1 files changed, 246 insertions, 0 deletions
diff --git a/net/ncsi/ncsi-aen.c b/net/ncsi/ncsi-aen.c
new file mode 100644
index 000000000..62fb10317
--- /dev/null
+++ b/net/ncsi/ncsi-aen.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright Gavin Shan, IBM Corporation 2016.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+#include <net/ncsi.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "internal.h"
+#include "ncsi-pkt.h"
+
+static int ncsi_validate_aen_pkt(struct ncsi_aen_pkt_hdr *h,
+				 const unsigned short payload)
+{
+	u32 checksum;
+	__be32 *pchecksum;
+
+	if (h->common.revision != NCSI_PKT_REVISION)
+		return -EINVAL;
+	if (ntohs(h->common.length) != payload)
+		return -EINVAL;
+
+	/* Validate checksum, which might be zeroes if the
+	 * sender doesn't support checksum according to NCSI
+	 * specification.
+	 */
+	pchecksum = (__be32 *)((void *)(h + 1) + payload - 4);
+	if (ntohl(*pchecksum) == 0)
+		return 0;
+
+	checksum = ncsi_calculate_checksum((unsigned char *)h,
+					   sizeof(*h) + payload - 4);
+	if (*pchecksum != htonl(checksum))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
+				struct ncsi_aen_pkt_hdr *h)
+{
+	struct ncsi_channel *nc, *tmp;
+	struct ncsi_channel_mode *ncm;
+	unsigned long old_data, data;
+	struct ncsi_aen_lsc_pkt *lsc;
+	struct ncsi_package *np;
+	bool had_link, has_link;
+	unsigned long flags;
+	bool chained;
+	int state;
+
+	/* Find the NCSI channel */
+	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
+	if (!nc)
+		return -ENODEV;
+
+	/* Update the link status */
+	lsc = (struct ncsi_aen_lsc_pkt *)h;
+
+	spin_lock_irqsave(&nc->lock, flags);
+	ncm = &nc->modes[NCSI_MODE_LINK];
+	old_data = ncm->data[2];
+	data = ntohl(lsc->status);
+	ncm->data[2] = data;
+	ncm->data[4] = ntohl(lsc->oem_status);
+
+	had_link = !!(old_data & 0x1);
+	has_link = !!(data & 0x1);
+
+	netdev_dbg(ndp->ndev.dev, "NCSI: LSC AEN - channel %u state %s\n",
+		   nc->id, data & 0x1 ? "up" : "down");
+
+	chained = !list_empty(&nc->link);
+	state = nc->state;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
+	if (state == NCSI_CHANNEL_INACTIVE)
+		netdev_warn(ndp->ndev.dev,
+			    "NCSI: Inactive channel %u received AEN!\n",
+			    nc->id);
+
+	if ((had_link == has_link) || chained)
+		return 0;
+
+	if (!ndp->multi_package && !nc->package->multi_channel) {
+		if (had_link) {
+			ndp->flags |= NCSI_DEV_RESHUFFLE;
+			ncsi_stop_channel_monitor(nc);
+			spin_lock_irqsave(&ndp->lock, flags);
+			list_add_tail_rcu(&nc->link, &ndp->channel_queue);
+			spin_unlock_irqrestore(&ndp->lock, flags);
+			return ncsi_process_next_channel(ndp);
+		}
+		/* Configured channel came up */
+		return 0;
+	}
+
+	if (had_link) {
+		ncm = &nc->modes[NCSI_MODE_TX_ENABLE];
+		if (ncsi_channel_is_last(ndp, nc)) {
+			/* No channels left, reconfigure */
+			return ncsi_reset_dev(&ndp->ndev);
+		} else if (ncm->enable) {
+			/* Need to failover Tx channel */
+			ncsi_update_tx_channel(ndp, nc->package, nc, NULL);
+		}
+	} else if (has_link && nc->package->preferred_channel == nc) {
+		/* Return Tx to preferred channel */
+		ncsi_update_tx_channel(ndp, nc->package, NULL, nc);
+	} else if (has_link) {
+		NCSI_FOR_EACH_PACKAGE(ndp, np) {
+			NCSI_FOR_EACH_CHANNEL(np, tmp) {
+				/* Enable Tx on this channel if the current Tx
+				 * channel is down.
+				 */
+				ncm = &tmp->modes[NCSI_MODE_TX_ENABLE];
+				if (ncm->enable &&
+				    !ncsi_channel_has_link(tmp)) {
+					ncsi_update_tx_channel(ndp, nc->package,
+							       tmp, nc);
+					break;
+				}
+			}
+		}
+	}
+
+	/* Leave configured channels active in a multi-channel scenario so
+	 * AEN events are still received.
+	 */
+	return 0;
+}
+
+static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
+			       struct ncsi_aen_pkt_hdr *h)
+{
+	struct ncsi_channel *nc;
+	unsigned long flags;
+
+	/* Find the NCSI channel */
+	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
+	if (!nc)
+		return -ENODEV;
+
+	spin_lock_irqsave(&nc->lock, flags);
+	if (!list_empty(&nc->link) ||
+	    nc->state != NCSI_CHANNEL_ACTIVE) {
+		spin_unlock_irqrestore(&nc->lock, flags);
+		return 0;
+	}
+	spin_unlock_irqrestore(&nc->lock, flags);
+
+	ncsi_stop_channel_monitor(nc);
+	spin_lock_irqsave(&nc->lock, flags);
+	nc->state = NCSI_CHANNEL_INVISIBLE;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
+	spin_lock_irqsave(&ndp->lock, flags);
+	nc->state = NCSI_CHANNEL_INACTIVE;
+	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
+	spin_unlock_irqrestore(&ndp->lock, flags);
+	nc->modes[NCSI_MODE_TX_ENABLE].enable = 0;
+
+	return ncsi_process_next_channel(ndp);
+}
+
+static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
+				   struct ncsi_aen_pkt_hdr *h)
+{
+	struct ncsi_channel *nc;
+	struct ncsi_channel_mode *ncm;
+	struct ncsi_aen_hncdsc_pkt *hncdsc;
+	unsigned long flags;
+
+	/* Find the NCSI channel */
+	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
+	if (!nc)
+		return -ENODEV;
+
+	spin_lock_irqsave(&nc->lock, flags);
+	ncm = &nc->modes[NCSI_MODE_LINK];
+	hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
+	ncm->data[3] = ntohl(hncdsc->status);
+	spin_unlock_irqrestore(&nc->lock, flags);
+	netdev_dbg(ndp->ndev.dev,
+		   "NCSI: host driver %srunning on channel %u\n",
+		   ncm->data[3] & 0x1 ? "" : "not ", nc->id);
+
+	return 0;
+}
+
+static struct ncsi_aen_handler {
+	unsigned char type;
+	int           payload;
+	int           (*handler)(struct ncsi_dev_priv *ndp,
+				 struct ncsi_aen_pkt_hdr *h);
+} ncsi_aen_handlers[] = {
+	{ NCSI_PKT_AEN_LSC,    12, ncsi_aen_handler_lsc    },
+	{ NCSI_PKT_AEN_CR,      4, ncsi_aen_handler_cr     },
+	{ NCSI_PKT_AEN_HNCDSC,  8, ncsi_aen_handler_hncdsc }
+};
+
+int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
+{
+	struct ncsi_aen_pkt_hdr *h;
+	struct ncsi_aen_handler *nah = NULL;
+	int i, ret;
+
+	/* Find the handler */
+	h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
+	for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
+		if (ncsi_aen_handlers[i].type == h->type) {
+			nah = &ncsi_aen_handlers[i];
+			break;
+		}
+	}
+
+	if (!nah) {
+		netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
+			    h->type);
+		return -ENOENT;
+	}
+
+	ret = ncsi_validate_aen_pkt(h, nah->payload);
+	if (ret) {
+		netdev_warn(ndp->ndev.dev,
+			    "NCSI: 'bad' packet ignored for AEN type 0x%x\n",
+			    h->type);
+		goto out;
+	}
+
+	ret = nah->handler(ndp, h);
+	if (ret)
+		netdev_err(ndp->ndev.dev,
+			   "NCSI: Handler for AEN type 0x%x returned %d\n",
+			   h->type, ret);
+out:
+	consume_skb(skb);
+	return ret;
+}