From 5303a0fe8ce8c7493025a3b60a403439edb4159a Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Sat, 9 Feb 2013 14:07:50 +0100
Subject: 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>
---
 arch/s390/net/bpf_jit_comp.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

(limited to 'arch/s390/net')

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)> */
-- 
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