On Mon, 12 Jun 2023 14:31:14 PDT (-0700), Conor Dooley wrote:
Hey Heiko,
On Mon, Jun 12, 2023 at 11:04:39PM +0200, Heiko Stuebner wrote:
From: Heiko Stuebner <heiko.stuebner@xxxxxxxx>
Add handling for Zbc extension.
Zbc provides instruction for carry-less multiplication.
Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxx>
---
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(+)
Plumbing into the hwprobe stuff would be nice, but that's not a
requirement for getting stuff merged :)
IIRC we talked about this on IRC, but IMO we shouldn't require something
be user visible for it to be merged in the kernel.
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a3d54cd14fca..754cd154eca5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -523,6 +523,28 @@ 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
Nit: s/ZBC/Zbc/
Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Cheers,
Conor.
