aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clocksource/timer-riscv.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clocksource/timer-riscv.c')
-rw-r--r--drivers/clocksource/timer-riscv.c31
1 files changed, 23 insertions, 8 deletions
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index 470c7ef02ea4..4e54856ce2a5 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -3,9 +3,9 @@
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*
- * All RISC-V systems have a timer attached to every hart. These timers can be
- * read from the "time" and "timeh" CSRs, and can use the SBI to setup
- * events.
+ * All RISC-V systems have a timer attached to every hart. These timers can
+ * either be read from the "time" and "timeh" CSRs, and can use the SBI to
+ * setup events, or directly accessed using MMIO registers.
*/
#include <linux/clocksource.h>
#include <linux/clockchips.h>
@@ -13,14 +13,29 @@
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/sched_clock.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
#include <asm/smp.h>
#include <asm/sbi.h>
+u64 __iomem *riscv_time_cmp;
+u64 __iomem *riscv_time_val;
+
+static inline void mmio_set_timer(u64 val)
+{
+ void __iomem *r;
+
+ r = riscv_time_cmp + cpuid_to_hartid_map(smp_processor_id());
+ writeq_relaxed(val, r);
+}
+
static int riscv_clock_next_event(unsigned long delta,
struct clock_event_device *ce)
{
- csr_set(sie, SIE_STIE);
- sbi_set_timer(get_cycles64() + delta);
+ csr_set(CSR_IE, IE_TIE);
+ if (IS_ENABLED(CONFIG_RISCV_SBI))
+ sbi_set_timer(get_cycles64() + delta);
+ else
+ mmio_set_timer(get_cycles64() + delta);
return 0;
}
@@ -61,13 +76,13 @@ static int riscv_timer_starting_cpu(unsigned int cpu)
ce->cpumask = cpumask_of(cpu);
clockevents_config_and_register(ce, riscv_timebase, 100, 0x7fffffff);
- csr_set(sie, SIE_STIE);
+ csr_set(CSR_IE, IE_TIE);
return 0;
}
static int riscv_timer_dying_cpu(unsigned int cpu)
{
- csr_clear(sie, SIE_STIE);
+ csr_clear(CSR_IE, IE_TIE);
return 0;
}
@@ -76,7 +91,7 @@ void riscv_timer_interrupt(void)
{
struct clock_event_device *evdev = this_cpu_ptr(&riscv_clock_event);
- csr_clear(sie, SIE_STIE);
+ csr_clear(CSR_IE, IE_TIE);
evdev->event_handler(evdev);
}