net: Introduce helper functions to get the per cpu data

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -202,10 +202,20 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
 
+u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 unsigned long snmp_fold_field(void __percpu *mib, int offt);
 #if BITS_PER_LONG==32
+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+			 size_t syncp_offset);
 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 #else
+static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+					size_t syncp_offset)
+{
+	return snmp_get_cpu_field(mib, cpu, offct);
+
+}
+
 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
 {
 	return snmp_fold_field(mib, offt);

net/ipv4/af_inet.c

@@ -1452,38 +1452,51 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family,
 }
 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
 
+u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
+{
+	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
+}
+EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
+
 unsigned long snmp_fold_field(void __percpu *mib, int offt)
 {
 	unsigned long res = 0;
 	int i;
 
 	for_each_possible_cpu(i)
-		res += *(((unsigned long *) per_cpu_ptr(mib, i)) + offt);
+		res += snmp_get_cpu_field(mib, i, offt);
 	return res;
 }
 EXPORT_SYMBOL_GPL(snmp_fold_field);
 
 #if BITS_PER_LONG==32
 
+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+			 size_t syncp_offset)
+{
+	void *bhptr;
+	struct u64_stats_sync *syncp;
+	u64 v;
+	unsigned int start;
+
+	bhptr = per_cpu_ptr(mib, cpu);
+	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
+	do {
+		start = u64_stats_fetch_begin_irq(syncp);
+		v = *(((u64 *)bhptr) + offt);
+	} while (u64_stats_fetch_retry_irq(syncp, start));
+
+	return v;
+}
+EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
+
 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
 {
 	u64 res = 0;
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
-		void *bhptr;
-		struct u64_stats_sync *syncp;
-		u64 v;
-		unsigned int start;
-
-		bhptr = per_cpu_ptr(mib, cpu);
-		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
-		do {
-			start = u64_stats_fetch_begin_irq(syncp);
-			v = *(((u64 *) bhptr) + offt);
-		} while (u64_stats_fetch_retry_irq(syncp, start));
-
-		res += v;
+		res += snmp_get_cpu_field(mib, cpu, offct, syncp_offset);
 	}
 	return res;
 }