net/ncsi: Package and channel management

This manages NCSI packages and channels:

 * The available packages and channels are enumerated in the first
   time of calling ncsi_start_dev(). The channels' capabilities are
   probed in the meanwhile. The NCSI network topology won't change
   until the NCSI device is destroyed.
 * There in a queue in every NCSI device. The element in the queue,
   channel, is waiting for configuration (bringup) or suspending
   (teardown). The channel's state (inactive/active) indicates the
   futher action (configuration or suspending) will be applied on the
   channel. Another channel's state (invisible) means the requested
   action is being applied.
 * The hardware arbitration will be enabled if all available packages
   and channels support it. All available channels try to provide
   service when hardware arbitration is enabled. Otherwise, one channel
   is selected as the active one at once.
 * When channel is in active state, meaning it's providing service, a
   timer started to retrieve the channe's link status. If the channel's
   link status fails to be updated in the determined period, the channel
   is going to be reconfigured. It's the error handling implementation
   as defined in NCSI spec.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 0 deletions

diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index 6ec25cb2608c..a21af88330aa 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -69,6 +69,9 @@ static int ncsi_rsp_handler_cis(struct ncsi_request *nr)
 	rsp = (struct ncsi_rsp_pkt *)skb_network_header(nr->rsp);
 	ncsi_find_package_and_channel(ndp, rsp->rsp.common.channel, &np, &nc);
 	if (!nc) {
+		if (ndp->flags & NCSI_DEV_PROBED)
+			return -ENXIO;
+
 		id = NCSI_CHANNEL_INDEX(rsp->rsp.common.channel);
 		nc = ncsi_add_channel(np, id);
 	}
@@ -90,6 +93,9 @@ static int ncsi_rsp_handler_sp(struct ncsi_request *nr)
 	ncsi_find_package_and_channel(ndp, rsp->rsp.common.channel,
 				      &np, NULL);
 	if (!np) {
+		if (ndp->flags & NCSI_DEV_PROBED)
+			return -ENXIO;
+
 		id = NCSI_PACKAGE_INDEX(rsp->rsp.common.channel);
 		np = ncsi_add_package(ndp, id);
 		if (!np)
@@ -297,6 +303,7 @@ static int ncsi_rsp_handler_gls(struct ncsi_request *nr)
 	struct ncsi_dev_priv *ndp = nr->ndp;
 	struct ncsi_channel *nc;
 	struct ncsi_channel_mode *ncm;
+	unsigned long flags;
 
 	/* Find the package and channel */
 	rsp = (struct ncsi_rsp_gls_pkt *)skb_network_header(nr->rsp);
@@ -310,6 +317,14 @@ static int ncsi_rsp_handler_gls(struct ncsi_request *nr)
 	ncm->data[3] = ntohl(rsp->other);
 	ncm->data[4] = ntohl(rsp->oem_status);
 
+	if (nr->driven)
+		return 0;
+
+	/* Reset the channel monitor if it has been enabled */
+	spin_lock_irqsave(&nc->lock, flags);
+	nc->timeout = 0;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
 	return 0;
 }