Differences

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--- alloc_netdev_etherdev [2018/08/28 07:12] – [alloc_netdev_mqs] rpjday
+++ alloc_netdev_etherdev [2018/08/28 08:00] (current) – [netdev private data] rpjday
@@ Line 5: / Line 5: @@
 ===== netdev private data =====
-From ''netdevice.h'', private data is stored (aligned) after the end of the structure:
+From ''include/linux/netdevice.h'', optional private data is stored (aligned) after the end of the structure:
 <code>
@@ Line 18: / Line 18: @@
 </code>
-===== The variations of allocating net devices =====
+Explanation of ''NETDEV_ALIGN'' [[https://stackoverflow.com/questions/31459565/memory-alignment-in-the-alloc-netdev-mqs|here]].
-==== alloc_netdev_mqs ====
-The base allocation routine from ''net/core/dev.c'' for allocating a single device:
+===== alloc_netdev_mqs =====
+The base allocation routine from ''net/core/dev.c'' for allocating a //single// device:
 <code>
@@ Line 75: / Line 76: @@
 </code>
+Not a lot of drivers call this routine directly given that you can call more convenient wrappers (see below).
-==== More ====
+===== Wrappers/variations =====
+==== alloc_netdev()/alloc_netdev_mq() ====
+From ''include/linux/netdevice.h'':
+<code>
+#define alloc_netdev(sizeof_priv, name, name_assign_type, setup) \
+	alloc_netdev_mqs(sizeof_priv, name, name_assign_type, setup, 1, 1)
+#define alloc_netdev_mq(sizeof_priv, name, name_assign_type, setup, count) \
+	alloc_netdev_mqs(sizeof_priv, name, name_assign_type, setup, count, \
+			 count)
+</code>
+==== alloc_etherdev(),alloc_etherdev_mq(),alloc_etherdev_mqs() ====
+From ''include/linux/etherdevice.h'':
+<code>
+struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
+					    unsigned int rxqs);
+#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
+#define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
+</code>
+From ''net/ethernet/net.c'':
 <code>
@@ Line 84: / Line 113: @@
 	return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_UNKNOWN,
 				ether_setup, txqs, rxqs);
+}
+</code>
+==== devm_alloc_etherdev*() ====
+From ''include/linux/etherdevice.h'':
+<code>
+struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
+					   unsigned int txqs,
+					   unsigned int rxqs);
+#define devm_alloc_etherdev(dev, sizeof_priv) devm_alloc_etherdev_mqs(dev, sizeof_priv, 1, 1)
+</code>
+From ''net/ethernet/net.c'':
+<code>
+struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
+					   unsigned int txqs, unsigned int rxqs)
+{
+	struct net_device **dr;
+	struct net_device *netdev;
+	dr = devres_alloc(devm_free_netdev, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return NULL;
+	netdev = alloc_etherdev_mqs(sizeof_priv, txqs, rxqs);
+	if (!netdev) {
+		devres_free(dr);
+		return NULL;
+	}
+	*dr = netdev;
+	devres_add(dev, dr);
+	return netdev;
 }
 </code>