[PATCH v4 10/20] riscv: hwprobe: export Zfh[min] ISA extensions

From: Clément Léger
Date: Tue Nov 14 2023 - 09:14:10 EST


Export Zfh[min] ISA extensions[1] through hwprobe only if FPU support
is available.

Link: https://drive.google.com/file/d/1z3tQQLm5ALsAD77PM0l0CHnapxWCeVzP/view [1]
Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
Reviewed-by: Evan Green <evan@xxxxxxxxxxxx>
---
Documentation/arch/riscv/hwprobe.rst | 6 ++++++
arch/riscv/include/uapi/asm/hwprobe.h | 2 ++
arch/riscv/kernel/sys_riscv.c | 5 +++++
3 files changed, 13 insertions(+)

diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index a08fcd899b6d..397d53195f49 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -140,6 +140,12 @@ The following keys are defined:
* :c:macro:`RISCV_HWPROBE_EXT_ZVKT`: The Zvkt extension is supported as
defined in version 1.0 of the RISC-V Cryptography Extensions Volume II.

+ * :c:macro:`RISCV_HWPROBE_EXT_ZFH`: The Zfh extension version 1.0 is supported
+ as defined in the RISC-V ISA manual.
+
+ * :c:macro:`RISCV_HWPROBE_EXT_ZFHMIN`: The Zfhmin extension version 1.0 is
+ supported as defined in the RISC-V ISA manual.
+
* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance
information about the selected set of processors.

diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 89628a76ca04..2d960777ea43 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -50,6 +50,8 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_EXT_ZVKSED (1 << 24)
#define RISCV_HWPROBE_EXT_ZVKSH (1 << 25)
#define RISCV_HWPROBE_EXT_ZVKT (1 << 26)
+#define RISCV_HWPROBE_EXT_ZFH (1 << 27)
+#define RISCV_HWPROBE_EXT_ZFHMIN (1 << 28)
#define RISCV_HWPROBE_KEY_CPUPERF_0 5
#define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0)
#define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0)
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index 9bbcd7334d96..d776c6c39fcd 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -186,6 +186,11 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
EXT_KEY(ZVKSH);
EXT_KEY(ZVKT);
}
+
+ if (has_fpu()) {
+ EXT_KEY(ZFH);
+ EXT_KEY(ZFHMIN);
+ }
#undef EXT_KEY
}

--
2.42.0