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-rw-r--r--arch/riscv/include/asm/csr.h5
-rw-r--r--arch/riscv/include/asm/hwcap.h1
-rw-r--r--arch/riscv/kernel/cpu.c1
-rw-r--r--arch/riscv/kernel/cpufeature.c1
-rw-r--r--drivers/clocksource/timer-riscv.c25
5 files changed, 32 insertions, 1 deletions
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 17516afc389a..0e571f6483d9 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -247,6 +247,9 @@
#define CSR_SIP 0x144
#define CSR_SATP 0x180
+#define CSR_STIMECMP 0x14D
+#define CSR_STIMECMPH 0x15D
+
#define CSR_VSSTATUS 0x200
#define CSR_VSIE 0x204
#define CSR_VSTVEC 0x205
@@ -256,6 +259,8 @@
#define CSR_VSTVAL 0x243
#define CSR_VSIP 0x244
#define CSR_VSATP 0x280
+#define CSR_VSTIMECMP 0x24D
+#define CSR_VSTIMECMPH 0x25D
#define CSR_HSTATUS 0x600
#define CSR_HEDELEG 0x602
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 3c8a5ca95c72..6f59ec64175e 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -57,6 +57,7 @@ enum riscv_isa_ext_id {
RISCV_ISA_EXT_SVPBMT,
RISCV_ISA_EXT_ZICBOM,
RISCV_ISA_EXT_ZIHINTPAUSE,
+ RISCV_ISA_EXT_SSTC,
RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
};
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index a77c380703c5..0be8a2403212 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -95,6 +95,7 @@ static struct riscv_isa_ext_data isa_ext_arr[] = {
__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
+ __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
__RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX),
};
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index c233fbc5b873..553d755483ed 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -203,6 +203,7 @@ void __init riscv_fill_hwcap(void)
SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT);
SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM);
SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
+ SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC);
}
#undef SET_ISA_EXT_MAP
}
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index e460df7ed799..969a552da8d2 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;
}
@@ -166,6 +183,12 @@ 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;
}