powerpc/bpf/64: add support for BPF_ATOMIC bitwise operations

Adding instructions for ppc64 for

atomic[64]_and
atomic[64]_or
atomic[64]_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/20220610155552.25892-2-hbathini@linux.ibm.com

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 594c54931e2098970e0ac4a2a0126815201a13d0..c421bedd0e9805577115eb78093aff3363c353c2 100644 (file)
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -777,41 +777,42 @@ emit_clear:
                 * 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 */
-
-                       /* Get EA into TMP_REG_1 */
-                       EMIT(PPC_RAW_ADDI(tmp1_reg, dst_reg, off));
+               case BPF_STX | BPF_ATOMIC | BPF_DW:
+                       /* Get offset into TMP_REG_1 */
+                       EMIT(PPC_RAW_LI(tmp1_reg, off));
                        tmp_idx = ctx->idx * 4;
                        /* load value from memory into TMP_REG_2 */
-                       EMIT(PPC_RAW_LWARX(tmp2_reg, 0, tmp1_reg, 0));
-                       /* add value from src_reg into this */
-                       EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
-                       /* store result back */
-                       EMIT(PPC_RAW_STWCX(tmp2_reg, 0, tmp1_reg));
-                       /* we're done if this succeeded */
-                       PPC_BCC_SHORT(COND_NE, tmp_idx);
-                       break;
-               case BPF_STX | BPF_ATOMIC | BPF_DW:
-                       if (imm != BPF_ADD) {
+                       if (size == BPF_DW)
+                               EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));
+                       else
+                               EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
+
+                       switch (imm) {
+                       case BPF_ADD:
+                               EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
+                               break;
+                       case BPF_AND:
+                               EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
+                               break;
+                       case BPF_OR:
+                               EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
+                               break;
+                       case BPF_XOR:
+                               EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
+                               break;
+                       default:
                                pr_err_ratelimited(
                                        "eBPF filter atomic op code %02x (@%d) unsupported\n",
                                        code, i);
-                               return -ENOTSUPP;
+                               return -EOPNOTSUPP;
                        }
-                       /* *(u64 *)(dst + off) += src */
 
-                       EMIT(PPC_RAW_ADDI(tmp1_reg, dst_reg, off));
-                       tmp_idx = ctx->idx * 4;
-                       EMIT(PPC_RAW_LDARX(tmp2_reg, 0, tmp1_reg, 0));
-                       EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
-                       EMIT(PPC_RAW_STDCX(tmp2_reg, 0, tmp1_reg));
+                       /* store result back */
+                       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);
                        break;