - int cpu = smp_processor_id();
> -
> - clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
> -
> - decrementer_clockevent.max_delta_ns =
> - clockevent_delta2ns(decrementer_max, &decrementer_clockevent);
> - decrementer_clockevent.max_delta_ticks = decrementer_max;
> - decrementer_clockevent.min_delta_ns =
> - clockevent_delta2ns(2, &decrementer_clockevent);
> - decrementer_clockevent.min_delta_ticks = 2;
> -
> - register_decrementer_clockevent(cpu);
> + register_decrementer_clockevent(smp_processor_id());
> }
This broke KVM PR :)
Because we no longer set the mult/shift in decrementer_clockevent, which
is used in kvmppc_emulate_dec().
The patch below fixes it, though it'd be nice to come up with something
cleaner eventually.
cheers
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 6a1f0a084ca3..d21b2b88c0a7 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -1036,6 +1036,9 @@ static void __init set_decrementer_max(void)
static void __init init_decrementer_clockevent(void)
{
register_decrementer_clockevent(smp_processor_id());
+
+ /* Set values for KVM, see kvm_emulate_dec() */
+ decrementer_clockevent = *dec;
}
void secondary_cpu_time_init(void)
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer
@ 2018-09-29 1:26 Anton Blanchard
0 siblings, 0 replies; 5+ messages in thread
From: Anton Blanchard @ 2018-09-29 1:26 UTC (permalink / raw)
To: benh, paulus, mpe, npiggin, mikey, oohall; +Cc: linuxppc-dev
We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
arch/powerpc/kernel/time.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 70f145e02487..6a1f0a084ca3 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -984,10 +984,10 @@ static void register_decrementer_clockevent(int cpu)
*dec = decrementer_clockevent;
dec->cpumask = cpumask_of(cpu);
+ clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max);
+
printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
dec->name, dec->mult, dec->shift, cpu);
-
- clockevents_register_device(dec);
}
static void enable_large_decrementer(void)
@@ -1035,18 +1035,7 @@ static void __init set_decrementer_max(void)
static void __init init_decrementer_clockevent(void)
{
- int cpu = smp_processor_id();
-
- clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
-
- decrementer_clockevent.max_delta_ns =
- clockevent_delta2ns(decrementer_max, &decrementer_clockevent);
- decrementer_clockevent.max_delta_ticks = decrementer_max;
- decrementer_clockevent.min_delta_ns =
- clockevent_delta2ns(2, &decrementer_clockevent);
- decrementer_clockevent.min_delta_ticks = 2;
-
- register_decrementer_clockevent(cpu);
+ register_decrementer_clockevent(smp_processor_id());
}
void secondary_cpu_time_init(void)
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
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2018-10-01 23:01 [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Anton Blanchard
2018-10-01 23:01 ` [PATCH 2/2] powerpc/time: Add set_state_oneshot_stopped decrementer callback Anton Blanchard
2018-10-11 8:35 ` [1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Michael Ellerman
2018-10-14 12:39 ` [PATCH 1/2] " Michael Ellerman
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2018-09-29 1:26 Anton Blanchard
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