net: core: add devm_netdev_alloc_pcpu_stats

We have netdev_alloc_pcpu_stats(), and we have devm_alloc_percpu().
Add a managed version of netdev_alloc_pcpu_stats, e.g. for allocating
the per-cpu stats in the probe() callback of a driver. It needs to be
a macro for dealing properly with the type argument.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 568fab7..a53ed2d 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2596,6 +2596,20 @@ static inline void dev_lstats_add(struct net_device *dev, unsigned int len)
 #define netdev_alloc_pcpu_stats(type)                                  \
        __netdev_alloc_pcpu_stats(type, GFP_KERNEL)
 
+#define devm_netdev_alloc_pcpu_stats(dev, type)                                \
+({                                                                     \
+       typeof(type) __percpu *pcpu_stats = devm_alloc_percpu(dev, type);\
+       if (pcpu_stats) {                                               \
+               int __cpu;                                              \
+               for_each_possible_cpu(__cpu) {                          \
+                       typeof(type) *stat;                             \
+                       stat = per_cpu_ptr(pcpu_stats, __cpu);          \
+                       u64_stats_init(&stat->syncp);                   \
+               }                                                       \
+       }                                                               \
+       pcpu_stats;                                                     \
+})
+
 enum netdev_lag_tx_type {
        NETDEV_LAG_TX_TYPE_UNKNOWN,
        NETDEV_LAG_TX_TYPE_RANDOM,