v4.19.13 snapshot.
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
new file mode 100644
index 0000000..711d715
--- /dev/null
+++ b/net/caif/caif_dev.c
@@ -0,0 +1,575 @@
+/*
+ * CAIF Interface registration.
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author: Sjur Brendeland
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ * Borrowed heavily from file: pn_dev.c. Thanks to Remi Denis-Courmont
+ * and Sakari Ailus <sakari.ailus@nokia.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/if_arp.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <net/netns/generic.h>
+#include <net/net_namespace.h>
+#include <net/pkt_sched.h>
+#include <net/caif/caif_device.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/caif_dev.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+#include <net/caif/cfserl.h>
+
+MODULE_LICENSE("GPL");
+
+/* Used for local tracking of the CAIF net devices */
+struct caif_device_entry {
+ struct cflayer layer;
+ struct list_head list;
+ struct net_device *netdev;
+ int __percpu *pcpu_refcnt;
+ spinlock_t flow_lock;
+ struct sk_buff *xoff_skb;
+ void (*xoff_skb_dtor)(struct sk_buff *skb);
+ bool xoff;
+};
+
+struct caif_device_entry_list {
+ struct list_head list;
+ /* Protects simulanous deletes in list */
+ struct mutex lock;
+};
+
+struct caif_net {
+ struct cfcnfg *cfg;
+ struct caif_device_entry_list caifdevs;
+};
+
+static unsigned int caif_net_id;
+static int q_high = 50; /* Percent */
+
+struct cfcnfg *get_cfcnfg(struct net *net)
+{
+ struct caif_net *caifn;
+ caifn = net_generic(net, caif_net_id);
+ return caifn->cfg;
+}
+EXPORT_SYMBOL(get_cfcnfg);
+
+static struct caif_device_entry_list *caif_device_list(struct net *net)
+{
+ struct caif_net *caifn;
+ caifn = net_generic(net, caif_net_id);
+ return &caifn->caifdevs;
+}
+
+static void caifd_put(struct caif_device_entry *e)
+{
+ this_cpu_dec(*e->pcpu_refcnt);
+}
+
+static void caifd_hold(struct caif_device_entry *e)
+{
+ this_cpu_inc(*e->pcpu_refcnt);
+}
+
+static int caifd_refcnt_read(struct caif_device_entry *e)
+{
+ int i, refcnt = 0;
+ for_each_possible_cpu(i)
+ refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
+ return refcnt;
+}
+
+/* Allocate new CAIF device. */
+static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
+{
+ struct caif_device_entry *caifd;
+
+ caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
+ if (!caifd)
+ return NULL;
+ caifd->pcpu_refcnt = alloc_percpu(int);
+ if (!caifd->pcpu_refcnt) {
+ kfree(caifd);
+ return NULL;
+ }
+ caifd->netdev = dev;
+ dev_hold(dev);
+ return caifd;
+}
+
+static struct caif_device_entry *caif_get(struct net_device *dev)
+{
+ struct caif_device_entry_list *caifdevs =
+ caif_device_list(dev_net(dev));
+ struct caif_device_entry *caifd;
+
+ list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
+ if (caifd->netdev == dev)
+ return caifd;
+ }
+ return NULL;
+}
+
+static void caif_flow_cb(struct sk_buff *skb)
+{
+ struct caif_device_entry *caifd;
+ void (*dtor)(struct sk_buff *skb) = NULL;
+ bool send_xoff;
+
+ WARN_ON(skb->dev == NULL);
+
+ rcu_read_lock();
+ caifd = caif_get(skb->dev);
+
+ WARN_ON(caifd == NULL);
+ if (!caifd) {
+ rcu_read_unlock();
+ return;
+ }
+
+ caifd_hold(caifd);
+ rcu_read_unlock();
+
+ spin_lock_bh(&caifd->flow_lock);
+ send_xoff = caifd->xoff;
+ caifd->xoff = 0;
+ dtor = caifd->xoff_skb_dtor;
+
+ if (WARN_ON(caifd->xoff_skb != skb))
+ skb = NULL;
+
+ caifd->xoff_skb = NULL;
+ caifd->xoff_skb_dtor = NULL;
+
+ spin_unlock_bh(&caifd->flow_lock);
+
+ if (dtor && skb)
+ dtor(skb);
+
+ if (send_xoff)
+ 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, high = 0, qlen = 0;
+ struct caif_device_entry *caifd =
+ container_of(layer, struct caif_device_entry, layer);
+ struct sk_buff *skb;
+ struct netdev_queue *txq;
+
+ rcu_read_lock_bh();
+
+ skb = cfpkt_tonative(pkt);
+ skb->dev = caifd->netdev;
+ skb_reset_network_header(skb);
+ skb->protocol = htons(ETH_P_CAIF);
+
+ /* Check if we need to handle xoff */
+ if (likely(caifd->netdev->priv_flags & IFF_NO_QUEUE))
+ goto noxoff;
+
+ if (unlikely(caifd->xoff))
+ goto noxoff;
+
+ if (likely(!netif_queue_stopped(caifd->netdev))) {
+ /* If we run with a TX queue, check if the queue is too long*/
+ txq = netdev_get_tx_queue(skb->dev, 0);
+ qlen = qdisc_qlen(rcu_dereference_bh(txq->qdisc));
+
+ if (likely(qlen == 0))
+ goto noxoff;
+
+ high = (caifd->netdev->tx_queue_len * q_high) / 100;
+ if (likely(qlen < high))
+ goto noxoff;
+ }
+
+ /* Hold lock while accessing xoff */
+ spin_lock_bh(&caifd->flow_lock);
+ if (caifd->xoff) {
+ spin_unlock_bh(&caifd->flow_lock);
+ goto noxoff;
+ }
+
+ /*
+ * Handle flow off, we do this by temporary hi-jacking this
+ * skb's destructor function, and replace it with our own
+ * flow-on callback. The callback will set flow-on and call
+ * the original destructor.
+ */
+
+ pr_debug("queue has stopped(%d) or is full (%d > %d)\n",
+ netif_queue_stopped(caifd->netdev),
+ qlen, high);
+ caifd->xoff = 1;
+ caifd->xoff_skb = skb;
+ caifd->xoff_skb_dtor = skb->destructor;
+ skb->destructor = caif_flow_cb;
+ spin_unlock_bh(&caifd->flow_lock);
+
+ caifd->layer.up->ctrlcmd(caifd->layer.up,
+ _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+ caifd->layer.id);
+noxoff:
+ rcu_read_unlock_bh();
+
+ err = dev_queue_xmit(skb);
+ if (err > 0)
+ err = -EIO;
+
+ return err;
+}
+
+/*
+ * Stuff received packets into the CAIF stack.
+ * On error, returns non-zero and releases the skb.
+ */
+static int receive(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pkttype, struct net_device *orig_dev)
+{
+ struct cfpkt *pkt;
+ struct caif_device_entry *caifd;
+ int err;
+
+ pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
+
+ rcu_read_lock();
+ caifd = caif_get(dev);
+
+ if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
+ !netif_oper_up(caifd->netdev)) {
+ rcu_read_unlock();
+ kfree_skb(skb);
+ return NET_RX_DROP;
+ }
+
+ /* Hold reference to netdevice while using CAIF stack */
+ caifd_hold(caifd);
+ rcu_read_unlock();
+
+ err = caifd->layer.up->receive(caifd->layer.up, pkt);
+
+ /* For -EILSEQ the packet is not freed so so it now */
+ if (err == -EILSEQ)
+ cfpkt_destroy(pkt);
+
+ /* Release reference to stack upwards */
+ caifd_put(caifd);
+
+ if (err != 0)
+ err = NET_RX_DROP;
+ return err;
+}
+
+static struct packet_type caif_packet_type __read_mostly = {
+ .type = cpu_to_be16(ETH_P_CAIF),
+ .func = receive,
+};
+
+static void dev_flowctrl(struct net_device *dev, int on)
+{
+ struct caif_device_entry *caifd;
+
+ rcu_read_lock();
+
+ caifd = caif_get(dev);
+ if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
+ rcu_read_unlock();
+ return;
+ }
+
+ caifd_hold(caifd);
+ rcu_read_unlock();
+
+ caifd->layer.up->ctrlcmd(caifd->layer.up,
+ on ?
+ _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
+ _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+ caifd->layer.id);
+ caifd_put(caifd);
+}
+
+void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+ struct cflayer *link_support, int head_room,
+ struct cflayer **layer,
+ int (**rcv_func)(struct sk_buff *, struct net_device *,
+ struct packet_type *,
+ struct net_device *))
+{
+ struct caif_device_entry *caifd;
+ enum cfcnfg_phy_preference pref;
+ struct cfcnfg *cfg = get_cfcnfg(dev_net(dev));
+ struct caif_device_entry_list *caifdevs;
+
+ caifdevs = caif_device_list(dev_net(dev));
+ caifd = caif_device_alloc(dev);
+ if (!caifd)
+ return;
+ *layer = &caifd->layer;
+ spin_lock_init(&caifd->flow_lock);
+
+ switch (caifdev->link_select) {
+ case CAIF_LINK_HIGH_BANDW:
+ pref = CFPHYPREF_HIGH_BW;
+ break;
+ case CAIF_LINK_LOW_LATENCY:
+ pref = CFPHYPREF_LOW_LAT;
+ break;
+ default:
+ pref = CFPHYPREF_HIGH_BW;
+ break;
+ }
+ mutex_lock(&caifdevs->lock);
+ list_add_rcu(&caifd->list, &caifdevs->list);
+
+ strlcpy(caifd->layer.name, dev->name,
+ sizeof(caifd->layer.name));
+ caifd->layer.transmit = transmit;
+ cfcnfg_add_phy_layer(cfg,
+ dev,
+ &caifd->layer,
+ pref,
+ link_support,
+ caifdev->use_fcs,
+ head_room);
+ mutex_unlock(&caifdevs->lock);
+ if (rcv_func)
+ *rcv_func = receive;
+}
+EXPORT_SYMBOL(caif_enroll_dev);
+
+/* notify Caif of device events */
+static int caif_device_notify(struct notifier_block *me, unsigned long what,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct caif_device_entry *caifd = NULL;
+ struct caif_dev_common *caifdev;
+ struct cfcnfg *cfg;
+ struct cflayer *layer, *link_support;
+ int head_room = 0;
+ struct caif_device_entry_list *caifdevs;
+
+ cfg = get_cfcnfg(dev_net(dev));
+ caifdevs = caif_device_list(dev_net(dev));
+
+ caifd = caif_get(dev);
+ if (caifd == NULL && dev->type != ARPHRD_CAIF)
+ return 0;
+
+ switch (what) {
+ case NETDEV_REGISTER:
+ if (caifd != NULL)
+ break;
+
+ caifdev = netdev_priv(dev);
+
+ link_support = NULL;
+ if (caifdev->use_frag) {
+ head_room = 1;
+ link_support = cfserl_create(dev->ifindex,
+ caifdev->use_stx);
+ if (!link_support) {
+ pr_warn("Out of memory\n");
+ break;
+ }
+ }
+ caif_enroll_dev(dev, caifdev, link_support, head_room,
+ &layer, NULL);
+ caifdev->flowctrl = dev_flowctrl;
+ break;
+
+ case NETDEV_UP:
+ rcu_read_lock();
+
+ caifd = caif_get(dev);
+ if (caifd == NULL) {
+ rcu_read_unlock();
+ break;
+ }
+
+ caifd->xoff = 0;
+ cfcnfg_set_phy_state(cfg, &caifd->layer, true);
+ rcu_read_unlock();
+
+ break;
+
+ case NETDEV_DOWN:
+ rcu_read_lock();
+
+ caifd = caif_get(dev);
+ if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+ cfcnfg_set_phy_state(cfg, &caifd->layer, false);
+ caifd_hold(caifd);
+ rcu_read_unlock();
+
+ caifd->layer.up->ctrlcmd(caifd->layer.up,
+ _CAIF_CTRLCMD_PHYIF_DOWN_IND,
+ caifd->layer.id);
+
+ spin_lock_bh(&caifd->flow_lock);
+
+ /*
+ * Replace our xoff-destructor with original destructor.
+ * We trust that skb->destructor *always* is called before
+ * the skb reference is invalid. The hijacked SKB destructor
+ * takes the flow_lock so manipulating the skb->destructor here
+ * should be safe.
+ */
+ if (caifd->xoff_skb_dtor != NULL && caifd->xoff_skb != NULL)
+ caifd->xoff_skb->destructor = caifd->xoff_skb_dtor;
+
+ caifd->xoff = 0;
+ caifd->xoff_skb_dtor = NULL;
+ caifd->xoff_skb = NULL;
+
+ spin_unlock_bh(&caifd->flow_lock);
+ caifd_put(caifd);
+ break;
+
+ case NETDEV_UNREGISTER:
+ mutex_lock(&caifdevs->lock);
+
+ caifd = caif_get(dev);
+ if (caifd == NULL) {
+ mutex_unlock(&caifdevs->lock);
+ break;
+ }
+ list_del_rcu(&caifd->list);
+
+ /*
+ * NETDEV_UNREGISTER is called repeatedly until all reference
+ * counts for the net-device are released. If references to
+ * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
+ * the next call to NETDEV_UNREGISTER.
+ *
+ * If any packets are in flight down the CAIF Stack,
+ * cfcnfg_del_phy_layer will return nonzero.
+ * If no packets are in flight, the CAIF Stack associated
+ * with the net-device un-registering is freed.
+ */
+
+ if (caifd_refcnt_read(caifd) != 0 ||
+ cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
+
+ pr_info("Wait for device inuse\n");
+ /* Enrole device if CAIF Stack is still in use */
+ list_add_rcu(&caifd->list, &caifdevs->list);
+ mutex_unlock(&caifdevs->lock);
+ break;
+ }
+
+ synchronize_rcu();
+ dev_put(caifd->netdev);
+ free_percpu(caifd->pcpu_refcnt);
+ kfree(caifd);
+
+ mutex_unlock(&caifdevs->lock);
+ break;
+ }
+ return 0;
+}
+
+static struct notifier_block caif_device_notifier = {
+ .notifier_call = caif_device_notify,
+ .priority = 0,
+};
+
+/* Per-namespace Caif devices handling */
+static int caif_init_net(struct net *net)
+{
+ struct caif_net *caifn = net_generic(net, caif_net_id);
+ INIT_LIST_HEAD(&caifn->caifdevs.list);
+ mutex_init(&caifn->caifdevs.lock);
+
+ caifn->cfg = cfcnfg_create();
+ if (!caifn->cfg)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void caif_exit_net(struct net *net)
+{
+ struct caif_device_entry *caifd, *tmp;
+ struct caif_device_entry_list *caifdevs =
+ caif_device_list(net);
+ struct cfcnfg *cfg = get_cfcnfg(net);
+
+ rtnl_lock();
+ mutex_lock(&caifdevs->lock);
+
+ list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
+ int i = 0;
+ list_del_rcu(&caifd->list);
+ cfcnfg_set_phy_state(cfg, &caifd->layer, false);
+
+ while (i < 10 &&
+ (caifd_refcnt_read(caifd) != 0 ||
+ cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
+
+ pr_info("Wait for device inuse\n");
+ msleep(250);
+ i++;
+ }
+ synchronize_rcu();
+ dev_put(caifd->netdev);
+ free_percpu(caifd->pcpu_refcnt);
+ kfree(caifd);
+ }
+ cfcnfg_remove(cfg);
+
+ mutex_unlock(&caifdevs->lock);
+ rtnl_unlock();
+}
+
+static struct pernet_operations caif_net_ops = {
+ .init = caif_init_net,
+ .exit = caif_exit_net,
+ .id = &caif_net_id,
+ .size = sizeof(struct caif_net),
+};
+
+/* Initialize Caif devices list */
+static int __init caif_device_init(void)
+{
+ int result;
+
+ result = register_pernet_subsys(&caif_net_ops);
+
+ if (result)
+ return result;
+
+ register_netdevice_notifier(&caif_device_notifier);
+ dev_add_pack(&caif_packet_type);
+
+ return result;
+}
+
+static void __exit caif_device_exit(void)
+{
+ unregister_netdevice_notifier(&caif_device_notifier);
+ dev_remove_pack(&caif_packet_type);
+ unregister_pernet_subsys(&caif_net_ops);
+}
+
+module_init(caif_device_init);
+module_exit(caif_device_exit);