s390/bpf,jit: add support MOD instruction

Add support for MOD operation for s390's JIT.

Same as 280050cc "x86 bpf_jit: support MOD operation" for x86 which
adds JIT support for the generic new MOD operation introduced with
b6069a9570 "filter: add MOD operation".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 9b355b406afa..1ff930167348 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -341,6 +341,27 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter,
                 /* lr %r5,%r4 */
                 EMIT2(0x1854);
                 break;
+        case BPF_S_ALU_MOD_X: /* A %= X */
+                jit->seen |= SEEN_XREG | SEEN_RET0;
+                /* ltr %r12,%r12 */
+                EMIT2(0x12cc);
+                /* jz <ret0> */
+                EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg));
+                /* lhi %r4,0 */
+                EMIT4(0xa7480000);
+                /* dr %r4,%r12 */
+                EMIT2(0x1d4c);
+                /* lr %r5,%r4 */
+                EMIT2(0x1854);
+                break;
+        case BPF_S_ALU_MOD_K: /* A %= K */
+                /* lhi %r4,0 */
+                EMIT4(0xa7480000);
+                /* d %r4,<d(K)>(%r13) */
+                EMIT4_DISP(0x5d40d000, EMIT_CONST(K));
+                /* lr %r5,%r4 */
+                EMIT2(0x1854);
+                break;
         case BPF_S_ALU_AND_X: /* A &= X */
                 jit->seen |= SEEN_XREG;
                 /* nr %r5,%r12 */