Merge patch series "membarrier: riscv: Core serializing command"

RISC-V was lacking a membarrier implementation for the store/fetch
ordering, which is a bit tricky because of the deferred icache flushing
we use in RISC-V.

* b4-shazam-merge:
  membarrier: riscv: Provide core serializing command
  locking: Introduce prepare_sync_core_cmd()
  membarrier: Create Documentation/scheduler/membarrier.rst
  membarrier: riscv: Add full memory barrier in switch_mm()

Link: https://lore.kernel.org/r/20240131144936.29190-1-parri.andrea@gmail.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>