From 7cb24b700349f4287f4104bb9f3266d7f383d4cc Mon Sep 17 00:00:00 2001 From: Deng-Cheng Zhu Date: Sat, 7 Mar 2015 10:30:28 -0800 Subject: [PATCH] MIPS: csrc-ioasic: Implement read_sched_clock Use DEC I/O ASIC's free-running counter for sched_clock source. This implementation will give high resolution cputime accounting. Acked-by: Maciej W. Rozycki Signed-off-by: Deng-Cheng Zhu Cc: linux-mips@linux-mips.org Cc: macro@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9482/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/csrc-ioasic.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/mips/kernel/csrc-ioasic.c b/arch/mips/kernel/csrc-ioasic.c index 54e394df9f7a..722f5589cd1d 100644 --- a/arch/mips/kernel/csrc-ioasic.c +++ b/arch/mips/kernel/csrc-ioasic.c @@ -14,6 +14,7 @@ * GNU General Public License for more details. */ #include +#include #include #include @@ -33,6 +34,11 @@ static struct clocksource clocksource_dec = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +static u64 notrace dec_ioasic_read_sched_clock(void) +{ + return ioasic_read(IO_REG_FCTR); +} + int __init dec_ioasic_clocksource_init(void) { unsigned int freq; @@ -61,5 +67,8 @@ int __init dec_ioasic_clocksource_init(void) clocksource_dec.rating = 200 + freq / 10000000; clocksource_register_hz(&clocksource_dec, freq); + + sched_clock_register(dec_ioasic_read_sched_clock, 32, freq); + return 0; }