net: remove the caif_hsi driver

The caif_hsi driver relies on a cfhsi_get_ops symbol using symbol_get,
but this symbol is not provided anywhere in the kernel tree. Remove
this driver given that it is dead code.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/caif/Kconfig

···
 	  identified as N_CAIF. When this ldisc is opened from user space
 	  it will redirect the TTY's traffic into the CAIF stack.
 
-config CAIF_HSI
-	tristate "CAIF HSI transport driver"
-	depends on CAIF
-	default n
-	help
-	  The CAIF low level driver for CAIF over HSI.
-	  Be aware that if you enable this then you also need to
-	  enable a low-level HSI driver.
-
 config CAIF_VIRTIO
 	tristate "CAIF virtio transport driver"
 	depends on CAIF && HAS_DMA

drivers/net/caif/Makefile

···
 # Serial interface
 obj-$(CONFIG_CAIF_TTY) += caif_serial.o
 
-# HSI interface
-obj-$(CONFIG_CAIF_HSI) += caif_hsi.o
-
 # Virtio interface
 obj-$(CONFIG_CAIF_VIRTIO) += caif_virtio.o

drivers/net/caif/caif_hsi.c

···
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) ST-Ericsson AB 2010
- * Author:  Daniel Martensson
- *	    Dmitry.Tarnyagin  / [e-mail]
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME fmt
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/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>
-#include <net/rtnetlink.h>
-#include <linux/pkt_sched.h>
-#include <net/caif/caif_layer.h>
-#include <net/caif/caif_hsi.h>
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Daniel Martensson");
-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)))))
-
-static const struct cfhsi_config  hsi_default_config = {
-
-	/* Inactivity timeout on HSI, ms */
-	.inactivity_timeout = HZ,
-
-	/* Aggregation timeout (ms) of zero means no aggregation is done*/
-	.aggregation_timeout = 1,
-
-	/*
-	 * HSI link layer flow-control thresholds.
-	 * Threshold values for the HSI packet queue. Flow-control will be
-	 * asserted when the number of packets exceeds q_high_mark. It will
-	 * not be de-asserted before the number of packets drops below
-	 * q_low_mark.
-	 * Warning: A high threshold value might 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.
-	 */
-	.q_high_mark = 100,
-	.q_low_mark = 50,
-
-	/*
-	 * HSI padding options.
-	 * Warning: must be a base of 2 (& operation used) and can not be zero !
-	 */
-	.head_align = 4,
-	.tail_align = 4,
-};
-
-#define ON 1
-#define OFF 0
-
-static LIST_HEAD(cfhsi_list);
-
-static void cfhsi_inactivity_tout(struct timer_list *t)
-{
-	struct cfhsi *cfhsi = from_timer(cfhsi, t, inactivity_timer);
-
-	netdev_dbg(cfhsi->ndev, "%s.\n",
-		__func__);
-
-	/* Schedule power down work queue. */
-	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
-		queue_work(cfhsi->wq, &cfhsi->wake_down_work);
-}
-
-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), cfhsi->cfg.head_align);
-	tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.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->cfg.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;
-}
-
-static void cfhsi_abort_tx(struct cfhsi *cfhsi)
-{
-	struct sk_buff *skb;
-
-	for (;;) {
-		spin_lock_bh(&cfhsi->lock);
-		skb = cfhsi_dequeue(cfhsi);
-		if (!skb)
-			break;
-
-		cfhsi->ndev->stats.tx_errors++;
-		cfhsi->ndev->stats.tx_dropped++;
-		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
-		spin_unlock_bh(&cfhsi->lock);
-		kfree_skb(skb);
-	}
-	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
-	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
-		mod_timer(&cfhsi->inactivity_timer,
-			jiffies + cfhsi->cfg.inactivity_timeout);
-	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;
-
-	netdev_dbg(cfhsi->ndev, "%s.\n",
-		__func__);
-
-	do {
-		ret = cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
-				&fifo_occupancy);
-		if (ret) {
-			netdev_warn(cfhsi->ndev,
-				"%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->ops->cfhsi_rx(buffer, fifo_occupancy,
-				cfhsi->ops);
-		if (ret) {
-			clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
-			netdev_warn(cfhsi->ndev,
-				"%s: can't read data: %d.\n",
-				__func__, ret);
-			break;
-		}
-
-		ret = 5 * HZ;
-		ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
-			 !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
-
-		if (ret < 0) {
-			netdev_warn(cfhsi->ndev,
-				"%s: can't wait for flush complete: %d.\n",
-				__func__, ret);
-			break;
-		} else if (!ret) {
-			ret = -ETIMEDOUT;
-			netdev_warn(cfhsi->ndev,
-				"%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;
-
-	skb = cfhsi_dequeue(cfhsi);
-	if (!skb)
-		return 0;
-
-	/* Clear offset. */
-	desc->offset = 0;
-
-	/* Check if we can embed a CAIF frame. */
-	if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
-		struct caif_payload_info *info;
-		int hpad;
-		int tpad;
-
-		/* Calculate needed head alignment and tail alignment. */
-		info = (struct caif_payload_info *)&skb->cb;
-
-		hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
-		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.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. */
-			spin_lock_bh(&cfhsi->lock);
-			cfhsi->ndev->stats.tx_packets++;
-			cfhsi->ndev->stats.tx_bytes += skb->len;
-			cfhsi_update_aggregation_stats(cfhsi, skb, -1);
-			spin_unlock_bh(&cfhsi->lock);
-
-			/* Copy in embedded CAIF frame. */
-			skb_copy_bits(skb, 0, pemb, skb->len);
-
-			/* Consume the SKB */
-			consume_skb(skb);
-			skb = NULL;
-		}
-	}
-
-	/* Create payload CAIF frames. */
-	while (nfrms < CFHSI_MAX_PKTS) {
-		struct caif_payload_info *info;
-		int hpad;
-		int tpad;
-
-		if (!skb)
-			skb = cfhsi_dequeue(cfhsi);
-
-		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), cfhsi->cfg.head_align);
-		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.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. */
-		spin_lock_bh(&cfhsi->lock);
-		cfhsi->ndev->stats.tx_packets++;
-		cfhsi->ndev->stats.tx_bytes += skb->len;
-		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
-		spin_unlock_bh(&cfhsi->lock);
-
-		/* 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;
-
-		/* Consume the SKB */
-		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. */
-	if (cfhsi_can_send_aggregate(cfhsi))
-		desc->header |= CFHSI_PIGGY_DESC;
-	else
-		desc->header &= ~CFHSI_PIGGY_DESC;
-
-	return CFHSI_DESC_SZ + pld_len;
-}
-
-static void cfhsi_start_tx(struct cfhsi *cfhsi)
-{
-	struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
-	int len, res;
-
-	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
-
-	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
-		return;
-
-	do {
-		/* Create HSI frame. */
-		len = cfhsi_tx_frm(desc, cfhsi);
-		if (!len) {
-			spin_lock_bh(&cfhsi->lock);
-			if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
-				spin_unlock_bh(&cfhsi->lock);
-				res = -EAGAIN;
-				continue;
-			}
-			cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
-			/* Start inactivity timer. */
-			mod_timer(&cfhsi->inactivity_timer,
-				jiffies + cfhsi->cfg.inactivity_timeout);
-			spin_unlock_bh(&cfhsi->lock);
-			break;
-		}
-
-		/* Set up new transfer. */
-		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
-		if (WARN_ON(res < 0))
-			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
-				__func__, res);
-	} while (res < 0);
-}
-
-static void cfhsi_tx_done(struct cfhsi *cfhsi)
-{
-	netdev_dbg(cfhsi->ndev, "%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->cfg.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->cfg.aggregation_timeout);
-		spin_unlock_bh(&cfhsi->lock);
-	}
-
-	return;
-}
-
-static void cfhsi_tx_done_cb(struct cfhsi_cb_ops *cb_ops)
-{
-	struct cfhsi *cfhsi;
-
-	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
-	netdev_dbg(cfhsi->ndev, "%s.\n",
-		__func__);
-
-	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
-		return;
-	cfhsi_tx_done(cfhsi);
-}
-
-static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
-{
-	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)) {
-		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
-			__func__);
-		return -EPROTO;
-	}
-
-	/* Check for embedded CAIF frame. */
-	if (desc->offset) {
-		struct sk_buff *skb;
-		int len = 0;
-		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. */
-
-		/* Sanity check length of CAIF frame. */
-		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
-			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
-				__func__);
-			return -EPROTO;
-		}
-
-		/* Allocate SKB (OK even in IRQ context). */
-		skb = alloc_skb(len + 1, GFP_ATOMIC);
-		if (!skb) {
-			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
-				__func__);
-			return -ENOMEM;
-		}
-		caif_assert(skb != NULL);
-
-		skb_put_data(skb, pfrm, len);
-
-		skb->protocol = htons(ETH_P_CAIF);
-		skb_reset_mac_header(skb);
-		skb->dev = cfhsi->ndev;
-
-		netif_rx_any_context(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;
-
-	if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
-		netdev_err(cfhsi->ndev,
-				"%s: Invalid payload len: %d, ignored.\n",
-			__func__, xfer_sz);
-		return -EPROTO;
-	}
-	return xfer_sz;
-}
-
-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;
-}
-
-static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
-{
-	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))) {
-		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
-			__func__);
-		return -EPROTO;
-	}
-
-	/* Set frame pointer to start of payload. */
-	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
-	plen = desc->cffrm_len;
-
-	/* Skip already processed frames. */
-	while (nfrms < cfhsi->rx_state.nfrms) {
-		pfrm += *plen;
-		rx_sz += *plen;
-		plen++;
-		nfrms++;
-	}
-
-	/* Parse payload. */
-	while (nfrms < CFHSI_MAX_PKTS && *plen) {
-		struct sk_buff *skb;
-		u8 *pcffrm = NULL;
-		int len;
-
-		/* 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. */
-
-		/* Sanity check length of CAIF frames. */
-		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
-			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
-				__func__);
-			return -EPROTO;
-		}
-
-		/* Allocate SKB (OK even in IRQ context). */
-		skb = alloc_skb(len + 1, GFP_ATOMIC);
-		if (!skb) {
-			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
-				__func__);
-			cfhsi->rx_state.nfrms = nfrms;
-			return -ENOMEM;
-		}
-		caif_assert(skb != NULL);
-
-		skb_put_data(skb, pcffrm, len);
-
-		skb->protocol = htons(ETH_P_CAIF);
-		skb_reset_mac_header(skb);
-		skb->dev = cfhsi->ndev;
-
-		netif_rx_any_context(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;
-}
-
-static void cfhsi_rx_done(struct cfhsi *cfhsi)
-{
-	int res;
-	int desc_pld_len = 0, rx_len, rx_state;
-	struct cfhsi_desc *desc = NULL;
-	u8 *rx_ptr, *rx_buf;
-	struct cfhsi_desc *piggy_desc = NULL;
-
-	desc = (struct cfhsi_desc *)cfhsi->rx_buf;
-
-	netdev_dbg(cfhsi->ndev, "%s\n", __func__);
-
-	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
-		return;
-
-	/* Update inactivity timer if pending. */
-	spin_lock_bh(&cfhsi->lock);
-	mod_timer_pending(&cfhsi->inactivity_timer,
-			jiffies + cfhsi->cfg.inactivity_timeout);
-	spin_unlock_bh(&cfhsi->lock);
-
-	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
-		desc_pld_len = cfhsi_rx_desc_len(desc);
-
-		if (desc_pld_len < 0)
-			goto out_of_sync;
-
-		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;
-	} else {
-		rx_buf = cfhsi->rx_flip_buf;
-
-		rx_len = CFHSI_DESC_SZ;
-		if (cfhsi->rx_state.pld_len > 0 &&
-				(desc->header & CFHSI_PIGGY_DESC)) {
-
-			piggy_desc = (struct cfhsi_desc *)
-				(desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
-						cfhsi->rx_state.pld_len);
-
-			cfhsi->rx_state.piggy_desc = true;
-
-			/* 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 (piggy_desc->header & CFHSI_PIGGY_DESC)
-					rx_len += CFHSI_DESC_SZ;
-			}
-
-			/*
-			 * Copy needed information from the piggy-backed
-			 * descriptor to the descriptor in the start.
-			 */
-			memcpy(rx_buf, (u8 *)piggy_desc,
-					CFHSI_DESC_SHORT_SZ);
-		}
-	}
-
-	if (desc_pld_len) {
-		rx_state = CFHSI_RX_STATE_PAYLOAD;
-		rx_ptr = rx_buf + CFHSI_DESC_SZ;
-	} else {
-		rx_state = CFHSI_RX_STATE_DESC;
-		rx_ptr = rx_buf;
-		rx_len = CFHSI_DESC_SZ;
-	}
-
-	/* Initiate next read */
-	if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
-		/* Set up new transfer. */
-		netdev_dbg(cfhsi->ndev, "%s: Start RX.\n",
-				__func__);
-
-		res = cfhsi->ops->cfhsi_rx(rx_ptr, rx_len,
-				cfhsi->ops);
-		if (WARN_ON(res < 0)) {
-			netdev_err(cfhsi->ndev, "%s: RX error %d.\n",
-				__func__, res);
-			cfhsi->ndev->stats.rx_errors++;
-			cfhsi->ndev->stats.rx_dropped++;
-		}
-	}
-
-	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;
-			/* Mark no embedded frame after extracting it */
-			piggy_desc->offset = 0;
-		}
-	}
-
-	/* 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);
-	return;
-
-out_of_sync:
-	netdev_err(cfhsi->ndev, "%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);
-}
-
-static void cfhsi_rx_slowpath(struct timer_list *t)
-{
-	struct cfhsi *cfhsi = from_timer(cfhsi, t, rx_slowpath_timer);
-
-	netdev_dbg(cfhsi->ndev, "%s.\n",
-		__func__);
-
-	cfhsi_rx_done(cfhsi);
-}
-
-static void cfhsi_rx_done_cb(struct cfhsi_cb_ops *cb_ops)
-{
-	struct cfhsi *cfhsi;
-
-	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
-	netdev_dbg(cfhsi->ndev, "%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
-		cfhsi_rx_done(cfhsi);
-}
-
-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);
-		clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
-		return;
-	}
-
-	/* Activate wake line. */
-	cfhsi->ops->cfhsi_wake_up(cfhsi->ops);
-
-	netdev_dbg(cfhsi->ndev, "%s: Start waiting.\n",
-		__func__);
-
-	/* Wait for acknowledge. */
-	ret = CFHSI_WAKE_TOUT;
-	ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
-					test_and_clear_bit(CFHSI_WAKE_UP_ACK,
-							&cfhsi->bits), ret);
-	if (unlikely(ret < 0)) {
-		/* Interrupted by signal. */
-		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
-			__func__, ret);
-
-		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
-		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
-		return;
-	} else if (!ret) {
-		bool ca_wake = false;
-		size_t fifo_occupancy = 0;
-
-		/* Wakeup timeout */
-		netdev_dbg(cfhsi->ndev, "%s: Timeout.\n",
-			__func__);
-
-		/* Check FIFO to check if modem has sent something. */
-		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
-					&fifo_occupancy));
-
-		netdev_dbg(cfhsi->ndev, "%s: Bytes in FIFO: %u.\n",
-				__func__, (unsigned) fifo_occupancy);
-
-		/* Check if we misssed the interrupt. */
-		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
-							&ca_wake));
-
-		if (ca_wake) {
-			netdev_err(cfhsi->ndev, "%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;
-		}
-
-		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
-		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
-		return;
-	}
-wake_ack:
-	netdev_dbg(cfhsi->ndev, "%s: Woken.\n",
-		__func__);
-
-	/* Clear power up bit. */
-	set_bit(CFHSI_AWAKE, &cfhsi->bits);
-	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
-
-	/* Resume read operation. */
-	netdev_dbg(cfhsi->ndev, "%s: Start RX.\n", __func__);
-	res = cfhsi->ops->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->ops);
-
-	if (WARN_ON(res < 0))
-		netdev_err(cfhsi->ndev, "%s: RX err %d.\n", __func__, res);
-
-	/* Clear power up acknowledment. */
-	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
-
-	spin_lock_bh(&cfhsi->lock);
-
-	/* Resume transmit if queues are not empty. */
-	if (!cfhsi_tx_queue_len(cfhsi)) {
-		netdev_dbg(cfhsi->ndev, "%s: Peer wake, start timer.\n",
-			__func__);
-		/* Start inactivity timer. */
-		mod_timer(&cfhsi->inactivity_timer,
-				jiffies + cfhsi->cfg.inactivity_timeout);
-		spin_unlock_bh(&cfhsi->lock);
-		return;
-	}
-
-	netdev_dbg(cfhsi->ndev, "%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->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
-		if (WARN_ON(res < 0)) {
-			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
-				__func__, res);
-			cfhsi_abort_tx(cfhsi);
-		}
-	} else {
-		netdev_err(cfhsi->ndev,
-				"%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;
-	size_t fifo_occupancy = 0;
-	int retry = CFHSI_WAKE_TOUT;
-
-	cfhsi = container_of(work, struct cfhsi, wake_down_work);
-	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
-
-	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
-		return;
-
-	/* Deactivate wake line. */
-	cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
-
-	/* Wait for acknowledge. */
-	ret = CFHSI_WAKE_TOUT;
-	ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
-					test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
-							&cfhsi->bits), ret);
-	if (ret < 0) {
-		/* Interrupted by signal. */
-		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
-			__func__, ret);
-		return;
-	} else if (!ret) {
-		bool ca_wake = true;
-
-		/* Timeout */
-		netdev_err(cfhsi->ndev, "%s: Timeout.\n", __func__);
-
-		/* Check if we misssed the interrupt. */
-		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
-							&ca_wake));
-		if (!ca_wake)
-			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
-				__func__);
-	}
-
-	/* Check FIFO occupancy. */
-	while (retry) {
-		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
-							&fifo_occupancy));
-
-		if (!fifo_occupancy)
-			break;
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(1);
-		retry--;
-	}
-
-	if (!retry)
-		netdev_err(cfhsi->ndev, "%s: FIFO Timeout.\n", __func__);
-
-	/* Clear AWAKE condition. */
-	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
-
-	/* Cancel pending RX requests. */
-	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
-}
-
-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();
-}
-
-static void cfhsi_wake_up_cb(struct cfhsi_cb_ops *cb_ops)
-{
-	struct cfhsi *cfhsi = NULL;
-
-	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
-	netdev_dbg(cfhsi->ndev, "%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_cb_ops *cb_ops)
-{
-	struct cfhsi *cfhsi = NULL;
-
-	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
-	netdev_dbg(cfhsi->ndev, "%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);
-}
-
-static void cfhsi_aggregation_tout(struct timer_list *t)
-{
-	struct cfhsi *cfhsi = from_timer(cfhsi, t, aggregation_timer);
-
-	netdev_dbg(cfhsi->ndev, "%s.\n",
-		__func__);
-
-	cfhsi_start_tx(cfhsi);
-}
-
-static netdev_tx_t cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
-{
-	struct cfhsi *cfhsi = NULL;
-	int start_xfer = 0;
-	int timer_active;
-	int prio;
-
-	if (!dev)
-		return -EINVAL;
-
-	cfhsi = netdev_priv(dev);
-
-	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;
-	}
-
-	spin_lock_bh(&cfhsi->lock);
-
-	/* Update aggregation statistics  */
-	cfhsi_update_aggregation_stats(cfhsi, skb, 1);
-
-	/* Queue the SKB */
-	skb_queue_tail(&cfhsi->qhead[prio], skb);
-
-	/* 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 &&
-		cfhsi_tx_queue_len(cfhsi) > cfhsi->cfg.q_high_mark &&
-		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;
-	}
-
-	if (!start_xfer) {
-		/* Send aggregate if it is possible */
-		bool aggregate_ready =
-			cfhsi_can_send_aggregate(cfhsi) &&
-			del_timer(&cfhsi->aggregation_timer) > 0;
-		spin_unlock_bh(&cfhsi->lock);
-		if (aggregate_ready)
-			cfhsi_start_tx(cfhsi);
-		return NETDEV_TX_OK;
-	}
-
-	/* Delete inactivity timer if started. */
-	timer_active = del_timer_sync(&cfhsi->inactivity_timer);
-
-	spin_unlock_bh(&cfhsi->lock);
-
-	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);
-		WARN_ON(!len);
-
-		/* Set up new transfer. */
-		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
-		if (WARN_ON(res < 0)) {
-			netdev_err(cfhsi->ndev, "%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 NETDEV_TX_OK;
-}
-
-static const struct net_device_ops cfhsi_netdevops;
-
-static void cfhsi_setup(struct net_device *dev)
-{
-	int i;
-	struct cfhsi *cfhsi = netdev_priv(dev);
-	dev->features = 0;
-	dev->type = ARPHRD_CAIF;
-	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
-	dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
-	dev->priv_flags |= IFF_NO_QUEUE;
-	dev->needs_free_netdev = true;
-	dev->netdev_ops = &cfhsi_netdevops;
-	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
-		skb_queue_head_init(&cfhsi->qhead[i]);
-	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;
-	cfhsi->cfg = hsi_default_config;
-}
-
-static int cfhsi_open(struct net_device *ndev)
-{
-	struct cfhsi *cfhsi = netdev_priv(ndev);
-	int res;
-
-	clear_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
-
-	/* Initialize state vaiables. */
-	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
-	cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
-
-	/* Set flow info */
-	cfhsi->flow_off_sent = 0;
-
-	/*
-	 * 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;
-	}
-
-	cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
-	if (!cfhsi->rx_flip_buf) {
-		res = -ENODEV;
-		goto err_alloc_rx_flip;
-	}
-
-	/* Initialize aggregation timeout */
-	cfhsi->cfg.aggregation_timeout = hsi_default_config.aggregation_timeout;
-
-	/* Initialize recieve vaiables. */
-	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->cb_ops.tx_done_cb = cfhsi_tx_done_cb;
-	cfhsi->cb_ops.rx_done_cb = cfhsi_rx_done_cb;
-	cfhsi->cb_ops.wake_up_cb = cfhsi_wake_up_cb;
-	cfhsi->cb_ops.wake_down_cb = cfhsi_wake_down_cb;
-
-	/* Initialize the work queues. */
-	INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
-	INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
-	INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
-
-	/* 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 = alloc_ordered_workqueue(cfhsi->ndev->name, WQ_MEM_RECLAIM);
-	if (!cfhsi->wq) {
-		netdev_err(cfhsi->ndev, "%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. */
-	timer_setup(&cfhsi->inactivity_timer, cfhsi_inactivity_tout, 0);
-	/* Setup the slowpath RX timer. */
-	timer_setup(&cfhsi->rx_slowpath_timer, cfhsi_rx_slowpath, 0);
-	/* Setup the aggregation timer. */
-	timer_setup(&cfhsi->aggregation_timer, cfhsi_aggregation_tout, 0);
-
-	/* Activate HSI interface. */
-	res = cfhsi->ops->cfhsi_up(cfhsi->ops);
-	if (res) {
-		netdev_err(cfhsi->ndev,
-			"%s: can't activate HSI interface: %d.\n",
-			__func__, res);
-		goto err_activate;
-	}
-
-	/* Flush FIFO */
-	res = cfhsi_flush_fifo(cfhsi);
-	if (res) {
-		netdev_err(cfhsi->ndev, "%s: Can't flush FIFO: %d.\n",
-			__func__, res);
-		goto err_net_reg;
-	}
-	return res;
-
- err_net_reg:
-	cfhsi->ops->cfhsi_down(cfhsi->ops);
- err_activate:
-	destroy_workqueue(cfhsi->wq);
- err_create_wq:
-	kfree(cfhsi->rx_flip_buf);
- err_alloc_rx_flip:
-	kfree(cfhsi->rx_buf);
- err_alloc_rx:
-	kfree(cfhsi->tx_buf);
- err_alloc_tx:
-	return res;
-}
-
-static int cfhsi_close(struct net_device *ndev)
-{
-	struct cfhsi *cfhsi = netdev_priv(ndev);
-	u8 *tx_buf, *rx_buf, *flip_buf;
-
-	/* going to shutdown driver */
-	set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
-
-	/* Delete timers if pending */
-	del_timer_sync(&cfhsi->inactivity_timer);
-	del_timer_sync(&cfhsi->rx_slowpath_timer);
-	del_timer_sync(&cfhsi->aggregation_timer);
-
-	/* Cancel pending RX request (if any) */
-	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
-
-	/* Destroy workqueue */
-	destroy_workqueue(cfhsi->wq);
-
-	/* Store bufferes: will be freed later. */
-	tx_buf = cfhsi->tx_buf;
-	rx_buf = cfhsi->rx_buf;
-	flip_buf = cfhsi->rx_flip_buf;
-	/* Flush transmit queues. */
-	cfhsi_abort_tx(cfhsi);
-
-	/* Deactivate interface */
-	cfhsi->ops->cfhsi_down(cfhsi->ops);
-
-	/* Free buffers. */
-	kfree(tx_buf);
-	kfree(rx_buf);
-	kfree(flip_buf);
-	return 0;
-}
-
-static void cfhsi_uninit(struct net_device *dev)
-{
-	struct cfhsi *cfhsi = netdev_priv(dev);
-	ASSERT_RTNL();
-	symbol_put(cfhsi_get_device);
-	list_del(&cfhsi->list);
-}
-
-static const struct net_device_ops cfhsi_netdevops = {
-	.ndo_uninit = cfhsi_uninit,
-	.ndo_open = cfhsi_open,
-	.ndo_stop = cfhsi_close,
-	.ndo_start_xmit = cfhsi_xmit
-};
-
-static void cfhsi_netlink_parms(struct nlattr *data[], struct cfhsi *cfhsi)
-{
-	int i;
-
-	if (!data) {
-		pr_debug("no params data found\n");
-		return;
-	}
-
-	i = __IFLA_CAIF_HSI_INACTIVITY_TOUT;
-	/*
-	 * Inactivity timeout in millisecs. Lowest possible value is 1,
-	 * and highest possible is NEXT_TIMER_MAX_DELTA.
-	 */
-	if (data[i]) {
-		u32 inactivity_timeout = nla_get_u32(data[i]);
-		/* Pre-calculate inactivity timeout. */
-		cfhsi->cfg.inactivity_timeout =	inactivity_timeout * HZ / 1000;
-		if (cfhsi->cfg.inactivity_timeout == 0)
-			cfhsi->cfg.inactivity_timeout = 1;
-		else if (cfhsi->cfg.inactivity_timeout > NEXT_TIMER_MAX_DELTA)
-			cfhsi->cfg.inactivity_timeout = NEXT_TIMER_MAX_DELTA;
-	}
-
-	i = __IFLA_CAIF_HSI_AGGREGATION_TOUT;
-	if (data[i])
-		cfhsi->cfg.aggregation_timeout = nla_get_u32(data[i]);
-
-	i = __IFLA_CAIF_HSI_HEAD_ALIGN;
-	if (data[i])
-		cfhsi->cfg.head_align = nla_get_u32(data[i]);
-
-	i = __IFLA_CAIF_HSI_TAIL_ALIGN;
-	if (data[i])
-		cfhsi->cfg.tail_align = nla_get_u32(data[i]);
-
-	i = __IFLA_CAIF_HSI_QHIGH_WATERMARK;
-	if (data[i])
-		cfhsi->cfg.q_high_mark = nla_get_u32(data[i]);
-
-	i = __IFLA_CAIF_HSI_QLOW_WATERMARK;
-	if (data[i])
-		cfhsi->cfg.q_low_mark = nla_get_u32(data[i]);
-}
-
-static int caif_hsi_changelink(struct net_device *dev, struct nlattr *tb[],
-			       struct nlattr *data[],
-			       struct netlink_ext_ack *extack)
-{
-	cfhsi_netlink_parms(data, netdev_priv(dev));
-	netdev_state_change(dev);
-	return 0;
-}
-
-static const struct nla_policy caif_hsi_policy[__IFLA_CAIF_HSI_MAX + 1] = {
-	[__IFLA_CAIF_HSI_INACTIVITY_TOUT] = { .type = NLA_U32, .len = 4 },
-	[__IFLA_CAIF_HSI_AGGREGATION_TOUT] = { .type = NLA_U32, .len = 4 },
-	[__IFLA_CAIF_HSI_HEAD_ALIGN] = { .type = NLA_U32, .len = 4 },
-	[__IFLA_CAIF_HSI_TAIL_ALIGN] = { .type = NLA_U32, .len = 4 },
-	[__IFLA_CAIF_HSI_QHIGH_WATERMARK] = { .type = NLA_U32, .len = 4 },
-	[__IFLA_CAIF_HSI_QLOW_WATERMARK] = { .type = NLA_U32, .len = 4 },
-};
-
-static size_t caif_hsi_get_size(const struct net_device *dev)
-{
-	int i;
-	size_t s = 0;
-	for (i = __IFLA_CAIF_HSI_UNSPEC + 1; i < __IFLA_CAIF_HSI_MAX; i++)
-		s += nla_total_size(caif_hsi_policy[i].len);
-	return s;
-}
-
-static int caif_hsi_fill_info(struct sk_buff *skb, const struct net_device *dev)
-{
-	struct cfhsi *cfhsi = netdev_priv(dev);
-
-	if (nla_put_u32(skb, __IFLA_CAIF_HSI_INACTIVITY_TOUT,
-			cfhsi->cfg.inactivity_timeout) ||
-	    nla_put_u32(skb, __IFLA_CAIF_HSI_AGGREGATION_TOUT,
-			cfhsi->cfg.aggregation_timeout) ||
-	    nla_put_u32(skb, __IFLA_CAIF_HSI_HEAD_ALIGN,
-			cfhsi->cfg.head_align) ||
-	    nla_put_u32(skb, __IFLA_CAIF_HSI_TAIL_ALIGN,
-			cfhsi->cfg.tail_align) ||
-	    nla_put_u32(skb, __IFLA_CAIF_HSI_QHIGH_WATERMARK,
-			cfhsi->cfg.q_high_mark) ||
-	    nla_put_u32(skb, __IFLA_CAIF_HSI_QLOW_WATERMARK,
-			cfhsi->cfg.q_low_mark))
-		return -EMSGSIZE;
-
-	return 0;
-}
-
-static int caif_hsi_newlink(struct net *src_net, struct net_device *dev,
-			    struct nlattr *tb[], struct nlattr *data[],
-			    struct netlink_ext_ack *extack)
-{
-	struct cfhsi *cfhsi = NULL;
-	struct cfhsi_ops *(*get_ops)(void);
-
-	ASSERT_RTNL();
-
-	cfhsi = netdev_priv(dev);
-	cfhsi_netlink_parms(data, cfhsi);
-
-	get_ops = symbol_get(cfhsi_get_ops);
-	if (!get_ops) {
-		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
-		return -ENODEV;
-	}
-
-	/* Assign the HSI device. */
-	cfhsi->ops = (*get_ops)();
-	if (!cfhsi->ops) {
-		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
-		goto err;
-	}
-
-	/* Assign the driver to this HSI device. */
-	cfhsi->ops->cb_ops = &cfhsi->cb_ops;
-	if (register_netdevice(dev)) {
-		pr_warn("%s: caif_hsi device registration failed\n", __func__);
-		goto err;
-	}
-	/* Add CAIF HSI device to list. */
-	list_add_tail(&cfhsi->list, &cfhsi_list);
-
-	return 0;
-err:
-	symbol_put(cfhsi_get_ops);
-	return -ENODEV;
-}
-
-static struct rtnl_link_ops caif_hsi_link_ops __read_mostly = {
-	.kind		= "cfhsi",
-	.priv_size	= sizeof(struct cfhsi),
-	.setup		= cfhsi_setup,
-	.maxtype	= __IFLA_CAIF_HSI_MAX,
-	.policy	= caif_hsi_policy,
-	.newlink	= caif_hsi_newlink,
-	.changelink	= caif_hsi_changelink,
-	.get_size	= caif_hsi_get_size,
-	.fill_info	= caif_hsi_fill_info,
-};
-
-static void __exit cfhsi_exit_module(void)
-{
-	struct list_head *list_node;
-	struct list_head *n;
-	struct cfhsi *cfhsi;
-
-	rtnl_link_unregister(&caif_hsi_link_ops);
-
-	rtnl_lock();
-	list_for_each_safe(list_node, n, &cfhsi_list) {
-		cfhsi = list_entry(list_node, struct cfhsi, list);
-		unregister_netdevice(cfhsi->ndev);
-	}
-	rtnl_unlock();
-}
-
-static int __init cfhsi_init_module(void)
-{
-	return rtnl_link_register(&caif_hsi_link_ops);
-}
-
-module_init(cfhsi_init_module);
-module_exit(cfhsi_exit_module);

include/net/caif/caif_hsi.h

···
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) ST-Ericsson AB 2010
- * Author:  Daniel Martensson / [e-mail]
- *	    Dmitry.Tarnyagin  / [e-mail]
- */
-
-#ifndef CAIF_HSI_H_
-#define CAIF_HSI_H_
-
-#include <net/caif/caif_layer.h>
-#include <net/caif/caif_device.h>
-#include <linux/atomic.h>
-
-/*
- * Maximum number of CAIF frames that can reside in the same HSI frame.
- */
-#define CFHSI_MAX_PKTS 15
-
-/*
- * Maximum number of bytes used for the frame that can be embedded in the
- * HSI descriptor.
- */
-#define CFHSI_MAX_EMB_FRM_SZ 96
-
-/*
- * Decides if HSI buffers should be prefilled with 0xFF pattern for easier
- * debugging. Both TX and RX buffers will be filled before the transfer.
- */
-#define CFHSI_DBG_PREFILL		0
-
-/* Structure describing a HSI packet descriptor. */
-#pragma pack(1) /* Byte alignment. */
-struct cfhsi_desc {
-	u8 header;
-	u8 offset;
-	u16 cffrm_len[CFHSI_MAX_PKTS];
-	u8 emb_frm[CFHSI_MAX_EMB_FRM_SZ];
-};
-#pragma pack() /* Default alignment. */
-
-/* Size of the complete HSI packet descriptor. */
-#define CFHSI_DESC_SZ (sizeof(struct cfhsi_desc))
-
-/*
- * Size of the complete HSI packet descriptor excluding the optional embedded
- * CAIF frame.
- */
-#define CFHSI_DESC_SHORT_SZ (CFHSI_DESC_SZ - CFHSI_MAX_EMB_FRM_SZ)
-
-/*
- * Maximum bytes transferred in one transfer.
- */
-#define CFHSI_MAX_CAIF_FRAME_SZ 4096
-
-#define CFHSI_MAX_PAYLOAD_SZ (CFHSI_MAX_PKTS * CFHSI_MAX_CAIF_FRAME_SZ)
-
-/* Size of the complete HSI TX buffer. */
-#define CFHSI_BUF_SZ_TX (CFHSI_DESC_SZ + CFHSI_MAX_PAYLOAD_SZ)
-
-/* Size of the complete HSI RX buffer. */
-#define CFHSI_BUF_SZ_RX ((2 * CFHSI_DESC_SZ) + CFHSI_MAX_PAYLOAD_SZ)
-
-/* Bitmasks for the HSI descriptor. */
-#define CFHSI_PIGGY_DESC		(0x01 << 7)
-
-#define CFHSI_TX_STATE_IDLE			0
-#define CFHSI_TX_STATE_XFER			1
-
-#define CFHSI_RX_STATE_DESC			0
-#define CFHSI_RX_STATE_PAYLOAD			1
-
-/* Bitmasks for power management. */
-#define CFHSI_WAKE_UP				0
-#define CFHSI_WAKE_UP_ACK			1
-#define CFHSI_WAKE_DOWN_ACK			2
-#define CFHSI_AWAKE				3
-#define CFHSI_WAKELOCK_HELD			4
-#define CFHSI_SHUTDOWN				5
-#define CFHSI_FLUSH_FIFO			6
-
-#ifndef CFHSI_INACTIVITY_TOUT
-#define CFHSI_INACTIVITY_TOUT			(1 * HZ)
-#endif /* CFHSI_INACTIVITY_TOUT */
-
-#ifndef CFHSI_WAKE_TOUT
-#define CFHSI_WAKE_TOUT			(3 * HZ)
-#endif /* CFHSI_WAKE_TOUT */
-
-#ifndef CFHSI_MAX_RX_RETRIES
-#define CFHSI_MAX_RX_RETRIES		(10 * HZ)
-#endif
-
-/* Structure implemented by the CAIF HSI driver. */
-struct cfhsi_cb_ops {
-	void (*tx_done_cb) (struct cfhsi_cb_ops *drv);
-	void (*rx_done_cb) (struct cfhsi_cb_ops *drv);
-	void (*wake_up_cb) (struct cfhsi_cb_ops *drv);
-	void (*wake_down_cb) (struct cfhsi_cb_ops *drv);
-};
-
-/* Structure implemented by HSI device. */
-struct cfhsi_ops {
-	int (*cfhsi_up) (struct cfhsi_ops *dev);
-	int (*cfhsi_down) (struct cfhsi_ops *dev);
-	int (*cfhsi_tx) (u8 *ptr, int len, struct cfhsi_ops *dev);
-	int (*cfhsi_rx) (u8 *ptr, int len, struct cfhsi_ops *dev);
-	int (*cfhsi_wake_up) (struct cfhsi_ops *dev);
-	int (*cfhsi_wake_down) (struct cfhsi_ops *dev);
-	int (*cfhsi_get_peer_wake) (struct cfhsi_ops *dev, bool *status);
-	int (*cfhsi_fifo_occupancy) (struct cfhsi_ops *dev, size_t *occupancy);
-	int (*cfhsi_rx_cancel)(struct cfhsi_ops *dev);
-	struct cfhsi_cb_ops *cb_ops;
-};
-
-/* Structure holds status of received CAIF frames processing */
-struct cfhsi_rx_state {
-	int state;
-	int nfrms;
-	int pld_len;
-	int retries;
-	bool piggy_desc;
-};
-
-/* Priority mapping */
-enum {
-	CFHSI_PRIO_CTL = 0,
-	CFHSI_PRIO_VI,
-	CFHSI_PRIO_VO,
-	CFHSI_PRIO_BEBK,
-	CFHSI_PRIO_LAST,
-};
-
-struct cfhsi_config {
-	u32 inactivity_timeout;
-	u32 aggregation_timeout;
-	u32 head_align;
-	u32 tail_align;
-	u32 q_high_mark;
-	u32 q_low_mark;
-};
-
-/* Structure implemented by CAIF HSI drivers. */
-struct cfhsi {
-	struct caif_dev_common cfdev;
-	struct net_device *ndev;
-	struct platform_device *pdev;
-	struct sk_buff_head qhead[CFHSI_PRIO_LAST];
-	struct cfhsi_cb_ops cb_ops;
-	struct cfhsi_ops *ops;
-	int tx_state;
-	struct cfhsi_rx_state rx_state;
-	struct cfhsi_config cfg;
-	int rx_len;
-	u8 *rx_ptr;
-	u8 *tx_buf;
-	u8 *rx_buf;
-	u8 *rx_flip_buf;
-	spinlock_t lock;
-	int flow_off_sent;
-	struct list_head list;
-	struct work_struct wake_up_work;
-	struct work_struct wake_down_work;
-	struct work_struct out_of_sync_work;
-	struct workqueue_struct *wq;
-	wait_queue_head_t wake_up_wait;
-	wait_queue_head_t wake_down_wait;
-	wait_queue_head_t flush_fifo_wait;
-	struct timer_list inactivity_timer;
-	struct timer_list rx_slowpath_timer;
-
-	/* TX aggregation */
-	int aggregation_len;
-	struct timer_list aggregation_timer;
-
-	unsigned long bits;
-};
-extern struct platform_driver cfhsi_driver;
-
-/**
- * enum ifla_caif_hsi - CAIF HSI NetlinkRT parameters.
- * @IFLA_CAIF_HSI_INACTIVITY_TOUT: Inactivity timeout before
- *			taking the HSI wakeline down, in milliseconds.
- * When using RT Netlink to create, destroy or configure a CAIF HSI interface,
- * enum ifla_caif_hsi is used to specify the configuration attributes.
- */
-enum ifla_caif_hsi {
-	__IFLA_CAIF_HSI_UNSPEC,
-	__IFLA_CAIF_HSI_INACTIVITY_TOUT,
-	__IFLA_CAIF_HSI_AGGREGATION_TOUT,
-	__IFLA_CAIF_HSI_HEAD_ALIGN,
-	__IFLA_CAIF_HSI_TAIL_ALIGN,
-	__IFLA_CAIF_HSI_QHIGH_WATERMARK,
-	__IFLA_CAIF_HSI_QLOW_WATERMARK,
-	__IFLA_CAIF_HSI_MAX
-};
-
-struct cfhsi_ops *cfhsi_get_ops(void);
-
-#endif		/* CAIF_HSI_H_ */