RISC-V: add Zbc extension detection
From: Heiko Stuebner <heiko.stuebner@...> Date: Mon, 30 Jan 2023 21:23:57 +0100
Commit-Message
Add handling for Zbc extension. Zbc provides instruction for carry-less multiplication. Signed-off-by: Heiko Stuebner <heiko.stuebner@...>
Patch-Comment
arch/riscv/Kconfig | 22 ++++++++++++++++++++++ arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/kernel/cpu.c | 1 + arch/riscv/kernel/cpufeature.c | 1 + 4 files changed, 25 insertions(+)
Statistics
- 25 lines added
- 0 lines removed
Changes
------------------------------ arch/riscv/Kconfig ------------------------------
index 179e52c7e531..471f0f42855d 100644
@@ -450,6 +450,28 @@ config RISCV_ISA_ZBB
If you don't know what to do here, say Y.
+config TOOLCHAIN_HAS_ZBC
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
+ depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+ depends on AS_IS_GNU
+
+config RISCV_ISA_ZBC
+ bool "Zbc extension support for bit manipulation instructions"
+ depends on TOOLCHAIN_HAS_ZBC
+ depends on !XIP_KERNEL && MMU
+ default y
+ help
+ Adds support to dynamically detect the presence of the ZBC
+ extension (carry-less multiplication) and enable its usage.
+
+ The Zbc extension provides instructions clmul, clmulh and clmulr
+ to accelerate carry-less multiplications.
+
+ If you don't know what to do here, say Y.
+
config TOOLCHAIN_HAS_ZICBOM
bool
default y
------------------------ arch/riscv/include/asm/hwcap.h ------------------------
index c8c69b49f0ad..8673c2146d20 100644
@@ -60,6 +60,7 @@ enum riscv_isa_ext_id {
RISCV_ISA_EXT_SVINVAL,
RISCV_ISA_EXT_SVPBMT,
RISCV_ISA_EXT_ZBB,
+ RISCV_ISA_EXT_ZBC,
RISCV_ISA_EXT_ZICBOM,
RISCV_ISA_EXT_ZIHINTPAUSE,
RISCV_ISA_EXT_ID_MAX
--------------------------- arch/riscv/kernel/cpu.c ----------------------------
index 8400f0cc9704..5d47a0c75c69 100644
@@ -188,6 +188,7 @@ static struct riscv_isa_ext_data isa_ext_arr[] = {
__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
__RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
+ __RISCV_ISA_EXT_DATA(zbc, RISCV_ISA_EXT_ZBC),
__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
------------------------ arch/riscv/kernel/cpufeature.c ------------------------
index af201b2b8933..696b39de7e09 100644
@@ -234,6 +234,7 @@ void __init riscv_fill_hwcap(void)
SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL);
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("zicbom", RISCV_ISA_EXT_ZICBOM);
SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
}