net-sysfs: add support for device-specific rx queue sysfs attributes

Extend existing support for netdevice receive queue sysfs attributes to
permit a device-specific attribute group. Initial use case for this
support will be to allow the virtio-net device to export per-receive
queue mergeable receive buffer size.

Signed-off-by: Michael Dalton <mwdalton@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d7668b881d08e214ccbe99c2ce1e2eb26bd4203a..e985231fe04bafee02670c83c9d892abd07420ff 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -668,15 +668,28 @@ extern struct rps_sock_flow_table __rcu *rps_sock_flow_table;
 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, u32 flow_id,
                         u16 filter_id);
 #endif
+#endif /* CONFIG_RPS */
 
 /* This structure contains an instance of an RX queue. */
 struct netdev_rx_queue {
+#ifdef CONFIG_RPS
        struct rps_map __rcu            *rps_map;
        struct rps_dev_flow_table __rcu *rps_flow_table;
+#endif
        struct kobject                  kobj;
        struct net_device               *dev;
 } ____cacheline_aligned_in_smp;
-#endif /* CONFIG_RPS */
+
+/*
+ * RX queue sysfs structures and functions.
+ */
+struct rx_queue_attribute {
+       struct attribute attr;
+       ssize_t (*show)(struct netdev_rx_queue *queue,
+           struct rx_queue_attribute *attr, char *buf);
+       ssize_t (*store)(struct netdev_rx_queue *queue,
+           struct rx_queue_attribute *attr, const char *buf, size_t len);
+};
 
 #ifdef CONFIG_XPS
 /*
@@ -1313,7 +1326,7 @@ struct net_device {
                                                   unicast) */
 
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        struct netdev_rx_queue  *_rx;
 
        /* Number of RX queues allocated at register_netdev() time */
@@ -1424,6 +1437,8 @@ struct net_device {
        struct device           dev;
        /* space for optional device, statistics, and wireless sysfs groups */
        const struct attribute_group *sysfs_groups[4];
+       /* space for optional per-rx queue attributes */
+       const struct attribute_group *sysfs_rx_queue_group;
 
        /* rtnetlink link ops */
        const struct rtnl_link_ops *rtnl_link_ops;
@@ -2375,7 +2390,7 @@ static inline bool netif_is_multiqueue(const struct net_device *dev)
 
 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq);
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq);
 #else
 static inline int netif_set_real_num_rx_queues(struct net_device *dev,
@@ -2394,7 +2409,7 @@ static inline int netif_copy_real_num_queues(struct net_device *to_dev,
                                           from_dev->real_num_tx_queues);
        if (err)
                return err;
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        return netif_set_real_num_rx_queues(to_dev,
                                            from_dev->real_num_rx_queues);
 #else
@@ -2402,6 +2417,18 @@ static inline int netif_copy_real_num_queues(struct net_device *to_dev,
 #endif
 }
 
+#ifdef CONFIG_SYSFS
+static inline unsigned int get_netdev_rx_queue_index(
+               struct netdev_rx_queue *queue)
+{
+       struct net_device *dev = queue->dev;
+       int index = queue - dev->_rx;
+
+       BUG_ON(index >= dev->num_rx_queues);
+       return index;
+}
+#endif
+
 #define DEFAULT_MAX_NUM_RSS_QUEUES     (8)
 int netif_get_num_default_rss_queues(void);
 

diff --git a/net/core/dev.c b/net/core/dev.c
index f87bedd51eed0abfce2d4b439ecb675c8cda93b7..288df62320067b072a7950c2924455f3e095bd17 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2083,7 +2083,7 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
 }
 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
 /**
  *     netif_set_real_num_rx_queues - set actual number of RX queues used
  *     @dev: Network device
@@ -5764,7 +5764,7 @@ void netif_stacked_transfer_operstate(const struct net_device *rootdev,
 }
 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
 static int netif_alloc_rx_queues(struct net_device *dev)
 {
        unsigned int i, count = dev->num_rx_queues;
@@ -6309,7 +6309,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
                return NULL;
        }
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        if (rxqs < 1) {
                pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
                return NULL;
@@ -6365,7 +6365,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
        if (netif_alloc_netdev_queues(dev))
                goto free_all;
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        dev->num_rx_queues = rxqs;
        dev->real_num_rx_queues = rxqs;
        if (netif_alloc_rx_queues(dev))
@@ -6385,7 +6385,7 @@ free_all:
 free_pcpu:
        free_percpu(dev->pcpu_refcnt);
        netif_free_tx_queues(dev);
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        kfree(dev->_rx);
 #endif
 
@@ -6410,7 +6410,7 @@ void free_netdev(struct net_device *dev)
        release_net(dev_net(dev));
 
        netif_free_tx_queues(dev);
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        kfree(dev->_rx);
 #endif
 

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 49843bf7e43e43986cbdf86d466cad8c3fbb4914..7eeadeecc5a22ec9d4dd38c177f639a48851032c 100644 (file)
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -498,17 +498,7 @@ static struct attribute_group wireless_group = {
 #define net_class_groups       NULL
 #endif /* CONFIG_SYSFS */
 
-#ifdef CONFIG_RPS
-/*
- * RX queue sysfs structures and functions.
- */
-struct rx_queue_attribute {
-       struct attribute attr;
-       ssize_t (*show)(struct netdev_rx_queue *queue,
-           struct rx_queue_attribute *attr, char *buf);
-       ssize_t (*store)(struct netdev_rx_queue *queue,
-           struct rx_queue_attribute *attr, const char *buf, size_t len);
-};
+#ifdef CONFIG_SYSFS
 #define to_rx_queue_attr(_attr) container_of(_attr,            \
     struct rx_queue_attribute, attr)
 
@@ -543,6 +533,7 @@ static const struct sysfs_ops rx_queue_sysfs_ops = {
        .store = rx_queue_attr_store,
 };
 
+#ifdef CONFIG_RPS
 static ssize_t show_rps_map(struct netdev_rx_queue *queue,
                            struct rx_queue_attribute *attribute, char *buf)
 {
@@ -718,16 +709,20 @@ static struct rx_queue_attribute rps_cpus_attribute =
 static struct rx_queue_attribute rps_dev_flow_table_cnt_attribute =
        __ATTR(rps_flow_cnt, S_IRUGO | S_IWUSR,
            show_rps_dev_flow_table_cnt, store_rps_dev_flow_table_cnt);
+#endif /* CONFIG_RPS */
 
 static struct attribute *rx_queue_default_attrs[] = {
+#ifdef CONFIG_RPS
        &rps_cpus_attribute.attr,
        &rps_dev_flow_table_cnt_attribute.attr,
+#endif
        NULL
 };
 
 static void rx_queue_release(struct kobject *kobj)
 {
        struct netdev_rx_queue *queue = to_rx_queue(kobj);
+#ifdef CONFIG_RPS
        struct rps_map *map;
        struct rps_dev_flow_table *flow_table;
 
@@ -743,6 +738,7 @@ static void rx_queue_release(struct kobject *kobj)
                RCU_INIT_POINTER(queue->rps_flow_table, NULL);
                call_rcu(&flow_table->rcu, rps_dev_flow_table_release);
        }
+#endif
 
        memset(kobj, 0, sizeof(*kobj));
        dev_put(queue->dev);
@@ -763,25 +759,36 @@ static int rx_queue_add_kobject(struct net_device *net, int index)
        kobj->kset = net->queues_kset;
        error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL,
            "rx-%u", index);
-       if (error) {
-               kobject_put(kobj);
-               return error;
+       if (error)
+               goto exit;
+
+       if (net->sysfs_rx_queue_group) {
+               error = sysfs_create_group(kobj, net->sysfs_rx_queue_group);
+               if (error)
+                       goto exit;
        }
 
        kobject_uevent(kobj, KOBJ_ADD);
        dev_hold(queue->dev);
 
+       return error;
+exit:
+       kobject_put(kobj);
        return error;
 }
-#endif /* CONFIG_RPS */
+#endif /* CONFIG_SYFS */
 
 int
 net_rx_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
 {
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        int i;
        int error = 0;
 
+#ifndef CONFIG_RPS
+       if (!net->sysfs_rx_queue_group)
+               return 0;
+#endif
        for (i = old_num; i < new_num; i++) {
                error = rx_queue_add_kobject(net, i);
                if (error) {
@@ -790,8 +797,12 @@ net_rx_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
                }
        }
 
-       while (--i >= new_num)
+       while (--i >= new_num) {
+               if (net->sysfs_rx_queue_group)
+                       sysfs_remove_group(&net->_rx[i].kobj,
+                                          net->sysfs_rx_queue_group);
                kobject_put(&net->_rx[i].kobj);
+       }
 
        return error;
 #else
@@ -1155,9 +1166,6 @@ static int register_queue_kobjects(struct net_device *net)
            NULL, &net->dev.kobj);
        if (!net->queues_kset)
                return -ENOMEM;
-#endif
-
-#ifdef CONFIG_RPS
        real_rx = net->real_num_rx_queues;
 #endif
        real_tx = net->real_num_tx_queues;
@@ -1184,7 +1192,7 @@ static void remove_queue_kobjects(struct net_device *net)
 {
        int real_rx = 0, real_tx = 0;
 
-#ifdef CONFIG_RPS
+#ifdef CONFIG_SYSFS
        real_rx = net->real_num_rx_queues;
 #endif
        real_tx = net->real_num_tx_queues;