s390/bpf,jit: add vlan tag support

s390 version of 855ddb56 "x86: bpf_jit_comp: add vlan tag support".

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 bb284419b0fd..0972e91cced2 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -7,6 +7,7 @@
  */
 #include <linux/moduleloader.h>
 #include <linux/netdevice.h>
+#include <linux/if_vlan.h>
 #include <linux/filter.h>
 #include <asm/cacheflush.h>
 #include <asm/processor.h>
@@ -254,6 +255,8 @@ static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter)
         case BPF_S_ANC_HATYPE:
         case BPF_S_ANC_RXHASH:
         case BPF_S_ANC_CPU:
+        case BPF_S_ANC_VLAN_TAG:
+        case BPF_S_ANC_VLAN_TAG_PRESENT:
         case BPF_S_RET_K:
                 /* first instruction sets A register */
                 break;
@@ -699,6 +702,24 @@ call_fn:	/* lg %r1,<d(function)>(%r13) */
                 /* l %r5,<d(rxhash)>(%r2) */
                 EMIT4_DISP(0x58502000, offsetof(struct sk_buff, rxhash));
                 break;
+        case BPF_S_ANC_VLAN_TAG:
+        case BPF_S_ANC_VLAN_TAG_PRESENT:
+                BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
+                BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
+                /* lhi %r5,0 */
+                EMIT4(0xa7580000);
+                /* icm  %r5,3,<d(vlan_tci)>(%r2) */
+                EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, vlan_tci));
+                if (filter->code == BPF_S_ANC_VLAN_TAG) {
+                        /* nill %r5,0xefff */
+                        EMIT4_IMM(0xa5570000, ~VLAN_TAG_PRESENT);
+                } else {
+                        /* nill %r5,0x1000 */
+                        EMIT4_IMM(0xa5570000, VLAN_TAG_PRESENT);
+                        /* srl %r5,12 */
+                        EMIT4_DISP(0x88500000, 12);
+                }
+                break;
         case BPF_S_ANC_CPU: /* A = smp_processor_id() */
 #ifdef CONFIG_SMP
                 /* l %r5,<d(cpu_nr)> */