riscv: Implement cmpxchg8/16() using Zabha

This adds runtime support for Zabha in cmpxchg8/16() operations. Note that in the absence of Zacas support in the toolchain, CAS instructions from Zabha won't be used. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Andrea Parri <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20241103145153.105097-6-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2026-11-10 20:48:12 +00:00 · 2024-11-03 15:51:45 +01:00 · 2024-11-03 15:51:45 +01:00 · 1658ef4314
commit 1658ef4314
parent 51624ddcf5
5 changed files with 72 additions and 29 deletions
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
--- a/arch/riscv/include/asm/cmpxchg.h
+++ b/arch/riscv/include/asm/cmpxchg.h
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c