Use the ZBbus cycle counter for sched_clock source. This implementation
will give high resolution cputime accounting.
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@xxxxxxxxxx>
---
arch/mips/kernel/csrc-bcm1480.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/mips/kernel/csrc-bcm1480.c b/arch/mips/kernel/csrc-bcm1480.c
index 0a20a0f..7f65b53 100644
--- a/arch/mips/kernel/csrc-bcm1480.c
+++ b/arch/mips/kernel/csrc-bcm1480.c
@@ -12,6 +12,7 @@
* GNU General Public License for more details.
*/
#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
#include <asm/addrspace.h>
#include <asm/io.h>
@@ -37,6 +38,11 @@ struct clocksource bcm1480_clocksource = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+static u64 notrace sb1480_read_sched_clock(void)
+{
+ return __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
+}
+
void __init sb1480_clocksource_init(void)
{
struct clocksource *cs = &bcm1480_clocksource;
@@ -46,4 +52,6 @@ void __init sb1480_clocksource_init(void)
plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG)));
zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000);
clocksource_register_hz(cs, zbbus);
+
+ sched_clock_register(sb1480_read_sched_clock, 64, zbbus);
}
--
2.3.2
