[PATCH -next v21 03/27] riscv: hwprobe: Add support for probing V in RISCV_HWPROBE_KEY_IMA_EXT_0

Andy Chiu
2023-06-05T15:40:10Z

Probing kernel support for Vector extension is available now. This only
add detection for V only. Extenions like Zvfh, Zk are not in this scope.

Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
---
Changelog v20:
- Fix a typo in document, and remove duplicated probes (Heiko)
- probe V extension in RISCV_HWPROBE_KEY_IMA_EXT_0 key only (Palmer,
Evan)
---
Documentation/riscv/hwprobe.rst | 3 +++
arch/riscv/include/uapi/asm/hwprobe.h | 1 +
arch/riscv/kernel/sys_riscv.c | 4 ++++
3 files changed, 8 insertions(+)

diff --git a/Documentation/riscv/hwprobe.rst b/Documentation/riscv/hwprobe.rst
index 9f0dd62dcb5d..7431d9d01c73 100644
--- a/Documentation/riscv/hwprobe.rst
+++ b/Documentation/riscv/hwprobe.rst
@@ -64,6 +64,9 @@ The following keys are defined:
* :c:macro:`RISCV_HWPROBE_IMA_C`: The C extension is supported, as defined
by version 2.2 of the RISC-V ISA manual.

+ * :c:macro:`RISCV_HWPROBE_IMA_V`: The V extension is supported, as defined by
+ version 1.0 of the RISC-V Vector extension 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 8d745a4ad8a2..7c6fdcf7ced5 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -25,6 +25,7 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_KEY_IMA_EXT_0 4
#define RISCV_HWPROBE_IMA_FD (1 << 0)
#define RISCV_HWPROBE_IMA_C (1 << 1)
+#define RISCV_HWPROBE_IMA_V (1 << 2)
#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 5db29683ebee..88357a848797 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -10,6 +10,7 @@
#include <asm/cpufeature.h>
#include <asm/hwprobe.h>
#include <asm/sbi.h>
+#include <asm/vector.h>
#include <asm/switch_to.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -171,6 +172,9 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
if (riscv_isa_extension_available(NULL, c))
pair->value |= RISCV_HWPROBE_IMA_C;

+ if (has_vector())
+ pair->value |= RISCV_HWPROBE_IMA_V;
+
break;

case RISCV_HWPROBE_KEY_CPUPERF_0:
--
2.17.1