diff options
Diffstat (limited to 'drivers/net/wimax/i2400m/rx.c')
| -rw-r--r-- | drivers/net/wimax/i2400m/rx.c | 142 |
1 files changed, 113 insertions, 29 deletions
diff --git a/drivers/net/wimax/i2400m/rx.c b/drivers/net/wimax/i2400m/rx.c index 82c200ad9fd..64a44ca0067 100644 --- a/drivers/net/wimax/i2400m/rx.c +++ b/drivers/net/wimax/i2400m/rx.c @@ -158,29 +158,104 @@ struct i2400m_report_hook_args { struct sk_buff *skb_rx; const struct i2400m_l3l4_hdr *l3l4_hdr; size_t size; + struct list_head list_node; }; /* * Execute i2400m_report_hook in a workqueue * - * Unpacks arguments from the deferred call, executes it and then - * drops the references. + * Goes over the list of queued reports in i2400m->rx_reports and + * processes them. * - * Obvious NOTE: References are needed because we are a separate - * thread; otherwise the buffer changes under us because it is - * released by the original caller. + * NOTE: refcounts on i2400m are not needed because we flush the + * workqueue this runs on (i2400m->work_queue) before destroying + * i2400m. */ -static void i2400m_report_hook_work(struct work_struct *ws) { - struct i2400m_work *iw = - container_of(ws, struct i2400m_work, ws); - struct i2400m_report_hook_args *args = (void *) iw->pl; - i2400m_report_hook(iw->i2400m, args->l3l4_hdr, args->size); - kfree_skb(args->skb_rx); - i2400m_put(iw->i2400m); - kfree(iw); + struct i2400m *i2400m = container_of(ws, struct i2400m, rx_report_ws); + struct device *dev = i2400m_dev(i2400m); + struct i2400m_report_hook_args *args, *args_next; + LIST_HEAD(list); + unsigned long flags; + + while (1) { + spin_lock_irqsave(&i2400m->rx_lock, flags); + list_splice_init(&i2400m->rx_reports, &list); + spin_unlock_irqrestore(&i2400m->rx_lock, flags); + if (list_empty(&list)) + break; + else + d_printf(1, dev, "processing queued reports\n"); + list_for_each_entry_safe(args, args_next, &list, list_node) { + d_printf(2, dev, "processing queued report %p\n", args); + i2400m_report_hook(i2400m, args->l3l4_hdr, args->size); + kfree_skb(args->skb_rx); + list_del(&args->list_node); + kfree(args); + } + } +} + + +/* + * Flush the list of queued reports + */ +static +void i2400m_report_hook_flush(struct i2400m *i2400m) +{ + struct device *dev = i2400m_dev(i2400m); + struct i2400m_report_hook_args *args, *args_next; + LIST_HEAD(list); + unsigned long flags; + + d_printf(1, dev, "flushing queued reports\n"); + spin_lock_irqsave(&i2400m->rx_lock, flags); + list_splice_init(&i2400m->rx_reports, &list); + spin_unlock_irqrestore(&i2400m->rx_lock, flags); + list_for_each_entry_safe(args, args_next, &list, list_node) { + d_printf(2, dev, "flushing queued report %p\n", args); + kfree_skb(args->skb_rx); + list_del(&args->list_node); + kfree(args); + } +} + + +/* + * Queue a report for later processing + * + * @i2400m: device descriptor + * @skb_rx: skb that contains the payload (for reference counting) + * @l3l4_hdr: pointer to the control + * @size: size of the message + */ +static +void i2400m_report_hook_queue(struct i2400m *i2400m, struct sk_buff *skb_rx, + const void *l3l4_hdr, size_t size) +{ + struct device *dev = i2400m_dev(i2400m); + unsigned long flags; + struct i2400m_report_hook_args *args; + + args = kzalloc(sizeof(*args), GFP_NOIO); + if (args) { + args->skb_rx = skb_get(skb_rx); + args->l3l4_hdr = l3l4_hdr; + args->size = size; + spin_lock_irqsave(&i2400m->rx_lock, flags); + list_add_tail(&args->list_node, &i2400m->rx_reports); + spin_unlock_irqrestore(&i2400m->rx_lock, flags); + d_printf(2, dev, "queued report %p\n", args); + rmb(); /* see i2400m->ready's documentation */ + if (likely(i2400m->ready)) /* only send if up */ + queue_work(i2400m->work_queue, &i2400m->rx_report_ws); + } else { + if (printk_ratelimit()) + dev_err(dev, "%s:%u: Can't allocate %zu B\n", + __func__, __LINE__, sizeof(*args)); + } } @@ -294,22 +369,29 @@ void i2400m_rx_ctl(struct i2400m *i2400m, struct sk_buff *skb_rx, msg_type, size); d_dump(2, dev, l3l4_hdr, size); if (msg_type & I2400M_MT_REPORT_MASK) { - /* These hooks have to be ran serialized; as well, the - * handling might force the execution of commands, and - * that might cause reentrancy issues with - * bus-specific subdrivers and workqueues. So we run - * it in a separate workqueue. */ - struct i2400m_report_hook_args args = { - .skb_rx = skb_rx, - .l3l4_hdr = l3l4_hdr, - .size = size - }; - rmb(); /* see i2400m->ready's documentation */ - if (likely(i2400m->ready)) { /* only send if up */ - skb_get(skb_rx); - i2400m_queue_work(i2400m, i2400m_report_hook_work, - GFP_KERNEL, &args, sizeof(args)); - } + /* + * Process each report + * + * - has to be ran serialized as well + * + * - the handling might force the execution of + * commands. That might cause reentrancy issues with + * bus-specific subdrivers and workqueues, so the we + * run it in a separate workqueue. + * + * - when the driver is not yet ready to handle them, + * they are queued and at some point the queue is + * restarted [NOTE: we can't queue SKBs directly, as + * this might be a piece of a SKB, not the whole + * thing, and this is cheaper than cloning the + * SKB]. + * + * Note we don't do refcounting for the device + * structure; this is because before destroying + * 'i2400m', we make sure to flush the + * i2400m->work_queue, so there are no issues. + */ + i2400m_report_hook_queue(i2400m, skb_rx, l3l4_hdr, size); if (unlikely(i2400m->trace_msg_from_user)) wimax_msg(&i2400m->wimax_dev, "echo", l3l4_hdr, size, GFP_KERNEL); @@ -1281,4 +1363,6 @@ void i2400m_rx_release(struct i2400m *i2400m) kfree(i2400m->rx_roq[0].log); kfree(i2400m->rx_roq); } + /* at this point, nothing can be received... */ + i2400m_report_hook_flush(i2400m); } |