[PATCH bpf-next v4 0/4] bpf, arm64: support more atomic ops

[Hou Tao]

Hi,

Atomics support in bpf has already been done by "Atomics for eBPF"
patch series [1], but it only adds support for x86, and this patchset
adds support for arm64.

Patch #1 & patch #2 are arm64 related. Patch #1 moves the common used
macro AARCH64_BREAK_FAULT into insn-def.h for insn.h. Patch #2 adds
necessary encoder helpers for atomic operations.

Patch #3 implements atomic[64]_fetch_add, atomic[64]_[fetch_]{and,or,xor}
and atomic[64]_{xchg|cmpxchg} for arm64 bpf. Patch #4 changes the type of
test program from fentry/ to raw_tp/ for atomics test.

For cpus_have_cap(ARM64_HAS_LSE_ATOMICS) case and no-LSE-ATOMICS case,
./test_verifier, "./test_progs -t atomic", and "insmod ./test_bpf.ko"
are exercised and passed correspondingly.

Comments are always welcome.

Regards,
Tao

[1]: https://lore.kernel.org/bpf/20210114181751.768687-2-jackmanb@google.com/

Change Log:
v4:
 * patch #2: update A64_STADD() accordingly to fix build failure after
   applying patch #1 & patch #2.

v3: https://lore.kernel.org/bpf/20220129220452.194585-1-houtao1@huawei.com/
 * split arm64 insn related code into a separated patch (from Mark)
 * update enum name in aarch64_insn_mem_atomic_op (from Mark)
 * consider all cases for aarch64_insn_mem_order_type and
   aarch64_insn_mb_type (from Mark)
 * exercise and pass "insmod ./test_bpf.ko" test (suggested by Daniel)
 * remove aarch64_insn_gen_store_release_ex() and extend
   aarch64_insn_ldst_type instead
 * compile aarch64_insn_gen_atomic_ld_op(), aarch64_insn_gen_cas() and
   emit_lse_atomic() out when CONFIG_ARM64_LSE_ATOMICS is disabled.

v2: https://lore.kernel.org/bpf/20220127075322.675323-1-houtao1@huawei.com/
  * patch #1: use two separated ASSERT_OK() instead of ASSERT_TRUE()
  * add Acked-by tag for both patches

v1: https://lore.kernel.org/bpf/20220121135632.136976-1-houtao1@huawei.com

Hou Tao (4):
  arm64: move AARCH64_BREAK_FAULT into insn-def.h
  arm64: insn: add encoders for atomic operations
  bpf, arm64: support more atomic operations
  selftests/bpf: use raw_tp program for atomic test

 arch/arm64/include/asm/debug-monitors.h       |  12 -
 arch/arm64/include/asm/insn-def.h             |  14 ++
 arch/arm64/include/asm/insn.h                 |  80 ++++++-
 arch/arm64/lib/insn.c                         | 185 +++++++++++++--
 arch/arm64/net/bpf_jit.h                      |  44 +++-
 arch/arm64/net/bpf_jit_comp.c                 | 223 ++++++++++++++----
 .../selftests/bpf/prog_tests/atomics.c        |  91 ++-----
 tools/testing/selftests/bpf/progs/atomics.c   |  28 +--
 8 files changed, 517 insertions(+), 160 deletions(-)

-- 
2.29.2