[PATCH net-next 2/2] percpu: add __percpu sparse annotations to netdrivers

From: Tejun Heo
Date: Tue Feb 16 2010 - 20:13:15 EST


Add __percpu sparse annotations to net drivers.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/chelsio/sge.c | 2 +-
drivers/net/loopback.c | 16 +++++++++-------
drivers/net/veth.c | 4 ++--
include/linux/if_macvlan.h | 2 +-
4 files changed, 13 insertions(+), 11 deletions(-)

Index: net-next/drivers/net/chelsio/sge.c
===================================================================
--- net-next.orig/drivers/net/chelsio/sge.c
+++ net-next/drivers/net/chelsio/sge.c
@@ -267,7 +267,7 @@ struct sge {
struct sk_buff *espibug_skb[MAX_NPORTS];
u32 sge_control; /* shadow value of sge control reg */
struct sge_intr_counts stats;
- struct sge_port_stats *port_stats[MAX_NPORTS];
+ struct sge_port_stats __percpu *port_stats[MAX_NPORTS];
struct sched *tx_sched;
struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
};
Index: net-next/drivers/net/loopback.c
===================================================================
--- net-next.orig/drivers/net/loopback.c
+++ net-next/drivers/net/loopback.c
@@ -72,7 +72,8 @@ struct pcpu_lstats {
static netdev_tx_t loopback_xmit(struct sk_buff *skb,
struct net_device *dev)
{
- struct pcpu_lstats *pcpu_lstats, *lb_stats;
+ struct pcpu_lstats __percpu *pcpu_lstats;
+ struct pcpu_lstats *lb_stats;
int len;

skb_orphan(skb);
@@ -80,7 +81,7 @@ static netdev_tx_t loopback_xmit(struct
skb->protocol = eth_type_trans(skb, dev);

/* it's OK to use per_cpu_ptr() because BHs are off */
- pcpu_lstats = dev->ml_priv;
+ pcpu_lstats = (void __percpu __force *)dev->ml_priv;
lb_stats = this_cpu_ptr(pcpu_lstats);

len = skb->len;
@@ -95,14 +96,14 @@ static netdev_tx_t loopback_xmit(struct

static struct net_device_stats *loopback_get_stats(struct net_device *dev)
{
- const struct pcpu_lstats *pcpu_lstats;
+ const struct pcpu_lstats __percpu *pcpu_lstats;
struct net_device_stats *stats = &dev->stats;
unsigned long bytes = 0;
unsigned long packets = 0;
unsigned long drops = 0;
int i;

- pcpu_lstats = dev->ml_priv;
+ pcpu_lstats = (void __percpu __force *)dev->ml_priv;
for_each_possible_cpu(i) {
const struct pcpu_lstats *lb_stats;

@@ -135,19 +136,20 @@ static const struct ethtool_ops loopback

static int loopback_dev_init(struct net_device *dev)
{
- struct pcpu_lstats *lstats;
+ struct pcpu_lstats __percpu *lstats;

lstats = alloc_percpu(struct pcpu_lstats);
if (!lstats)
return -ENOMEM;

- dev->ml_priv = lstats;
+ dev->ml_priv = (void __force *)lstats;
return 0;
}

static void loopback_dev_free(struct net_device *dev)
{
- struct pcpu_lstats *lstats = dev->ml_priv;
+ struct pcpu_lstats __percpu *lstats =
+ (void __percpu __force *)dev->ml_priv;

free_percpu(lstats);
free_netdev(dev);
Index: net-next/drivers/net/veth.c
===================================================================
--- net-next.orig/drivers/net/veth.c
+++ net-next/drivers/net/veth.c
@@ -34,7 +34,7 @@ struct veth_net_stats {

struct veth_priv {
struct net_device *peer;
- struct veth_net_stats *stats;
+ struct veth_net_stats __percpu *stats;
unsigned ip_summed;
};

@@ -263,7 +263,7 @@ static int veth_change_mtu(struct net_de

static int veth_dev_init(struct net_device *dev)
{
- struct veth_net_stats *stats;
+ struct veth_net_stats __percpu *stats;
struct veth_priv *priv;

stats = alloc_percpu(struct veth_net_stats);
Index: net-next/include/linux/if_macvlan.h
===================================================================
--- net-next.orig/include/linux/if_macvlan.h
+++ net-next/include/linux/if_macvlan.h
@@ -30,7 +30,7 @@ struct macvlan_dev {
struct hlist_node hlist;
struct macvlan_port *port;
struct net_device *lowerdev;
- struct macvlan_rx_stats *rx_stats;
+ struct macvlan_rx_stats __percpu *rx_stats;
enum macvlan_mode mode;
int (*receive)(struct sk_buff *skb);
int (*forward)(struct net_device *dev, struct sk_buff *skb);
--
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