/*
* Intel Wireless WiMAX Connection 2400m
* Handle incoming traffic and deliver it to the control or data planes
*
*
* Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
* Intel Corporation <linux-wimax@intel.com>
* Yanir Lubetkin <yanirx.lubetkin@intel.com>
* - Initial implementation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
* - Use skb_clone(), break up processing in chunks
* - Split transport/device specific
* - Make buffer size dynamic to exert less memory pressure
* - RX reorder support
*
* This handles the RX path.
*
* We receive an RX message from the bus-specific driver, which
* contains one or more payloads that have potentially different
* destinataries (data or control paths).
*
* So we just take that payload from the transport specific code in
* the form of an skb, break it up in chunks (a cloned skb each in the
* case of network packets) and pass it to netdev or to the
* command/ack handler (and from there to the WiMAX stack).
*
* PROTOCOL FORMAT
*
* The format of the buffer is:
*
* HEADER (struct i2400m_msg_hdr)
* PAYLOAD DESCRIPTOR 0 (struct i2400m_pld)
* PAYLOAD DESCRIPTOR 1
* ...
* PAYLOAD DESCRIPTOR N
* PAYLOAD 0 (raw bytes)
* PAYLOAD 1
* ...
* PAYLOAD N
*
* See tx.c for a deeper description on alignment requirements and
* other fun facts of it.
*
* DATA PACKETS
*
* In firmwares <= v1.3, data packets have no header for RX, but they
* do for TX (currently unused).
*
* In firmware >= 1.4, RX packets have an extended header (16
* bytes). This header conveys information for management of host
* reordering of packets (the device offloads storage of the packets
* for reordering to the host). Read below for more information.
*
* The header is used as dummy space to emulate an ethernet header and
* thus be able to act as an ethernet device without having to reallocate.
*
* DATA RX REORDERING
*
* Starting in firmware v1.4, the device can deliver packets for
* delivery with special reordering information; this allows it to
* more effectively do packet management when some frames were lost in
* the radio traffic.
*
* Thus, for RX packets that come out of order, the device gives the
* driver enough information to queue them properly and then at some
* point, the signal to deliver the whole (or part) of the queued
* packets to the networking stack. There are 16 such queues.
*
* This only happens when a packet comes in with the "need reorder"
* flag set in the RX header. When such bit is set, the following
* operations might be indicated:
*
* - reset queue: send all queued packets to the OS
*
* - queue: queue a packet
*
* - update ws: update the queue's window start and deliver queued
* packets that meet the criteria
*
* - queue & update ws: queue a packet, update the window start and
* deliver queued packets that meet the criteria
*
* (delivery criteria: the packet's [normalized] sequence number is
* lower than the new [normalized] window start).
*
* See the i2400m_roq_*() functions for details.
*
* ROADMAP
*
* i2400m_rx
* i2400m_rx_msg_hdr_check
* i2400m_rx_pl_descr_check
* i2400m_rx_payload
* i2400m_net_rx
* i2400m_rx_edata
* i2400m_net_erx
* i2400m_roq_reset
* i2400m_net_erx
* i2400m_roq_queue
* __i2400m_roq_queue
* i2400m_roq_update_ws
* __i2400m_roq_update_ws
* i2400m_net_erx
* i2400m_roq_queue_update_ws
* __i2400m_roq_queue
* __i2400m_roq_update_ws
* i2400m_net_erx
* i2400m_rx_ctl
* i2400m_msg_size_check
* i2400m_report_hook_work [in a workqueue]
* i2400m_report_hook
* wimax_msg_to_user
* i2400m_rx_ctl_ack
* wimax_msg_to_user_alloc
* i2400m_rx_trace
* i2400m_msg_size_check
* wimax_msg
*/
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/workqueue.h>
#include <linux/export.h>
#include <linux/moduleparam.h>
#include "i2400m.h"
#define D_SUBMODULE rx
#include "debug-levels.h"
static int i2400m_rx_reorder_disabled; /* 0 (rx reorder enabled) by default */
module_param_named(rx_reorder_disabled, i2400m_rx_reorder_disabled, int, 0644);
MODULE_PARM_DESC(rx_reorder_disabled,
"If true, RX reordering will be disabled.");
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
*
* Goes over the list of queued reports in i2400m->rx_reports and
* processes them.
*
* NOTE: refcounts on i2400m are not needed because we flush the
* workqueue this runs on (i2400m->work_queue) before destroying
* i2400m.
*/
void i2400m_report_hook_work(struct work_struct *ws)
{
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));
}
}
/*
* Process an ack to a command
*
* @i2400m: device descriptor
* @payload: pointer to message
* @size: size of the message
*
* Pass the acknodledgment (in an skb) to the thread that is waiting
* for it in i2400m->msg_completion.
*
* We need to coordinate properly with the thread waiting for the
* ack. Check if it is waiting or if it is gone. We loose the spinlock
* to avoid allocating on atomic contexts (yeah, could use GFP_ATOMIC,
* but this is not so speed critical).
*/
static
void i2400m_rx_ctl_ack(struct i2400m *i2400m,
const void *payload, size_t size)
{
struct device *dev = i2400m_dev(i2400m);
struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
unsigned long flags;
struct sk_buff *ack_skb;
/* Anyone waiting for an answer? */
spin_lock_irqsave(&i2400m->rx_lock, flags);
if (i2400m->ack_skb != ERR_PTR(-EINPROGRESS)) {
dev_err(dev, "Huh? reply to command with no waiters\n");
goto error_no_waiter;
}
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
ack_skb = wimax_msg_alloc(wimax_dev, NULL, payload, size, GFP_KERNEL);
/* Check waiter didn't time out waiting for the answer... */
spin_lock_irqsave(&i2400m->rx_lock, flags);
if (i2400m->ack_skb != ERR_PTR(-EINPROGRESS)) {
d_printf(1, dev, "Huh? waiter for command reply cancelled\n");
goto error_waiter_cancelled;
}
if (IS_ERR(ack_skb))
dev_err(dev, "CMD/GET/SET ack: cannot allocate SKB\n");
i2400m->ack_skb = ack_skb;
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
complete(&i2400m->msg_completion);
return;
error_waiter_cancelled:
if (!IS_ERR(ack_skb))
kfree_skb(ack_skb);
error_no_waiter:
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
}
/*
* Receive and process a control payload
*
* @i2400m: device descriptor
* @skb_rx: skb that contains the payload (for reference counting)
* @payload: pointer to message
* @size: size of the message
*
* There are two types of control RX messages: reports (asynchronous,
* like your every day interrupts) and 'acks' (reponses to a command,
* get or set request).
*
* If it is a report, we run hooks on it (to extract information for
* things we need to do in the driver) and then pass it over to the
* WiMAX stack to send it to user space.
*
* NOTE: report processing is done in a workqueue specific to the
* generic driver, to avoid deadlocks in the system.
*
* If it is not a report, it is an ack to a previously executed
* command, set or get, so wake up whoever is waiting for it from
* i2400m_msg_to_dev(). i2400m_rx_ctl_ack() takes care of that.
*
* Note that the sizes we pass to other functions from here are the
* sizes of the _l3l4_hdr + payload, not full buffer sizes, as we have
* verified in _msg_size_check() that they are congruent.
*
* For reports: We can't clone the original skb where the data is
* because we need to send this up via netlink; netlink has to add
* headers and we can't overwrite what's preceding the payload...as
* it is another message. So we just dup them.
*/
static
void i2400m_rx_ctl(struct i2400m *i2400m, struct sk_buff *skb_rx,
const void *payload, size_t size)
{
int result;
struct device *dev = i2400m_dev(i2400m);
const struct i2400m_l3l4_hdr *l3l4_hdr = payload;
unsigned msg_type;
result = i2400m_msg_size_check(i2400m, l3l4_hdr, size);
if (result < 0) {
dev_err(dev, "HW BUG? device sent a bad message: %d\n",
result);
goto error_check;
}
msg_type = le16_to_cpu(l3l4_hdr->type);
d_printf(1, dev, "%s 0x%04x: %zu bytes\n",
msg_type & I2400M_MT_REPORT_MASK ? "REPORT" : "CMD/SET/GET",
msg_type, size);
d_dump(2, dev, l3l4_hdr, size);
if (msg_type & I2400M_MT_REPORT_MASK) {
/*
* 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);
result = wimax_msg(&i2400m->wimax_dev, NULL, l3l4_hdr, size,
GFP_KERNEL);
if (result < 0)
dev_err(dev, "error sending report to userspace: %d\n",
result);
} else /* an ack to a CMD, GET or SET */
i2400m_rx_ctl_ack(i2400m, payload, size);
error_check:
return;
}
/*
* Receive and send up a trace
*
* @i2400m: device descriptor
* @skb_rx: skb that contains the trace (for reference counting)
* @payload: pointer to trace message inside the skb
* @size: size of the message
*
* THe i2400m might produce trace information (diagnostics) and we
* send them through a different kernel-to-user pipe (to avoid
* clogging it).
*
* As in i2400m_rx_ctl(), we can't clone the original skb where the
* data is because we need to send this up via netlink; netlink has to
* add headers and we can't overwrite what's preceding the
* payload...as it is another message. So we just dup them.
*/
static
void i2400m_rx_trace(struct i2400m *i2400m,
const void *payload, size_t size)
{
int result;
struct device *dev = i2400m_dev(i2400m);
struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
const struct i2400m_l3l4_hdr *l3l4_hdr = payload;
unsigned msg_type;
result = i2400m_msg_size_check(i2400m, l3l4_hdr, size);
if (result < 0) {
dev_err(dev, "HW BUG? device sent a bad trace message: %d\n",
result);
goto error_check;
}
msg_type = le16_to_cpu(l3l4_hdr->type);
d_printf(1, dev, "Trace %s 0x%04x: %zu bytes\n",
msg_type & I2400M_MT_REPORT_MASK ? "REPORT" : "CMD/SET/GET",
msg_type, size);
d_dump(2, dev, l3l4_hdr, size);
result = wimax_msg(wimax_dev, "trace", l3l4_hdr, size, GFP_KERNEL);
if (result < 0)
dev_err(dev, "error sending trace to userspace: %d\n",
result);
error_check:
return;
}
/*
* Reorder queue data stored on skb->cb while the skb is queued in the
* reorder queues.
*/
struct i2400m_roq_data {
unsigned sn; /* Serial number for the skb */
enum i2400m_cs cs; /* packet type for the skb */
};
/*
* ReOrder Queue
*
* @ws: Window Start; sequence number where the current window start
* is for this queue
* @queue: the skb queue itself
* @log: circular ring buffer used to log information about the
* reorder process in this queue that can be displayed in case of
* error to help diagnose it.
*
* This is the head for a list of skbs. In the skb->cb member of the
* skb when queued here contains a 'struct i2400m_roq_data' were we
* store the sequence number (sn) and the cs (packet type) coming from
* the RX payload header from the device.
*/
struct i2400m_roq
{
unsigned ws;
struct sk_buff_head queue;
struct i2400m_roq_log *log;
};
static
void __i2400m_roq_init(struct i2400m_roq *roq)
{
roq->ws = 0;
skb_queue_head_init(&roq->queue);
}
static
unsigned __i2400m_roq_index(struct i2400m *i2400m, struct i2400m_roq *roq)
{
return ((unsigned long) roq - (unsigned long) i2400m->rx_roq)
/ sizeof(*roq);
}
/*
* Normalize a sequence number based on the queue's window start
*
* nsn = (sn - ws) % 2048
*
* Note that if @sn < @roq->ws, we still need a positive number; %'s
* sign is implementation specific, so we normalize it by adding 2048
* to bring it to be positive.
*/
static
unsigned __i2400m_roq_nsn(struct i2400m_roq *roq, unsigned sn)
{
int r;
r = ((int) sn - (int) roq->ws) % 2048;
if (r < 0)
r += 2048;
return r;
}
/*
* Circular buffer to keep the last N reorder operations
*
* In case something fails, dumb then to try to come up with what
* happened.
*/
enum {
I2400M_ROQ_LOG_LENGTH = 32,
};
struct i2400m_roq_log {
struct i2400m_roq_log_entry {
enum i2400m_ro_type type;
unsigned ws, count, sn, nsn, new_ws;
} entry[I2400M_ROQ_LOG_LENGTH];
unsigned in, out;
};
/* Print a log entry */
static
void i2400m_roq_log_entry_print(struct i2400m *i2400m, unsigned index,
unsigned e_index,
struct i2400m_roq_log_entry *e)
{
struct device *dev = i2400m_dev(i2400m);
switch(e->type) {
case I2400M_RO_TYPE_RESET:
dev_err(dev, "q#%d reset ws %u cnt %u sn %u/%u"
" - new nws %u\n",
index, e->ws, e->count, e->sn, e->nsn, e->new_ws);
break;
case I2400M_RO_TYPE_PACKET:
dev_err(dev, "q#%d queue ws %u cnt %u sn %u/%u\n",
index, e->ws, e->count, e->sn, e->nsn);
break;
case I2400M_RO_TYPE_WS:
dev_err(dev, "q#%d update_ws ws %u cnt %u sn %u/%u"
" - new nws %u\n",
index, e->ws, e->count, e->sn, e->nsn, e->new_ws);
break;
case I2400M_RO_TYPE_PACKET_WS:
dev_err(dev, "q#%d queue_update_ws ws %u cnt %u sn %u/%u"
" - new nws %u\n",
index, e->ws, e->count, e->sn, e->nsn, e->new_ws);
break;
default:
dev_err(dev, "q#%d BUG? entry %u - unknown type %u\n",
index, e_index, e->type);
break;
}
}
static
void i2400m_roq_log_add(struct i2400m *i2400m,
struct i2400m_roq *roq, enum i2400m_ro_type type,
unsigned ws, unsigned count, unsigned sn,
unsigned nsn, unsigned new_ws)
{
struct i2400m_roq_log_entry *e;
unsigned cnt_idx;
int index = __i2400m_roq_index(i2400m, roq);
/* if we run out of space, we eat from the end */
if (roq->log->in - roq->log->out == I2400M_ROQ_LOG_LENGTH)
roq->log->out++;
cnt_idx = roq->log->in++ % I2400M_ROQ_LOG_LENGTH;
e = &roq->log->entry[cnt_idx];
e->type = type;
e->ws = ws;
e->count = count;
e->sn = sn;
e->nsn = nsn;
e->new_ws = new_ws;
if (d_test(1))
i2400m_roq_log_entry_print(i2400m, index, cnt_idx, e);
}
/* Dump all the entries in the FIFO and reinitialize it */
static
void i2400m_roq_log_dump(struct i2400m *i2400m, struct i2400m_roq *roq)
{
unsigned cnt, cnt_idx;
struct i2400m_roq_log_entry *e;
int index = __i2400m_roq_index(i2400m, roq);
BUG_ON(roq->log->out > roq->log->in);
for (cnt = roq->log->out; cnt < roq->log->in; cnt++) {
cnt_idx = cnt % I2400M_ROQ_LOG_LENGTH;
e = &roq->log->entry[cnt_idx];
i2400m_roq_log_entry_print(i2400m, index, cnt_idx, e);
memset(e, 0, sizeof(*e));
}
roq->log->in = roq->log->out = 0;
}
/*
* Backbone for the queuing of an skb (by normalized sequence number)
*
* @i2400m: device descriptor
* @roq: reorder queue where to add
* @skb: the skb to add
* @sn: the sequence number of the skb
* @nsn: the normalized sequence number of the skb (pre-computed by the
* caller from the @sn and @roq->ws).
*
* We try first a couple of quick cases:
*
* - the queue is empty
* - the skb would be appended to the queue
*
* These will be the most common operations.
*
* If these fail, then we have to do a sorted insertion in the queue,
* which is the slowest path.
*
* We don't have to acquire a reference count as we are going to own it.
*/
static
void __i2400m_roq_queue(struct i2400m *i2400m, struct i2400m_roq *roq,
struct sk_buff *skb, unsigned sn, unsigned nsn)
{
struct device *dev = i2400m_dev(i2400m);
struct sk_buff *skb_itr;
struct i2400m_roq_data *roq_data_itr, *roq_data;
unsigned nsn_itr;
d_fnstart(4, dev, "(i2400m %p roq %p skb %p sn %u nsn %u)\n",
i2400m, roq, skb, sn, nsn);
roq_data = (struct i2400m_roq_data *) &skb->cb;
BUILD_BUG_ON(sizeof(*roq_data) > sizeof(skb->cb));
roq_data->sn = sn;
d_printf(3, dev, "ERX: roq %p [ws %u] nsn %d sn %u\n",
roq, roq->ws, nsn, roq_data->sn);
/* Queues will be empty on not-so-bad environments, so try
* that first */
if (skb_queue_empty(&roq->queue)) {
d_printf(2, dev, "ERX: roq %p - first one\n", roq);
__skb_queue_head(&roq->queue, skb);
goto out;
}
/* Now try append, as most of the operations will be that */
skb_itr = skb_peek_tail(&roq->queue);
roq_data_itr = (struct i2400m_roq_data *) &skb_itr->cb;
nsn_itr = __i2400m_roq_nsn(roq, roq_data_itr->sn);
/* NSN bounds assumed correct (checked when it was queued) */
if (nsn >= nsn_itr) {
d_printf(2, dev, "ERX: roq %p - appended after %p (nsn %d sn %u)\n",
roq, skb_itr, nsn_itr, roq_data_itr->sn);
__skb_queue_tail(&roq->queue, skb);
goto out;
}
/* None of the fast paths option worked. Iterate to find the
* right spot where to insert the packet; we know the queue is
* not empty, so we are not the first ones; we also know we
* are not going to be the last ones. The list is sorted, so
* we have to insert before the the first guy with an nsn_itr
* greater that our nsn. */
skb_queue_walk(&roq->queue, skb_itr) {
roq_data_itr = (struct i2400m_roq_data *) &skb_itr->cb;
nsn_itr = __i2400m_roq_nsn(roq, roq_data_itr->sn);
/* NSN bounds assumed correct (checked when it was queued) */
if (nsn_itr > nsn) {
d_printf(2, dev, "ERX: roq %p - queued before %p "
"(nsn %d sn %u)\n", roq, skb_itr, nsn_itr,
roq_data_itr->sn);
__skb_queue_before(&roq->queue, skb_itr, skb);
goto out;
}
}
/* If we get here, that is VERY bad -- print info to help
* diagnose and crash it */
dev_err(dev, "SW BUG? failed to insert packet\n");
dev_err(dev, "ERX: roq %p [ws %u] skb %p nsn %d sn %u\n",
roq, roq->ws, skb, nsn, roq_data->sn);
skb_queue_walk(&roq->queue, skb_itr) {
roq_data_itr = (struct i2400m_roq_data *) &skb_itr->cb;
nsn_itr = __i2400m_roq_nsn(roq, roq_data_itr->sn);
/* NSN bounds assumed correct (checked when it was queued) */
dev_err(dev, "ERX: roq %p skb_itr %p nsn %d sn %u\n",
roq, skb_itr, nsn_itr, roq_data_itr->sn);
}
BUG();
out:
d_fnend(4, dev, "(i2400m %p roq %p skb %p sn %u nsn %d) = void\n",
i2400m, roq, skb, sn, nsn);
}
/*
* Backbone for the update window start operation
*
* @i2400m: device descriptor
* @roq: Reorder queue
* @sn: New sequence number
*
* Updates the window start of a queue; when doing so, it must deliver
* to the networking stack all the queued skb's whose normalized
* sequence number is lower than the new normalized window start.
*/
static
unsigned __i2400m_roq_update_ws(struct i2400m *i2400m, struct i2400m_roq *roq,
unsigned sn)
{
struct device *dev = i2400m_dev(i2400m);
struct sk_buff *skb_itr, *tmp_itr;
struct i2400m_roq_data *roq_data_itr;
unsigned new_nws, nsn_itr;
new_nws = __i2400m_roq_nsn(roq, sn);
/*
* For type 2(update_window_start) rx messages, there is no
* need to check if the normalized sequence number is greater 1023.
* Simply insert and deliver all packets to the host up to the
* window start.
*/
skb_queue_walk_safe(&roq->queue, skb_itr, tmp_itr) {
roq_data_itr = (struct i2400m_roq_data *) &skb_itr->cb;
nsn_itr = __i2400m_roq_nsn(roq, roq_data_itr->sn);
/* NSN bounds assumed correct (checked when it was queued) */
if (nsn_itr < new_nws) {
d_printf(2, dev, "ERX: roq %p - release skb %p "
"(nsn %u/%u new nws %u)\n",
roq, skb_itr, nsn_itr, roq_data_itr->sn,
new_nws);
__skb_unlink(skb_itr, &roq->queue);
i2400m_net_erx(i2400m, skb_itr, roq_data_itr->cs);
}
else
break; /* rest of packets all nsn_itr > nws */
}
roq->ws = sn;
return new_nws;
}
/*
* Reset a queue
*
* @i2400m: device descriptor
* @cin: Queue Index
*
* Deliver all the packets and reset the window-start to zero. Name is
* kind of misleading.
*/
static
void i2400m_roq_reset(struct i2400m *i2400m, struct i2400m_roq *roq)
{
struct device *dev = i2400m_dev(i2400m);
struct sk_buff *skb_itr, *tmp_itr;
struct i2400m_roq_data *roq_data_itr;
d_fnstart(2, dev, "(i2400m %p roq %p)\n", i2400m, roq);
i2400m_roq_log_add(i2400m, roq, I2400M_RO_TYPE_RESET,
roq->ws, skb_queue_len(&roq->queue),
~0, ~0, 0);
skb_queue_walk_safe(&roq->queue, skb_itr, tmp_itr) {
roq_data_itr = (struct i2400m_roq_data *) &skb_itr->cb;
d_printf(2, dev, "ERX: roq %p - release skb %p (sn %u)\n",
roq, skb_itr, roq_data_itr->sn);
__skb_unlink(skb_itr, &roq->queue);
i2400m_net_erx(i2400m, skb_itr, roq_data_itr->cs);
}
roq->ws = 0;
d_fnend(2, dev, "(i2400m %p roq %p) = void\n", i2400m, roq);
}
/*
* Queue a packet
*
* @i2400m: device descriptor
* @cin: Queue Index
* @skb: containing the packet data
* @fbn: First block number of the packet in @skb
* @lbn: Last block number of the packet in @skb
*
* The hardware is asking the driver to queue a packet for later
* delivery to the networking stack.
*/
static
void i2400m_roq_queue(struct i2400m *i2400m, struct i2400m_roq *roq,
struct sk_buff * skb, unsigned lbn)
{
struct device *dev = i2400m_dev(i2400m);
unsigned nsn, len;
d_fnstart(2, dev, "(i2400m %p roq %p skb %p lbn %u) = void\n",
i2400m, roq, skb, lbn);
len = skb_queue_len(&roq->queue);
nsn = __i2400m_roq_nsn(roq, lbn);
if (unlikely(nsn >= 1024)) {
dev_err(dev, "SW BUG? queue nsn %d (lbn %u ws %u)\n",
nsn, lbn, roq->ws);
i2400m_roq_log_dump(i2400m, roq);
i2400m_reset(i2400m, I2400M_RT_WARM);
} else {
__i2400m_roq_queue(i2400m, roq, skb, lbn, nsn);
i2400m_roq_log_add(i2400m, roq, I2400M_RO_TYPE_PACKET,
roq->ws, len, lbn, nsn, ~0);
}
d_fnend(2, dev, "(i2400m %p roq %p skb %p lbn %u) = void\n",
i2400m, roq, skb, lbn);
}
/*
* Update the window start in a reorder queue and deliver all skbs
* with a lower window start
*
* @i2400m: device descriptor
* @roq: Reorder queue
* @sn: New sequence number
*/
static
void i2400m_roq_update_ws(struct i2400m *i2400m, struct i2400m_roq *roq,
unsigned sn)
{
struct device *dev = i2400m_dev(i2400m);
unsigned old_ws, nsn, len;
d_fnstart(2, dev, "(i2400m %p roq %p sn %u)\n", i2400m, roq, sn);
old_ws = roq->ws;
len = skb_queue_len(&roq->queue);
nsn = __i2400m_roq_update_ws(i2400m, roq, sn);
i2400m_roq_log_add(i2400m, roq, I2400M_RO_TYPE_WS,
old_ws, len, sn, nsn, roq->ws);
d_fnstart(2, dev, "(i2400m %p roq %p sn %u) = void\n", i2400m, roq, sn);
}
/*
* Queue a packet and update the window start
*
* @i2400m: device descriptor
* @cin: Queue Index
* @skb: containing the packet data
* @fbn: First block number of the packet in @skb
* @sn: Last block number of the packet in @skb
*
* Note that unlike i2400m_roq_update_ws(), which sets the new window
* start to @sn, in here we'll set it to @sn + 1.
*/
static
void i2400m_roq_queue_update_ws(struct i2400m *i2400m, struct i2400m_roq *roq,
struct sk_buff * skb, unsigned sn)
{
struct device *dev = i2400m_dev(i2400m);
unsigned nsn, old_ws, len;
d_fnstart(2, dev, "(i2400m %p roq %p skb %p sn %u)\n",
i2400m, roq, skb, sn);
len = skb_queue_len(&roq->queue);
nsn = __i2400m_roq_nsn(roq, sn);
/*
* For type 3(queue_update_window_start) rx messages, there is no
* need to check if the normalized sequence number is greater 1023.
* Simply insert and deliver all packets to the host up to the
* window start.
*/
old_ws = roq->ws;
/* If the queue is empty, don't bother as we'd queue
* it and immediately unqueue it -- just deliver it.
*/
if (len == 0) {
struct i2400m_roq_data *roq_data;
roq_data = (struct i2400m_roq_data *) &skb->cb;
i2400m_net_erx(i2400m, skb, roq_data->cs);
} else
__i2400m_roq_queue(i2400m, roq, skb, sn, nsn);
__i2400m_roq_update_ws(i2400m, roq, sn + 1);
i2400m_roq_log_add(i2400m, roq, I2400M_RO_TYPE_PACKET_WS,
old_ws, len, sn, nsn, roq->ws);
d_fnend(2, dev, "(i2400m %p roq %p skb %p sn %u) = void\n",
i2400m, roq, skb, sn);
}
/*
* This routine destroys the memory allocated for rx_roq, when no
* other thread is accessing it. Access to rx_roq is refcounted by
* rx_roq_refcount, hence memory allocated must be destroyed when
* rx_roq_refcount becomes zero. This routine gets executed when
* rx_roq_refcount becomes zero.
*/
static void i2400m_rx_roq_destroy(struct kref *ref)
{
unsigned itr;
struct i2400m *i2400m
= container_of(ref, struct i2400m, rx_roq_refcount);
for (itr = 0; itr < I2400M_RO_CIN + 1; itr++)
__skb_queue_purge(&i2400m->rx_roq[itr].queue);
kfree(i2400m->rx_roq[0].log);
kfree(i2400m->rx_roq);
i2400m->rx_roq = NULL;
}
/*
* Receive and send up an extended data packet
*
* @i2400m: device descriptor
* @skb_rx: skb that contains the extended data packet
* @single_last: 1 if the payload is the only one or the last one of
* the skb.
* @payload: pointer to the packet's data inside the skb
* @size: size of the payload
*
* Starting in v1.4 of the i2400m's firmware, the device can send data
* packets to the host in an extended format that; this incudes a 16
* byte header (struct i2400m_pl_edata_hdr). Using this header's space
* we can fake ethernet headers for ethernet device emulation without
* having to copy packets around.
*
* This function handles said path.
*
*
* Receive and send up an extended data packet that requires no reordering
*
* @i2400m: device descriptor
* @skb_rx: skb that contains the extended data packet
* @single_last: 1 if the payload is the only one or the last one of
* the skb.
* @payload: pointer to the packet's data (past the actual extended
* data payload header).
* @size: size of the payload
*
* Pass over to the networking stack a data packet that might have
* reordering requirements.
*
* This needs to the decide if the skb in which the packet is
* contained can be reused or if it needs to be cloned. Then it has to
* be trimmed in the edges so that the beginning is the space for eth
* header and then pass it to i2400m_net_erx() for the stack
*
* Assumes the caller has verified the sanity of the payload (size,
* etc) already.
*/
static
void i2400m_rx_edata(struct i2400m *i2400m, struct sk_buff *skb_rx,
unsigned single_last, const void *payload, size_t size)
{
struct device *dev = i2400m_dev(i2400m);
const struct i2400m_pl_edata_hdr *hdr = payload;
struct net_device *net_dev = i2400m->wimax_dev.net_dev;
struct sk_buff *skb;
enum i2400m_cs cs;
u32 reorder;
unsigned ro_needed, ro_type, ro_cin, ro_sn;
struct i2400m_roq *roq;
struct i2400m_roq_data *roq_data;
unsigned long flags;
BUILD_BUG_ON(ETH_HLEN > sizeof(*hdr));
d_fnstart(2, dev, "(i2400m %p skb_rx %p single %u payload %p "
"size %zu)\n", i2400m, skb_rx, single_last, payload, size);
if (size < sizeof(*hdr)) {
dev_err(dev, "ERX: HW BUG? message with short header (%zu "
"vs %zu bytes expected)\n", size, sizeof(*hdr));
goto error;
}
if (single_last) {
skb = skb_get(skb_rx);
d_printf(3, dev, "ERX: skb %p reusing\n", skb);
} else {
skb = skb_clone(skb_rx, GFP_KERNEL);
if (skb == NULL) {
dev_err(dev, "ERX: no memory to clone skb\n");
net_dev->stats.rx_dropped++;
goto error_skb_clone;
}
d_printf(3, dev, "ERX: skb %p cloned from %p\n", skb, skb_rx);
}
/* now we have to pull and trim so that the skb points to the
* beginning of the IP packet; the netdev part will add the
* ethernet header as needed - we know there is enough space
* because we checked in i2400m_rx_edata(). */
skb_pull(skb, payload + sizeof(*hdr) - (void *) skb->data);
skb_trim(skb, (void *) skb_end_pointer(skb) - payload - sizeof(*hdr));
reorder = le32_to_cpu(hdr->reorder);
ro_needed = reorder & I2400M_RO_NEEDED;
cs = hdr->cs;
if (ro_needed) {
ro_type = (reorder >> I2400M_RO_TYPE_SHIFT) & I2400M_RO_TYPE;
ro_cin = (reorder >> I2400M_RO_CIN_SHIFT) & I2400M_RO_CIN;
ro_sn = (reorder >> I2400M_RO_SN_SHIFT) & I2400M_RO_SN;
spin_lock_irqsave(&i2400m->rx_lock, flags);
if (i2400m->rx_roq == NULL) {
kfree_skb(skb); /* rx_roq is already destroyed */
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
goto error;
}
roq = &i2400m->rx_roq[ro_cin];
kref_get(&i2400m->rx_roq_refcount);
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
roq_data = (struct i2400m_roq_data *) &skb->cb;
roq_data->sn = ro_sn;
roq_data->cs = cs;
d_printf(2, dev, "ERX: reorder needed: "
"type %u cin %u [ws %u] sn %u/%u len %zuB\n",
ro_type, ro_cin, roq->ws, ro_sn,
__i2400m_roq_nsn(roq, ro_sn), size);
d_dump(2, dev, payload, size);
switch(ro_type) {
case I2400M_RO_TYPE_RESET:
i2400m_roq_reset(i2400m, roq);
kfree_skb(skb); /* no data here */
break;
case I2400M_RO_TYPE_PACKET:
i2400m_roq_queue(i2400m, roq, skb, ro_sn);
break;
case I2400M_RO_TYPE_WS:
i2400m_roq_update_ws(i2400m, roq, ro_sn);
kfree_skb(skb); /* no data here */
break;
case I2400M_RO_TYPE_PACKET_WS:
i2400m_roq_queue_update_ws(i2400m, roq, skb, ro_sn);
break;
default:
dev_err(dev, "HW BUG? unknown reorder type %u\n", ro_type);
}
spin_lock_irqsave(&i2400m->rx_lock, flags);
kref_put(&i2400m->rx_roq_refcount, i2400m_rx_roq_destroy);
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
}
else
i2400m_net_erx(i2400m, skb, cs);
error_skb_clone:
error:
d_fnend(2, dev, "(i2400m %p skb_rx %p single %u payload %p "
"size %zu) = void\n", i2400m, skb_rx, single_last, payload, size);
}
/*
* Act on a received payload
*
* @i2400m: device instance
* @skb_rx: skb where the transaction was received
* @single_last: 1 this is the only payload or the last one (so the
* skb can be reused instead of cloned).
* @pld: payload descriptor
* @payload: payload data
*
* Upon reception of a payload, look at its guts in the payload
* descriptor and decide what to do with it. If it is a single payload
* skb or if the last skb is a data packet, the skb will be referenced
* and modified (so it doesn't have to be cloned).
*/
static
void i2400m_rx_payload(struct i2400m *i2400m, struct sk_buff *skb_rx,
unsigned single_last, const struct i2400m_pld *pld,
const void *payload)
{
struct device *dev = i2400m_dev(i2400m);
size_t pl_size = i2400m_pld_size(pld);
enum i2400m_pt pl_type = i2400m_pld_type(pld);
d_printf(7, dev, "RX: received payload type %u, %zu bytes\n",
pl_type, pl_size);
d_dump(8, dev, payload, pl_size);
switch (pl_type) {
case I2400M_PT_DATA:
d_printf(3, dev, "RX: data payload %zu bytes\n", pl_size);
i2400m_net_rx(i2400m, skb_rx, single_last, payload, pl_size);
break;
case I2400M_PT_CTRL:
i2400m_rx_ctl(i2400m, skb_rx, payload, pl_size);
break;
case I2400M_PT_TRACE:
i2400m_rx_trace(i2400m, payload, pl_size);
break;
case I2400M_PT_EDATA:
d_printf(3, dev, "ERX: data payload %zu bytes\n", pl_size);
i2400m_rx_edata(i2400m, skb_rx, single_last, payload, pl_size);
break;
default: /* Anything else shouldn't come to the host */
if (printk_ratelimit())
dev_err(dev, "RX: HW BUG? unexpected payload type %u\n",
pl_type);
}
}
/*
* Check a received transaction's message header
*
* @i2400m: device descriptor
* @msg_hdr: message header
* @buf_size: size of the received buffer
*
* Check that the declarations done by a RX buffer message header are
* sane and consistent with the amount of data that was received.
*/
static
int i2400m_rx_msg_hdr_check(struct i2400m *i2400m,
const struct i2400m_msg_hdr *msg_hdr,
size_t buf_size)
{
int result = -EIO;
struct device *dev = i2400m_dev(i2400m);
if (buf_size < sizeof(*msg_hdr)) {
dev_err(dev, "RX: HW BUG? message with short header (%zu "
"vs %zu bytes expected)\n", buf_size, sizeof(*msg_hdr));
goto error;
}
if (msg_hdr->barker != cpu_to_le32(I2400M_D2H_MSG_BARKER)) {
dev_err(dev, "RX: HW BUG? message received with unknown "
"barker 0x%08x (buf_size %zu bytes)\n",
le32_to_cpu(msg_hdr->barker), buf_size);
goto error;
}
if (msg_hdr->num_pls == 0) {
dev_err(dev, "RX: HW BUG? zero payload packets in message\n");
goto error;
}
if (le16_to_cpu(msg_hdr->num_pls) > I2400M_MAX_PLS_IN_MSG) {
dev_err(dev, "RX: HW BUG? message contains more payload "
"than maximum; ignoring.\n");
goto error;
}
result = 0;
error:
return result;
}
/*
* Check a payload descriptor against the received data
*
* @i2400m: device descriptor
* @pld: payload descriptor
* @pl_itr: offset (in bytes) in the received buffer the payload is
* located
* @buf_size: size of the received buffer
*
* Given a payload descriptor (part of a RX buffer), check it is sane
* and that the data it declares fits in the buffer.
*/
static
int i2400m_rx_pl_descr_check(struct i2400m *i2400m,
const struct i2400m_pld *pld,
size_t pl_itr, size_t buf_size)
{
int result = -EIO;
struct device *dev = i2400m_dev(i2400m);
size_t pl_size = i2400m_pld_size(pld);
enum i2400m_pt pl_type = i2400m_pld_type(pld);
if (pl_size > i2400m->bus_pl_size_max) {
dev_err(dev, "RX: HW BUG? payload @%zu: size %zu is "
"bigger than maximum %zu; ignoring message\n",
pl_itr, pl_size, i2400m->bus_pl_size_max);
goto error;
}
if (pl_itr + pl_size > buf_size) { /* enough? */
dev_err(dev, "RX: HW BUG? payload @%zu: size %zu "
"goes beyond the received buffer "
"size (%zu bytes); ignoring message\n",
pl_itr, pl_size, buf_size);
goto error;
}
if (pl_type >= I2400M_PT_ILLEGAL) {
dev_err(dev, "RX: HW BUG? illegal payload type %u; "
"ignoring message\n", pl_type);
goto error;
}
result = 0;
error:
return result;
}
/**
* i2400m_rx - Receive a buffer of data from the device
*
* @i2400m: device descriptor
* @skb: skbuff where the data has been received
*
* Parse in a buffer of data that contains an RX message sent from the
* device. See the file header for the format. Run all checks on the
* buffer header, then run over each payload's descriptors, verify
* their consistency and act on each payload's contents. If
* everything is successful, update the device's statistics.
*
* Note: You need to set the skb to contain only the length of the
* received buffer; for that, use skb_trim(skb, RECEIVED_SIZE).
*
* Returns:
*
* 0 if ok, < 0 errno on error
*
* If ok, this function owns now the skb and the caller DOESN'T have
* to run kfree_skb() on it. However, on error, the caller still owns
* the skb and it is responsible for releasing it.
*/
int i2400m_rx(struct i2400m *i2400m, struct sk_buff *skb)
{
int i, result;
struct device *dev = i2400m_dev(i2400m);
const struct i2400m_msg_hdr *msg_hdr;
size_t pl_itr, pl_size;
unsigned long flags;
unsigned num_pls, single_last, skb_len;
skb_len = skb->len;
d_fnstart(4, dev, "(i2400m %p skb %p [size %u])\n",
i2400m, skb, skb_len);
result = -EIO;
msg_hdr = (void *) skb->data;
result = i2400m_rx_msg_hdr_check(i2400m, msg_hdr, skb_len);
if (result < 0)
goto error_msg_hdr_check;
result = -EIO;
num_pls = le16_to_cpu(msg_hdr->num_pls);
/* Check payload descriptor(s) */
pl_itr = struct_size(msg_hdr, pld, num_pls);
pl_itr = ALIGN(pl_itr, I2400M_PL_ALIGN);
if (pl_itr > skb_len) { /* got all the payload descriptors? */
dev_err(dev, "RX: HW BUG? message too short (%u bytes) for "
"%u payload descriptors (%zu each, total %zu)\n",
skb_len, num_pls, sizeof(msg_hdr->pld[0]), pl_itr);
goto error_pl_descr_short;
}
/* Walk each payload payload--check we really got it */
for (i = 0; i < num_pls; i++) {
/* work around old gcc warnings */
pl_size = i2400m_pld_size(&msg_hdr->pld[i]);
result = i2400m_rx_pl_descr_check(i2400m, &msg_hdr->pld[i],
pl_itr, skb_len);
if (result < 0)
goto error_pl_descr_check;
single_last = num_pls == 1 || i == num_pls - 1;
i2400m_rx_payload(i2400m, skb, single_last, &msg_hdr->pld[i],
skb->data + pl_itr);
pl_itr += ALIGN(pl_size, I2400M_PL_ALIGN);
cond_resched(); /* Don't monopolize */
}
kfree_skb(skb);
/* Update device statistics */
spin_lock_irqsave(&i2400m->rx_lock, flags);
i2400m->rx_pl_num += i;
if (i > i2400m->rx_pl_max)
i2400m->rx_pl_max = i;
if (i < i2400m->rx_pl_min)
i2400m->rx_pl_min = i;
i2400m->rx_num++;
i2400m->rx_size_acc += skb_len;
if (skb_len < i2400m->rx_size_min)
i2400m->rx_size_min = skb_len;
if (skb_len > i2400m->rx_size_max)
i2400m->rx_size_max = skb_len;
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
error_pl_descr_check:
error_pl_descr_short:
error_msg_hdr_check:
d_fnend(4, dev, "(i2400m %p skb %p [size %u]) = %d\n",
i2400m, skb, skb_len, result);
return result;
}
EXPORT_SYMBOL_GPL(i2400m_rx);
void i2400m_unknown_barker(struct i2400m *i2400m,
const void *buf, size_t size)
{
struct device *dev = i2400m_dev(i2400m);
char prefix[64];
const __le32 *barker = buf;
dev_err(dev, "RX: HW BUG? unknown barker %08x, "
"dropping %zu bytes\n", le32_to_cpu(*barker), size);
snprintf(prefix, sizeof(prefix), "%s %s: ",
dev_driver_string(dev), dev_name(dev));
if (size > 64) {
print_hex_dump(KERN_ERR, prefix, DUMP_PREFIX_OFFSET,
8, 4, buf, 64, 0);
printk(KERN_ERR "%s... (only first 64 bytes "
"dumped)\n", prefix);
} else
print_hex_dump(KERN_ERR, prefix, DUMP_PREFIX_OFFSET,
8, 4, buf, size, 0);
}
EXPORT_SYMBOL(i2400m_unknown_barker);
/*
* Initialize the RX queue and infrastructure
*
* This sets up all the RX reordering infrastructures, which will not
* be used if reordering is not enabled or if the firmware does not
* support it. The device is told to do reordering in
* i2400m_dev_initialize(), where it also looks at the value of the
* i2400m->rx_reorder switch before taking a decission.
*
* Note we allocate the roq queues in one chunk and the actual logging
* support for it (logging) in another one and then we setup the
* pointers from the first to the last.
*/
int i2400m_rx_setup(struct i2400m *i2400m)
{
int result = 0;
i2400m->rx_reorder = i2400m_rx_reorder_disabled? 0 : 1;
if (i2400m->rx_reorder) {
unsigned itr;
struct i2400m_roq_log *rd;
result = -ENOMEM;
i2400m->rx_roq = kcalloc(I2400M_RO_CIN + 1,
sizeof(i2400m->rx_roq[0]), GFP_KERNEL);
if (i2400m->rx_roq == NULL)
goto error_roq_alloc;
rd = kcalloc(I2400M_RO_CIN + 1, sizeof(*i2400m->rx_roq[0].log),
GFP_KERNEL);
if (rd == NULL) {
result = -ENOMEM;
goto error_roq_log_alloc;
}
for(itr = 0; itr < I2400M_RO_CIN + 1; itr++) {
__i2400m_roq_init(&i2400m->rx_roq[itr]);
i2400m->rx_roq[itr].log = &rd[itr];
}
kref_init(&i2400m->rx_roq_refcount);
}
return 0;
error_roq_log_alloc:
kfree(i2400m->rx_roq);
error_roq_alloc:
return result;
}
/* Tear down the RX queue and infrastructure */
void i2400m_rx_release(struct i2400m *i2400m)
{
unsigned long flags;
if (i2400m->rx_reorder) {
spin_lock_irqsave(&i2400m->rx_lock, flags);
kref_put(&i2400m->rx_roq_refcount, i2400m_rx_roq_destroy);
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
}
/* at this point, nothing can be received... */
i2400m_report_hook_flush(i2400m);
}
