[PATCH v5 2/4] RISC-V: add Zbkb extension detection

Heiko Stuebner
2023-06-12T21:08:57Z

From: Heiko Stuebner <heiko.stuebner@vrull.eu>

Add detection for Zbkb extension.

Zbkb is part of the set of scalar cryptography extensions and provides
bitmanip instructions for cryptography, with them being a "subset of the
Zbb extension particularly useful for cryptography".

Zbkb was ratified in january 2022.

Expect code using the extension to pre-encode zbkb instructions, so
don't introduce special toolchain requirements for now.

Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
---
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/kernel/cpu.c | 1 +
arch/riscv/kernel/cpufeature.c | 1 +
3 files changed, 3 insertions(+)

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index e48ac52b9174..3d4820648a14 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -48,6 +48,7 @@
#define RISCV_ISA_EXT_SMAIA 35
#define RISCV_ISA_EXT_SSAIA 36
#define RISCV_ISA_EXT_ZBC 37
+#define RISCV_ISA_EXT_ZBKB 38

#define RISCV_ISA_EXT_MAX 64
#define RISCV_ISA_EXT_NAME_LEN_MAX 32
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index bbff98d4712a..a4ee61c18578 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -188,6 +188,7 @@ static struct riscv_isa_ext_data isa_ext_arr[] = {
__RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
__RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
+ __RISCV_ISA_EXT_DATA(zbkb, RISCV_ISA_EXT_ZBKB),
__RISCV_ISA_EXT_DATA(zbc, RISCV_ISA_EXT_ZBC),
__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index f46281f1e439..fceec9c60e07 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -262,6 +262,7 @@ void __init riscv_fill_hwcap(void)
SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT);
SET_ISA_EXT_MAP("zbb", RISCV_ISA_EXT_ZBB);
SET_ISA_EXT_MAP("zbc", RISCV_ISA_EXT_ZBC);
+ SET_ISA_EXT_MAP("zbkb", RISCV_ISA_EXT_ZBKB);
SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM);
SET_ISA_EXT_MAP("zicboz", RISCV_ISA_EXT_ZICBOZ);
SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
--
2.39.0