* [PATCH 2/3] caif: Add support for flow-control on device's tx-queue
2011-12-02 14:06 [PATCH 0/3] caif: CAIF for CDC NCM USB Sjur Brændeland
2011-12-02 14:06 ` [PATCH 1/3] if_ether.h: Add IEEE 802.1 Local Experimental Ethertype 1 Sjur Brændeland
@ 2011-12-02 14:06 ` Sjur Brændeland
2011-12-02 14:38 ` Eric Dumazet
2011-12-02 14:06 ` [PATCH 3/3] caif: Add support for CAIF over CDC NCM USB interface Sjur Brændeland
2 siblings, 1 reply; 6+ messages in thread
From: Sjur Brændeland @ 2011-12-02 14:06 UTC (permalink / raw)
To: netdev; +Cc: David Miller, Alexey Orishko, Sjur Brændeland
Flow control is implemented by inspecting the qdisc queue length
in order to detect potential overflow on the TX queue. When a threshold
is reached flow-off is sent upwards in the CAIF stack. At the same time
the skb->destructor is hi-jacked in order to detect when the last packet
put on queue is consumed. When this "hi-jacked" packet is consumed, flow-on
is sent upwards in the CAIF stack.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
---
net/caif/caif_dev.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index f7e8c70..415353e 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -34,6 +34,7 @@ struct caif_device_entry {
struct list_head list;
struct net_device *netdev;
int __percpu *pcpu_refcnt;
+ bool xoff;
};
struct caif_device_entry_list {
@@ -48,6 +49,7 @@ struct caif_net {
};
static int caif_net_id;
+static int q_high = 50; /* Percent */
struct cfcnfg *get_cfcnfg(struct net *net)
{
@@ -126,9 +128,28 @@ static struct caif_device_entry *caif_get(struct net_device *dev)
return NULL;
}
+void caif_flow_cb(struct sk_buff *skb)
+{
+ struct caif_device_entry *caifd;
+ WARN_ON(skb->dev == NULL);
+
+ rcu_read_lock();
+ caifd = caif_get(skb->dev);
+ caifd->xoff = 0;
+ caifd_hold(caifd);
+ rcu_read_unlock();
+
+ caifd->layer.up->
+ ctrlcmd(caifd->layer.up,
+ _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND,
+ caifd->layer.id);
+ caifd_put(caifd);
+}
+
static int transmit(struct cflayer *layer, struct cfpkt *pkt)
{
int err;
+ struct caif_dev_common *caifdev;
struct caif_device_entry *caifd =
container_of(layer, struct caif_device_entry, layer);
struct sk_buff *skb;
@@ -137,6 +158,33 @@ static int transmit(struct cflayer *layer, struct cfpkt *pkt)
skb->dev = caifd->netdev;
skb_reset_network_header(skb);
skb->protocol = htons(ETH_P_CAIF);
+ caifdev = netdev_priv(caifd->netdev);
+
+ if (caifdev->flowctrl == NULL && caifd->netdev->tx_queue_len > 0 &&
+ !caifd->xoff) {
+ struct netdev_queue *txq;
+ int high;
+
+ txq = netdev_get_tx_queue(skb->dev, 0);
+ high = (caifd->netdev->tx_queue_len * q_high) / 100;
+
+ /* If we run with a TX queue, check if the queue is too long*/
+ if (netif_queue_stopped(caifd->netdev) ||
+ qdisc_qlen(txq->qdisc) > high) {
+
+ pr_debug("queue stop(%d) or full (%d>%d) - XOFF\n",
+ netif_queue_stopped(caifd->netdev),
+ qdisc_qlen(txq->qdisc), high);
+ caifd->xoff = 1;
+ /* Hijack this skb free callback function. */
+ skb_orphan(skb);
+ skb->destructor = caif_flow_cb;
+ caifd->layer.up->
+ ctrlcmd(caifd->layer.up,
+ _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+ caifd->layer.id);
+ }
+ }
err = dev_queue_xmit(skb);
if (err > 0)
--
1.7.0.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/3] caif: Add support for CAIF over CDC NCM USB interface
2011-12-02 14:06 [PATCH 0/3] caif: CAIF for CDC NCM USB Sjur Brændeland
2011-12-02 14:06 ` [PATCH 1/3] if_ether.h: Add IEEE 802.1 Local Experimental Ethertype 1 Sjur Brændeland
2011-12-02 14:06 ` [PATCH 2/3] caif: Add support for flow-control on device's tx-queue Sjur Brændeland
@ 2011-12-02 14:06 ` Sjur Brændeland
2 siblings, 0 replies; 6+ messages in thread
From: Sjur Brændeland @ 2011-12-02 14:06 UTC (permalink / raw)
To: netdev; +Cc: David Miller, Alexey Orishko, Sjur Brændeland
NCM 1.0 does not support anything but Ethernet framing, hence
CAIF payload will be put into Ethernet frames.
Discovery is based on fixed USB vendor 0x04cc (ST-Ericsson),
product-id 0x230f (NCM). In this variant only CAIF payload is sent over
the NCM interface.
The CAIF stack (cfusbl.c) will when USB registers first check if
we got a CDC NCM USB interface with the right VID, PID.
It will then read the device's Ethernet address and create a 'template'
Ethernet TX header, using a broadcast address as the destination address,
and EthType 0x88b5 (802.1 Local Experimental - vendor specific).
A protocol handler for 0x88b5 is setup for reception of CAIF frames from
the CDC NCM USB interface.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
---
include/net/caif/cfusbl.h | 13 +++
net/caif/Kconfig | 11 +++
net/caif/Makefile | 4 +-
net/caif/caif_dev.c | 7 ++
net/caif/cfusbl.c | 199 +++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 233 insertions(+), 1 deletions(-)
create mode 100644 include/net/caif/cfusbl.h
create mode 100644 net/caif/cfusbl.c
diff --git a/include/net/caif/cfusbl.h b/include/net/caif/cfusbl.h
new file mode 100644
index 0000000..7ef2499
--- /dev/null
+++ b/include/net/caif/cfusbl.h
@@ -0,0 +1,13 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author: Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef CFUSBL_H_
+#define CFUSBL_H_
+
+void cfusbl_init(void);
+void cfusbl_exit(void);
+
+#endif /* CFUSBL_H_ */
diff --git a/net/caif/Kconfig b/net/caif/Kconfig
index 529750d..43cd844 100644
--- a/net/caif/Kconfig
+++ b/net/caif/Kconfig
@@ -40,3 +40,14 @@ config CAIF_NETDEV
If you select to build it as a built-in then the main CAIF device must
also be a built-in.
If unsure say Y.
+
+config CAIF_USB
+ bool "CAIF USB support"
+ depends on CAIF
+ default CAIF
+ ---help---
+ Say Y if you are using CAIF over USB CDC NCM.
+ This can be either built-in or a loadable module,
+ If you select to build it as a built-in then the main CAIF device must
+ also be a built-in.
+ If unsure say N.
diff --git a/net/caif/Makefile b/net/caif/Makefile
index ebcd4e7..3965f73 100644
--- a/net/caif/Makefile
+++ b/net/caif/Makefile
@@ -1,4 +1,5 @@
-ccflags-$(CONFIG_CAIF_DEBUG) := -DDEBUG
+ccflags-$(CONFIG_CAIF_DEBUG) += -DDEBUG
+ccflags-$(CONFIG_CAIF_USB) += -DCAIF_USB
caif-y := caif_dev.o \
cfcnfg.o cfmuxl.o cfctrl.o \
@@ -6,6 +7,7 @@ caif-y := caif_dev.o \
cfserl.o cfdgml.o \
cfrfml.o cfvidl.o cfutill.o \
cfsrvl.o cfpkt_skbuff.o
+caif-$(CONFIG_CAIF_USB) += cfusbl.o
obj-$(CONFIG_CAIF) += caif.o
obj-$(CONFIG_CAIF_NETDEV) += chnl_net.o
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index 415353e..6ef0e90 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -25,6 +25,7 @@
#include <net/caif/cfpkt.h>
#include <net/caif/cfcnfg.h>
#include <net/caif/cfserl.h>
+#include <net/caif/cfusbl.h>
MODULE_LICENSE("GPL");
@@ -506,6 +507,9 @@ static int __init caif_device_init(void)
if (result)
return result;
+#ifdef CAIF_USB
+ cfusbl_init();
+#endif
register_netdevice_notifier(&caif_device_notifier);
dev_add_pack(&caif_packet_type);
@@ -517,6 +521,9 @@ static void __exit caif_device_exit(void)
unregister_pernet_device(&caif_net_ops);
unregister_netdevice_notifier(&caif_device_notifier);
dev_remove_pack(&caif_packet_type);
+#ifdef CAIF_USB
+ cfusbl_exit();
+#endif
}
module_init(caif_device_init);
diff --git a/net/caif/cfusbl.c b/net/caif/cfusbl.c
new file mode 100644
index 0000000..8353a55
--- /dev/null
+++ b/net/caif/cfusbl.c
@@ -0,0 +1,199 @@
+/*
+ * CAIF USB handler
+ * Copyright (C) ST-Ericsson AB 2011
+ * Author: Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/usbnet.h>
+#include <net/netns/generic.h>
+#include <net/caif/caif_dev.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+
+MODULE_LICENSE("GPL");
+
+#define CFUSB_PAD_DESCR_SZ 1 /* Alignment descriptor length */
+#define CFUSB_ALIGNMENT 4 /* Number of bytes to align. */
+#define CFUSB_MAX_HEADLEN (CFUSB_PAD_DESCR_SZ + CFUSB_ALIGNMENT-1)
+#define STE_USB_VID 0x04cc /* USB Product ID for ST-Ericsson */
+#define STE_USB_PID_CAIF 0x2306 /* Product id for CAIF Modems */
+
+struct cfusbl {
+ struct cflayer layer;
+ u8 tx_eth_hdr[ETH_HLEN];
+};
+
+static bool pack_added;
+
+static int cfusbl_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+ u8 hpad;
+
+ /* Remove padding. */
+ cfpkt_extr_head(pkt, &hpad, 1);
+ cfpkt_extr_head(pkt, NULL, hpad);
+ return layr->up->receive(layr->up, pkt);
+}
+
+static int cfusbl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+ struct caif_payload_info *info;
+ u8 hpad;
+ u8 zeros[CFUSB_ALIGNMENT];
+ struct sk_buff *skb;
+ struct cfusbl *usbl = container_of(layr, struct cfusbl, layer);
+
+ skb = cfpkt_tonative(pkt);
+
+ skb_reset_network_header(skb);
+ skb->protocol = htons(ETH_P_IP);
+
+ info = cfpkt_info(pkt);
+ hpad = (info->hdr_len + CFUSB_PAD_DESCR_SZ) & (CFUSB_ALIGNMENT - 1);
+
+ if (skb_headroom(skb) < ETH_HLEN + CFUSB_PAD_DESCR_SZ + hpad) {
+ pr_warn("Headroom to small\n");
+ kfree_skb(skb);
+ return -EIO;
+ }
+ memset(zeros, 0, hpad);
+
+ cfpkt_add_head(pkt, zeros, hpad);
+ cfpkt_add_head(pkt, &hpad, 1);
+ cfpkt_add_head(pkt, usbl->tx_eth_hdr, sizeof(usbl->tx_eth_hdr));
+ return layr->dn->transmit(layr->dn, pkt);
+}
+
+static void cfusbl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+ int phyid)
+{
+ if (layr->up && layr->up->ctrlcmd)
+ layr->up->ctrlcmd(layr->up, ctrl, layr->id);
+}
+
+struct cflayer *cfusbl_create(int phyid, u8 ethaddr[ETH_ALEN],
+ u8 braddr[ETH_ALEN])
+{
+ struct cfusbl *this = kmalloc(sizeof(struct cfusbl), GFP_ATOMIC);
+
+ if (!this) {
+ pr_warn("Out of memory\n");
+ return NULL;
+ }
+ caif_assert(offsetof(struct cfusbl, layer) == 0);
+
+ memset(this, 0, sizeof(struct cflayer));
+ this->layer.receive = cfusbl_receive;
+ this->layer.transmit = cfusbl_transmit;
+ this->layer.ctrlcmd = cfusbl_ctrlcmd;
+ snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "usb%d", phyid);
+ this->layer.id = phyid;
+
+ /*
+ * Construct TX ethernet header:
+ * 0-5 destination address
+ * 5-11 source address
+ * 12-13 protocol type
+ */
+ memcpy(&this->tx_eth_hdr[ETH_ALEN], braddr, ETH_ALEN);
+ memcpy(&this->tx_eth_hdr[ETH_ALEN], ethaddr, ETH_ALEN);
+ this->tx_eth_hdr[12] = cpu_to_be16(ETH_P_802_EX1) & 0xff;
+ this->tx_eth_hdr[13] = (cpu_to_be16(ETH_P_802_EX1) >> 8) & 0xff;
+ pr_debug("caif ethernet TX-header dst:%pM src:%pM type:%02x%02x\n",
+ this->tx_eth_hdr, this->tx_eth_hdr + ETH_ALEN,
+ this->tx_eth_hdr[12], this->tx_eth_hdr[13]);
+
+ return (struct cflayer *) this;
+}
+
+static struct packet_type caif_usb_type __read_mostly = {
+ .type = cpu_to_be16(ETH_P_802_EX1),
+};
+
+static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
+ void *arg)
+{
+ struct net_device *dev = arg;
+ struct caif_dev_common common;
+ struct cflayer *layer, *link_support;
+ struct usbnet *usbnet = netdev_priv(dev);
+ struct usb_device *usbdev = usbnet->udev;
+ struct ethtool_drvinfo drvinfo;
+
+ if (what != NETDEV_REGISTER)
+ return 0;
+ /*
+ * Quirks: High-jack ethtool to find if we have a NCM device,
+ * and find it's VID/PID.
+ */
+ if (dev->ethtool_ops == NULL || dev->ethtool_ops->get_drvinfo == NULL)
+ return 0;
+
+ dev->ethtool_ops->get_drvinfo(dev, &drvinfo);
+ if (strncmp(drvinfo.driver, "cdc_ncm", 7) != 0)
+ return 0;
+
+ pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n",
+ le16_to_cpu(usbdev->descriptor.idVendor),
+ le16_to_cpu(usbdev->descriptor.idProduct));
+
+ /* Check for VID/PID that supports CAIF */
+ if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID &&
+ le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF))
+ return 0;
+
+ memset(&common, 0, sizeof(common));
+ common.use_frag = false;
+ common.use_fcs = false;
+ common.use_stx = false;
+ common.link_select = CAIF_LINK_HIGH_BANDW;
+ common.flowctrl = NULL;
+
+ link_support = cfusbl_create(dev->ifindex, dev->dev_addr,
+ dev->broadcast);
+ if (!link_support) {
+ pr_warn("Out of memory\n");
+ return -ENOMEM;
+ }
+
+ if (dev->num_tx_queues > 1)
+ pr_warn("USB device uses more than one tx queue\n");
+
+ caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
+ &layer, &caif_usb_type.func);
+ if (!pack_added)
+ dev_add_pack(&caif_usb_type);
+ pack_added = 1;
+
+ strncpy(layer->name, dev->name,
+ sizeof(layer->name) - 1);
+ layer->name[sizeof(layer->name) - 1] = 0;
+
+ return 0;
+}
+
+static struct notifier_block caif_device_notifier = {
+ .notifier_call = cfusbl_device_notify,
+ .priority = 0,
+};
+
+void cfusbl_init(void)
+{
+ register_netdevice_notifier(&caif_device_notifier);
+}
+
+void cfusbl_exit(void)
+{
+ unregister_netdevice_notifier(&caif_device_notifier);
+ dev_remove_pack(&caif_usb_type);
+}
--
1.7.0.4
^ permalink raw reply related [flat|nested] 6+ messages in thread