caif_hsi.c 34.5 KB
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/*
 * Copyright (C) ST-Ericsson AB 2010
 * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
 * Author:  Daniel Martensson / daniel.martensson@stericsson.com
 *	    Dmitry.Tarnyagin  / dmitry.tarnyagin@stericsson.com
 * License terms: GNU General Public License (GPL) version 2.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/if_arp.h>
#include <linux/timer.h>
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#include <linux/rtnetlink.h>
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#include <linux/pkt_sched.h>
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#include <net/caif/caif_layer.h>
#include <net/caif/caif_hsi.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Martensson<daniel.martensson@stericsson.com>");
MODULE_DESCRIPTION("CAIF HSI driver");

/* Returns the number of padding bytes for alignment. */
#define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
				(((pow)-((x)&((pow)-1)))))

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static int inactivity_timeout = 1000;
module_param(inactivity_timeout, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(inactivity_timeout, "Inactivity timeout on HSI, ms.");

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static int aggregation_timeout = 1;
module_param(aggregation_timeout, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(aggregation_timeout, "Aggregation timeout on HSI, ms.");

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/*
 * HSI padding options.
 * Warning: must be a base of 2 (& operation used) and can not be zero !
 */
static int hsi_head_align = 4;
module_param(hsi_head_align, int, S_IRUGO);
MODULE_PARM_DESC(hsi_head_align, "HSI head alignment.");

static int hsi_tail_align = 4;
module_param(hsi_tail_align, int, S_IRUGO);
MODULE_PARM_DESC(hsi_tail_align, "HSI tail alignment.");

/*
 * HSI link layer flowcontrol thresholds.
 * Warning: A high threshold value migth increase throughput but it will at
 * the same time prevent channel prioritization and increase the risk of
 * flooding the modem. The high threshold should be above the low.
 */
static int hsi_high_threshold = 100;
module_param(hsi_high_threshold, int, S_IRUGO);
MODULE_PARM_DESC(hsi_high_threshold, "HSI high threshold (FLOW OFF).");

static int hsi_low_threshold = 50;
module_param(hsi_low_threshold, int, S_IRUGO);
MODULE_PARM_DESC(hsi_low_threshold, "HSI high threshold (FLOW ON).");

#define ON 1
#define OFF 0

/*
 * Threshold values for the HSI packet queue. Flowcontrol will be asserted
 * when the number of packets exceeds HIGH_WATER_MARK. It will not be
 * de-asserted before the number of packets drops below LOW_WATER_MARK.
 */
#define LOW_WATER_MARK   hsi_low_threshold
#define HIGH_WATER_MARK  hsi_high_threshold

static LIST_HEAD(cfhsi_list);
static spinlock_t cfhsi_list_lock;

static void cfhsi_inactivity_tout(unsigned long arg)
{
	struct cfhsi *cfhsi = (struct cfhsi *)arg;

	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	/* Schedule power down work queue. */
	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		queue_work(cfhsi->wq, &cfhsi->wake_down_work);
}

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static void cfhsi_update_aggregation_stats(struct cfhsi *cfhsi,
					   const struct sk_buff *skb,
					   int direction)
{
	struct caif_payload_info *info;
	int hpad, tpad, len;

	info = (struct caif_payload_info *)&skb->cb;
	hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
	tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
	len = skb->len + hpad + tpad;

	if (direction > 0)
		cfhsi->aggregation_len += len;
	else if (direction < 0)
		cfhsi->aggregation_len -= len;
}

static bool cfhsi_can_send_aggregate(struct cfhsi *cfhsi)
{
	int i;

	if (cfhsi->aggregation_timeout < 0)
		return true;

	for (i = 0; i < CFHSI_PRIO_BEBK; ++i) {
		if (cfhsi->qhead[i].qlen)
			return true;
	}

	/* TODO: Use aggregation_len instead */
	if (cfhsi->qhead[CFHSI_PRIO_BEBK].qlen >= CFHSI_MAX_PKTS)
		return true;

	return false;
}

static struct sk_buff *cfhsi_dequeue(struct cfhsi *cfhsi)
{
	struct sk_buff *skb;
	int i;

	for (i = 0; i < CFHSI_PRIO_LAST; ++i) {
		skb = skb_dequeue(&cfhsi->qhead[i]);
		if (skb)
			break;
	}

	return skb;
}

static int cfhsi_tx_queue_len(struct cfhsi *cfhsi)
{
	int i, len = 0;
	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
		len += skb_queue_len(&cfhsi->qhead[i]);
	return len;
}

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static void cfhsi_abort_tx(struct cfhsi *cfhsi)
{
	struct sk_buff *skb;

	for (;;) {
		spin_lock_bh(&cfhsi->lock);
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		skb = cfhsi_dequeue(cfhsi);
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		if (!skb)
			break;

		cfhsi->ndev->stats.tx_errors++;
		cfhsi->ndev->stats.tx_dropped++;
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		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
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		spin_unlock_bh(&cfhsi->lock);
		kfree_skb(skb);
	}
	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
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		mod_timer(&cfhsi->inactivity_timer,
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			jiffies + cfhsi->inactivity_timeout);
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	spin_unlock_bh(&cfhsi->lock);
}

static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
{
	char buffer[32]; /* Any reasonable value */
	size_t fifo_occupancy;
	int ret;

	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	do {
		ret = cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
				&fifo_occupancy);
		if (ret) {
			dev_warn(&cfhsi->ndev->dev,
				"%s: can't get FIFO occupancy: %d.\n",
				__func__, ret);
			break;
		} else if (!fifo_occupancy)
			/* No more data, exitting normally */
			break;

		fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
		set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
		ret = cfhsi->dev->cfhsi_rx(buffer, fifo_occupancy,
				cfhsi->dev);
		if (ret) {
			clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
			dev_warn(&cfhsi->ndev->dev,
				"%s: can't read data: %d.\n",
				__func__, ret);
			break;
		}

		ret = 5 * HZ;
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		ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
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			 !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);

		if (ret < 0) {
			dev_warn(&cfhsi->ndev->dev,
				"%s: can't wait for flush complete: %d.\n",
				__func__, ret);
			break;
		} else if (!ret) {
			ret = -ETIMEDOUT;
			dev_warn(&cfhsi->ndev->dev,
				"%s: timeout waiting for flush complete.\n",
				__func__);
			break;
		}
	} while (1);

	return ret;
}

static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
{
	int nfrms = 0;
	int pld_len = 0;
	struct sk_buff *skb;
	u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;

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	skb = cfhsi_dequeue(cfhsi);
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	if (!skb)
		return 0;

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	/* Clear offset. */
	desc->offset = 0;

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	/* Check if we can embed a CAIF frame. */
	if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
		struct caif_payload_info *info;
		int hpad = 0;
		int tpad = 0;

		/* Calculate needed head alignment and tail alignment. */
		info = (struct caif_payload_info *)&skb->cb;

		hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
		tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);

		/* Check if frame still fits with added alignment. */
		if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
			u8 *pemb = desc->emb_frm;
			desc->offset = CFHSI_DESC_SHORT_SZ;
			*pemb = (u8)(hpad - 1);
			pemb += hpad;

			/* Update network statistics. */
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			spin_lock_bh(&cfhsi->lock);
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			cfhsi->ndev->stats.tx_packets++;
			cfhsi->ndev->stats.tx_bytes += skb->len;
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			cfhsi_update_aggregation_stats(cfhsi, skb, -1);
			spin_unlock_bh(&cfhsi->lock);
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			/* Copy in embedded CAIF frame. */
			skb_copy_bits(skb, 0, pemb, skb->len);
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			/* Consume the SKB */
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			consume_skb(skb);
			skb = NULL;
		}
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	}
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	/* Create payload CAIF frames. */
	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
	while (nfrms < CFHSI_MAX_PKTS) {
		struct caif_payload_info *info;
		int hpad = 0;
		int tpad = 0;

		if (!skb)
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			skb = cfhsi_dequeue(cfhsi);
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		if (!skb)
			break;

		/* Calculate needed head alignment and tail alignment. */
		info = (struct caif_payload_info *)&skb->cb;

		hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
		tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);

		/* Fill in CAIF frame length in descriptor. */
		desc->cffrm_len[nfrms] = hpad + skb->len + tpad;

		/* Fill head padding information. */
		*pfrm = (u8)(hpad - 1);
		pfrm += hpad;

		/* Update network statistics. */
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		spin_lock_bh(&cfhsi->lock);
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		cfhsi->ndev->stats.tx_packets++;
		cfhsi->ndev->stats.tx_bytes += skb->len;
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		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
		spin_unlock_bh(&cfhsi->lock);
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		/* Copy in CAIF frame. */
		skb_copy_bits(skb, 0, pfrm, skb->len);

		/* Update payload length. */
		pld_len += desc->cffrm_len[nfrms];

		/* Update frame pointer. */
		pfrm += skb->len + tpad;
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		/* Consume the SKB */
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		consume_skb(skb);
		skb = NULL;

		/* Update number of frames. */
		nfrms++;
	}

	/* Unused length fields should be zero-filled (according to SPEC). */
	while (nfrms < CFHSI_MAX_PKTS) {
		desc->cffrm_len[nfrms] = 0x0000;
		nfrms++;
	}

	/* Check if we can piggy-back another descriptor. */
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	if (cfhsi_can_send_aggregate(cfhsi))
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		desc->header |= CFHSI_PIGGY_DESC;
	else
		desc->header &= ~CFHSI_PIGGY_DESC;

	return CFHSI_DESC_SZ + pld_len;
}

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static void cfhsi_start_tx(struct cfhsi *cfhsi)
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{
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	struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
	int len, res;
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	dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
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	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	do {
		/* Create HSI frame. */
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		len = cfhsi_tx_frm(desc, cfhsi);
		if (!len) {
			spin_lock_bh(&cfhsi->lock);
			if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
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				spin_unlock_bh(&cfhsi->lock);
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				res = -EAGAIN;
				continue;
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			}
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			cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
			/* Start inactivity timer. */
			mod_timer(&cfhsi->inactivity_timer,
				jiffies + cfhsi->inactivity_timeout);
			spin_unlock_bh(&cfhsi->lock);
			break;
		}
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		/* Set up new transfer. */
		res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
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		if (WARN_ON(res < 0))
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			dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
				__func__, res);
	} while (res < 0);
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}

static void cfhsi_tx_done(struct cfhsi *cfhsi)
{
	dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);

	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	/*
	 * Send flow on if flow off has been previously signalled
	 * and number of packets is below low water mark.
	 */
	spin_lock_bh(&cfhsi->lock);
	if (cfhsi->flow_off_sent &&
			cfhsi_tx_queue_len(cfhsi) <= cfhsi->q_low_mark &&
			cfhsi->cfdev.flowctrl) {

		cfhsi->flow_off_sent = 0;
		cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
	}

	if (cfhsi_can_send_aggregate(cfhsi)) {
		spin_unlock_bh(&cfhsi->lock);
		cfhsi_start_tx(cfhsi);
	} else {
		mod_timer(&cfhsi->aggregation_timer,
			jiffies + cfhsi->aggregation_timeout);
		spin_unlock_bh(&cfhsi->lock);
	}
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	return;
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}

static void cfhsi_tx_done_cb(struct cfhsi_drv *drv)
{
	struct cfhsi *cfhsi;

	cfhsi = container_of(drv, struct cfhsi, drv);
	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;
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	cfhsi_tx_done(cfhsi);
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}

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static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
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{
	int xfer_sz = 0;
	int nfrms = 0;
	u16 *plen = NULL;
	u8 *pfrm = NULL;

	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
		dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
			__func__);
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		return -EPROTO;
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	}

	/* Check for embedded CAIF frame. */
	if (desc->offset) {
		struct sk_buff *skb;
		u8 *dst = NULL;
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		int len = 0;
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		pfrm = ((u8 *)desc) + desc->offset;

		/* Remove offset padding. */
		pfrm += *pfrm + 1;

		/* Read length of CAIF frame (little endian). */
		len = *pfrm;
		len |= ((*(pfrm+1)) << 8) & 0xFF00;
		len += 2;	/* Add FCS fields. */

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		/* Sanity check length of CAIF frame. */
		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
			dev_err(&cfhsi->ndev->dev, "%s: Invalid length.\n",
				__func__);
			return -EPROTO;
		}
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		/* Allocate SKB (OK even in IRQ context). */
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		skb = alloc_skb(len + 1, GFP_ATOMIC);
		if (!skb) {
			dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
				__func__);
			return -ENOMEM;
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		}
		caif_assert(skb != NULL);

		dst = skb_put(skb, len);
		memcpy(dst, pfrm, len);

		skb->protocol = htons(ETH_P_CAIF);
		skb_reset_mac_header(skb);
		skb->dev = cfhsi->ndev;

		/*
		 * We are called from a arch specific platform device.
		 * Unfortunately we don't know what context we're
		 * running in.
		 */
		if (in_interrupt())
			netif_rx(skb);
		else
			netif_rx_ni(skb);

		/* Update network statistics. */
		cfhsi->ndev->stats.rx_packets++;
		cfhsi->ndev->stats.rx_bytes += len;
	}

	/* Calculate transfer length. */
	plen = desc->cffrm_len;
	while (nfrms < CFHSI_MAX_PKTS && *plen) {
		xfer_sz += *plen;
		plen++;
		nfrms++;
	}

	/* Check for piggy-backed descriptor. */
	if (desc->header & CFHSI_PIGGY_DESC)
		xfer_sz += CFHSI_DESC_SZ;

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	if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
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		dev_err(&cfhsi->ndev->dev,
				"%s: Invalid payload len: %d, ignored.\n",
			__func__, xfer_sz);
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		return -EPROTO;
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	}
	return xfer_sz;
}

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static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
{
	int xfer_sz = 0;
	int nfrms = 0;
	u16 *plen;

	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {

		pr_err("Invalid descriptor. %x %x\n", desc->header,
				desc->offset);
		return -EPROTO;
	}

	/* Calculate transfer length. */
	plen = desc->cffrm_len;
	while (nfrms < CFHSI_MAX_PKTS && *plen) {
		xfer_sz += *plen;
		plen++;
		nfrms++;
	}

	if (xfer_sz % 4) {
		pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
		return -EPROTO;
	}
	return xfer_sz;
}

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static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
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{
	int rx_sz = 0;
	int nfrms = 0;
	u16 *plen = NULL;
	u8 *pfrm = NULL;

	/* Sanity check header and offset. */
	if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
			(desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
		dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
			__func__);
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		return -EPROTO;
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	}

	/* Set frame pointer to start of payload. */
	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
	plen = desc->cffrm_len;
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	/* Skip already processed frames. */
	while (nfrms < cfhsi->rx_state.nfrms) {
		pfrm += *plen;
		rx_sz += *plen;
		plen++;
		nfrms++;
	}

	/* Parse payload. */
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	while (nfrms < CFHSI_MAX_PKTS && *plen) {
		struct sk_buff *skb;
		u8 *dst = NULL;
		u8 *pcffrm = NULL;
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		int len = 0;
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		/* CAIF frame starts after head padding. */
		pcffrm = pfrm + *pfrm + 1;

		/* Read length of CAIF frame (little endian). */
		len = *pcffrm;
		len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
		len += 2;	/* Add FCS fields. */

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		/* Sanity check length of CAIF frames. */
		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
			dev_err(&cfhsi->ndev->dev, "%s: Invalid length.\n",
				__func__);
			return -EPROTO;
		}

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		/* Allocate SKB (OK even in IRQ context). */
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		skb = alloc_skb(len + 1, GFP_ATOMIC);
		if (!skb) {
			dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
				__func__);
			cfhsi->rx_state.nfrms = nfrms;
			return -ENOMEM;
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		}
		caif_assert(skb != NULL);

		dst = skb_put(skb, len);
		memcpy(dst, pcffrm, len);

		skb->protocol = htons(ETH_P_CAIF);
		skb_reset_mac_header(skb);
		skb->dev = cfhsi->ndev;

		/*
		 * We're called from a platform device,
		 * and don't know the context we're running in.
		 */
		if (in_interrupt())
			netif_rx(skb);
		else
			netif_rx_ni(skb);

		/* Update network statistics. */
		cfhsi->ndev->stats.rx_packets++;
		cfhsi->ndev->stats.rx_bytes += len;

		pfrm += *plen;
		rx_sz += *plen;
		plen++;
		nfrms++;
	}

	return rx_sz;
}

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static void cfhsi_rx_done(struct cfhsi *cfhsi)
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{
	int res;
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	int desc_pld_len = 0, rx_len, rx_state;
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	struct cfhsi_desc *desc = NULL;
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	u8 *rx_ptr, *rx_buf;
	struct cfhsi_desc *piggy_desc = NULL;
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	desc = (struct cfhsi_desc *)cfhsi->rx_buf;

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	dev_dbg(&cfhsi->ndev->dev, "%s\n", __func__);
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	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	/* Update inactivity timer if pending. */
646
	spin_lock_bh(&cfhsi->lock);
647
	mod_timer_pending(&cfhsi->inactivity_timer,
648
			jiffies + cfhsi->inactivity_timeout);
649
	spin_unlock_bh(&cfhsi->lock);
650

651
	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
652 653 654
		desc_pld_len = cfhsi_rx_desc_len(desc);

		if (desc_pld_len < 0)
655
			goto out_of_sync;
656 657 658 659 660 661 662

		rx_buf = cfhsi->rx_buf;
		rx_len = desc_pld_len;
		if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
			rx_len += CFHSI_DESC_SZ;
		if (desc_pld_len == 0)
			rx_buf = cfhsi->rx_flip_buf;
663
	} else {
664
		rx_buf = cfhsi->rx_flip_buf;
665

666 667 668
		rx_len = CFHSI_DESC_SZ;
		if (cfhsi->rx_state.pld_len > 0 &&
				(desc->header & CFHSI_PIGGY_DESC)) {
669 670 671

			piggy_desc = (struct cfhsi_desc *)
				(desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
672 673
						cfhsi->rx_state.pld_len);

674
			cfhsi->rx_state.piggy_desc = true;
675

676 677 678 679 680 681 682 683 684 685 686
			/* Extract payload len from piggy-backed descriptor. */
			desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
			if (desc_pld_len < 0)
				goto out_of_sync;

			if (desc_pld_len > 0)
				rx_len = desc_pld_len;

			if (desc_pld_len > 0 &&
					(piggy_desc->header & CFHSI_PIGGY_DESC))
				rx_len += CFHSI_DESC_SZ;
687 688 689 690 691

			/*
			 * Copy needed information from the piggy-backed
			 * descriptor to the descriptor in the start.
			 */
692
			memcpy(rx_buf, (u8 *)piggy_desc,
693
					CFHSI_DESC_SHORT_SZ);
694 695
			/* Mark no embedded frame here */
			piggy_desc->offset = 0;
696 697 698
			if (desc_pld_len == -EPROTO)
				goto out_of_sync;
		}
699 700
	}

701
	if (desc_pld_len) {
702 703
		rx_state = CFHSI_RX_STATE_PAYLOAD;
		rx_ptr = rx_buf + CFHSI_DESC_SZ;
704
	} else {
705 706 707
		rx_state = CFHSI_RX_STATE_DESC;
		rx_ptr = rx_buf;
		rx_len = CFHSI_DESC_SZ;
708 709
	}

710
	/* Initiate next read */
711 712 713
	if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
		/* Set up new transfer. */
		dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n",
714 715 716
				__func__);

		res = cfhsi->dev->cfhsi_rx(rx_ptr, rx_len,
717 718 719 720 721 722 723 724
				cfhsi->dev);
		if (WARN_ON(res < 0)) {
			dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n",
				__func__, res);
			cfhsi->ndev->stats.rx_errors++;
			cfhsi->ndev->stats.rx_dropped++;
		}
	}
725

726 727 728 729 730 731 732 733 734 735 736 737 738
	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
		/* Extract payload from descriptor */
		if (cfhsi_rx_desc(desc, cfhsi) < 0)
			goto out_of_sync;
	} else {
		/* Extract payload */
		if (cfhsi_rx_pld(desc, cfhsi) < 0)
			goto out_of_sync;
		if (piggy_desc) {
			/* Extract any payload in piggyback descriptor. */
			if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
				goto out_of_sync;
		}
739
	}
740 741 742 743 744 745 746 747 748 749 750

	/* Update state info */
	memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
	cfhsi->rx_state.state = rx_state;
	cfhsi->rx_ptr = rx_ptr;
	cfhsi->rx_len = rx_len;
	cfhsi->rx_state.pld_len = desc_pld_len;
	cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;

	if (rx_buf != cfhsi->rx_buf)
		swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
751 752 753 754 755 756 757
	return;

out_of_sync:
	dev_err(&cfhsi->ndev->dev, "%s: Out of sync.\n", __func__);
	print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
			cfhsi->rx_buf, CFHSI_DESC_SZ);
	schedule_work(&cfhsi->out_of_sync_work);
758 759 760 761 762 763 764 765 766 767
}

static void cfhsi_rx_slowpath(unsigned long arg)
{
	struct cfhsi *cfhsi = (struct cfhsi *)arg;

	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	cfhsi_rx_done(cfhsi);
768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
}

static void cfhsi_rx_done_cb(struct cfhsi_drv *drv)
{
	struct cfhsi *cfhsi;

	cfhsi = container_of(drv, struct cfhsi, drv);
	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
		wake_up_interruptible(&cfhsi->flush_fifo_wait);
	else
784
		cfhsi_rx_done(cfhsi);
785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
}

static void cfhsi_wake_up(struct work_struct *work)
{
	struct cfhsi *cfhsi = NULL;
	int res;
	int len;
	long ret;

	cfhsi = container_of(work, struct cfhsi, wake_up_work);

	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
		/* It happenes when wakeup is requested by
		 * both ends at the same time. */
		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
803
		clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
804 805 806 807 808 809 810 811 812 813
		return;
	}

	/* Activate wake line. */
	cfhsi->dev->cfhsi_wake_up(cfhsi->dev);

	dev_dbg(&cfhsi->ndev->dev, "%s: Start waiting.\n",
		__func__);

	/* Wait for acknowledge. */
814 815 816
	ret = CFHSI_WAKE_TOUT;
	ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
					test_and_clear_bit(CFHSI_WAKE_UP_ACK,
817 818 819
							&cfhsi->bits), ret);
	if (unlikely(ret < 0)) {
		/* Interrupted by signal. */
820
		dev_err(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
821
			__func__, ret);
822

823 824 825 826
		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
		cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
		return;
	} else if (!ret) {
827 828 829
		bool ca_wake = false;
		size_t fifo_occupancy = 0;

830
		/* Wakeup timeout */
831
		dev_dbg(&cfhsi->ndev->dev, "%s: Timeout.\n",
832
			__func__);
833 834 835 836 837

		/* Check FIFO to check if modem has sent something. */
		WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
					&fifo_occupancy));

838
		dev_dbg(&cfhsi->ndev->dev, "%s: Bytes in FIFO: %u.\n",
839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855
				__func__, (unsigned) fifo_occupancy);

		/* Check if we misssed the interrupt. */
		WARN_ON(cfhsi->dev->cfhsi_get_peer_wake(cfhsi->dev,
							&ca_wake));

		if (ca_wake) {
			dev_err(&cfhsi->ndev->dev, "%s: CA Wake missed !.\n",
				__func__);

			/* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
			clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);

			/* Continue execution. */
			goto wake_ack;
		}

856 857 858 859
		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
		cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
		return;
	}
860
wake_ack:
861 862 863 864 865 866 867 868
	dev_dbg(&cfhsi->ndev->dev, "%s: Woken.\n",
		__func__);

	/* Clear power up bit. */
	set_bit(CFHSI_AWAKE, &cfhsi->bits);
	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);

	/* Resume read operation. */
869 870 871 872 873
	dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n", __func__);
	res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->dev);

	if (WARN_ON(res < 0))
		dev_err(&cfhsi->ndev->dev, "%s: RX err %d.\n", __func__, res);
874 875 876 877 878 879

	/* Clear power up acknowledment. */
	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);

	spin_lock_bh(&cfhsi->lock);

880 881
	/* Resume transmit if queues are not empty. */
	if (!cfhsi_tx_queue_len(cfhsi)) {
882 883 884
		dev_dbg(&cfhsi->ndev->dev, "%s: Peer wake, start timer.\n",
			__func__);
		/* Start inactivity timer. */
885
		mod_timer(&cfhsi->inactivity_timer,
886
				jiffies + cfhsi->inactivity_timeout);
887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917
		spin_unlock_bh(&cfhsi->lock);
		return;
	}

	dev_dbg(&cfhsi->ndev->dev, "%s: Host wake.\n",
		__func__);

	spin_unlock_bh(&cfhsi->lock);

	/* Create HSI frame. */
	len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);

	if (likely(len > 0)) {
		/* Set up new transfer. */
		res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
		if (WARN_ON(res < 0)) {
			dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
				__func__, res);
			cfhsi_abort_tx(cfhsi);
		}
	} else {
		dev_err(&cfhsi->ndev->dev,
				"%s: Failed to create HSI frame: %d.\n",
				__func__, len);
	}
}

static void cfhsi_wake_down(struct work_struct *work)
{
	long ret;
	struct cfhsi *cfhsi = NULL;
918 919
	size_t fifo_occupancy = 0;
	int retry = CFHSI_WAKE_TOUT;
920 921

	cfhsi = container_of(work, struct cfhsi, wake_down_work);
922
	dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
923 924 925 926 927 928 929 930

	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	/* Deactivate wake line. */
	cfhsi->dev->cfhsi_wake_down(cfhsi->dev);

	/* Wait for acknowledge. */
931
	ret = CFHSI_WAKE_TOUT;
932
	ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
933 934
					test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
							&cfhsi->bits), ret);
935 936
	if (ret < 0) {
		/* Interrupted by signal. */
937
		dev_err(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
938 939 940
			__func__, ret);
		return;
	} else if (!ret) {
941 942
		bool ca_wake = true;

943
		/* Timeout */
944
		dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n", __func__);
945 946 947 948 949 950 951

		/* Check if we misssed the interrupt. */
		WARN_ON(cfhsi->dev->cfhsi_get_peer_wake(cfhsi->dev,
							&ca_wake));
		if (!ca_wake)
			dev_err(&cfhsi->ndev->dev, "%s: CA Wake missed !.\n",
				__func__);
952 953
	}

954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970
	/* Check FIFO occupancy. */
	while (retry) {
		WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
							&fifo_occupancy));

		if (!fifo_occupancy)
			break;

		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(1);
		retry--;
	}

	if (!retry)
		dev_err(&cfhsi->ndev->dev, "%s: FIFO Timeout.\n", __func__);

	/* Clear AWAKE condition. */
971 972
	clear_bit(CFHSI_AWAKE, &cfhsi->bits);

973 974
	/* Cancel pending RX requests. */
	cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
975 976 977

}

978 979 980 981 982 983 984 985 986 987 988
static void cfhsi_out_of_sync(struct work_struct *work)
{
	struct cfhsi *cfhsi = NULL;

	cfhsi = container_of(work, struct cfhsi, out_of_sync_work);

	rtnl_lock();
	dev_close(cfhsi->ndev);
	rtnl_unlock();
}

989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020
static void cfhsi_wake_up_cb(struct cfhsi_drv *drv)
{
	struct cfhsi *cfhsi = NULL;

	cfhsi = container_of(drv, struct cfhsi, drv);
	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
	wake_up_interruptible(&cfhsi->wake_up_wait);

	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
		return;

	/* Schedule wake up work queue if the peer initiates. */
	if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
		queue_work(cfhsi->wq, &cfhsi->wake_up_work);
}

static void cfhsi_wake_down_cb(struct cfhsi_drv *drv)
{
	struct cfhsi *cfhsi = NULL;

	cfhsi = container_of(drv, struct cfhsi, drv);
	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	/* Initiating low power is only permitted by the host (us). */
	set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
	wake_up_interruptible(&cfhsi->wake_down_wait);
}

1021 1022 1023 1024 1025 1026 1027 1028 1029 1030
static void cfhsi_aggregation_tout(unsigned long arg)
{
	struct cfhsi *cfhsi = (struct cfhsi *)arg;

	dev_dbg(&cfhsi->ndev->dev, "%s.\n",
		__func__);

	cfhsi_start_tx(cfhsi);
}

1031 1032 1033 1034 1035
static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct cfhsi *cfhsi = NULL;
	int start_xfer = 0;
	int timer_active;
1036
	int prio;
1037 1038 1039 1040 1041 1042

	if (!dev)
		return -EINVAL;

	cfhsi = netdev_priv(dev);

1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060
	switch (skb->priority) {
	case TC_PRIO_BESTEFFORT:
	case TC_PRIO_FILLER:
	case TC_PRIO_BULK:
		prio = CFHSI_PRIO_BEBK;
		break;
	case TC_PRIO_INTERACTIVE_BULK:
		prio = CFHSI_PRIO_VI;
		break;
	case TC_PRIO_INTERACTIVE:
		prio = CFHSI_PRIO_VO;
		break;
	case TC_PRIO_CONTROL:
	default:
		prio = CFHSI_PRIO_CTL;
		break;
	}

1061 1062
	spin_lock_bh(&cfhsi->lock);

1063 1064 1065 1066 1067
	/* Update aggregation statistics  */
	cfhsi_update_aggregation_stats(cfhsi, skb, 1);

	/* Queue the SKB */
	skb_queue_tail(&cfhsi->qhead[prio], skb);
1068 1069 1070 1071 1072 1073 1074 1075 1076 1077

	/* Sanity check; xmit should not be called after unregister_netdev */
	if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
		spin_unlock_bh(&cfhsi->lock);
		cfhsi_abort_tx(cfhsi);
		return -EINVAL;
	}

	/* Send flow off if number of packets is above high water mark. */
	if (!cfhsi->flow_off_sent &&
1078
		cfhsi_tx_queue_len(cfhsi) > cfhsi->q_high_mark &&
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088
		cfhsi->cfdev.flowctrl) {
		cfhsi->flow_off_sent = 1;
		cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
	}

	if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
		cfhsi->tx_state = CFHSI_TX_STATE_XFER;
		start_xfer = 1;
	}

1089
	if (!start_xfer) {
1090 1091 1092 1093
		/* Send aggregate if it is possible */
		bool aggregate_ready =
			cfhsi_can_send_aggregate(cfhsi) &&
			del_timer(&cfhsi->aggregation_timer) > 0;
1094
		spin_unlock_bh(&cfhsi->lock);
1095 1096
		if (aggregate_ready)
			cfhsi_start_tx(cfhsi);
1097
		return 0;
1098
	}
1099 1100

	/* Delete inactivity timer if started. */
1101
	timer_active = del_timer_sync(&cfhsi->inactivity_timer);
1102

1103 1104
	spin_unlock_bh(&cfhsi->lock);

1105 1106 1107 1108 1109 1110 1111
	if (timer_active) {
		struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
		int len;
		int res;

		/* Create HSI frame. */
		len = cfhsi_tx_frm(desc, cfhsi);
1112
		WARN_ON(!len);
1113 1114 1115 1116 1117 1118 1119 1120 1121 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

		/* Set up new transfer. */
		res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
		if (WARN_ON(res < 0)) {
			dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
				__func__, res);
			cfhsi_abort_tx(cfhsi);
		}
	} else {
		/* Schedule wake up work queue if the we initiate. */
		if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
			queue_work(cfhsi->wq, &cfhsi->wake_up_work);
	}

	return 0;
}

static int cfhsi_open(struct net_device *dev)
{
	return 0;
}

static int cfhsi_close(struct net_device *dev)
{
	return 0;
}

static const struct net_device_ops cfhsi_ops = {
	.ndo_open = cfhsi_open,
	.ndo_stop = cfhsi_close,
	.ndo_start_xmit = cfhsi_xmit
};

static void cfhsi_setup(struct net_device *dev)
{
1148
	int i;
1149 1150 1151 1152 1153
	struct cfhsi *cfhsi = netdev_priv(dev);
	dev->features = 0;
	dev->netdev_ops = &cfhsi_ops;
	dev->type = ARPHRD_CAIF;
	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1154
	dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
1155 1156
	dev->tx_queue_len = 0;
	dev->destructor = free_netdev;
1157 1158
	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
		skb_queue_head_init(&cfhsi->qhead[i]);
1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173
	cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
	cfhsi->cfdev.use_frag = false;
	cfhsi->cfdev.use_stx = false;
	cfhsi->cfdev.use_fcs = false;
	cfhsi->ndev = dev;
}

int cfhsi_probe(struct platform_device *pdev)
{
	struct cfhsi *cfhsi = NULL;
	struct net_device *ndev;
	struct cfhsi_dev *dev;
	int res;

	ndev = alloc_netdev(sizeof(struct cfhsi), "cfhsi%d", cfhsi_setup);
1174
	if (!ndev)
1175 1176 1177 1178 1179 1180 1181 1182
		return -ENODEV;

	cfhsi = netdev_priv(ndev);
	cfhsi->ndev = ndev;
	cfhsi->pdev = pdev;

	/* Initialize state vaiables. */
	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
1183
	cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
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

	/* Set flow info */
	cfhsi->flow_off_sent = 0;
	cfhsi->q_low_mark = LOW_WATER_MARK;
	cfhsi->q_high_mark = HIGH_WATER_MARK;

	/* Assign the HSI device. */
	dev = (struct cfhsi_dev *)pdev->dev.platform_data;
	cfhsi->dev = dev;

	/* Assign the driver to this HSI device. */
	dev->drv = &cfhsi->drv;

	/*
	 * Allocate a TX buffer with the size of a HSI packet descriptors
	 * and the necessary room for CAIF payload frames.
	 */
	cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
	if (!cfhsi->tx_buf) {
		res = -ENODEV;
		goto err_alloc_tx;
	}

	/*
	 * Allocate a RX buffer with the size of two HSI packet descriptors and
	 * the necessary room for CAIF payload frames.
	 */
	cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
	if (!cfhsi->rx_buf) {
		res = -ENODEV;
		goto err_alloc_rx;
	}

1217 1218 1219 1220 1221 1222
	cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
	if (!cfhsi->rx_flip_buf) {
		res = -ENODEV;
		goto err_alloc_rx_flip;
	}

1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234
	/* Pre-calculate inactivity timeout. */
	if (inactivity_timeout != -1) {
		cfhsi->inactivity_timeout =
				inactivity_timeout * HZ / 1000;
		if (!cfhsi->inactivity_timeout)
			cfhsi->inactivity_timeout = 1;
		else if (cfhsi->inactivity_timeout > NEXT_TIMER_MAX_DELTA)
			cfhsi->inactivity_timeout = NEXT_TIMER_MAX_DELTA;
	} else {
		cfhsi->inactivity_timeout = NEXT_TIMER_MAX_DELTA;
	}

1235 1236 1237
	/* Initialize aggregation timeout */
	cfhsi->aggregation_timeout = aggregation_timeout;

1238
	/* Initialize recieve vaiables. */
1239 1240 1241 1242 1243 1244 1245 1246 1247
	cfhsi->rx_ptr = cfhsi->rx_buf;
	cfhsi->rx_len = CFHSI_DESC_SZ;

	/* Initialize spin locks. */
	spin_lock_init(&cfhsi->lock);

	/* Set up the driver. */
	cfhsi->drv.tx_done_cb = cfhsi_tx_done_cb;
	cfhsi->drv.rx_done_cb = cfhsi_rx_done_cb;
1248 1249
	cfhsi->drv.wake_up_cb = cfhsi_wake_up_cb;
	cfhsi->drv.wake_down_cb = cfhsi_wake_down_cb;
1250 1251 1252 1253

	/* Initialize the work queues. */
	INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
	INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1254
	INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276

	/* Clear all bit fields. */
	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
	clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
	clear_bit(CFHSI_AWAKE, &cfhsi->bits);

	/* Create work thread. */
	cfhsi->wq = create_singlethread_workqueue(pdev->name);
	if (!cfhsi->wq) {
		dev_err(&ndev->dev, "%s: Failed to create work queue.\n",
			__func__);
		res = -ENODEV;
		goto err_create_wq;
	}

	/* Initialize wait queues. */
	init_waitqueue_head(&cfhsi->wake_up_wait);
	init_waitqueue_head(&cfhsi->wake_down_wait);
	init_waitqueue_head(&cfhsi->flush_fifo_wait);

	/* Setup the inactivity timer. */
1277 1278 1279
	init_timer(&cfhsi->inactivity_timer);
	cfhsi->inactivity_timer.data = (unsigned long)cfhsi;
	cfhsi->inactivity_timer.function = cfhsi_inactivity_tout;
1280 1281 1282 1283
	/* Setup the slowpath RX timer. */
	init_timer(&cfhsi->rx_slowpath_timer);
	cfhsi->rx_slowpath_timer.data = (unsigned long)cfhsi;
	cfhsi->rx_slowpath_timer.function = cfhsi_rx_slowpath;
1284 1285 1286 1287
	/* Setup the aggregation timer. */
	init_timer(&cfhsi->aggregation_timer);
	cfhsi->aggregation_timer.data = (unsigned long)cfhsi;
	cfhsi->aggregation_timer.function = cfhsi_aggregation_tout;
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	/* Add CAIF HSI device to list. */
	spin_lock(&cfhsi_list_lock);
	list_add_tail(&cfhsi->list, &cfhsi_list);
	spin_unlock(&cfhsi_list_lock);

	/* Activate HSI interface. */
	res = cfhsi->dev->cfhsi_up(cfhsi->dev);
	if (res) {
		dev_err(&cfhsi->ndev->dev,
			"%s: can't activate HSI interface: %d.\n",
			__func__, res);
		goto err_activate;
	}

	/* Flush FIFO */
	res = cfhsi_flush_fifo(cfhsi);
	if (res) {
		dev_err(&ndev->dev, "%s: Can't flush FIFO: %d.\n",
			__func__, res);
		goto err_net_reg;
	}

	/* Register network device. */
	res = register_netdev(ndev);
	if (res) {
		dev_err(&ndev->dev, "%s: Registration error: %d.\n",
			__func__, res);
		goto err_net_reg;
	}
	return res;

 err_net_reg:
	cfhsi->dev->cfhsi_down(cfhsi->dev);
 err_activate:
	destroy_workqueue(cfhsi->wq);
 err_create_wq:
1325 1326
	kfree(cfhsi->rx_flip_buf);
 err_alloc_rx_flip:
1327 1328 1329 1330 1331 1332 1333 1334 1335
	kfree(cfhsi->rx_buf);
 err_alloc_rx:
	kfree(cfhsi->tx_buf);
 err_alloc_tx:
	free_netdev(ndev);

	return res;
}

1336
static void cfhsi_shutdown(struct cfhsi *cfhsi)
1337
{
1338
	u8 *tx_buf, *rx_buf, *flip_buf;
1339 1340 1341 1342 1343 1344 1345

	/* going to shutdown driver */
	set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);

	/* Flush workqueue */
	flush_workqueue(cfhsi->wq);

1346
	/* Delete timers if pending */
1347
	del_timer_sync(&cfhsi->inactivity_timer);