mirror of https://gitee.com/openkylin/linux.git
firewire: net: replace lists by counters
The current transmit code does not at all make use of - fwnet_device.packet_list and only very limited use of - fwnet_device.broadcasted_list, - fwnet_device.queued_packets. Their current function is to track whether the TX soft-IRQ finished dealing with an skb when the AT-req tasklet takes over, and to discard pending tx datagrams (if there are any) when the local node is removed. The latter does actually contain a race condition bug with TX soft-IRQ and AT-req tasklet. Instead of these lists and the corresponding link in fwnet_packet_task, - a flag in fwnet_packet_task to track whether fwnet_tx is done, - a counter of queued datagrams in fwnet_device do the job as well. The above mentioned theoretic race condition is resolved by letting fwnet_remove sleep until all datagrams were flushed. It may sleep almost arbitrarily long since fwnet_remove is executed in the context of a multithreaded (concurrency managed) workqueue. The type of max_payload is changed to u16 here to avoid waste in struct fwnet_packet_task. This value cannot exceed 4096 per IEEE 1394:2008 table 16-18 (or 32678 per specification of packet headers, if there is ever going to be something else than beta mode). Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Stefan Richter
parent
7ee11fa8d0
commit
48553011ce
|
|
@ -7,6 +7,7 @@
|
|||
*/
|
||||
|
||||
#include <linux/bug.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/firewire.h>
|
||||
#include <linux/firewire-constants.h>
|
||||
|
|
@ -169,15 +170,8 @@ struct fwnet_device {
|
|||
struct fw_address_handler handler;
|
||||
u64 local_fifo;
|
||||
|
||||
/* List of packets to be sent */
|
||||
struct list_head packet_list;
|
||||
/*
|
||||
* List of packets that were broadcasted. When we get an ISO interrupt
|
||||
* one of them has been sent
|
||||
*/
|
||||
struct list_head broadcasted_list;
|
||||
/* List of packets that have been sent but not yet acked */
|
||||
struct list_head sent_list;
|
||||
/* Number of tx datagrams that have been queued but not yet acked */
|
||||
int queued_datagrams;
|
||||
|
||||
struct list_head peer_list;
|
||||
struct fw_card *card;
|
||||
|
|
@ -195,7 +189,7 @@ struct fwnet_peer {
|
|||
unsigned pdg_size; /* pd_list size */
|
||||
|
||||
u16 datagram_label; /* outgoing datagram label */
|
||||
unsigned max_payload; /* includes RFC2374_FRAG_HDR_SIZE overhead */
|
||||
u16 max_payload; /* includes RFC2374_FRAG_HDR_SIZE overhead */
|
||||
int node_id;
|
||||
int generation;
|
||||
unsigned speed;
|
||||
|
|
@ -203,22 +197,18 @@ struct fwnet_peer {
|
|||
|
||||
/* This is our task struct. It's used for the packet complete callback. */
|
||||
struct fwnet_packet_task {
|
||||
/*
|
||||
* ptask can actually be on dev->packet_list, dev->broadcasted_list,
|
||||
* or dev->sent_list depending on its current state.
|
||||
*/
|
||||
struct list_head pt_link;
|
||||
struct fw_transaction transaction;
|
||||
struct rfc2734_header hdr;
|
||||
struct sk_buff *skb;
|
||||
struct fwnet_device *dev;
|
||||
|
||||
int outstanding_pkts;
|
||||
unsigned max_payload;
|
||||
u64 fifo_addr;
|
||||
u16 dest_node;
|
||||
u16 max_payload;
|
||||
u8 generation;
|
||||
u8 speed;
|
||||
u8 enqueued;
|
||||
};
|
||||
|
||||
/*
|
||||
|
|
@ -915,9 +905,9 @@ static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
|
|||
ptask->outstanding_pkts--;
|
||||
|
||||
/* Check whether we or the networking TX soft-IRQ is last user. */
|
||||
free = (ptask->outstanding_pkts == 0 && !list_empty(&ptask->pt_link));
|
||||
free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
|
||||
if (free)
|
||||
list_del(&ptask->pt_link);
|
||||
dev->queued_datagrams--;
|
||||
|
||||
if (ptask->outstanding_pkts == 0) {
|
||||
dev->netdev->stats.tx_packets++;
|
||||
|
|
@ -986,9 +976,9 @@ static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
|
|||
ptask->outstanding_pkts = 0;
|
||||
|
||||
/* Check whether we or the networking TX soft-IRQ is last user. */
|
||||
free = !list_empty(&ptask->pt_link);
|
||||
free = ptask->enqueued;
|
||||
if (free)
|
||||
list_del(&ptask->pt_link);
|
||||
dev->queued_datagrams--;
|
||||
|
||||
dev->netdev->stats.tx_dropped++;
|
||||
dev->netdev->stats.tx_errors++;
|
||||
|
|
@ -1069,9 +1059,11 @@ static int fwnet_send_packet(struct fwnet_packet_task *ptask)
|
|||
spin_lock_irqsave(&dev->lock, flags);
|
||||
|
||||
/* If the AT tasklet already ran, we may be last user. */
|
||||
free = (ptask->outstanding_pkts == 0 && list_empty(&ptask->pt_link));
|
||||
free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
|
||||
if (!free)
|
||||
list_add_tail(&ptask->pt_link, &dev->broadcasted_list);
|
||||
ptask->enqueued = true;
|
||||
else
|
||||
dev->queued_datagrams--;
|
||||
|
||||
spin_unlock_irqrestore(&dev->lock, flags);
|
||||
|
||||
|
|
@ -1086,9 +1078,11 @@ static int fwnet_send_packet(struct fwnet_packet_task *ptask)
|
|||
spin_lock_irqsave(&dev->lock, flags);
|
||||
|
||||
/* If the AT tasklet already ran, we may be last user. */
|
||||
free = (ptask->outstanding_pkts == 0 && list_empty(&ptask->pt_link));
|
||||
free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
|
||||
if (!free)
|
||||
list_add_tail(&ptask->pt_link, &dev->sent_list);
|
||||
ptask->enqueued = true;
|
||||
else
|
||||
dev->queued_datagrams--;
|
||||
|
||||
spin_unlock_irqrestore(&dev->lock, flags);
|
||||
|
||||
|
|
@ -1350,10 +1344,12 @@ static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
|
|||
max_payload += RFC2374_FRAG_HDR_SIZE;
|
||||
}
|
||||
|
||||
dev->queued_datagrams++;
|
||||
|
||||
spin_unlock_irqrestore(&dev->lock, flags);
|
||||
|
||||
ptask->max_payload = max_payload;
|
||||
INIT_LIST_HEAD(&ptask->pt_link);
|
||||
ptask->enqueued = 0;
|
||||
|
||||
fwnet_send_packet(ptask);
|
||||
|
||||
|
|
@ -1487,14 +1483,9 @@ static int fwnet_probe(struct device *_dev)
|
|||
dev->broadcast_rcv_context = NULL;
|
||||
dev->broadcast_xmt_max_payload = 0;
|
||||
dev->broadcast_xmt_datagramlabel = 0;
|
||||
|
||||
dev->local_fifo = FWNET_NO_FIFO_ADDR;
|
||||
|
||||
INIT_LIST_HEAD(&dev->packet_list);
|
||||
INIT_LIST_HEAD(&dev->broadcasted_list);
|
||||
INIT_LIST_HEAD(&dev->sent_list);
|
||||
dev->queued_datagrams = 0;
|
||||
INIT_LIST_HEAD(&dev->peer_list);
|
||||
|
||||
dev->card = card;
|
||||
dev->netdev = net;
|
||||
|
||||
|
|
@ -1552,7 +1543,7 @@ static int fwnet_remove(struct device *_dev)
|
|||
struct fwnet_peer *peer = dev_get_drvdata(_dev);
|
||||
struct fwnet_device *dev = peer->dev;
|
||||
struct net_device *net;
|
||||
struct fwnet_packet_task *ptask, *pt_next;
|
||||
int i;
|
||||
|
||||
mutex_lock(&fwnet_device_mutex);
|
||||
|
||||
|
|
@ -1570,21 +1561,9 @@ static int fwnet_remove(struct device *_dev)
|
|||
dev->card);
|
||||
fw_iso_context_destroy(dev->broadcast_rcv_context);
|
||||
}
|
||||
list_for_each_entry_safe(ptask, pt_next,
|
||||
&dev->packet_list, pt_link) {
|
||||
dev_kfree_skb_any(ptask->skb);
|
||||
kmem_cache_free(fwnet_packet_task_cache, ptask);
|
||||
}
|
||||
list_for_each_entry_safe(ptask, pt_next,
|
||||
&dev->broadcasted_list, pt_link) {
|
||||
dev_kfree_skb_any(ptask->skb);
|
||||
kmem_cache_free(fwnet_packet_task_cache, ptask);
|
||||
}
|
||||
list_for_each_entry_safe(ptask, pt_next,
|
||||
&dev->sent_list, pt_link) {
|
||||
dev_kfree_skb_any(ptask->skb);
|
||||
kmem_cache_free(fwnet_packet_task_cache, ptask);
|
||||
}
|
||||
for (i = 0; dev->queued_datagrams && i < 5; i++)
|
||||
ssleep(1);
|
||||
WARN_ON(dev->queued_datagrams);
|
||||
list_del(&dev->dev_link);
|
||||
|
||||
free_netdev(net);
|
||||
|
|
|
|||
Loading…
Reference in New Issue