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powerpc/bpf/32: add support for BPF_ATOMIC bitwise operations

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Adding instructions for ppc32 for

atomic_and
atomic_or
atomic_xor
atomic_fetch_add
atomic_fetch_and
atomic_fetch_or
atomic_fetch_xor

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> (ppc64le)
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220610155552.25892-5-hbathini@linux.ibm.com
This commit is contained in:
Hari Bathini 2022-06-10 21:25:51 +05:30 committed by Michael Ellerman
parent 1e82dfaa78
commit aea7ef8a82
1 changed files with 41 additions and 12 deletions
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53
arch/powerpc/net/bpf_jit_comp32.c
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@ -294,6 +294,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
u32 dst_reg_h = dst_reg - 1;
u32 src_reg = bpf_to_ppc(insn[i].src_reg);
u32 src_reg_h = src_reg - 1;
u32 ax_reg = bpf_to_ppc(BPF_REG_AX);
u32 tmp_reg = bpf_to_ppc(TMP_REG);
u32 size = BPF_SIZE(code);
s16 off = insn[i].off;
@ -798,25 +799,53 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
* BPF_STX ATOMIC (atomic ops)
*/
case BPF_STX | BPF_ATOMIC | BPF_W:
if (imm != BPF_ADD) {
pr_err_ratelimited("eBPF filter atomic op code %02x (@%d) unsupported\n",
code, i);
return -ENOTSUPP;
}
/* *(u32 *)(dst + off) += src */
bpf_set_seen_register(ctx, tmp_reg);
bpf_set_seen_register(ctx, ax_reg);
/* Get offset into TMP_REG */
EMIT(PPC_RAW_LI(tmp_reg, off));
tmp_idx = ctx->idx * 4;
/* load value from memory into r0 */
EMIT(PPC_RAW_LWARX(_R0, tmp_reg, dst_reg, 0));
/* add value from src_reg into this */
EMIT(PPC_RAW_ADD(_R0, _R0, src_reg));
/* store result back */
/* Save old value in BPF_REG_AX */
if (imm & BPF_FETCH)
EMIT(PPC_RAW_MR(ax_reg, _R0));
switch (imm) {
case BPF_ADD:
case BPF_ADD | BPF_FETCH:
EMIT(PPC_RAW_ADD(_R0, _R0, src_reg));
break;
case BPF_AND:
case BPF_AND | BPF_FETCH:
EMIT(PPC_RAW_AND(_R0, _R0, src_reg));
break;
case BPF_OR:
case BPF_OR | BPF_FETCH:
EMIT(PPC_RAW_OR(_R0, _R0, src_reg));
break;
case BPF_XOR:
case BPF_XOR | BPF_FETCH:
EMIT(PPC_RAW_XOR(_R0, _R0, src_reg));
break;
default:
pr_err_ratelimited("eBPF filter atomic op code %02x (@%d) unsupported\n",
code, i);
return -EOPNOTSUPP;
}
/* store new value */
EMIT(PPC_RAW_STWCX(_R0, tmp_reg, dst_reg));
/* we're done if this succeeded */
PPC_BCC_SHORT(COND_NE, (ctx->idx - 3) * 4);
PPC_BCC_SHORT(COND_NE, tmp_idx);
/* For the BPF_FETCH variant, get old data into src_reg */
if (imm & BPF_FETCH) {
EMIT(PPC_RAW_MR(src_reg, ax_reg));
if (!fp->aux->verifier_zext)
EMIT(PPC_RAW_LI(src_reg_h, 0));
}
break;
case BPF_STX | BPF_ATOMIC | BPF_DW: /* *(u64 *)(dst + off) += src */