Linux kernel patches for supporting RISC-V’s Zalasr ISA extension are now under review. This extension provides “real” load acquire/store release instructions for RISC-V processors.
Zalasr provides atomic Load-Acquire Store-Release support. Its v0.9 ISA spec was finalized two months ago and its public review period wrapped up in August.
Given the freshness of the Zalasr ISA exntesion, the Linux kernel support patches have so far only been tested with a patched version of QEMU providing its emulated Zalasr support. Within the Linux kernel, Zalasr can be used for the smp_load_acquire and smp_store_release functionality in place of fence instructions.
Those interested in RISC-V Zalasr support can see this mailing list patch series for that pending Linux kernel support.
