diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/timer-riscv.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c index 593d5a957b69..05f6cf067289 100644 --- a/drivers/clocksource/timer-riscv.c +++ b/drivers/clocksource/timer-riscv.c @@ -7,6 +7,9 @@ * either be read from the "time" and "timeh" CSRs, and can use the SBI to * setup events, or directly accessed using MMIO registers. */ + +#define pr_fmt(fmt) "riscv-timer: " fmt + #include <linux/clocksource.h> #include <linux/clockchips.h> #include <linux/cpu.h> @@ -20,14 +23,28 @@ #include <linux/of_irq.h> #include <clocksource/timer-riscv.h> #include <asm/smp.h> +#include <asm/hwcap.h> #include <asm/sbi.h> #include <asm/timex.h> +static DEFINE_STATIC_KEY_FALSE(riscv_sstc_available); + static int riscv_clock_next_event(unsigned long delta, struct clock_event_device *ce) { + u64 next_tval = get_cycles64() + delta; + csr_set(CSR_IE, IE_TIE); - sbi_set_timer(get_cycles64() + delta); + if (static_branch_likely(&riscv_sstc_available)) { +#if defined(CONFIG_32BIT) + csr_write(CSR_STIMECMP, next_tval & 0xFFFFFFFF); + csr_write(CSR_STIMECMPH, next_tval >> 32); +#else + csr_write(CSR_STIMECMP, next_tval); +#endif + } else + sbi_set_timer(next_tval); + return 0; } @@ -165,6 +182,12 @@ static int __init riscv_timer_init_dt(struct device_node *n) if (error) pr_err("cpu hp setup state failed for RISCV timer [%d]\n", error); + + if (riscv_isa_extension_available(NULL, SSTC)) { + pr_info("Timer interrupt in S-mode is available via sstc extension\n"); + static_branch_enable(&riscv_sstc_available); + } + return error; } |