rx.c 42.8 KB
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/*
 * 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
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 *  - RX reorder support
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 *
 * 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.
 *
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 * 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
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 * for reordering to the host). Read below for more information.
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 *
 * 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.
 *
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 * 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.
 *
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 * ROADMAP
 *
 * i2400m_rx
 *   i2400m_rx_msg_hdr_check
 *   i2400m_rx_pl_descr_check
 *   i2400m_rx_payload
 *     i2400m_net_rx
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 *     i2400m_rx_edata
 *       i2400m_net_erx
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 *       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
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 *     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
 */
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#include <linux/slab.h>
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#include <linux/kernel.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/workqueue.h>
#include "i2400m.h"


#define D_SUBMODULE rx
#include "debug-levels.h"

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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.");

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struct i2400m_report_hook_args {
	struct sk_buff *skb_rx;
	const struct i2400m_l3l4_hdr *l3l4_hdr;
	size_t size;
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	struct list_head list_node;
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};


/*
 * Execute i2400m_report_hook in a workqueue
 *
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 * Goes over the list of queued reports in i2400m->rx_reports and
 * processes them.
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 *
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 * NOTE: refcounts on i2400m are not needed because we flush the
 *     workqueue this runs on (i2400m->work_queue) before destroying
 *     i2400m.
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 */
void i2400m_report_hook_work(struct work_struct *ws)
{
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	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));
	}
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}


/*
 * 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;
	}
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	if (IS_ERR(ack_skb))
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		dev_err(dev, "CMD/GET/SET ack: cannot allocate SKB\n");
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	i2400m->ack_skb = ack_skb;
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	spin_unlock_irqrestore(&i2400m->rx_lock, flags);
	complete(&i2400m->msg_completion);
	return;

error_waiter_cancelled:
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	if (!IS_ERR(ack_skb))
		kfree_skb(ack_skb);
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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 preceeding 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) {
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		/*
		 * 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);
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		if (unlikely(i2400m->trace_msg_from_user))
			wimax_msg(&i2400m->wimax_dev, "echo",
				  l3l4_hdr, size, GFP_KERNEL);
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		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 preceeding 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;
}

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/*
 * 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);
748 749 750 751 752 753
	/*
	 * 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.
	 */
754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832
	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);
833
		i2400m_reset(i2400m, I2400M_RT_WARM);
834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
	} 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);
892 893 894 895 896 897
	/*
	 * 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.
	 */
898
	old_ws = roq->ws;
899 900 901 902 903 904 905 906 907 908 909 910 911 912
	/* 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);

913 914 915 916 917
	d_fnend(2, dev, "(i2400m %p roq %p skb %p sn %u) = void\n",
		i2400m, roq, skb, sn);
}


918 919 920 921 922 923 924
/*
 * 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.
 */
925
static void i2400m_rx_roq_destroy(struct kref *ref)
926 927 928 929 930 931 932 933 934 935 936
{
	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;
}

937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
/*
 * 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.
954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975
 *
 *
 * 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.
976 977 978 979 980 981 982 983 984 985
 */
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;
986 987 988 989
	u32 reorder;
	unsigned ro_needed, ro_type, ro_cin, ro_sn;
	struct i2400m_roq *roq;
	struct i2400m_roq_data *roq_data;
990
	unsigned long flags;
991

992 993 994
	BUILD_BUG_ON(ETH_HLEN > sizeof(*hdr));

	d_fnstart(2, dev, "(i2400m %p skb_rx %p single %u payload %p "
995 996 997 998 999 1000
		  "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;
	}
1001

1002 1003
	if (single_last) {
		skb = skb_get(skb_rx);
1004
		d_printf(3, dev, "ERX: skb %p reusing\n", skb);
1005 1006 1007 1008 1009 1010 1011
	} 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;
		}
1012
		d_printf(3, dev, "ERX: skb %p cloned from %p\n", skb, skb_rx);
1013 1014 1015
	}
	/* 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
1016 1017
	 * ethernet header as needed - we know there is enough space
	 * because we checked in i2400m_rx_edata(). */
1018
	skb_pull(skb, payload + sizeof(*hdr) - (void *) skb->data);
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
	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;

1029
		spin_lock_irqsave(&i2400m->rx_lock, flags);
1030
		if (i2400m->rx_roq == NULL) {
1031 1032 1033 1034
			kfree_skb(skb);	/* rx_roq is already destroyed */
			spin_unlock_irqrestore(&i2400m->rx_lock, flags);
			goto error;
		}
1035
		roq = &i2400m->rx_roq[ro_cin];
1036 1037 1038
		kref_get(&i2400m->rx_roq_refcount);
		spin_unlock_irqrestore(&i2400m->rx_lock, flags);

1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064
		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);
		}
1065 1066 1067 1068

		spin_lock_irqsave(&i2400m->rx_lock, flags);
		kref_put(&i2400m->rx_roq_refcount, i2400m_rx_roq_destroy);
		spin_unlock_irqrestore(&i2400m->rx_lock, flags);
1069 1070 1071
	}
	else
		i2400m_net_erx(i2400m, skb, cs);
1072 1073
error_skb_clone:
error:
1074
	d_fnend(2, dev, "(i2400m %p skb_rx %p single %u payload %p "
1075 1076 1077 1078
		"size %zu) = void\n", i2400m, skb_rx, single_last, payload, size);
}


1079 1080 1081 1082 1083
/*
 * Act on a received payload
 *
 * @i2400m: device instance
 * @skb_rx: skb where the transaction was received
1084 1085
 * @single_last: 1 this is the only payload or the last one (so the
 *     skb can be reused instead of cloned).
1086 1087 1088 1089
 * @pld: payload descriptor
 * @payload: payload data
 *
 * Upon reception of a payload, look at its guts in the payload
1090 1091 1092
 * 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).
1093 1094 1095
 */
static
void i2400m_rx_payload(struct i2400m *i2400m, struct sk_buff *skb_rx,
1096
		       unsigned single_last, const struct i2400m_pld *pld,
1097 1098 1099 1100 1101 1102
		       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);

1103 1104 1105 1106
	d_printf(7, dev, "RX: received payload type %u, %zu bytes\n",
		 pl_type, pl_size);
	d_dump(8, dev, payload, pl_size);

1107 1108 1109
	switch (pl_type) {
	case I2400M_PT_DATA:
		d_printf(3, dev, "RX: data payload %zu bytes\n", pl_size);
1110
		i2400m_net_rx(i2400m, skb_rx, single_last, payload, pl_size);
1111 1112 1113 1114 1115 1116 1117
		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;
1118 1119 1120 1121
	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;
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
	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
1229
 * everything is successful, update the device's statistics.
1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248
 *
 * 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, skb_len;
	unsigned long flags;
1249
	unsigned num_pls, single_last;
1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262

	skb_len = skb->len;
	d_fnstart(4, dev, "(i2400m %p skb %p [size %zu])\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);
	pl_itr = sizeof(*msg_hdr) +	/* Check payload descriptor(s) */
		num_pls * sizeof(msg_hdr->pld[0]);
1263
	pl_itr = ALIGN(pl_itr, I2400M_PL_ALIGN);
1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277
	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;
1278 1279
		single_last = num_pls == 1 || i == num_pls - 1;
		i2400m_rx_payload(i2400m, skb, single_last, &msg_hdr->pld[i],
1280
				  skb->data + pl_itr);
1281
		pl_itr += ALIGN(pl_size, I2400M_PL_ALIGN);
1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306
		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 %zu]) = %d\n",
		i2400m, skb, skb_len, result);
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_rx);
1307 1308


1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
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);


1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377
/*
 * 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;
	struct device *dev = i2400m_dev(i2400m);

	i2400m->rx_reorder = i2400m_rx_reorder_disabled? 0 : 1;
	if (i2400m->rx_reorder) {
		unsigned itr;
		size_t size;
		struct i2400m_roq_log *rd;

		result = -ENOMEM;

		size = sizeof(i2400m->rx_roq[0]) * (I2400M_RO_CIN + 1);
		i2400m->rx_roq = kzalloc(size, GFP_KERNEL);
		if (i2400m->rx_roq == NULL) {
			dev_err(dev, "RX: cannot allocate %zu bytes for "
				"reorder queues\n", size);
			goto error_roq_alloc;
		}

		size = sizeof(*i2400m->rx_roq[0].log) * (I2400M_RO_CIN + 1);
		rd = kzalloc(size, GFP_KERNEL);
		if (rd == NULL) {
			dev_err(dev, "RX: cannot allocate %zu bytes for "
				"reorder queues log areas\n", size);
			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];
		}
1378
		kref_init(&i2400m->rx_roq_refcount);
1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
	}
	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)
{
1392 1393
	unsigned long flags;

1394
	if (i2400m->rx_reorder) {
1395 1396 1397
		spin_lock_irqsave(&i2400m->rx_lock, flags);
		kref_put(&i2400m->rx_roq_refcount, i2400m_rx_roq_destroy);
		spin_unlock_irqrestore(&i2400m->rx_lock, flags);
1398
	}
1399 1400
	/* at this point, nothing can be received... */
	i2400m_report_hook_flush(i2400m);
1401
}