drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c

/*
 * Copyright (c) 2010 Broadcom Corporation
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <linux/types.h>
#include <linux/module.h>
#include <linux/if_ether.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/err.h>
#include <uapi/linux/nl80211.h>
#include <net/cfg80211.h>

#include <brcmu_utils.h>
#include <brcmu_wifi.h>
#include "dhd.h"
#include "dhd_proto.h"
#include "dhd_dbg.h"
#include "dhd_bus.h"
#include "fwil.h"
#include "fweh.h"
#include "fwsignal.h"

/**
 * DOC: Firmware Signalling
 *
 * Firmware can send signals to host and vice versa, which are passed in the
 * data packets using TLV based header. This signalling layer is on top of the
 * BDC bus protocol layer.
 */

/*
 * single definition for firmware-driver flow control tlv's.
 *
 * each tlv is specified by BRCMF_FWS_TLV_DEF(name, ID, length).
 * A length value 0 indicates variable length tlv.
 */
#define BRCMF_FWS_TLV_DEFLIST \
	BRCMF_FWS_TLV_DEF(MAC_OPEN, 1, 1) \
	BRCMF_FWS_TLV_DEF(MAC_CLOSE, 2, 1) \
	BRCMF_FWS_TLV_DEF(MAC_REQUEST_CREDIT, 3, 2) \
	BRCMF_FWS_TLV_DEF(TXSTATUS, 4, 4) \
	BRCMF_FWS_TLV_DEF(PKTTAG, 5, 4) \
	BRCMF_FWS_TLV_DEF(MACDESC_ADD,	6, 8) \
	BRCMF_FWS_TLV_DEF(MACDESC_DEL, 7, 8) \
	BRCMF_FWS_TLV_DEF(RSSI, 8, 1) \
	BRCMF_FWS_TLV_DEF(INTERFACE_OPEN, 9, 1) \
	BRCMF_FWS_TLV_DEF(INTERFACE_CLOSE, 10, 1) \
	BRCMF_FWS_TLV_DEF(FIFO_CREDITBACK, 11, 6) \
	BRCMF_FWS_TLV_DEF(PENDING_TRAFFIC_BMP, 12, 2) \
	BRCMF_FWS_TLV_DEF(MAC_REQUEST_PACKET, 13, 3) \
	BRCMF_FWS_TLV_DEF(HOST_REORDER_RXPKTS, 14, 10) \
	BRCMF_FWS_TLV_DEF(TRANS_ID, 18, 6) \
	BRCMF_FWS_TLV_DEF(COMP_TXSTATUS, 19, 1) \
	BRCMF_FWS_TLV_DEF(FILLER, 255, 0)

/*
 * enum brcmf_fws_tlv_type - definition of tlv identifiers.
 */
#define BRCMF_FWS_TLV_DEF(name, id, len) \
	BRCMF_FWS_TYPE_ ## name =  id,
enum brcmf_fws_tlv_type {
	BRCMF_FWS_TLV_DEFLIST
	BRCMF_FWS_TYPE_INVALID
};
#undef BRCMF_FWS_TLV_DEF

/*
 * enum brcmf_fws_tlv_len - definition of tlv lengths.
 */
#define BRCMF_FWS_TLV_DEF(name, id, len) \
	BRCMF_FWS_TYPE_ ## name ## _LEN = (len),
enum brcmf_fws_tlv_len {
	BRCMF_FWS_TLV_DEFLIST
};
#undef BRCMF_FWS_TLV_DEF

#ifdef DEBUG
/*
 * brcmf_fws_tlv_names - array of tlv names.
 */
#define BRCMF_FWS_TLV_DEF(name, id, len) \
	{ id, #name },
static struct {
	enum brcmf_fws_tlv_type id;
	const char *name;
} brcmf_fws_tlv_names[] = {
	BRCMF_FWS_TLV_DEFLIST
};
#undef BRCMF_FWS_TLV_DEF

static const char *brcmf_fws_get_tlv_name(enum brcmf_fws_tlv_type id)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(brcmf_fws_tlv_names); i++)
		if (brcmf_fws_tlv_names[i].id == id)
			return brcmf_fws_tlv_names[i].name;

	return "INVALID";
}
#else
static const char *brcmf_fws_get_tlv_name(enum brcmf_fws_tlv_type id)
{
	return "NODEBUG";
}
#endif /* DEBUG */

/*
 * flags used to enable tlv signalling from firmware.
 */
#define BRCMF_FWS_FLAGS_RSSI_SIGNALS			0x0001
#define BRCMF_FWS_FLAGS_XONXOFF_SIGNALS			0x0002
#define BRCMF_FWS_FLAGS_CREDIT_STATUS_SIGNALS		0x0004
#define BRCMF_FWS_FLAGS_HOST_PROPTXSTATUS_ACTIVE	0x0008
#define BRCMF_FWS_FLAGS_PSQ_GENERATIONFSM_ENABLE	0x0010
#define BRCMF_FWS_FLAGS_PSQ_ZERO_BUFFER_ENABLE		0x0020
#define BRCMF_FWS_FLAGS_HOST_RXREORDER_ACTIVE		0x0040

#define BRCMF_FWS_STATE_OPEN				1
#define BRCMF_FWS_STATE_CLOSE				2

#define BRCMF_FWS_MAC_DESC_TABLE_SIZE			32
#define BRCMF_FWS_MAX_IFNUM				16
#define BRCMF_FWS_MAC_DESC_ID_INVALID			0xff

#define BRCMF_FWS_HOSTIF_FLOWSTATE_OFF			0
#define BRCMF_FWS_HOSTIF_FLOWSTATE_ON			1

#define BRCMF_FWS_PSQ_PREC_COUNT		((NL80211_NUM_ACS + 1) * 2)
#define BRCMF_FWS_PSQ_LEN				256

#define BRCMF_FWS_HTOD_FLAG_PKTFROMHOST			0x01
#define BRCMF_FWS_HTOD_FLAG_PKT_REQUESTED		0x02

/**
 * enum brcmf_fws_skb_state - indicates processing state of skb.
 *
 * @BRCMF_FWS_SKBSTATE_NEW: sk_buff is newly arrived in the driver.
 * @BRCMF_FWS_SKBSTATE_DELAYED: sk_buff had to wait on queue.
 * @BRCMF_FWS_SKBSTATE_SUPPRESSED: sk_buff has been suppressed by firmware.
 */
enum brcmf_fws_skb_state {
	BRCMF_FWS_SKBSTATE_NEW,
	BRCMF_FWS_SKBSTATE_DELAYED,
	BRCMF_FWS_SKBSTATE_SUPPRESSED
};

/**
 * struct brcmf_skbuff_cb - control buffer associated with skbuff.
 *
 * @if_flags: holds interface index and packet related flags.
 * @htod: host to device packet identifier (used in PKTTAG tlv).
 * @state: transmit state of the packet.
 * @mac: descriptor related to destination for this packet.
 *
 * This information is stored in control buffer struct sk_buff::cb, which
 * provides 48 bytes of storage so this structure should not exceed that.
 */
struct brcmf_skbuff_cb {
	u16 if_flags;
	u32 htod;
	enum brcmf_fws_skb_state state;
	struct brcmf_fws_mac_descriptor *mac;
};

/*
 * macro casting skbuff control buffer to struct brcmf_skbuff_cb.
 */
#define brcmf_skbcb(skb)	((struct brcmf_skbuff_cb *)((skb)->cb))

/*
 * sk_buff control if flags
 *
 *	b[11]  - packet sent upon firmware request.
 *	b[10]  - packet only contains signalling data.
 *	b[9]   - packet is a tx packet.
 *	b[8]   - packet uses FIFO credit (non-pspoll).
 *	b[7]   - interface in AP mode.
 *	b[6:4] - AC FIFO number.
 *	b[3:0] - interface index.
 */
#define BRCMF_SKB_IF_FLAGS_REQUESTED_MASK	0x0800
#define BRCMF_SKB_IF_FLAGS_REQUESTED_SHIFT	11
#define BRCMF_SKB_IF_FLAGS_SIGNAL_ONLY_MASK	0x0400
#define BRCMF_SKB_IF_FLAGS_SIGNAL_ONLY_SHIFT	10
#define BRCMF_SKB_IF_FLAGS_TRANSMIT_MASK        0x0200
#define BRCMF_SKB_IF_FLAGS_TRANSMIT_SHIFT	9
#define BRCMF_SKB_IF_FLAGS_CREDITCHECK_MASK	0x0100
#define BRCMF_SKB_IF_FLAGS_CREDITCHECK_SHIFT	8
#define BRCMF_SKB_IF_FLAGS_IF_AP_MASK		0x0080
#define BRCMF_SKB_IF_FLAGS_IF_AP_SHIFT		7
#define BRCMF_SKB_IF_FLAGS_FIFO_MASK		0x0070
#define BRCMF_SKB_IF_FLAGS_FIFO_SHIFT		4
#define BRCMF_SKB_IF_FLAGS_INDEX_MASK		0x000f
#define BRCMF_SKB_IF_FLAGS_INDEX_SHIFT		0

#define brcmf_skb_if_flags_set_field(skb, field, value) \
	brcmu_maskset16(&(brcmf_skbcb(skb)->if_flags), \
			BRCMF_SKB_IF_FLAGS_ ## field ## _MASK, \
			BRCMF_SKB_IF_FLAGS_ ## field ## _SHIFT, (value))
#define brcmf_skb_if_flags_get_field(skb, field) \
	brcmu_maskget16(brcmf_skbcb(skb)->if_flags, \
			BRCMF_SKB_IF_FLAGS_ ## field ## _MASK, \
			BRCMF_SKB_IF_FLAGS_ ## field ## _SHIFT)

/*
 * sk_buff control packet identifier
 *
 * 32-bit packet identifier used in PKTTAG tlv from host to dongle.
 *
 * - Generated at the host (e.g. dhd)
 * - Seen as a generic sequence number by firmware except for the flags field.
 *
 * Generation	: b[31]	=> generation number for this packet [host->fw]
 *			   OR, current generation number [fw->host]
 * Flags	: b[30:27] => command, status flags
 * FIFO-AC	: b[26:24] => AC-FIFO id
 * h-slot	: b[23:8] => hanger-slot
 * freerun	: b[7:0] => A free running counter
 */
#define BRCMF_SKB_HTOD_TAG_GENERATION_MASK		0x80000000
#define BRCMF_SKB_HTOD_TAG_GENERATION_SHIFT		31
#define BRCMF_SKB_HTOD_TAG_FLAGS_MASK			0x78000000
#define BRCMF_SKB_HTOD_TAG_FLAGS_SHIFT			27
#define BRCMF_SKB_HTOD_TAG_FIFO_MASK			0x07000000
#define BRCMF_SKB_HTOD_TAG_FIFO_SHIFT			24
#define BRCMF_SKB_HTOD_TAG_HSLOT_MASK			0x00ffff00
#define BRCMF_SKB_HTOD_TAG_HSLOT_SHIFT			8
#define BRCMF_SKB_HTOD_TAG_FREERUN_MASK			0x000000ff
#define BRCMF_SKB_HTOD_TAG_FREERUN_SHIFT			0

#define brcmf_skb_htod_tag_set_field(skb, field, value) \
	brcmu_maskset32(&(brcmf_skbcb(skb)->htod), \
			BRCMF_SKB_HTOD_TAG_ ## field ## _MASK, \
			BRCMF_SKB_HTOD_TAG_ ## field ## _SHIFT, (value))
#define brcmf_skb_htod_tag_get_field(skb, field) \
	brcmu_maskget32(brcmf_skbcb(skb)->htod, \
			BRCMF_SKB_HTOD_TAG_ ## field ## _MASK, \
			BRCMF_SKB_HTOD_TAG_ ## field ## _SHIFT)

#define BRCMF_FWS_TXSTAT_GENERATION_MASK	0x80000000
#define BRCMF_FWS_TXSTAT_GENERATION_SHIFT	31
#define BRCMF_FWS_TXSTAT_FLAGS_MASK		0x78000000
#define BRCMF_FWS_TXSTAT_FLAGS_SHIFT		27
#define BRCMF_FWS_TXSTAT_FIFO_MASK		0x07000000
#define BRCMF_FWS_TXSTAT_FIFO_SHIFT		24
#define BRCMF_FWS_TXSTAT_HSLOT_MASK		0x00FFFF00
#define BRCMF_FWS_TXSTAT_HSLOT_SHIFT		8
#define BRCMF_FWS_TXSTAT_PKTID_MASK		0x00FFFFFF
#define BRCMF_FWS_TXSTAT_PKTID_SHIFT		0

#define brcmf_txstatus_get_field(txs, field) \
	brcmu_maskget32(txs, BRCMF_FWS_TXSTAT_ ## field ## _MASK, \
			BRCMF_FWS_TXSTAT_ ## field ## _SHIFT)

/**
 * enum brcmf_fws_fifo - fifo indices used by dongle firmware.
 *
 * @BRCMF_FWS_FIFO_AC_BK: fifo for background traffic.
 * @BRCMF_FWS_FIFO_AC_BE: fifo for best-effort traffic.
 * @BRCMF_FWS_FIFO_AC_VI: fifo for video traffic.
 * @BRCMF_FWS_FIFO_AC_VO: fifo for voice traffic.
 * @BRCMF_FWS_FIFO_BCMC: fifo for broadcast/multicast (AP only).
 * @BRCMF_FWS_FIFO_ATIM: fifo for ATIM (AP only).
 * @BRCMF_FWS_FIFO_COUNT: number of fifos.
 */
enum brcmf_fws_fifo {
	BRCMF_FWS_FIFO_AC_BK,
	BRCMF_FWS_FIFO_AC_BE,
	BRCMF_FWS_FIFO_AC_VI,
	BRCMF_FWS_FIFO_AC_VO,
	BRCMF_FWS_FIFO_BCMC,
	BRCMF_FWS_FIFO_ATIM,
	BRCMF_FWS_FIFO_COUNT
};

/**
 * enum brcmf_fws_txstatus - txstatus flag values.
 *
 * @BRCMF_FWS_TXSTATUS_DISCARD:
 *	host is free to discard the packet.
 * @BRCMF_FWS_TXSTATUS_CORE_SUPPRESS:
 *	802.11 core suppressed the packet.
 * @BRCMF_FWS_TXSTATUS_FW_PS_SUPPRESS:
 *	firmware suppress the packet as device is already in PS mode.
 * @BRCMF_FWS_TXSTATUS_FW_TOSSED:
 *	firmware tossed the packet.
 */
enum brcmf_fws_txstatus {
	BRCMF_FWS_TXSTATUS_DISCARD,
	BRCMF_FWS_TXSTATUS_CORE_SUPPRESS,
	BRCMF_FWS_TXSTATUS_FW_PS_SUPPRESS,
	BRCMF_FWS_TXSTATUS_FW_TOSSED
};

enum brcmf_fws_fcmode {
	BRCMF_FWS_FCMODE_NONE,
	BRCMF_FWS_FCMODE_IMPLIED_CREDIT,
	BRCMF_FWS_FCMODE_EXPLICIT_CREDIT
};

/**
 * struct brcmf_fws_mac_descriptor - firmware signalling data per node/interface
 *
 * @occupied: slot is in use.
 * @mac_handle: handle for mac entry determined by firmware.
 * @interface_id: interface index.
 * @state: current state.
 * @suppressed: mac entry is suppressed.
 * @generation: generation bit.
 * @ac_bitmap: ac queue bitmap.
 * @requested_credit: credits requested by firmware.
 * @ea: ethernet address.
 * @seq: per-node free-running sequence.
 * @psq: power-save queue.
 * @transit_count: packet in transit to firmware.
 */
struct brcmf_fws_mac_descriptor {
	u8 occupied;
	u8 mac_handle;
	u8 interface_id;
	u8 state;
	bool suppressed;
	u8 generation;
	u8 ac_bitmap;
	u8 requested_credit;
	u8 ea[ETH_ALEN];
	u8 seq[BRCMF_FWS_FIFO_COUNT];
	struct pktq psq;
	int transit_count;
};

#define BRCMF_FWS_HANGER_MAXITEMS	1024

/**
 * enum brcmf_fws_hanger_item_state - state of hanger item.
 *
 * @BRCMF_FWS_HANGER_ITEM_STATE_FREE: item is free for use.
 * @BRCMF_FWS_HANGER_ITEM_STATE_INUSE: item is in use.
 * @BRCMF_FWS_HANGER_ITEM_STATE_INUSE_SUPPRESSED: item was suppressed.
 */
enum brcmf_fws_hanger_item_state {
	BRCMF_FWS_HANGER_ITEM_STATE_FREE = 1,
	BRCMF_FWS_HANGER_ITEM_STATE_INUSE,
	BRCMF_FWS_HANGER_ITEM_STATE_INUSE_SUPPRESSED
};


/**
 * struct brcmf_fws_hanger_item - single entry for tx pending packet.
 *
 * @state: entry is either free or occupied.
 * @gen: generation.
 * @pkt: packet itself.
 */
struct brcmf_fws_hanger_item {
	enum brcmf_fws_hanger_item_state state;
	u8 gen;
	struct sk_buff *pkt;
};

/**
 * struct brcmf_fws_hanger - holds packets awaiting firmware txstatus.
 *
 * @pushed: packets pushed to await txstatus.
 * @popped: packets popped upon handling txstatus.
 * @failed_to_push: packets that could not be pushed.
 * @failed_to_pop: packets that could not be popped.
 * @failed_slotfind: packets for which failed to find an entry.
 * @slot_pos: last returned item index for a free entry.
 * @items: array of hanger items.
 */
struct brcmf_fws_hanger {
	u32 pushed;
	u32 popped;
	u32 failed_to_push;
	u32 failed_to_pop;
	u32 failed_slotfind;
	u32 slot_pos;
	struct brcmf_fws_hanger_item items[BRCMF_FWS_HANGER_MAXITEMS];
};

struct brcmf_fws_info {
	struct brcmf_pub *drvr;
	struct brcmf_fws_stats stats;
	struct brcmf_fws_hanger hanger;
	struct brcmf_fws_mac_descriptor nodes[BRCMF_FWS_MAC_DESC_TABLE_SIZE];
	struct brcmf_fws_mac_descriptor other;
	enum brcmf_fws_fcmode fcmode;
	int fifo_credit[BRCMF_FWS_FIFO_COUNT];
};

/*
 * brcmf_fws_prio2fifo - mapping from 802.1d priority to firmware fifo index.
 */
static const int brcmf_fws_prio2fifo[] = {
	BRCMF_FWS_FIFO_AC_BE,
	BRCMF_FWS_FIFO_AC_BK,
	BRCMF_FWS_FIFO_AC_BK,
	BRCMF_FWS_FIFO_AC_BE,
	BRCMF_FWS_FIFO_AC_VI,
	BRCMF_FWS_FIFO_AC_VI,
	BRCMF_FWS_FIFO_AC_VO,
	BRCMF_FWS_FIFO_AC_VO
};

static int fcmode;
module_param(fcmode, int, S_IRUSR);
MODULE_PARM_DESC(fcmode, "mode of firmware signalled flow control");

#define BRCMF_FWS_TLV_DEF(name, id, len) \
	case BRCMF_FWS_TYPE_ ## name: \
		return len;

/**
 * brcmf_fws_get_tlv_len() - returns defined length for given tlv id.
 *
 * @fws: firmware-signalling information.
 * @id: identifier of the TLV.
 *
 * Return: the specified length for the given TLV; Otherwise -EINVAL.
 */
static int brcmf_fws_get_tlv_len(struct brcmf_fws_info *fws,
				 enum brcmf_fws_tlv_type id)
{
	switch (id) {
	BRCMF_FWS_TLV_DEFLIST
	default:
		fws->stats.tlv_invalid_type++;
		break;
	}
	return -EINVAL;
}
#undef BRCMF_FWS_TLV_DEF

static bool brcmf_fws_ifidx_match(struct sk_buff *skb, void *arg)
{
	u32 ifidx = brcmf_skb_if_flags_get_field(skb, INDEX);
	return ifidx == *(int *)arg;
}

static void brcmf_fws_psq_flush(struct brcmf_fws_info *fws, struct pktq *q,
				int ifidx)
{
	bool (*matchfn)(struct sk_buff *, void *) = NULL;
	struct sk_buff *skb;
	int prec;

	if (ifidx != -1)
		matchfn = brcmf_fws_ifidx_match;
	for (prec = 0; prec < q->num_prec; prec++) {
		skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx);
		while (skb) {
			brcmf_txfinalize(fws->drvr, skb, false);
			skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx);
		}
	}
}

static void brcmf_fws_hanger_init(struct brcmf_fws_hanger *hanger)
{
	int i;

	brcmf_dbg(TRACE, "enter\n");
	memset(hanger, 0, sizeof(*hanger));
	for (i = 0; i < ARRAY_SIZE(hanger->items); i++)
		hanger->items[i].state = BRCMF_FWS_HANGER_ITEM_STATE_FREE;
}

static u32 brcmf_fws_hanger_get_free_slot(struct brcmf_fws_hanger *h)
{
	u32 i;

	brcmf_dbg(TRACE, "enter\n");
	i = (h->slot_pos + 1) % BRCMF_FWS_HANGER_MAXITEMS;

	while (i != h->slot_pos) {
		if (h->items[i].state == BRCMF_FWS_HANGER_ITEM_STATE_FREE) {
			h->slot_pos = i;
			return i;
		}
		i++;
		if (i == BRCMF_FWS_HANGER_MAXITEMS)
			i = 0;
	}
	brcmf_err("all slots occupied\n");
	h->failed_slotfind++;
	return BRCMF_FWS_HANGER_MAXITEMS;
}

static int brcmf_fws_hanger_pushpkt(struct brcmf_fws_hanger *h,
					   struct sk_buff *pkt, u32 slot_id)
{
	brcmf_dbg(TRACE, "enter\n");
	if (slot_id >= BRCMF_FWS_HANGER_MAXITEMS)
		return -ENOENT;

	if (h->items[slot_id].state != BRCMF_FWS_HANGER_ITEM_STATE_FREE) {
		brcmf_err("slot is not free\n");
		h->failed_to_push++;
		return -EINVAL;
	}

	h->items[slot_id].state = BRCMF_FWS_HANGER_ITEM_STATE_INUSE;
	h->items[slot_id].pkt = pkt;
	h->pushed++;
	return 0;
}

static int brcmf_fws_hanger_poppkt(struct brcmf_fws_hanger *h,
					  u32 slot_id, struct sk_buff **pktout,
					  bool remove_item)
{
	brcmf_dbg(TRACE, "enter\n");
	if (slot_id >= BRCMF_FWS_HANGER_MAXITEMS)
		return -ENOENT;

	if (h->items[slot_id].state == BRCMF_FWS_HANGER_ITEM_STATE_FREE) {
		brcmf_err("entry not in use\n");
		h->failed_to_pop++;
		return -EINVAL;
	}

	*pktout = h->items[slot_id].pkt;
	if (remove_item) {
		h->items[slot_id].state = BRCMF_FWS_HANGER_ITEM_STATE_FREE;
		h->items[slot_id].pkt = NULL;
		h->items[slot_id].gen = 0xff;
		h->popped++;
	}
	return 0;
}

static __used int brcmf_fws_hanger_mark_suppressed(struct brcmf_fws_hanger *h,
						   u32 slot_id, u8 gen)
{
	brcmf_dbg(TRACE, "enter\n");

	if (slot_id >= BRCMF_FWS_HANGER_MAXITEMS)
		return -ENOENT;

	h->items[slot_id].gen = gen;

	if (h->items[slot_id].state != BRCMF_FWS_HANGER_ITEM_STATE_INUSE) {
		brcmf_err("entry not in use\n");
		return -EINVAL;
	}

	h->items[slot_id].state = BRCMF_FWS_HANGER_ITEM_STATE_INUSE_SUPPRESSED;
	return 0;
}

static int brcmf_fws_hanger_get_genbit(struct brcmf_fws_hanger *hanger,
					      struct sk_buff *pkt, u32 slot_id,
					      int *gen)
{
	brcmf_dbg(TRACE, "enter\n");
	*gen = 0xff;

	if (slot_id >= BRCMF_FWS_HANGER_MAXITEMS)
		return -ENOENT;

	if (hanger->items[slot_id].state == BRCMF_FWS_HANGER_ITEM_STATE_FREE) {
		brcmf_err("slot not in use\n");
		return -EINVAL;
	}

	*gen = hanger->items[slot_id].gen;
	return 0;
}

static void brcmf_fws_hanger_cleanup(struct brcmf_fws_hanger *h,
				     bool (*fn)(struct sk_buff *, void *),
				     int ifidx)
{
	struct sk_buff *skb;
	int i;
	enum brcmf_fws_hanger_item_state s;

	brcmf_dbg(TRACE, "enter: ifidx=%d\n", ifidx);
	for (i = 0; i < ARRAY_SIZE(h->items); i++) {
		s = h->items[i].state;
		if (s == BRCMF_FWS_HANGER_ITEM_STATE_INUSE ||
		    s == BRCMF_FWS_HANGER_ITEM_STATE_INUSE_SUPPRESSED) {
			skb = h->items[i].pkt;
			if (fn == NULL || fn(skb, &ifidx)) {
				/* suppress packets freed from psq */
				if (s == BRCMF_FWS_HANGER_ITEM_STATE_INUSE)
					brcmu_pkt_buf_free_skb(skb);
				h->items[i].state =
					BRCMF_FWS_HANGER_ITEM_STATE_FREE;
			}
		}
	}
}

static void brcmf_fws_init_mac_descriptor(struct brcmf_fws_mac_descriptor *desc,
					  u8 *addr, u8 ifidx)
{
	brcmf_dbg(TRACE, "enter: ea=%pM, ifidx=%u\n", addr, ifidx);
	desc->occupied = 1;
	desc->state = BRCMF_FWS_STATE_OPEN;
	desc->requested_credit = 0;
	/* depending on use may need ifp->bssidx instead */
	desc->interface_id = ifidx;
	desc->ac_bitmap = 0xff; /* update this when handling APSD */
	memcpy(&desc->ea[0], addr, ETH_ALEN);
}

static
void brcmf_fws_clear_mac_descriptor(struct brcmf_fws_mac_descriptor *desc)
{
	brcmf_dbg(TRACE,
		  "enter: ea=%pM, ifidx=%u\n", desc->ea, desc->interface_id);
	desc->occupied = 0;
	desc->state = BRCMF_FWS_STATE_CLOSE;
	desc->requested_credit = 0;
}

static struct brcmf_fws_mac_descriptor *
brcmf_fws_mac_descriptor_lookup(struct brcmf_fws_info *fws, u8 *ea)
{
	struct brcmf_fws_mac_descriptor *entry;
	int i;

	brcmf_dbg(TRACE, "enter: ea=%pM\n", ea);
	if (ea == NULL)
		return ERR_PTR(-EINVAL);

	entry = &fws->nodes[0];
	for (i = 0; i < ARRAY_SIZE(fws->nodes); i++) {
		if (entry->occupied && !memcmp(entry->ea, ea, ETH_ALEN))
			return entry;
		entry++;
	}

	return ERR_PTR(-ENOENT);
}

static struct brcmf_fws_mac_descriptor*
brcmf_fws_find_mac_desc(struct brcmf_fws_info *fws, int ifidx, u8 *da)
{
	struct brcmf_fws_mac_descriptor *entry = &fws->other;
	struct brcmf_if *ifp;
	bool multicast;

	brcmf_dbg(TRACE, "enter: ifidx=%d\n", ifidx);

	multicast = is_multicast_ether_addr(da);
	ifp = fws->drvr->iflist[ifidx ? ifidx + 1 : 0];
	if (WARN_ON(!ifp))
		goto done;

	/* Multicast destination and P2P clients get the interface entry.
	 * STA gets the interface entry if there is no exact match. For
	 * example, TDLS destinations have their own entry.
	 */
	entry = NULL;
	if ((/* ifp->iftype == 0 ||*/ multicast) && ifp->fws_desc)
		entry = ifp->fws_desc;

	if (entry != NULL && multicast)
		goto done;

	entry = brcmf_fws_mac_descriptor_lookup(fws, da);
	if (IS_ERR(entry))
		entry = &fws->other;

done:
	brcmf_dbg(TRACE, "exit: entry=%p\n", entry);
	return entry;
}

static void brcmf_fws_mac_desc_cleanup(struct brcmf_fws_info *fws,
				       struct brcmf_fws_mac_descriptor *entry,
				       int ifidx)
{
	brcmf_dbg(TRACE, "enter: entry=(ea=%pM, ifid=%d), ifidx=%d\n",
		  entry->ea, entry->interface_id, ifidx);
	if (entry->occupied && (ifidx == -1 || ifidx == entry->interface_id)) {
		brcmf_dbg(TRACE, "flush psq: ifidx=%d, qlen=%d\n",
			  ifidx, entry->psq.len);
		brcmf_fws_psq_flush(fws, &entry->psq, ifidx);
		entry->occupied = !!(entry->psq.len);
	}
}

static void brcmf_fws_bus_txq_cleanup(struct brcmf_fws_info *fws,
				      bool (*fn)(struct sk_buff *, void *),
				      int ifidx)
{
	struct brcmf_fws_hanger_item *hi;
	struct pktq *txq;
	struct sk_buff *skb;
	int prec;
	u32 hslot;

	brcmf_dbg(TRACE, "enter: ifidx=%d\n", ifidx);
	txq = brcmf_bus_gettxq(fws->drvr->bus_if);
	if (IS_ERR(txq)) {
		brcmf_dbg(TRACE, "no txq to clean up\n");
		return;
	}

	for (prec = 0; prec < txq->num_prec; prec++) {
		skb = brcmu_pktq_pdeq_match(txq, prec, fn, &ifidx);
		while (skb) {
			hslot = brcmf_skb_htod_tag_get_field(skb, HSLOT);
			hi = &fws->hanger.items[hslot];
			WARN_ON(skb != hi->pkt);
			hi->state = BRCMF_FWS_HANGER_ITEM_STATE_FREE;
			brcmu_pkt_buf_free_skb(skb);
			skb = brcmu_pktq_pdeq_match(txq, prec, fn, &ifidx);
		}
	}
}

static void brcmf_fws_cleanup(struct brcmf_fws_info *fws, int ifidx)
{
	int i;
	struct brcmf_fws_mac_descriptor *table;
	bool (*matchfn)(struct sk_buff *, void *) = NULL;

	brcmf_dbg(TRACE, "enter: ifidx=%d\n", ifidx);
	if (fws == NULL)
		return;

	if (ifidx != -1)
		matchfn = brcmf_fws_ifidx_match;

	/* cleanup individual nodes */
	table = &fws->nodes[0];
	for (i = 0; i < ARRAY_SIZE(fws->nodes); i++)
		brcmf_fws_mac_desc_cleanup(fws, &table[i], ifidx);

	brcmf_fws_mac_desc_cleanup(fws, &fws->other, ifidx);
	brcmf_fws_bus_txq_cleanup(fws, matchfn, ifidx);
	brcmf_fws_hanger_cleanup(&fws->hanger, matchfn, ifidx);
}

static int brcmf_fws_rssi_indicate(struct brcmf_fws_info *fws, s8 rssi)
{
	brcmf_dbg(CTL, "rssi %d\n", rssi);
	return 0;
}

static
int brcmf_fws_macdesc_indicate(struct brcmf_fws_info *fws, u8 type, u8 *data)
{
	struct brcmf_fws_mac_descriptor *entry, *existing;
	u8 mac_handle;
	u8 ifidx;
	u8 *addr;

	mac_handle = *data++;
	ifidx = *data++;
	addr = data;

	entry = &fws->nodes[mac_handle & 0x1F];
	if (type == BRCMF_FWS_TYPE_MACDESC_DEL) {
		brcmf_dbg(TRACE, "deleting mac %pM idx %d\n", addr, ifidx);
		if (entry->occupied)
			brcmf_fws_clear_mac_descriptor(entry);
		else
			fws->stats.mac_update_failed++;
		return 0;
	}

	brcmf_dbg(TRACE,
		  "add mac %pM handle %u idx %d\n", addr, mac_handle, ifidx);
	existing = brcmf_fws_mac_descriptor_lookup(fws, addr);
	if (IS_ERR(existing)) {
		if (!entry->occupied) {
			entry->mac_handle = mac_handle;
			brcmf_fws_init_mac_descriptor(entry, addr, ifidx);
			brcmu_pktq_init(&entry->psq, BRCMF_FWS_PSQ_PREC_COUNT,
					BRCMF_FWS_PSQ_LEN);
		} else {
			fws->stats.mac_update_failed++;
		}
	} else {
		if (entry != existing) {
			brcmf_dbg(TRACE, "relocate mac\n");
			memcpy(entry, existing,
			       offsetof(struct brcmf_fws_mac_descriptor, psq));
			entry->mac_handle = mac_handle;
			brcmf_fws_clear_mac_descriptor(existing);
		} else {
			brcmf_dbg(TRACE, "use existing\n");
			WARN_ON(entry->mac_handle != mac_handle);
			/* TODO: what should we do here: continue, reinit, .. */
		}
	}
	return 0;
}

static int
brcmf_fws_txstatus_process(struct brcmf_fws_info *fws, u8 flags, u32 hslot)
{
	int ret;
	struct sk_buff *skb;
	struct brcmf_fws_mac_descriptor *entry = NULL;

	brcmf_dbg(TRACE, "status: flags=0x%X, hslot=%d\n",
		  flags, hslot);

	if (flags == BRCMF_FWS_TXSTATUS_DISCARD)
		fws->stats.txs_discard++;
	else if (flags == BRCMF_FWS_TXSTATUS_FW_TOSSED)
		fws->stats.txs_tossed++;
	else
		brcmf_err("unexpected txstatus\n");

	ret = brcmf_fws_hanger_poppkt(&fws->hanger, hslot, &skb,
				      true);
	if (ret != 0) {
		brcmf_err("no packet in hanger slot: hslot=%d\n", hslot);
		return ret;
	}

	entry = brcmf_skbcb(skb)->mac;
	if (WARN_ON(!entry)) {
		ret = -EINVAL;
		goto done;
	}

	entry->transit_count--;

done:
	brcmf_txfinalize(fws->drvr, skb, true);
	return ret;
}

static int brcmf_fws_txstatus_indicate(struct brcmf_fws_info *fws, u8 *data)
{
	u32 status;
	u32 hslot;
	u8 flags;

	fws->stats.txs_indicate++;
	status = le32_to_cpu(*(__le32 *)data);
	flags = brcmf_txstatus_get_field(status, FLAGS);
	hslot = brcmf_txstatus_get_field(status, HSLOT);

	return brcmf_fws_txstatus_process(fws, flags, hslot);
}

static int brcmf_fws_dbg_seqnum_check(struct brcmf_fws_info *fws, u8 *data)
{
	__le32 timestamp;

	memcpy(&timestamp, &data[2], sizeof(timestamp));
	brcmf_dbg(INFO, "received: seq %d, timestamp %d\n", data[1],
		  le32_to_cpu(timestamp));
	return 0;
}

/* using macro so sparse checking does not complain
 * about locking imbalance.
 */
#define brcmf_fws_lock(drvr, flags)				\
do {								\
	flags = 0;						\
	spin_lock_irqsave(&((drvr)->fws_spinlock), (flags));	\
} while (0)

/* using macro so sparse checking does not complain
 * about locking imbalance.
 */
#define brcmf_fws_unlock(drvr, flags) \
	spin_unlock_irqrestore(&((drvr)->fws_spinlock), (flags))

static int brcmf_fws_notify_credit_map(struct brcmf_if *ifp,
				       const struct brcmf_event_msg *e,
				       void *data)
{
	struct brcmf_fws_info *fws = ifp->drvr->fws;
	int i;
	ulong flags;
	u8 *credits = data;

	brcmf_fws_lock(ifp->drvr, flags);
	for (i = 0; i < ARRAY_SIZE(fws->fifo_credit); i++)
		fws->fifo_credit[i] = *credits++;
	brcmf_fws_unlock(ifp->drvr, flags);
	return 0;
}

int brcmf_fws_hdrpull(struct brcmf_pub *drvr, int ifidx, s16 signal_len,
		      struct sk_buff *skb)
{
	struct brcmf_fws_info *fws = drvr->fws;
	ulong flags;
	u8 *signal_data;
	s16 data_len;
	u8 type;
	u8 len;
	u8 *data;

	brcmf_dbg(TRACE, "enter: ifidx %d, skblen %u, sig %d\n",
		  ifidx, skb->len, signal_len);

	WARN_ON(signal_len > skb->len);

	/* if flow control disabled, skip to packet data and leave */
	if (!signal_len || !drvr->fw_signals) {
		skb_pull(skb, signal_len);
		return 0;
	}

	/* lock during tlv parsing */
	brcmf_fws_lock(drvr, flags);

	fws->stats.header_pulls++;
	data_len = signal_len;
	signal_data = skb->data;

	while (data_len > 0) {
		/* extract tlv info */
		type = signal_data[0];

		/* FILLER type is actually not a TLV, but
		 * a single byte that can be skipped.
		 */
		if (type == BRCMF_FWS_TYPE_FILLER) {
			signal_data += 1;
			data_len -= 1;
			continue;
		}
		len = signal_data[1];
		data = signal_data + 2;

		brcmf_dbg(INFO, "tlv type=%d (%s), len=%d, data[0]=%d\n", type,
			  brcmf_fws_get_tlv_name(type), len, *data);

		/* abort parsing when length invalid */
		if (data_len < len + 2)
			break;

		if (len != brcmf_fws_get_tlv_len(fws, type))
			break;

		switch (type) {
		case BRCMF_FWS_TYPE_MAC_OPEN:
		case BRCMF_FWS_TYPE_MAC_CLOSE:
		case BRCMF_FWS_TYPE_MAC_REQUEST_CREDIT:
		case BRCMF_FWS_TYPE_PKTTAG:
		case BRCMF_FWS_TYPE_INTERFACE_OPEN:
		case BRCMF_FWS_TYPE_INTERFACE_CLOSE:
		case BRCMF_FWS_TYPE_FIFO_CREDITBACK:
		case BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP:
		case BRCMF_FWS_TYPE_MAC_REQUEST_PACKET:
		case BRCMF_FWS_TYPE_HOST_REORDER_RXPKTS:
		case BRCMF_FWS_TYPE_COMP_TXSTATUS:
			break;
		case BRCMF_FWS_TYPE_MACDESC_ADD:
		case BRCMF_FWS_TYPE_MACDESC_DEL:
			brcmf_fws_macdesc_indicate(fws, type, data);
			break;
		case BRCMF_FWS_TYPE_TXSTATUS:
			brcmf_fws_txstatus_indicate(fws, data);
			break;
		case BRCMF_FWS_TYPE_RSSI:
			brcmf_fws_rssi_indicate(fws, *data);
			break;
		case BRCMF_FWS_TYPE_TRANS_ID:
			brcmf_fws_dbg_seqnum_check(fws, data);
			break;
		default:
			fws->stats.tlv_invalid_type++;
			break;
		}

		signal_data += len + 2;
		data_len -= len + 2;
	}

	if (data_len != 0)
		fws->stats.tlv_parse_failed++;

	/* signalling processing result does
	 * not affect the actual ethernet packet.
	 */
	skb_pull(skb, signal_len);

	/* this may be a signal-only packet
	 */
	if (skb->len == 0)
		fws->stats.header_only_pkt++;

	brcmf_fws_unlock(drvr, flags);
	return 0;
}

static int brcmf_fws_hdrpush(struct brcmf_fws_info *fws, struct sk_buff *skb)
{
	struct brcmf_fws_mac_descriptor *entry = brcmf_skbcb(skb)->mac;
	u8 *wlh;
	u16 data_offset;
	u8 fillers;
	__le32 pkttag = cpu_to_le32(brcmf_skbcb(skb)->htod);

	brcmf_dbg(TRACE, "enter: ea=%pM, ifidx=%u, pkttag=0x%08X\n",
		  entry->ea, entry->interface_id, le32_to_cpu(pkttag));
	/* +2 is for Type[1] and Len[1] in TLV, plus TIM signal */
	data_offset = 2 + BRCMF_FWS_TYPE_PKTTAG_LEN;
	fillers = round_up(data_offset, 4) - data_offset;
	data_offset += fillers;

	skb_push(skb, data_offset);
	wlh = skb->data;

	wlh[0] = BRCMF_FWS_TYPE_PKTTAG;
	wlh[1] = BRCMF_FWS_TYPE_PKTTAG_LEN;
	memcpy(&wlh[2], &pkttag, sizeof(pkttag));
	wlh += BRCMF_FWS_TYPE_PKTTAG_LEN + 2;

	if (fillers)
		memset(wlh, BRCMF_FWS_TYPE_FILLER, fillers);

	brcmf_proto_hdrpush(fws->drvr, brcmf_skb_if_flags_get_field(skb, INDEX),
			    data_offset >> 2, skb);
	return 0;
}

static int brcmf_fws_precommit_skb(struct brcmf_fws_info *fws, int fifo,
				   struct sk_buff *p)
{
	struct brcmf_skbuff_cb *skcb = brcmf_skbcb(p);
	struct brcmf_fws_mac_descriptor *entry = skcb->mac;
	int rc = 0;
	bool header_needed;
	int hslot = BRCMF_FWS_HANGER_MAXITEMS;
	u8 free_ctr;
	u8 ifidx;
	u8 flags;

	header_needed = skcb->state == BRCMF_FWS_SKBSTATE_NEW;

	if (header_needed) {
		/* obtaining free slot may fail, but that will be caught
		 * by the hanger push. This assures the packet has a BDC
		 * header upon return.
		 */
		hslot = brcmf_fws_hanger_get_free_slot(&fws->hanger);
		free_ctr = entry->seq[fifo];
		brcmf_skb_htod_tag_set_field(p, HSLOT, hslot);
		brcmf_skb_htod_tag_set_field(p, FREERUN, free_ctr);
		brcmf_skb_htod_tag_set_field(p, GENERATION, 1);
		entry->transit_count++;
	}
	brcmf_skb_if_flags_set_field(p, TRANSMIT, 1);
	brcmf_skb_htod_tag_set_field(p, FIFO, fifo);

	flags = BRCMF_FWS_HTOD_FLAG_PKTFROMHOST;
	if (!(skcb->if_flags & BRCMF_SKB_IF_FLAGS_CREDITCHECK_MASK)) {
		/*
		Indicate that this packet is being sent in response to an
		explicit request from the firmware side.
		*/
		flags |= BRCMF_FWS_HTOD_FLAG_PKT_REQUESTED;
	}
	brcmf_skb_htod_tag_set_field(p, FLAGS, flags);
	if (header_needed) {
		brcmf_fws_hdrpush(fws, p);
		rc = brcmf_fws_hanger_pushpkt(&fws->hanger, p, hslot);
		if (rc)
			brcmf_err("hanger push failed: rc=%d\n", rc);
	} else {
		int gen;

		/* remove old header */
		rc = brcmf_proto_hdrpull(fws->drvr, false, &ifidx, p);
		if (rc == 0) {
			hslot = brcmf_skb_htod_tag_get_field(p, HSLOT);
			brcmf_fws_hanger_get_genbit(&fws->hanger, p,
						    hslot, &gen);
			brcmf_skb_htod_tag_set_field(p, GENERATION, gen);

			/* push new header */
			brcmf_fws_hdrpush(fws, p);
		}
	}

	return rc;
}

static int brcmf_fws_commit_skb(struct brcmf_fws_info *fws, int fifo,
				struct sk_buff *skb)
{
	struct brcmf_skbuff_cb *skcb = brcmf_skbcb(skb);
	struct brcmf_fws_mac_descriptor *entry;
	struct brcmf_bus *bus = fws->drvr->bus_if;
	int rc;

	entry = skcb->mac;
	if (IS_ERR(entry))
		return PTR_ERR(entry);

	rc = brcmf_fws_precommit_skb(fws, fifo, skb);
	if (rc < 0) {
		fws->stats.generic_error++;
		goto done;
	}

	rc = brcmf_bus_txdata(bus, skb);
	if (rc < 0)
		goto done;

	entry->seq[fifo]++;
	fws->stats.pkt2bus++;
	return rc;

done:
	brcmf_txfinalize(fws->drvr, skb, false);
	return rc;
}

int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb)
{
	struct brcmf_pub *drvr = ifp->drvr;
	struct brcmf_skbuff_cb *skcb = brcmf_skbcb(skb);
	struct ethhdr *eh = (struct ethhdr *)(skb->data);
	ulong flags;
	u8 ifidx = ifp->ifidx;
	int fifo = BRCMF_FWS_FIFO_BCMC;
	bool multicast = is_multicast_ether_addr(eh->h_dest);

	/* determine the priority */
	if (!skb->priority)
		skb->priority = cfg80211_classify8021d(skb);

	drvr->tx_multicast += !!multicast;
	if (ntohs(eh->h_proto) == ETH_P_PAE)
		atomic_inc(&ifp->pend_8021x_cnt);

	if (!brcmf_fws_fc_active(drvr->fws)) {
		/* If the protocol uses a data header, apply it */
		brcmf_proto_hdrpush(drvr, ifidx, 0, skb);

		/* Use bus module to send data frame */
		return brcmf_bus_txdata(drvr->bus_if, skb);
	}

	/* set control buffer information */
	skcb->mac = brcmf_fws_find_mac_desc(drvr->fws, ifidx, eh->h_dest);
	skcb->state = BRCMF_FWS_SKBSTATE_NEW;
	brcmf_skb_if_flags_set_field(skb, INDEX, ifidx);
	if (!multicast)
		fifo = brcmf_fws_prio2fifo[skb->priority];
	brcmf_skb_if_flags_set_field(skb, FIFO, fifo);
	brcmf_skb_if_flags_set_field(skb, CREDITCHECK, 0);

	brcmf_dbg(TRACE, "ea=%pM, multi=%d, fifo=%d\n", eh->h_dest,
		  multicast, fifo);

	brcmf_fws_lock(drvr, flags);
	brcmf_fws_commit_skb(drvr->fws, fifo, skb);
	brcmf_fws_unlock(drvr, flags);
	return 0;
}

void brcmf_fws_reset_interface(struct brcmf_if *ifp)
{
	struct brcmf_fws_mac_descriptor *entry = ifp->fws_desc;

	brcmf_dbg(TRACE, "enter: idx=%d\n", ifp->bssidx);
	if (!entry)
		return;

	brcmf_fws_init_mac_descriptor(entry, ifp->mac_addr, ifp->ifidx);
}

void brcmf_fws_add_interface(struct brcmf_if *ifp)
{
	struct brcmf_fws_mac_descriptor *entry;

	brcmf_dbg(TRACE, "enter: idx=%d, mac=%pM\n",
		  ifp->bssidx, ifp->mac_addr);
	if (!ifp->drvr->fw_signals)
		return;

	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (entry) {
		ifp->fws_desc = entry;
		brcmf_fws_init_mac_descriptor(entry, ifp->mac_addr, ifp->ifidx);
		brcmu_pktq_init(&entry->psq, BRCMF_FWS_PSQ_PREC_COUNT,
				BRCMF_FWS_PSQ_LEN);
	} else {
		brcmf_err("no firmware signalling\n");
	}
}

void brcmf_fws_del_interface(struct brcmf_if *ifp)
{
	struct brcmf_fws_mac_descriptor *entry = ifp->fws_desc;

	brcmf_dbg(TRACE, "enter: idx=%d\n", ifp->bssidx);
	if (!entry)
		return;

	ifp->fws_desc = NULL;
	brcmf_fws_clear_mac_descriptor(entry);
	brcmf_fws_cleanup(ifp->drvr->fws, ifp->ifidx);
	kfree(entry);
}

int brcmf_fws_init(struct brcmf_pub *drvr)
{
	u32 tlv = 0;
	int rc;

	/* enable rssi signals */
	if (drvr->fw_signals)
		tlv = BRCMF_FWS_FLAGS_RSSI_SIGNALS |
		      BRCMF_FWS_FLAGS_XONXOFF_SIGNALS |
		      BRCMF_FWS_FLAGS_CREDIT_STATUS_SIGNALS;

	spin_lock_init(&drvr->fws_spinlock);

	drvr->fws = kzalloc(sizeof(*(drvr->fws)), GFP_KERNEL);
	if (!drvr->fws) {
		rc = -ENOMEM;
		goto fail;
	}

	/* set linkage back */
	drvr->fws->drvr = drvr;
	drvr->fws->fcmode = fcmode;

	/* enable proptxtstatus signaling by default */
	rc = brcmf_fil_iovar_int_set(drvr->iflist[0], "tlv", tlv);
	if (rc < 0) {
		brcmf_err("failed to set bdcv2 tlv signaling\n");
		goto fail;
	}

	if (brcmf_fweh_register(drvr, BRCMF_E_FIFO_CREDIT_MAP,
				brcmf_fws_notify_credit_map)) {
		brcmf_err("register credit map handler failed\n");
		goto fail;
	}

	brcmf_fws_hanger_init(&drvr->fws->hanger);

	/* create debugfs file for statistics */
	brcmf_debugfs_create_fws_stats(drvr, &drvr->fws->stats);

	/* TODO: remove upon feature delivery */
	brcmf_err("%s bdcv2 tlv signaling [%x]\n",
		  drvr->fw_signals ? "enabled" : "disabled", tlv);
	return 0;

fail:
	/* disable flow control entirely */
	drvr->fw_signals = false;
	brcmf_fws_deinit(drvr);
	return rc;
}

void brcmf_fws_deinit(struct brcmf_pub *drvr)
{
	struct brcmf_fws_info *fws = drvr->fws;
	ulong flags;

	/* cleanup */
	brcmf_fws_lock(drvr, flags);
	brcmf_fws_cleanup(fws, -1);
	drvr->fws = NULL;
	brcmf_fws_unlock(drvr, flags);

	/* free top structure */
	kfree(fws);
}

bool brcmf_fws_fc_active(struct brcmf_fws_info *fws)
{
	if (!fws)
		return false;

	brcmf_dbg(TRACE, "enter: mode=%d\n", fws->fcmode);
	return fws->fcmode != BRCMF_FWS_FCMODE_NONE;
}

void brcmf_fws_bustxfail(struct brcmf_fws_info *fws, struct sk_buff *skb)
{
	ulong flags;

	brcmf_fws_lock(fws->drvr, flags);
	brcmf_fws_txstatus_process(fws, BRCMF_FWS_TXSTATUS_FW_TOSSED,
				   brcmf_skb_htod_tag_get_field(skb, HSLOT));
	brcmf_fws_unlock(fws->drvr, flags);
}