diff mbox series

[v3,net-next,08/21] net: usb: aqc111: Implement TX data path

Message ID 8b6748790baa1b8034c9c46ecd438c1f392854c7.1542794577.git.igor.russkikh@aquantia.com (mailing list archive)
State Superseded
Headers show
Series Add support for Aquantia AQtion USB to 5/2.5GbE devices | expand

Commit Message

Igor Russkikh Nov. 21, 2018, 10:13 a.m. UTC 
From: Dmitry Bezrukov <dmitry.bezrukov@aquantia.com>

Signed-off-by: Dmitry Bezrukov <dmitry.bezrukov@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
---
 drivers/net/usb/aqc111.c | 72 ++++++++++++++++++++++++++++++++++++++++
 drivers/net/usb/aqc111.h |  8 +++++
 2 files changed, 80 insertions(+)

Comments

David Miller Nov. 22, 2018, 7:07 p.m. UTC | #1 
From: Igor Russkikh <Igor.Russkikh@aquantia.com>
Date: Wed, 21 Nov 2018 10:13:37 +0000

> +	if (padding_size != 0)
> +		skb_put(skb, padding_size);

I think you want to use skb_put_zero() here rather than leaving it
uninitialized.  I know it's padding, but if for some reason this leaks
onto the wire or elsewhere we'll regret not initializing this buffer.

> +	/* Copy TX header */
> +	skb_push(skb, sizeof(tx_desc));
> +	cpu_to_le64s(&tx_desc);
> +	skb_copy_to_linear_data(skb, &tx_desc, sizeof(tx_desc));

I seriously wonder if, with all of the invariants wrt. length modulus
and padding, that you can safely just go:

	__le64 *p;

	p = skb_push(skb, sizeof(tx_desc));
	*p = cpu_to_le64(tx_desc);

or something like that.
diff mbox series

Patch

diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c
index 390ed6cbc3fd..dc9f0996afaf 100644
--- a/drivers/net/usb/aqc111.c
+++ b/drivers/net/usb/aqc111.c
@@ -222,6 +222,9 @@  static int aqc111_set_mac_addr(struct net_device *net, void *p)
 static const struct net_device_ops aqc111_netdev_ops = {
 	.ndo_open		= usbnet_open,
 	.ndo_stop		= usbnet_stop,
+	.ndo_start_xmit		= usbnet_start_xmit,
+	.ndo_tx_timeout		= usbnet_tx_timeout,
+	.ndo_get_stats64	= usbnet_get_stats64,
 	.ndo_set_mac_address	= aqc111_set_mac_addr,
 	.ndo_validate_addr	= eth_validate_addr,
 };
@@ -290,8 +293,19 @@  static int aqc111_bind(struct usbnet *dev, struct usb_interface *intf)
 		goto out;
 
 	ether_addr_copy(dev->net->dev_addr, dev->net->perm_addr);
+
+	/* Set TX needed headroom & tailroom */
+	dev->net->needed_headroom += sizeof(u64);
+	dev->net->needed_tailroom += sizeof(u64);
+
 	dev->net->netdev_ops = &aqc111_netdev_ops;
 
+	if (usb_device_no_sg_constraint(dev->udev))
+		dev->can_dma_sg = 1;
+
+	dev->net->hw_features |= AQ_SUPPORT_HW_FEATURE;
+	dev->net->features |= AQ_SUPPORT_FEATURE;
+
 	aqc111_read_fw_version(dev, aqc111_data);
 	aqc111_data->autoneg = AUTONEG_ENABLE;
 	aqc111_data->advertised_speed = (usb_speed == USB_SPEED_SUPER) ?
@@ -505,6 +519,12 @@  static int aqc111_reset(struct usbnet *dev)
 	struct aqc111_data *aqc111_data = dev->driver_priv;
 	u8 reg8 = 0;
 
+	if (usb_device_no_sg_constraint(dev->udev))
+		dev->can_dma_sg = 1;
+
+	dev->net->hw_features |= AQ_SUPPORT_HW_FEATURE;
+	dev->net->features |= AQ_SUPPORT_FEATURE;
+
 	/* Power up ethernet PHY */
 	aqc111_data->phy_cfg = AQ_PHY_POWER_EN;
 	aqc111_write32_cmd(dev, AQ_PHY_OPS, 0, 0,
@@ -558,6 +578,55 @@  static int aqc111_stop(struct usbnet *dev)
 	return 0;
 }
 
+static struct sk_buff *aqc111_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
+				       gfp_t flags)
+{
+	int frame_size = dev->maxpacket;
+	struct sk_buff *new_skb = NULL;
+	int padding_size = 0;
+	int headroom = 0;
+	int tailroom = 0;
+	u64 tx_desc = 0;
+
+	/*Length of actual data*/
+	tx_desc |= skb->len & AQ_TX_DESC_LEN_MASK;
+
+	headroom = (skb->len + sizeof(tx_desc)) % 8;
+	if (headroom != 0)
+		padding_size = 8 - headroom;
+
+	if (((skb->len + sizeof(tx_desc) + padding_size) % frame_size) == 0) {
+		padding_size += 8;
+		tx_desc |= AQ_TX_DESC_DROP_PADD;
+	}
+
+	if (!dev->can_dma_sg && (dev->net->features & NETIF_F_SG) &&
+	    skb_linearize(skb))
+		return NULL;
+
+	headroom = skb_headroom(skb);
+	tailroom = skb_tailroom(skb);
+
+	if (!(headroom >= sizeof(tx_desc) && tailroom >= padding_size)) {
+		new_skb = skb_copy_expand(skb, sizeof(tx_desc),
+					  padding_size, flags);
+		dev_kfree_skb_any(skb);
+		skb = new_skb;
+		if (!skb)
+			return NULL;
+	}
+	if (padding_size != 0)
+		skb_put(skb, padding_size);
+	/* Copy TX header */
+	skb_push(skb, sizeof(tx_desc));
+	cpu_to_le64s(&tx_desc);
+	skb_copy_to_linear_data(skb, &tx_desc, sizeof(tx_desc));
+
+	usbnet_set_skb_tx_stats(skb, 1, 0);
+
+	return skb;
+}
+
 static const struct driver_info aqc111_info = {
 	.description	= "Aquantia AQtion USB to 5GbE Controller",
 	.bind		= aqc111_bind,
@@ -566,6 +635,9 @@  static const struct driver_info aqc111_info = {
 	.link_reset	= aqc111_link_reset,
 	.reset		= aqc111_reset,
 	.stop		= aqc111_stop,
+	.flags		= FLAG_ETHER | FLAG_FRAMING_AX |
+			  FLAG_AVOID_UNLINK_URBS | FLAG_MULTI_PACKET,
+	.tx_fixup	= aqc111_tx_fixup,
 };
 
 #define AQC111_USB_ETH_DEV(vid, pid, table) \
diff --git a/drivers/net/usb/aqc111.h b/drivers/net/usb/aqc111.h
index 0c8e1ee29893..c09f188b9f3d 100644
--- a/drivers/net/usb/aqc111.h
+++ b/drivers/net/usb/aqc111.h
@@ -18,6 +18,10 @@ 
 #define AQ_USB_PHY_SET_TIMEOUT		10000
 #define AQ_USB_SET_TIMEOUT		4000
 
+/* Feature. ********************************************/
+#define AQ_SUPPORT_FEATURE	(NETIF_F_SG)
+#define AQ_SUPPORT_HW_FEATURE	(NETIF_F_SG)
+
 /* SFR Reg. ********************************************/
 
 #define SFR_GENERAL_STATUS		0x03
@@ -149,6 +153,10 @@  struct aqc111_data {
 #define AQ_INT_SPEED_1G		0x0011
 #define AQ_INT_SPEED_100M	0x0013
 
+/* TX Descriptor */
+#define AQ_TX_DESC_LEN_MASK	0x1FFFFF
+#define AQ_TX_DESC_DROP_PADD	BIT(28)
+
 static struct {
 	unsigned char ctrl;
 	unsigned char timer_l;