[openwrt/staging/blocktrron.git] /

From e7e0b3b89da97e3186fbe3774a1ca9b77402d893 Mon Sep 17 00:00:00 2001
From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Wed, 27 Nov 2019 15:27:57 +0800
Subject: [PATCH] net: mscc: ocelot: use skb queue instead of skbs list

Convert to use skb queue instead of the list of skbs.
The skb queue could provide protection with lock.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/mscc/ocelot.c | 54 +++++++++++++-------------------------
 include/soc/mscc/ocelot.h          |  9 +------
 2 files changed, 19 insertions(+), 44 deletions(-)

--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -583,18 +583,10 @@ int ocelot_port_add_txtstamp_skb(struct
 
        if (ocelot->ptp && shinfo->tx_flags & SKBTX_HW_TSTAMP &&
            ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
-               struct ocelot_skb *oskb =
-                       kzalloc(sizeof(struct ocelot_skb), GFP_ATOMIC);
-
-               if (unlikely(!oskb))
-                       return -ENOMEM;
-
                shinfo->tx_flags |= SKBTX_IN_PROGRESS;
-
-               oskb->skb = skb;
-               oskb->id = ocelot_port->ts_id % 4;
-
-               list_add_tail(&oskb->head, &ocelot_port->skbs);
+               /* Store timestamp ID in cb[0] of sk_buff */
+               skb->cb[0] = ocelot_port->ts_id % 4;
+               skb_queue_tail(&ocelot_port->tx_skbs, skb);
                return 0;
        }
        return -ENODATA;
@@ -704,12 +696,11 @@ void ocelot_get_txtstamp(struct ocelot *
        int budget = OCELOT_PTP_QUEUE_SZ;
 
        while (budget--) {
+               struct sk_buff *skb, *skb_tmp, *skb_match = NULL;
                struct skb_shared_hwtstamps shhwtstamps;
-               struct list_head *pos, *tmp;
-               struct sk_buff *skb = NULL;
-               struct ocelot_skb *entry;
                struct ocelot_port *port;
                struct timespec64 ts;
+               unsigned long flags;
                u32 val, id, txport;
 
                val = ocelot_read(ocelot, SYS_PTP_STATUS);
@@ -727,22 +718,22 @@ void ocelot_get_txtstamp(struct ocelot *
                /* Retrieve its associated skb */
                port = ocelot->ports[txport];
 
-               list_for_each_safe(pos, tmp, &port->skbs) {
-                       entry = list_entry(pos, struct ocelot_skb, head);
-                       if (entry->id != id)
-                               continue;
+               spin_lock_irqsave(&port->tx_skbs.lock, flags);
 
-                       skb = entry->skb;
-
-                       list_del(pos);
-                       kfree(entry);
+               skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) {
+                       if (skb->cb[0] != id)
+                               continue;
+                       __skb_unlink(skb, &port->tx_skbs);
+                       skb_match = skb;
                        break;
                }
 
+               spin_unlock_irqrestore(&port->tx_skbs.lock, flags);
+
                /* Next ts */
                ocelot_write(ocelot, SYS_PTP_NXT_PTP_NXT, SYS_PTP_NXT);
 
-               if (unlikely(!skb))
+               if (unlikely(!skb_match))
                        continue;
 
                /* Get the h/w timestamp */
@@ -751,9 +742,9 @@ void ocelot_get_txtstamp(struct ocelot *
                /* Set the timestamp into the skb */
                memset(&shhwtstamps, 0, sizeof(shhwtstamps));
                shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
-               skb_tstamp_tx(skb, &shhwtstamps);
+               skb_tstamp_tx(skb_match, &shhwtstamps);
 
-               dev_kfree_skb_any(skb);
+               dev_kfree_skb_any(skb_match);
        }
 }
 EXPORT_SYMBOL(ocelot_get_txtstamp);
@@ -2208,7 +2199,7 @@ void ocelot_init_port(struct ocelot *oce
 {
        struct ocelot_port *ocelot_port = ocelot->ports[port];
 
-       INIT_LIST_HEAD(&ocelot_port->skbs);
+       skb_queue_head_init(&ocelot_port->tx_skbs);
 
        /* Basic L2 initialization */
 
@@ -2493,9 +2484,7 @@ EXPORT_SYMBOL(ocelot_init);
 
 void ocelot_deinit(struct ocelot *ocelot)
 {
-       struct list_head *pos, *tmp;
        struct ocelot_port *port;
-       struct ocelot_skb *entry;
        int i;
 
        cancel_delayed_work(&ocelot->stats_work);
@@ -2507,14 +2496,7 @@ void ocelot_deinit(struct ocelot *ocelot
 
        for (i = 0; i < ocelot->num_phys_ports; i++) {
                port = ocelot->ports[i];
-
-               list_for_each_safe(pos, tmp, &port->skbs) {
-                       entry = list_entry(pos, struct ocelot_skb, head);
-
-                       list_del(pos);
-                       dev_kfree_skb_any(entry->skb);
-                       kfree(entry);
-               }
+               skb_queue_purge(&port->tx_skbs);
        }
 }
 EXPORT_SYMBOL(ocelot_deinit);
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -406,13 +406,6 @@ struct ocelot_ops {
        int (*reset)(struct ocelot *ocelot);
 };
 
-struct ocelot_skb {
-       struct list_head head;
-       struct sk_buff *skb;
-       u8 id;
-};
-
-
 struct ocelot_port {
        struct ocelot                   *ocelot;
 
@@ -425,7 +418,7 @@ struct ocelot_port {
        u16                             vid;
 
        u8                              ptp_cmd;
-       struct list_head                skbs;
+       struct sk_buff_head             tx_skbs;
        u8                              ts_id;
 };