[PATCH 04/20] net: Add a slice to struct eth_device

[Sascha Hauer]

Add ethernet code safe for being called from a poller.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 include/net.h |  8 +++++
 net/eth.c     | 88 +++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 93 insertions(+), 3 deletions(-)

diff --git a/include/net.h b/include/net.h
index 54db8a179a..8d2b4923de 100644
--- a/include/net.h
+++ b/include/net.h
@@ -19,6 +19,7 @@
 #include <stdlib.h>
 #include <clock.h>
 #include <led.h>
+#include <slice.h>
 #include <xfuncs.h>
 #include <linux/phy.h>
 #include <linux/string.h>	/* memcpy */
@@ -63,6 +64,8 @@ struct eth_device {
 	char *bootarg;
 	char *linuxdevname;
 
+	struct slice slice;
+
 	bool ifup;
 #define ETH_MODE_DHCP 0
 #define ETH_MODE_STATIC 1
@@ -72,6 +75,11 @@ struct eth_device {
 
 #define dev_to_edev(d) container_of(d, struct eth_device, dev)
 
+static inline struct slice *eth_device_slice(struct eth_device *edev)
+{
+	return &edev->slice;
+}
+
 static inline const char *eth_name(struct eth_device *edev)
 {
 	return edev->devname;
diff --git a/net/eth.c b/net/eth.c
index e3d0d06efe..e67cc306c2 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -22,6 +22,7 @@
 #include <init.h>
 #include <dhcp.h>
 #include <net.h>
+#include <dma.h>
 #include <of.h>
 #include <linux/phy.h>
 #include <errno.h>
@@ -208,6 +209,56 @@ static int eth_carrier_check(struct eth_device *edev, int force)
 	return edev->phydev->link ? 0 : -ENETDOWN;
 }
 
+struct eth_q {
+	struct eth_device *edev;
+	int length;
+	struct list_head list;
+	void *data;
+};
+
+static int eth_queue(struct list_head *list, struct eth_device *edev,
+		     void *packet, int length)
+{
+	struct eth_q *q;
+
+	q = xzalloc(sizeof(*q));
+	if (!q)
+		return -ENOMEM;
+
+	q->data = dma_alloc(length);
+	if (!q->data) {
+		free(q);
+		return -ENOMEM;
+	}
+
+	q->length = length;
+	q->edev = edev;
+
+	memcpy(q->data, packet, length);
+	list_add_tail(&q->list, list);
+
+	return 0;
+}
+
+static LIST_HEAD(eth_send_list);
+
+static void eth_send_queue(void)
+{
+	struct eth_q *q, *tmp;
+
+	list_for_each_entry_safe(q, tmp, &eth_send_list, list) {
+		if (slice_acquired(eth_device_slice(q->edev)))
+			continue;
+
+		if (q->edev->active)
+			eth_send(q->edev, q->data, q->length);
+
+		list_del(&q->list);
+		free(q->data);
+		free(q);
+	}
+}
+
 int eth_send(struct eth_device *edev, void *packet, int length)
 {
 	int ret;
@@ -215,24 +266,39 @@ int eth_send(struct eth_device *edev, void *packet, int length)
 	if (!edev->active)
 		return -ENETDOWN;
 
+	if (slice_acquired(eth_device_slice(edev)))
+		return eth_queue(&eth_send_list, edev, packet, length);
+
 	ret = eth_carrier_check(edev, 0);
 	if (ret)
 		return ret;
 
+	slice_acquire(eth_device_slice(edev));
+
 	led_trigger_network(LED_TRIGGER_NET_TX);
 
-	return edev->send(edev, packet, length);
+	ret = edev->send(edev, packet, length);
+
+	slice_release(eth_device_slice(edev));
+
+	return ret;
 }
 
 static int __eth_rx(struct eth_device *edev)
 {
 	int ret;
 
+	slice_acquire(eth_device_slice(edev));
+
 	ret = eth_carrier_check(edev, 0);
 	if (ret)
-		return ret;
+		goto out;
 
-	return edev->recv(edev);
+	ret = edev->recv(edev);
+out:
+	slice_release(eth_device_slice(edev));
+
+	return ret;
 }
 
 int eth_rx(void)
@@ -244,6 +310,8 @@ int eth_rx(void)
 			__eth_rx(edev);
 	}
 
+	eth_send_queue();
+
 	return 0;
 }
 
@@ -353,6 +421,8 @@ int eth_register(struct eth_device *edev)
 	if (ret)
 		return ret;
 
+	slice_init(&edev->slice, dev_name(dev));
+
 	edev->devname = xstrdup(dev_name(&edev->dev));
 
 	dev_add_param_ip(dev, "ipaddr", NULL, NULL, &edev->ipaddr, edev);
@@ -422,15 +492,27 @@ void eth_close(struct eth_device *edev)
 
 void eth_unregister(struct eth_device *edev)
 {
+	struct eth_q *q, *tmp;
+
 	if (edev->active)
 		edev->halt(edev);
 
+	list_for_each_entry_safe(q, tmp, &eth_send_list, list) {
+		if (q->edev != edev)
+			continue;
+
+		list_del(&q->list);
+		free(q->data);
+		free(q);
+	}
+
 	if (IS_ENABLED(CONFIG_OFDEVICE))
 		free(edev->nodepath);
 
 	free(edev->devname);
 
 	unregister_device(&edev->dev);
+	slice_exit(&edev->slice);
 	list_del(&edev->list);
 }
 
-- 
2.28.0