[PATCH v2 2/5] bpf ppc64: add support for atomic fetch operations
Hari Bathini
hbathini at linux.ibm.com
Sat Jun 11 01:55:49 AEST 2022
Adding instructions for ppc64 for
atomic[64]_fetch_add
atomic[64]_fetch_and
atomic[64]_fetch_or
atomic[64]_fetch_xor
Signed-off-by: Hari Bathini <hbathini at linux.ibm.com>
---
* No changes in v2.
arch/powerpc/net/bpf_jit_comp64.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index c421bedd0e98..c53236b3a8b1 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -787,17 +787,25 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
else
EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
+ /* Save old value in _R0 */
+ if (imm & BPF_FETCH)
+ EMIT(PPC_RAW_MR(_R0, tmp2_reg));
+
switch (imm) {
case BPF_ADD:
+ case BPF_ADD | BPF_FETCH:
EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_AND:
+ case BPF_AND | BPF_FETCH:
EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_OR:
+ case BPF_OR | BPF_FETCH:
EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_XOR:
+ case BPF_XOR | BPF_FETCH:
EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
break;
default:
@@ -807,13 +815,17 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
return -EOPNOTSUPP;
}
- /* store result back */
+ /* store new value */
if (size == BPF_DW)
EMIT(PPC_RAW_STDCX(tmp2_reg, tmp1_reg, dst_reg));
else
EMIT(PPC_RAW_STWCX(tmp2_reg, tmp1_reg, dst_reg));
/* we're done if this succeeded */
PPC_BCC_SHORT(COND_NE, tmp_idx);
+
+ /* For the BPF_FETCH variant, get old value into src_reg */
+ if (imm & BPF_FETCH)
+ EMIT(PPC_RAW_MR(src_reg, _R0));
break;
/*
--
2.35.3
More information about the Linuxppc-dev
mailing list