powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer

BugLink: https://bugs.launchpad.net/bugs/1854216
[ Upstream commit 8b78fdb045de60a4eb35460092bbd3cffa925353 ]

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index fe6f3a28545578524045a6f8583e691b233f3738..870e75d30459178b37ce52a72c3844dc864b590e 100644 (file)
--- 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)