From: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
A handful of user-visible behavior is based on the frequency of the
time CSR.
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Yunhui Cui <cuiyunhui@xxxxxxxxxxxxx>
Reviewed-by: Evan Green <evan@xxxxxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
---
Documentation/arch/riscv/hwprobe.rst | 2 ++
arch/riscv/include/asm/hwprobe.h | 2 +-
arch/riscv/include/uapi/asm/hwprobe.h | 1 +
arch/riscv/kernel/sys_hwprobe.c | 5 +++++
4 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index df5045103e73..ec3c99474ed7 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -233,3 +233,5 @@ The following keys are defined:
* :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
represents the size of the Zicboz block in bytes.
+
+* :c:macro:`RISCV_HWPROBE_KEY_TIME_CSR_FREQ`: Frequency (in Hz) of `time CSR`.
diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 150a9877b0af..ef01c182af2b 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -8,7 +8,7 @@
#include <uapi/asm/hwprobe.h>
-#define RISCV_HWPROBE_MAX_KEY 7
+#define RISCV_HWPROBE_MAX_KEY 8
static inline bool riscv_hwprobe_key_is_valid(__s64 key)
{
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 2fb8a8185e7a..5053a9b18710 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -74,6 +74,7 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0)
#define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
#define RISCV_HWPROBE_KEY_MISALIGNED_PERF 7
+#define RISCV_HWPROBE_KEY_TIME_CSR_FREQ 8
/* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
/* Flags */
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index e4ec9166339f..3d47edc04a3f 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -8,6 +8,7 @@
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/hwprobe.h>
+#include <asm/delay.h>
#include <asm/sbi.h>
#include <asm/switch_to.h>
#include <asm/uaccess.h>
@@ -227,6 +228,10 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
pair->value = riscv_cboz_block_size;
break;
+ case RISCV_HWPROBE_KEY_TIME_CSR_FREQ:
+ pair->value = riscv_timebase;
+ break;
+
/*
* For forward compatibility, unknown keys don't fail the whole
* call, but get their element key set to -1 and value set to 0
--
2.20.1
