[PATCH 6/9] RISC-V: Support per-hart timebase-frequency

From: Christoph Hellwig
Date: Thu Jul 26 2018 - 10:37:54 EST


From: Palmer Dabbelt <palmer@xxxxxxxxxx>

This isn't actually how I want to do it, I just needed something right
now.

Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxx>
---
arch/riscv/kernel/time.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
index 0df9b2cbd645..1bb01dc2d0f1 100644
--- a/arch/riscv/kernel/time.c
+++ b/arch/riscv/kernel/time.c
@@ -24,17 +24,24 @@ void __init init_clockevent(void)
csr_set(sie, SIE_STIE);
}

-void __init time_init(void)
+static long __init timebase_frequency(void)
{
struct device_node *cpu;
u32 prop;

cpu = of_find_node_by_path("/cpus");
- if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
- panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
- riscv_timebase = prop;
+ if (cpu && !of_property_read_u32(cpu, "timebase-frequency", &prop))
+ return prop;
+ cpu = of_find_node_by_path("/cpus/cpu@0");
+ if (cpu && !of_property_read_u32(cpu, "timebase-frequency", &prop))
+ return prop;

- lpj_fine = riscv_timebase / HZ;
+ panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
+}

+void __init time_init(void)
+{
+ riscv_timebase = timebase_frequency();
+ lpj_fine = riscv_timebase / HZ;
init_clockevent();
}
--
2.18.0