[PATCH v1 06/13] riscv: hwprobe: export Zfh/Zfhmin ISA extensions

From: Clément Léger
Date: Wed Oct 11 2023 - 07:20:15 EST


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

[1] https://drive.google.com/file/d/1z3tQQLm5ALsAD77PM0l0CHnapxWCeVzP/view

Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
---
Documentation/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/riscv/hwprobe.rst b/Documentation/riscv/hwprobe.rst
index edfed33669ea..06f49a095f19 100644
--- a/Documentation/riscv/hwprobe.rst
+++ b/Documentation/riscv/hwprobe.rst
@@ -125,6 +125,12 @@ 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 d868eb431cd6..c9016abf099e 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -45,6 +45,8 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_EXT_ZVKSH (1 << 19)
#define RISCV_HWPROBE_EXT_ZVKSG (1 << 20)
#define RISCV_HWPROBE_EXT_ZVKT (1 << 21)
+#define RISCV_HWPROBE_EXT_ZFH (1 << 22)
+#define RISCV_HWPROBE_EXT_ZFHMIN (1 << 23)
#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 4f5e51c192d5..da916981934b 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -175,6 +175,11 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
CHECK_ISA_EXT(ZVKSG);
CHECK_ISA_EXT(ZVKT);
}
+
+ if (has_fpu()) {
+ CHECK_ISA_EXT(ZFH);
+ CHECK_ISA_EXT(ZFHMIN);
+ }
#undef CHECK_ISA_EXT
}

--
2.42.0