From 8df9ffb888c021fa68f9075d545f2ec5eca37200 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Mon, 8 Oct 2018 09:02:39 +0200 Subject: [PATCH] can: make use of preallocated can_ml_priv for per device struct can_dev_rcv_lists This patch removes the old method of allocating the per device protocol specific memory via a netdevice_notifier. This had the drawback, that the allocation can fail, leading to a lot of null pointer checks in the code. This also makes the live cycle management of this memory quite complicated. This patch switches from the allocating the struct can_dev_rcv_lists in a NETDEV_REGISTER call to using the dev->ml_priv, which is allocated by the driver since the previous patch. Signed-off-by: Oleksij Rempel Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev.c | 2 ++ drivers/net/can/slcan.c | 1 + drivers/net/can/vcan.c | 1 + drivers/net/can/vxcan.c | 1 + include/linux/can/can-ml.h | 1 - net/can/af_can.c | 45 +++++++-------------------------------------- 6 files changed, 12 insertions(+), 39 deletions(-) diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index 9e688dc..b429550 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -746,6 +746,8 @@ struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, priv = netdev_priv(dev); priv->dev = dev; + dev->ml_priv = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN); + if (echo_skb_max) { priv->echo_skb_max = echo_skb_max; priv->echo_skb = (void *)priv + diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 5b2e954..bb60322 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -536,6 +536,7 @@ static struct slcan *slc_alloc(void) dev->base_addr = i; sl = netdev_priv(dev); + dev->ml_priv = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN); /* Initialize channel control data */ sl->magic = SLCAN_MAGIC; diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c index 6973ae0..39ca14b 100644 --- a/drivers/net/can/vcan.c +++ b/drivers/net/can/vcan.c @@ -153,6 +153,7 @@ static void vcan_setup(struct net_device *dev) dev->addr_len = 0; dev->tx_queue_len = 0; dev->flags = IFF_NOARP; + dev->ml_priv = netdev_priv(dev); /* set flags according to driver capabilities */ if (echo) diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c index 4c3eed7..d6ba942 100644 --- a/drivers/net/can/vxcan.c +++ b/drivers/net/can/vxcan.c @@ -147,6 +147,7 @@ static void vxcan_setup(struct net_device *dev) dev->flags = (IFF_NOARP|IFF_ECHO); dev->netdev_ops = &vxcan_netdev_ops; dev->needs_free_netdev = true; + dev->ml_priv = netdev_priv(dev) + ALIGN(sizeof(struct vxcan_priv), NETDEV_ALIGN); } /* forward declaration for rtnl_create_link() */ diff --git a/include/linux/can/can-ml.h b/include/linux/can/can-ml.h index 0a9d778..79ccf6b 100644 --- a/include/linux/can/can-ml.h +++ b/include/linux/can/can-ml.h @@ -55,7 +55,6 @@ struct can_dev_rcv_lists { struct hlist_head rx[RX_MAX]; struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ]; struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ]; - int remove_on_zero_entries; int entries; }; diff --git a/net/can/af_can.c b/net/can/af_can.c index 723299d..6ed85e2 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -302,10 +302,12 @@ EXPORT_SYMBOL(can_send); static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net, struct net_device *dev) { - if (!dev) + if (dev) { + struct can_ml_priv *ml_priv = dev->ml_priv; + return &ml_priv->dev_rcv_lists; + } else { return net->can.rx_alldev_list; - else - return (struct can_dev_rcv_lists *)dev->ml_priv; + } } /** @@ -561,12 +563,6 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, if (rcv_lists_stats->rcv_entries > 0) rcv_lists_stats->rcv_entries--; - /* remove device structure requested by NETDEV_UNREGISTER */ - if (dev_rcv_lists->remove_on_zero_entries && !dev_rcv_lists->entries) { - kfree(dev_rcv_lists); - dev->ml_priv = NULL; - } - out: spin_unlock(&net->can.rcvlists_lock); @@ -788,41 +784,14 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); - struct can_dev_rcv_lists *dev_rcv_lists; if (dev->type != ARPHRD_CAN) return NOTIFY_DONE; switch (msg) { case NETDEV_REGISTER: - - /* create new dev_rcv_lists for this device */ - dev_rcv_lists = kzalloc(sizeof(*dev_rcv_lists), GFP_KERNEL); - if (!dev_rcv_lists) - return NOTIFY_DONE; - BUG_ON(dev->ml_priv); - dev->ml_priv = dev_rcv_lists; - - break; - - case NETDEV_UNREGISTER: - spin_lock(&dev_net(dev)->can.rcvlists_lock); - - dev_rcv_lists = dev->ml_priv; - if (dev_rcv_lists) { - if (dev_rcv_lists->entries) - dev_rcv_lists->remove_on_zero_entries = 1; - else { - kfree(dev_rcv_lists); - dev->ml_priv = NULL; - } - } else { - pr_err("can: notifier: receive list not found for dev %s\n", - dev->name); - } - - spin_unlock(&dev_net(dev)->can.rcvlists_lock); - + WARN(!dev->ml_priv, + "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n"); break; } -- 2.7.4