riscv, bpf: Implement more atomic operations for RV64

This patch implement more BPF atomic operations for RV64. The newly
added operations are shown below:

  atomic[64]_[fetch_]add
  atomic[64]_[fetch_]and
  atomic[64]_[fetch_]or
  atomic[64]_xchg
  atomic[64]_cmpxchg

Since riscv specification does not provide AMO instruction for CAS
operation, we use lr/sc instruction for cmpxchg operation, and AMO
instructions for the rest ops.

Tests "test_bpf.ko" and "test_progs -t atomic" have passed, as well
as "test_verifier" with no new failure cases.

Signed-off-by: Pu Lehui <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Björn Töpel <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

0 files changed, 0 insertions, 0 deletions