[IPV4]: Consolidate common SNMP code

This patch moves the SNMP code shared between IPv4/IPv6 from proc.c
into net/ipv4/af_inet.c.  This makes sense because these functions
aren't specific to /proc.

As a result we can again skip proc.o if /proc is disabled.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index a33ca7e..16aae8e 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1219,6 +1219,46 @@
 	return segs;
 }
 
+unsigned long snmp_fold_field(void *mib[], int offt)
+{
+	unsigned long res = 0;
+	int i;
+
+	for_each_possible_cpu(i) {
+		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
+		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
+	}
+	return res;
+}
+EXPORT_SYMBOL_GPL(snmp_fold_field);
+
+int snmp_mib_init(void *ptr[2], size_t mibsize, size_t mibalign)
+{
+	BUG_ON(ptr == NULL);
+	ptr[0] = __alloc_percpu(mibsize);
+	if (!ptr[0])
+		goto err0;
+	ptr[1] = __alloc_percpu(mibsize);
+	if (!ptr[1])
+		goto err1;
+	return 0;
+err1:
+	free_percpu(ptr[0]);
+	ptr[0] = NULL;
+err0:
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(snmp_mib_init);
+
+void snmp_mib_free(void *ptr[2])
+{
+	BUG_ON(ptr == NULL);
+	free_percpu(ptr[0]);
+	free_percpu(ptr[1]);
+	ptr[0] = ptr[1] = NULL;
+}
+EXPORT_SYMBOL_GPL(snmp_mib_free);
+
 #ifdef CONFIG_IP_MULTICAST
 static struct net_protocol igmp_protocol = {
 	.handler =	igmp_rcv,