[PATCH 0/6] atm: propagate atm_dev signal carrier to LOWER_UP of netdevice

[PATCH 0/6] atm: propagate atm_dev signal carrier to LOWER_UP of netdevice

[Karl Hiramoto]

In userspace it's helpfull to know if a network device has a carrier signal. 
Often it is monitored via netlink.  This patchset allows a way for the 
struct atm_dev drivers to pass carrier on/off to the netdevice.

For DSL, carrier is on when the line has reached showtime state.

Currently this patchset only propagates the changes to br2684 vccs,
as this is the only type of hardware I have to test.

If you prefer git you can pull from:
git://github.com/karlhiramoto/linux-2.6.git linux-atm

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>

Karl Hiramoto (6):
  atm: add hooks to propagate signal changes to netdevice
  atm br2684: add callback for carrier signal changes.
  atm/idt77105.c: call atm_dev_signal_change() when signal changes.
  atm/solos-pci: call atm_dev_signal_change() when signal changes.
  atm/suni.c: call atm_dev_signal_change() when signal changes.
  atm/adummy: add syfs DEVICE_ATTR to change signal

 drivers/atm/adummy.c    |   39 +++++++++++++++++++++++++++++++++++++++
 drivers/atm/idt77105.c  |   11 ++++++-----
 drivers/atm/solos-pci.c |    6 +++---
 drivers/atm/suni.c      |    5 +++--
 include/linux/atmdev.h  |    5 +++++
 net/atm/br2684.c        |   13 +++++++++++++
 net/atm/common.c        |   33 +++++++++++++++++++++++++++++++++
 7 files changed, 102 insertions(+), 10 deletions(-)

[PATCH 1/6] atm: add hooks to propagate signal changes to netdevice

[Karl Hiramoto]

On DSL and ATM devices it's usefull to have a know if you have a carrier signal.
netdevice LOWER_UP changes can be propagated to userspace via netlink monitor.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 include/linux/atmdev.h |    5 +++++
 net/atm/common.c       |   33 +++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
index 817b237..c6958ec 100644
--- a/include/linux/atmdev.h
+++ b/include/linux/atmdev.h
@@ -311,6 +311,7 @@ struct atm_vcc {
 	void (*pop)(struct atm_vcc *vcc,struct sk_buff *skb); /* optional */
 	int (*push_oam)(struct atm_vcc *vcc,void *cell);
 	int (*send)(struct atm_vcc *vcc,struct sk_buff *skb);
+	void (*signal_change)(struct atm_vcc *vcc); /* optional. to propagate LOWER_UP */
 	void		*dev_data;	/* per-device data */
 	void		*proto_data;	/* per-protocol data */
 	struct k_atm_aal_stats *stats;	/* pointer to AAL stats group */
@@ -431,6 +432,10 @@ struct atm_dev *atm_dev_register(const char *type,const struct atmdev_ops *ops,
     int number,unsigned long *flags); /* number == -1: pick first available */
 struct atm_dev *atm_dev_lookup(int number);
 void atm_dev_deregister(struct atm_dev *dev);
+/**
+* Propagate lower layer signal change in atm_dev->signal to netdevice.
+*/
+void atm_dev_signal_change(struct atm_dev *dev, char signal);
 void vcc_insert_socket(struct sock *sk);
 
 
diff --git a/net/atm/common.c b/net/atm/common.c
index b43feb1..ccf09f2 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -212,6 +212,39 @@ void vcc_release_async(struct atm_vcc *vcc, int reply)
 }
 EXPORT_SYMBOL(vcc_release_async);
 
+void atm_dev_signal_change(struct atm_dev *dev, char signal)
+{
+	int i;
+	pr_debug("%s signal=%d dev=%p number=%d dev->signal=%d\n",
+		__func__, signal, dev, dev->number, dev->signal);
+
+	if (dev->signal == signal)
+		return; /* no change */
+
+	dev->signal = signal;
+
+	read_lock_irq(&vcc_sklist_lock);
+	for (i = 0; i < VCC_HTABLE_SIZE; i++) {
+		struct hlist_head *head = &vcc_hash[i];
+		struct hlist_node *node, *tmp;
+		struct sock *s;
+		struct atm_vcc *vcc;
+		sk_for_each_safe(s, node, tmp, head) {
+			vcc = atm_sk(s);
+			pr_debug("%s signal=%d vcc=%p dev=%p vcc->dev=%p %d.%d itf=%d meta=%d\n",
+				__func__, signal, vcc, dev, vcc->dev,
+				vcc->vpi, vcc->vci, vcc->itf, test_bit(ATM_VF_META, &vcc->flags));
+			/* if there is a signal change callback and dev matches,
+				or if this is a meta dev (clip atm_dev is arpd) */
+			if (vcc->signal_change && (vcc->dev == dev
+				|| test_bit(ATM_VF_META, &vcc->flags))) {
+				vcc->signal_change(vcc);
+			}
+		}
+	}
+	read_unlock_irq(&vcc_sklist_lock);
+}
+EXPORT_SYMBOL(atm_dev_signal_change);
 
 void atm_dev_release_vccs(struct atm_dev *dev)
 {
-- 
1.7.1

[PATCH 2/6] atm br2684: add callback for carrier signal changes.

[Karl Hiramoto]

When a signal change event occurs call netif_carrier_on/off.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 net/atm/br2684.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index 6719af6..e0136ec 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -448,6 +448,17 @@ free_skb:
 	dev_kfree_skb(skb);
 }
 
+static void br2684_signal_change(struct atm_vcc *atmvcc)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+	struct net_device *net_dev = brvcc->device;
+
+	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
+		netif_carrier_off(net_dev);
+	else
+		netif_carrier_on(net_dev);
+}
+
 /*
  * Assign a vcc to a dev
  * Note: we do not have explicit unassign, but look at _push()
@@ -514,6 +525,7 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 	barrier();
 	atmvcc->push = br2684_push;
 	atmvcc->pop = br2684_pop;
+	atmvcc->signal_change = br2684_signal_change;
 
 	__skb_queue_head_init(&queue);
 	rq = &sk_atm(atmvcc)->sk_receive_queue;
@@ -530,6 +542,7 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 
 		br2684_push(atmvcc, skb);
 	}
+	br2684_signal_change(atmvcc); /* initialize netdev carrier state */
 	__module_get(THIS_MODULE);
 	return 0;
 
-- 
1.7.1

[PATCH 3/6] atm/idt77105.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/idt77105.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/atm/idt77105.c b/drivers/atm/idt77105.c
index dab5cf5..bca9cb8 100644
--- a/drivers/atm/idt77105.c
+++ b/drivers/atm/idt77105.c
@@ -126,7 +126,7 @@ static void idt77105_restart_timer_func(unsigned long dummy)
                 istat = GET(ISTAT); /* side effect: clears all interrupt status bits */
                 if (istat & IDT77105_ISTAT_GOODSIG) {
                     /* Found signal again */
-                    dev->signal = ATM_PHY_SIG_FOUND;
+                    atm_dev_signal_change(dev, ATM_PHY_SIG_FOUND);
 	            printk(KERN_NOTICE "%s(itf %d): signal detected again\n",
                         dev->type,dev->number);
                     /* flush the receive FIFO */
@@ -222,7 +222,7 @@ static void idt77105_int(struct atm_dev *dev)
             /* Rx Signal Condition Change - line went up or down */
             if (istat & IDT77105_ISTAT_GOODSIG) {   /* signal detected again */
                 /* This should not happen (restart timer does it) but JIC */
-                dev->signal = ATM_PHY_SIG_FOUND;
+		atm_dev_signal_change(dev, ATM_PHY_SIG_FOUND);
             } else {    /* signal lost */
                 /*
                  * Disable interrupts and stop all transmission and
@@ -235,7 +235,7 @@ static void idt77105_int(struct atm_dev *dev)
                     IDT77105_MCR_DRIC|
                     IDT77105_MCR_HALTTX
                     ) & ~IDT77105_MCR_EIP, MCR);
-                dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(dev, ATM_PHY_SIG_LOST);
 	        printk(KERN_NOTICE "%s(itf %d): signal lost\n",
                     dev->type,dev->number);
             }
@@ -272,8 +272,9 @@ static int idt77105_start(struct atm_dev *dev)
 	memset(&PRIV(dev)->stats,0,sizeof(struct idt77105_stats));
         
         /* initialise dev->signal from Good Signal Bit */
-        dev->signal = GET(ISTAT) & IDT77105_ISTAT_GOODSIG ? ATM_PHY_SIG_FOUND :
-	  ATM_PHY_SIG_LOST;
+	atm_dev_signal_change(dev,
+		GET(ISTAT) & IDT77105_ISTAT_GOODSIG ?
+		ATM_PHY_SIG_FOUND : ATM_PHY_SIG_LOST);
 	if (dev->signal == ATM_PHY_SIG_LOST)
 		printk(KERN_WARNING "%s(itf %d): no signal\n",dev->type,
 		    dev->number);
-- 
1.7.1

[PATCH 4/6] atm/solos-pci: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate changes to upper atm layer, so userspace netmontor knows when DSL showtime reached.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/solos-pci.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index ded76c4..6174965 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -383,7 +383,7 @@ static int process_status(struct solos_card *card, int port, struct sk_buff *skb
 
 	/* Anything but 'Showtime' is down */
 	if (strcmp(state_str, "Showtime")) {
-		card->atmdev[port]->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(card->atmdev[port], ATM_PHY_SIG_LOST);
 		release_vccs(card->atmdev[port]);
 		dev_info(&card->dev->dev, "Port %d: %s\n", port, state_str);
 		return 0;
@@ -401,7 +401,7 @@ static int process_status(struct solos_card *card, int port, struct sk_buff *skb
 		 snr[0]?", SNR ":"", snr, attn[0]?", Attn ":"", attn);
 	
 	card->atmdev[port]->link_rate = rate_down / 424;
-	card->atmdev[port]->signal = ATM_PHY_SIG_FOUND;
+	atm_dev_signal_change(card->atmdev[port], ATM_PHY_SIG_FOUND);
 
 	return 0;
 }
@@ -1246,7 +1246,7 @@ static int atm_init(struct solos_card *card)
 		card->atmdev[i]->ci_range.vci_bits = 16;
 		card->atmdev[i]->dev_data = card;
 		card->atmdev[i]->phy_data = (void *)(unsigned long)i;
-		card->atmdev[i]->signal = ATM_PHY_SIG_UNKNOWN;
+		atm_dev_signal_change(card->atmdev[i], ATM_PHY_SIG_UNKNOWN);
 
 		skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
 		if (!skb) {
-- 
1.7.1

[PATCH 5/6] atm/suni.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/suni.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/atm/suni.c b/drivers/atm/suni.c
index da4b91f..41c56ea 100644
--- a/drivers/atm/suni.c
+++ b/drivers/atm/suni.c
@@ -291,8 +291,9 @@ static int suni_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
 
 static void poll_los(struct atm_dev *dev)
 {
-	dev->signal = GET(RSOP_SIS) & SUNI_RSOP_SIS_LOSV ? ATM_PHY_SIG_LOST :
-	  ATM_PHY_SIG_FOUND;
+	atm_dev_signal_change(dev,
+		GET(RSOP_SIS) & SUNI_RSOP_SIS_LOSV ?
+		ATM_PHY_SIG_LOST : ATM_PHY_SIG_FOUND);
 }
 
 
-- 
1.7.1

[PATCH 6/6] atm/adummy: add syfs DEVICE_ATTR to change signal

[Karl Hiramoto]

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/adummy.c |   39 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 39 insertions(+), 0 deletions(-)

diff --git a/drivers/atm/adummy.c b/drivers/atm/adummy.c
index 6d44f07..46b9476 100644
--- a/drivers/atm/adummy.c
+++ b/drivers/atm/adummy.c
@@ -40,6 +40,42 @@ struct adummy_dev {
 
 static LIST_HEAD(adummy_devs);
 
+static ssize_t __set_signal(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
+	int signal;
+
+	if (sscanf(buf, "%d", &signal) == 1) {
+
+		if (signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND)
+			signal = ATM_PHY_SIG_UNKNOWN;
+
+		atm_dev_signal_change(atm_dev, signal);
+		return 1;
+	}
+	return -EINVAL;
+}
+
+static ssize_t __show_signal(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
+	return sprintf(buf, "%d\n", atm_dev->signal);
+}
+static DEVICE_ATTR(signal, 0644, __show_signal, __set_signal);
+
+static struct attribute *adummy_attrs[] = {
+	&dev_attr_signal.attr,
+	NULL
+};
+
+static struct attribute_group adummy_group_attrs = {
+	.name = NULL, /* We want them in dev's root folder */
+	.attrs = adummy_attrs
+};
+
 static int __init
 adummy_start(struct atm_dev *dev)
 {
@@ -128,6 +164,9 @@ static int __init adummy_init(void)
 	adummy_dev->atm_dev = atm_dev;
 	atm_dev->dev_data = adummy_dev;
 
+	if (sysfs_create_group(&atm_dev->class_dev.kobj, &adummy_group_attrs))
+		dev_err(&atm_dev->class_dev, "Could not register attrs for adummy\n");
+
 	if (adummy_start(atm_dev)) {
 		printk(KERN_ERR DEV_LABEL ": adummy_start() failed\n");
 		err = -ENODEV;
-- 
1.7.1

Re: [Linux-ATM-General] [PATCH 0/6] atm: propagate atm_dev signal carrier to LOWER_UP of netdevice

[chas williams - CONTRACTOR]

thanks for writing this.  this is something that has been missing for
some time in the atm stack.  however, i was hoping it could take a
different approach.  i would prefer this mechanism to be more generic
instead of being only suitable for signalling carrier changes.   take a
look at the notifier/register_netdevice_notifier scheme.

clients (like br2684) who wish to get these notifications, would need
to call register_atmdevice_notifier().  and yes, instead of handling
setting the signal flag yourself, everyone (including the drivers in
usb/atm) should be using the atm_dev_signal_change().

i am not fond of the idea of adding to the vcc struct something that
is really per device, not per vcc.

On Fri,  2 Jul 2010 19:47:04 +0200
Karl Hiramoto <karl@hiramoto.org> wrote:

> In userspace it's helpfull to know if a network device has a carrier
> signal. Often it is monitored via netlink.  This patchset allows a
> way for the struct atm_dev drivers to pass carrier on/off to the
> netdevice.
> 
> For DSL, carrier is on when the line has reached showtime state.
> 
> Currently this patchset only propagates the changes to br2684 vccs,
> as this is the only type of hardware I have to test.
> 
> If you prefer git you can pull from:
> git://github.com/karlhiramoto/linux-2.6.git linux-atm
> 
> Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
> 
> Karl Hiramoto (6):
>   atm: add hooks to propagate signal changes to netdevice
>   atm br2684: add callback for carrier signal changes.
>   atm/idt77105.c: call atm_dev_signal_change() when signal changes.
>   atm/solos-pci: call atm_dev_signal_change() when signal changes.
>   atm/suni.c: call atm_dev_signal_change() when signal changes.
>   atm/adummy: add syfs DEVICE_ATTR to change signal
> 
>  drivers/atm/adummy.c    |   39
> +++++++++++++++++++++++++++++++++++++++ drivers/atm/idt77105.c  |
> 11 ++++++----- drivers/atm/solos-pci.c |    6 +++---
>  drivers/atm/suni.c      |    5 +++--
>  include/linux/atmdev.h  |    5 +++++
>  net/atm/br2684.c        |   13 +++++++++++++
>  net/atm/common.c        |   33 +++++++++++++++++++++++++++++++++
>  7 files changed, 102 insertions(+), 10 deletions(-)
> 
> 
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