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

[Clément Léger]

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 at rivosinc.com>
Reviewed-by: Evan Green <evan at rivosinc.com>
---
 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