/*
 * 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 <linux/jiffies.h>
#include <net/cfg80211.h>

#include <brcmu_utils.h>
#include <brcmu_wifi.h>
#include "core.h"
#include "debug.h"
#include "bus.h"
#include "fwil.h"
#include "fwil_types.h"
#include "fweh.h"
#include "fwsignal.h"
#include "p2p.h"
#include "cfg80211.h"
#include "proto.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 */

/*
 * The PKTTAG tlv has additional bytes when firmware-signalling
 * mode has REUSESEQ flag set.
 */
#define BRCMF_FWS_TYPE_SEQ_LEN                          2

/*
 * 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_MAC_DESC_TABLE_SIZE                   32
#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_FLOWCONTROL_HIWATER                   128
#define BRCMF_FWS_FLOWCONTROL_LOWATER                   64

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

#define BRCMF_FWS_HTOD_FLAG_PKTFROMHOST                 0x01
#define BRCMF_FWS_HTOD_FLAG_PKT_REQUESTED               0x02

#define BRCMF_FWS_RET_OK_NOSCHEDULE                     0
#define BRCMF_FWS_RET_OK_SCHEDULE                       1

#define BRCMF_FWS_MODE_REUSESEQ_SHIFT                   3       /* seq reuse */
#define BRCMF_FWS_MODE_SET_REUSESEQ(x, val)     ((x) = \
                ((x) & ~(1 << BRCMF_FWS_MODE_REUSESEQ_SHIFT)) | \
                (((val) & 1) << BRCMF_FWS_MODE_REUSESEQ_SHIFT))
#define BRCMF_FWS_MODE_GET_REUSESEQ(x)  \
                (((x) >> BRCMF_FWS_MODE_REUSESEQ_SHIFT) & 1)

/**
 * 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.
 * @BRCMF_FWS_SKBSTATE_TIM: allocated for TIM update info.
 */
enum brcmf_fws_skb_state {
        BRCMF_FWS_SKBSTATE_NEW,
        BRCMF_FWS_SKBSTATE_DELAYED,
        BRCMF_FWS_SKBSTATE_SUPPRESSED,
        BRCMF_FWS_SKBSTATE_TIM
};

/**
 * struct brcmf_skbuff_cb - control buffer associated with skbuff.
 *
 * @bus_flags: 2 bytes reserved for bus specific parameters
 * @if_flags: holds interface index and packet related flags.
 * @htod: host to device packet identifier (used in PKTTAG tlv).
 * @htod_seq: this 16-bit is original seq number for every suppress packet.
 * @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 bus_flags;
        u16 if_flags;
        u32 htod;
        u16 htod_seq;
        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 used requested credit
 *      b[7]   - interface in AP mode.
 *      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_REQ_CREDIT_MASK      0x0100
#define BRCMF_SKB_IF_FLAGS_REQ_CREDIT_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_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_SKB_HTOD_SEQ_FROMFW_MASK                  0x2000
#define BRCMF_SKB_HTOD_SEQ_FROMFW_SHIFT                 13
#define BRCMF_SKB_HTOD_SEQ_FROMDRV_MASK                 0x1000
#define BRCMF_SKB_HTOD_SEQ_FROMDRV_SHIFT                12
#define BRCMF_SKB_HTOD_SEQ_NR_MASK                      0x0fff
#define BRCMF_SKB_HTOD_SEQ_NR_SHIFT                     0

#define brcmf_skb_htod_seq_set_field(skb, field, value) \
        brcmu_maskset16(&(brcmf_skbcb(skb)->htod_seq), \
                        BRCMF_SKB_HTOD_SEQ_ ## field ## _MASK, \
                        BRCMF_SKB_HTOD_SEQ_ ## field ## _SHIFT, (value))
#define brcmf_skb_htod_seq_get_field(skb, field) \
        brcmu_maskget16(brcmf_skbcb(skb)->htod_seq, \
                        BRCMF_SKB_HTOD_SEQ_ ## field ## _MASK, \
                        BRCMF_SKB_HTOD_SEQ_ ## 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_FREERUN_MASK           0x000000FF
#define BRCMF_FWS_TXSTAT_FREERUN_SHIFT          0

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

/* How long to defer borrowing in jiffies */
#define BRCMF_FWS_BORROW_DEFER_PERIOD           (HZ / 10)

/**
 * enum brcmf_fws_fifo - fifo indices used by dongle firmware.
 *
 * @BRCMF_FWS_FIFO_FIRST: first fifo, ie. background.
 * @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_FIRST,
        BRCMF_FWS_FIFO_AC_BK = BRCMF_FWS_FIFO_FIRST,
        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.
 * @BRCMF_FWS_TXSTATUS_HOST_TOSSED:
 *      host 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,
        BRCMF_FWS_TXSTATUS_HOST_TOSSED
};

enum brcmf_fws_fcmode {
        BRCMF_FWS_FCMODE_NONE,
        BRCMF_FWS_FCMODE_IMPLIED_CREDIT,
        BRCMF_FWS_FCMODE_EXPLICIT_CREDIT
};

enum brcmf_fws_mac_desc_state {
        BRCMF_FWS_STATE_OPEN = 1,
        BRCMF_FWS_STATE_CLOSE
};

/**
 * 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 {
        char name[16];
        u8 occupied;
        u8 mac_handle;
        u8 interface_id;
        u8 state;
        bool suppressed;
        u8 generation;
        u8 ac_bitmap;
        u8 requested_credit;
        u8 requested_packet;
        u8 ea[ETH_ALEN];
        u8 seq[BRCMF_FWS_FIFO_COUNT];
        struct pktq psq;
        int transit_count;
        int suppr_transit_count;
        bool send_tim_signal;
        u8 traffic_pending_bmp;
        u8 traffic_lastreported_bmp;
};

#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.
 * @pkt: packet itself.
 */
struct brcmf_fws_hanger_item {
        enum brcmf_fws_hanger_item_state state;
        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_macdesc_table {
        struct brcmf_fws_mac_descriptor nodes[BRCMF_FWS_MAC_DESC_TABLE_SIZE];
        struct brcmf_fws_mac_descriptor iface[BRCMF_MAX_IFS];
        struct brcmf_fws_mac_descriptor other;
};

struct brcmf_fws_stats {
        u32 tlv_parse_failed;
        u32 tlv_invalid_type;
        u32 header_only_pkt;
        u32 header_pulls;
        u32 pkt2bus;
        u32 send_pkts[5];
        u32 requested_sent[5];
        u32 generic_error;
        u32 mac_update_failed;
        u32 mac_ps_update_failed;
        u32 if_update_failed;
        u32 packet_request_failed;
        u32 credit_request_failed;
        u32 rollback_success;
        u32 rollback_failed;
        u32 delayq_full_error;
        u32 supprq_full_error;
        u32 txs_indicate;
        u32 txs_discard;
        u32 txs_supp_core;
        u32 txs_supp_ps;
        u32 txs_tossed;
        u32 txs_host_tossed;
        u32 bus_flow_block;
        u32 fws_flow_block;
};

struct brcmf_fws_info {
        struct brcmf_pub *drvr;
        spinlock_t spinlock;
        ulong flags;
        struct brcmf_fws_stats stats;
        struct brcmf_fws_hanger hanger;
        enum brcmf_fws_fcmode fcmode;
        bool fw_signals;
        bool bcmc_credit_check;
        struct brcmf_fws_macdesc_table desc;
        struct workqueue_struct *fws_wq;
        struct work_struct fws_dequeue_work;
        u32 fifo_enqpkt[BRCMF_FWS_FIFO_COUNT];
        int fifo_credit[BRCMF_FWS_FIFO_COUNT];
        int credits_borrowed[BRCMF_FWS_FIFO_AC_VO + 1];
        int deq_node_pos[BRCMF_FWS_FIFO_COUNT];
        u32 fifo_credit_map;
        u32 fifo_delay_map;
        unsigned long borrow_defer_timestamp;
        bool bus_flow_blocked;
        bool creditmap_received;
        u8 mode;
        bool avoid_queueing;
};

/*
 * 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 void brcmf_fws_lock(struct brcmf_fws_info *fws)
                __acquires(&fws->spinlock)
{
        spin_lock_irqsave(&fws->spinlock, fws->flags);
}

static void brcmf_fws_unlock(struct brcmf_fws_info *fws)
                __releases(&fws->spinlock)
{
        spin_unlock_irqrestore(&fws->spinlock, fws->flags);
}

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) {
                        brcmu_pkt_buf_free_skb(skb);
                        skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx);
                }
        }
}

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

        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;

        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;
                        goto done;
                }
                i++;
                if (i == BRCMF_FWS_HANGER_MAXITEMS)
                        i = 0;
        }
        brcmf_err("all slots occupied\n");
        h->failed_slotfind++;
        i = BRCMF_FWS_HANGER_MAXITEMS;
done:
        return i;
}

static int brcmf_fws_hanger_pushpkt(struct brcmf_fws_hanger *h,
                                    struct sk_buff *pkt, u32 slot_id)
{
        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)
{
        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->popped++;
        }
        return 0;
}

static int brcmf_fws_hanger_mark_suppressed(struct brcmf_fws_hanger *h,
                                            u32 slot_id)
{
        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");
                return -EINVAL;
        }

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

static void brcmf_fws_hanger_cleanup(struct brcmf_fws_info *fws,
                                     bool (*fn)(struct sk_buff *, void *),
                                     int ifidx)
{
        struct brcmf_fws_hanger *h = &fws->hanger;
        struct sk_buff *skb;
        int i;
        enum brcmf_fws_hanger_item_state s;

        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_macdesc_set_name(struct brcmf_fws_info *fws,
                                       struct brcmf_fws_mac_descriptor *desc)
{
        if (desc == &fws->desc.other)
                strlcpy(desc->name, "MAC-OTHER", sizeof(desc->name));
        else if (desc->mac_handle)
                scnprintf(desc->name, sizeof(desc->name), "MAC-%d:%d",
                          desc->mac_handle, desc->interface_id);
        else
                scnprintf(desc->name, sizeof(desc->name), "MACIF:%d",
                          desc->interface_id);
}

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

static
void brcmf_fws_macdesc_deinit(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;
        desc->requested_packet = 0;
}

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

        if (ea == NULL)
                return ERR_PTR(-EINVAL);

        entry = &fws->desc.nodes[0];
        for (i = 0; i < ARRAY_SIZE(fws->desc.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_macdesc_find(struct brcmf_fws_info *fws, struct brcmf_if *ifp, u8 *da)
{
        struct brcmf_fws_mac_descriptor *entry = &fws->desc.other;
        bool multicast;

        multicast = is_multicast_ether_addr(da);

        /* Multicast destination, STA and P2P clients get the interface entry.
         * STA/GC gets the Mac Entry for TDLS destinations, TDLS destinations
         * have their own entry.
         */
        if (multicast && ifp->fws_desc) {
                entry = ifp->fws_desc;
                goto done;
        }

        entry = brcmf_fws_macdesc_lookup(fws, da);
        if (IS_ERR(entry))
                entry = ifp->fws_desc;

done:
        return entry;
}

static bool brcmf_fws_macdesc_closed(struct brcmf_fws_info *fws,
                                     struct brcmf_fws_mac_descriptor *entry,
                                     int fifo)
{
        struct brcmf_fws_mac_descriptor *if_entry;
        bool closed;

        /* for unique destination entries the related interface
         * may be closed.
         */
        if (entry->mac_handle) {
                if_entry = &fws->desc.iface[entry->interface_id];
                if (if_entry->state == BRCMF_FWS_STATE_CLOSE)
                        return true;
        }
        /* an entry is closed when the state is closed and
         * the firmware did not request anything.
         */
        closed = entry->state == BRCMF_FWS_STATE_CLOSE &&
                 !entry->requested_credit && !entry->requested_packet;

        /* Or firmware does not allow traffic for given fifo */
        return closed || !(entry->ac_bitmap & BIT(fifo));
}

static void brcmf_fws_macdesc_cleanup(struct brcmf_fws_info *fws,
                                      struct brcmf_fws_mac_descriptor *entry,
                                      int ifidx)
{
        if (entry->occupied && (ifidx == -1 || ifidx == entry->interface_id)) {
                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;

        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;

        if (fws == NULL)
                return;

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

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

        brcmf_fws_macdesc_cleanup(fws, &fws->desc.other, ifidx);
        brcmf_fws_bus_txq_cleanup(fws, matchfn, ifidx);
        brcmf_fws_hanger_cleanup(fws, matchfn, ifidx);
}

static u8 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 = 0;
        u8 fillers;
        __le32 pkttag = cpu_to_le32(brcmf_skbcb(skb)->htod);
        __le16 pktseq = cpu_to_le16(brcmf_skbcb(skb)->htod_seq);

        brcmf_dbg(TRACE, "enter: %s, idx=%d hslot=%d htod %X seq %X\n",
                  entry->name, brcmf_skb_if_flags_get_field(skb, INDEX),
                  (le32_to_cpu(pkttag) >> 8) & 0xffff,
                  brcmf_skbcb(skb)->htod, brcmf_skbcb(skb)->htod_seq);
        if (entry->send_tim_signal)
                data_offset += 2 + BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP_LEN;
        if (BRCMF_FWS_MODE_GET_REUSESEQ(fws->mode))
                data_offset += BRCMF_FWS_TYPE_SEQ_LEN;
        /* +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));
        if (BRCMF_FWS_MODE_GET_REUSESEQ(fws->mode)) {
                wlh[1] += BRCMF_FWS_TYPE_SEQ_LEN;
                memcpy(&wlh[2 + BRCMF_FWS_TYPE_PKTTAG_LEN], &pktseq,
                       sizeof(pktseq));
        }
        wlh += wlh[1] + 2;

        if (entry->send_tim_signal) {
                entry->send_tim_signal = 0;
                wlh[0] = BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP;
                wlh[1] = BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP_LEN;
                wlh[2] = entry->mac_handle;
                wlh[3] = entry->traffic_pending_bmp;
                brcmf_dbg(TRACE, "adding TIM info: handle %d bmp 0x%X\n",
                          entry->mac_handle, entry->traffic_pending_bmp);
                wlh += BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP_LEN + 2;
                entry->traffic_lastreported_bmp = entry->traffic_pending_bmp;
        }
        if (fillers)
                memset(wlh, BRCMF_FWS_TYPE_FILLER, fillers);

        return (u8)(data_offset >> 2);
}

static bool brcmf_fws_tim_update(struct brcmf_fws_info *fws,
                                 struct brcmf_fws_mac_descriptor *entry,
                                 int fifo, bool send_immediately)
{
        struct sk_buff *skb;
        struct brcmf_skbuff_cb *skcb;
        s32 err;
        u32 len;
        u8 data_offset;
        int ifidx;

        /* check delayedQ and suppressQ in one call using bitmap */
        if (brcmu_pktq_mlen(&entry->psq, 3 << (fifo * 2)) == 0)
                entry->traffic_pending_bmp &= ~NBITVAL(fifo);
        else
                entry->traffic_pending_bmp |= NBITVAL(fifo);

        entry->send_tim_signal = false;
        if (entry->traffic_lastreported_bmp != entry->traffic_pending_bmp)
                entry->send_tim_signal = true;
        if (send_immediately && entry->send_tim_signal &&
            entry->state == BRCMF_FWS_STATE_CLOSE) {
                /* create a dummy packet and sent that. The traffic          */
                /* bitmap info will automatically be attached to that packet */
                len = BRCMF_FWS_TYPE_PKTTAG_LEN + 2 +
                      BRCMF_FWS_TYPE_SEQ_LEN +
                      BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP_LEN + 2 +
                      4 + fws->drvr->hdrlen;
                skb = brcmu_pkt_buf_get_skb(len);
                if (skb == NULL)
                        return false;
                skb_pull(skb, len);
                skcb = brcmf_skbcb(skb);
                skcb->mac = entry;
                skcb->state = BRCMF_FWS_SKBSTATE_TIM;
                skcb->htod = 0;
                skcb->htod_seq = 0;
                data_offset = brcmf_fws_hdrpush(fws, skb);
                ifidx = brcmf_skb_if_flags_get_field(skb, INDEX);
                brcmf_fws_unlock(fws);
                err = brcmf_proto_txdata(fws->drvr, ifidx, data_offset, skb);
                brcmf_fws_lock(fws);
                if (err)
                        brcmu_pkt_buf_free_skb(skb);
                return true;
        }
        return false;
}

static void
brcmf_fws_flow_control_check(struct brcmf_fws_info *fws, struct pktq *pq,
                             u8 if_id)
{
        struct brcmf_if *ifp = fws->drvr->iflist[!if_id ? 0 : if_id + 1];

        if (WARN_ON(!ifp))
                return;

        if ((ifp->netif_stop & BRCMF_NETIF_STOP_REASON_FWS_FC) &&
            pq->len <= BRCMF_FWS_FLOWCONTROL_LOWATER)
                brcmf_txflowblock_if(ifp,
                                     BRCMF_NETIF_STOP_REASON_FWS_FC, false);
        if (!(ifp->netif_stop & BRCMF_NETIF_STOP_REASON_FWS_FC) &&
            pq->len >= BRCMF_FWS_FLOWCONTROL_HIWATER) {
                fws->stats.fws_flow_block++;
                brcmf_txflowblock_if(ifp, BRCMF_NETIF_STOP_REASON_FWS_FC, true);
        }
        return;
}

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->desc.nodes[mac_handle & 0x1F];
        if (type == BRCMF_FWS_TYPE_MACDESC_DEL) {
                if (entry->occupied) {
                        brcmf_dbg(TRACE, "deleting %s mac %pM\n",
                                  entry->name, addr);
                        brcmf_fws_lock(fws);
                        brcmf_fws_macdesc_cleanup(fws, entry, -1);
                        brcmf_fws_macdesc_deinit(entry);
                        brcmf_fws_unlock(fws);
                } else
                        fws->stats.mac_update_failed++;
                return 0;
        }

        existing = brcmf_fws_macdesc_lookup(fws, addr);
        if (IS_ERR(existing)) {
                if (!entry->occupied) {
                        brcmf_fws_lock(fws);
                        entry->mac_handle = mac_handle;
                        brcmf_fws_macdesc_init(entry, addr, ifidx);
                        brcmf_fws_macdesc_set_name(fws, entry);
                        brcmu_pktq_init(&entry->psq, BRCMF_FWS_PSQ_PREC_COUNT,
                                        BRCMF_FWS_PSQ_LEN);
                        brcmf_fws_unlock(fws);
                        brcmf_dbg(TRACE, "add %s mac %pM\n", entry->name, addr);
                } else {
                        fws->stats.mac_update_failed++;
                }
        } else {
                if (entry != existing) {
                        brcmf_dbg(TRACE, "copy mac %s\n", existing->name);
                        brcmf_fws_lock(fws);
                        memcpy(entry, existing,
                               offsetof(struct brcmf_fws_mac_descriptor, psq));
                        entry->mac_handle = mac_handle;
                        brcmf_fws_macdesc_deinit(existing);
                        brcmf_fws_macdesc_set_name(fws, entry);
                        brcmf_fws_unlock(fws);
                        brcmf_dbg(TRACE, "relocate %s mac %pM\n", entry->name,
                                  addr);
                } 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_macdesc_state_indicate(struct brcmf_fws_info *fws,
                                            u8 type, u8 *data)
{
        struct brcmf_fws_mac_descriptor *entry;
        u8 mac_handle;
        int ret;

        mac_handle = data[0];
        entry = &fws->desc.nodes[mac_handle & 0x1F];
        if (!entry->occupied) {
                fws->stats.mac_ps_update_failed++;
                return -ESRCH;
        }
        brcmf_fws_lock(fws);
        /* a state update should wipe old credits */
        entry->requested_credit = 0;
        entry->requested_packet = 0;
        if (type == BRCMF_FWS_TYPE_MAC_OPEN) {
                entry->state = BRCMF_FWS_STATE_OPEN;
                ret = BRCMF_FWS_RET_OK_SCHEDULE;
        } else {
                entry->state = BRCMF_FWS_STATE_CLOSE;
                brcmf_fws_tim_update(fws, entry, BRCMF_FWS_FIFO_AC_BK, false);
                brcmf_fws_tim_update(fws, entry, BRCMF_FWS_FIFO_AC_BE, false);
                brcmf_fws_tim_update(fws, entry, BRCMF_FWS_FIFO_AC_VI, false);
                brcmf_fws_tim_update(fws, entry, BRCMF_FWS_FIFO_AC_VO, true);
                ret = BRCMF_FWS_RET_OK_NOSCHEDULE;
        }
        brcmf_fws_unlock(fws);
        return ret;
}

static int brcmf_fws_interface_state_indicate(struct brcmf_fws_info *fws,
                                              u8 type, u8 *data)
{
        struct brcmf_fws_mac_descriptor *entry;
        u8 ifidx;
        int ret;

        ifidx = data[0];

        if (ifidx >= BRCMF_MAX_IFS) {
                ret = -ERANGE;
                goto fail;
        }

        entry = &fws->desc.iface[ifidx];
        if (!entry->occupied) {
                ret = -ESRCH;
                goto fail;
        }

        brcmf_dbg(TRACE, "%s (%d): %s\n", brcmf_fws_get_tlv_name(type), type,
                  entry->name);
        brcmf_fws_lock(fws);
        switch (type) {
        case BRCMF_FWS_TYPE_INTERFACE_OPEN:
                entry->state = BRCMF_FWS_STATE_OPEN;
                ret = BRCMF_FWS_RET_OK_SCHEDULE;
                break;
        case BRCMF_FWS_TYPE_INTERFACE_CLOSE:
                entry->state = BRCMF_FWS_STATE_CLOSE;
                ret = BRCMF_FWS_RET_OK_NOSCHEDULE;
                break;
        default:
                ret = -EINVAL;
                brcmf_fws_unlock(fws);
                goto fail;
        }
        brcmf_fws_unlock(fws);
        return ret;

fail:
        fws->stats.if_update_failed++;
        return ret;
}

static int brcmf_fws_request_indicate(struct brcmf_fws_info *fws, u8 type,
                                      u8 *data)
{
        struct brcmf_fws_mac_descriptor *entry;

        entry = &fws->desc.nodes[data[1] & 0x1F];
        if (!entry->occupied) {
                if (type == BRCMF_FWS_TYPE_MAC_REQUEST_CREDIT)
                        fws->stats.credit_request_failed++;
                else
                        fws->stats.packet_request_failed++;
                return -ESRCH;
        }

        brcmf_dbg(TRACE, "%s (%d): %s cnt %d bmp %d\n",
                  brcmf_fws_get_tlv_name(type), type, entry->name,
                  data[0], data[2]);
        brcmf_fws_lock(fws);
        if (type == BRCMF_FWS_TYPE_MAC_REQUEST_CREDIT)
                entry->requested_credit = data[0];
        else
                entry->requested_packet = data[0];

        entry->ac_bitmap = data[2];
        brcmf_fws_unlock(fws);
        return BRCMF_FWS_RET_OK_SCHEDULE;
}

static void
brcmf_fws_macdesc_use_req_credit(struct brcmf_fws_mac_descriptor *entry,
                                 struct sk_buff *skb)
{
        if (entry->requested_credit > 0) {
                entry->requested_credit--;
                brcmf_skb_if_flags_set_field(skb, REQUESTED, 1);
                brcmf_skb_if_flags_set_field(skb, REQ_CREDIT, 1);
                if (entry->state != BRCMF_FWS_STATE_CLOSE)
                        brcmf_err("requested credit set while mac not closed!\n");
        } else if (entry->requested_packet > 0) {
                entry->requested_packet--;
                brcmf_skb_if_flags_set_field(skb, REQUESTED, 1);
                brcmf_skb_if_flags_set_field(skb, REQ_CREDIT, 0);
                if (entry->state != BRCMF_FWS_STATE_CLOSE)
                        brcmf_err("requested packet set while mac not closed!\n");
        } else {
                brcmf_skb_if_flags_set_field(skb, REQUESTED, 0);
                brcmf_skb_if_flags_set_field(skb, REQ_CREDIT, 0);
        }
}

static void brcmf_fws_macdesc_return_req_credit(struct sk_buff *skb)
{
        struct brcmf_fws_mac_descriptor *entry = brcmf_skbcb(skb)->mac;

        if ((brcmf_skb_if_flags_get_field(skb, REQ_CREDIT)) &&
            (entry->state == BRCMF_FWS_STATE_CLOSE))
                entry->requested_credit++;
}

static void brcmf_fws_return_credits(struct brcmf_fws_info *fws,
                                     u8 fifo, u8 credits)
{
        int lender_ac;
        int *borrowed;
        int *fifo_credit;

        if (!credits)
                return;

        fws->fifo_credit_map |= 1 << fifo;

        if ((fifo == BRCMF_FWS_FIFO_AC_BE) &&
            (fws->credits_borrowed[0])) {
                for (lender_ac = BRCMF_FWS_FIFO_AC_VO; lender_ac >= 0;
                     lender_ac--) {
                        borrowed = &fws->credits_borrowed[lender_ac];
                        if (*borrowed) {
                                fws->fifo_credit_map |= (1 << lender_ac);
                                fifo_credit = &fws->fifo_credit[lender_ac];
                                if (*borrowed >= credits) {
                                        *borrowed -= credits;
                                        *fifo_credit += credits;
                                        return;
                                } else {
                                        credits -= *borrowed;
                                        *fifo_credit += *borrowed;
                                        *borrowed = 0;
                                }
                        }
                }
        }

        fws->fifo_credit[fifo] += credits;
}

static void brcmf_fws_schedule_deq(struct brcmf_fws_info *fws)
{
        /* only schedule dequeue when there are credits for delayed traffic */
        if ((fws->fifo_credit_map & fws->fifo_delay_map) ||
            (!brcmf_fws_fc_active(fws) && fws->fifo_delay_map))
                queue_work(fws->fws_wq, &fws->fws_dequeue_work);
}

static int brcmf_fws_enq(struct brcmf_fws_info *fws,
                         enum brcmf_fws_skb_state state, int fifo,
                         struct sk_buff *p)
{
        int prec = 2 * fifo;
        u32 *qfull_stat = &fws->stats.delayq_full_error;
        struct brcmf_fws_mac_descriptor *entry;
        struct pktq *pq;
        struct sk_buff_head *queue;
        struct sk_buff *p_head;
        struct sk_buff *p_tail;
        u32 fr_new;
        u32 fr_compare;

        entry = brcmf_skbcb(p)->mac;
        if (entry == NULL) {
                brcmf_err("no mac descriptor found for skb %p\n", p);
                return -ENOENT;
        }

        brcmf_dbg(DATA, "enter: fifo %d skb %p\n", fifo, p);
        if (state == BRCMF_FWS_SKBSTATE_SUPPRESSED) {
                prec += 1;
                qfull_stat = &fws->stats.supprq_full_error;

                /* Fix out of order delivery of frames. Dont assume frame    */
                /* can be inserted at the end, but look for correct position */
                pq = &entry->psq;
                if (pktq_full(pq) || pktq_pfull(pq, prec)) {
                        *qfull_stat += 1;
                        return -ENFILE;
                }
                queue = &pq->q[prec].skblist;

                p_head = skb_peek(queue);
                p_tail = skb_peek_tail(queue);
                fr_new = brcmf_skb_htod_tag_get_field(p, FREERUN);

                while (p_head != p_tail) {
                        fr_compare = brcmf_skb_htod_tag_get_field(p_tail,
                                                                  FREERUN);
                        /* be sure to handle wrap of 256 */
                        if (((fr_new > fr_compare) &&
                             ((fr_new - fr_compare) < 128)) ||
                            ((fr_new < fr_compare) &&
                             ((fr_compare - fr_new) > 128)))
                                break;
                        p_tail = skb_queue_prev(queue, p_tail);
                }
                /* Position found. Determine what to do */
                if (p_tail == NULL) {
                        /* empty list */
                        __skb_queue_tail(queue, p);
                } else {
                        fr_compare = brcmf_skb_htod_tag_get_field(p_tail,
                                                                  FREERUN);
                        if (((fr_new > fr_compare) &&
                             ((fr_new - fr_compare) < 128)) ||
                            ((fr_new < fr_compare) &&
                             ((fr_compare - fr_new) > 128))) {
                                /* After tail */
                                __skb_queue_after(queue, p_tail, p);
                        } else {
                                /* Before tail */
                                __skb_insert(p, p_tail->prev, p_tail, queue);
                        }
                }

                /* Complete the counters and statistics */
                pq->len++;
                if (pq->hi_prec < prec)
                        pq->hi_prec = (u8) prec;
        } else if (brcmu_pktq_penq(&entry->psq, prec, p) == NULL) {
                *qfull_stat += 1;
                return -ENFILE;
        }

        /* increment total enqueued packet count */
        fws->fifo_delay_map |= 1 << fifo;
        fws->fifo_enqpkt[fifo]++;

        /* update the sk_buff state */
        brcmf_skbcb(p)->state = state;

        /*
         * A packet has been pushed so update traffic
         * availability bitmap, if applicable
         */
        brcmf_fws_tim_update(fws, entry, fifo, true);
        brcmf_fws_flow_control_check(fws, &entry->psq,
                                     brcmf_skb_if_flags_get_field(p, INDEX));
        return 0;
}

static struct sk_buff *brcmf_fws_deq(struct brcmf_fws_info *fws, int fifo)
{
        struct brcmf_fws_mac_descriptor *table;
        struct brcmf_fws_mac_descriptor *entry;
        struct sk_buff *p;
        int num_nodes;
        int node_pos;
        int prec_out;
        int pmsk;
        int i;

        table = (struct brcmf_fws_mac_descriptor *)&fws->desc;
        num_nodes = sizeof(fws->desc) / sizeof(struct brcmf_fws_mac_descriptor);
        node_pos = fws->deq_node_pos[fifo];

        for (i = 0; i < num_nodes; i++) {
                entry = &table[(node_pos + i) % num_nodes];
                if (!entry->occupied ||
                    brcmf_fws_macdesc_closed(fws, entry, fifo))
                        continue;

                if (entry->suppressed)
                        pmsk = 2;
                else
                        pmsk = 3;
                p = brcmu_pktq_mdeq(&entry->psq, pmsk << (fifo * 2), &prec_out);
                if (p == NULL) {
                        if (entry->suppressed) {
                                if (entry->suppr_transit_count)
                                        continue;
                                entry->suppressed = false;
                                p = brcmu_pktq_mdeq(&entry->psq,
                                                    1 << (fifo * 2), &prec_out);
                        }
                }
                if  (p == NULL)
                        continue;

                brcmf_fws_macdesc_use_req_credit(entry, p);

                /* move dequeue position to ensure fair round-robin */
                fws->deq_node_pos[fifo] = (node_pos + i + 1) % num_nodes;
                brcmf_fws_flow_control_check(fws, &entry->psq,
                                             brcmf_skb_if_flags_get_field(p,
                                                                          INDEX)
                                             );
                /*
                 * A packet has been picked up, update traffic
                 * availability bitmap, if applicable
                 */
                brcmf_fws_tim_update(fws, entry, fifo, false);

                /*
                 * decrement total enqueued fifo packets and
                 * clear delay bitmap if done.
                 */
                fws->fifo_enqpkt[fifo]--;
                if (fws->fifo_enqpkt[fifo] == 0)
                        fws->fifo_delay_map &= ~(1 << fifo);
                goto done;
        }
        p = NULL;
done:
        brcmf_dbg(DATA, "exit: fifo %d skb %p\n", fifo, p);
        return p;
}

static int brcmf_fws_txstatus_suppressed(struct brcmf_fws_info *fws, int fifo,
                                         struct sk_buff *skb, u8 ifidx,
                                         u32 genbit, u16 seq)
{
        struct brcmf_fws_mac_descriptor *entry = brcmf_skbcb(skb)->mac;
        u32 hslot;
        int ret;

        hslot = brcmf_skb_htod_tag_get_field(skb, HSLOT);

        /* this packet was suppressed */
        if (!entry->suppressed) {
                entry->suppressed = true;
                entry->suppr_transit_count = entry->transit_count;
                brcmf_dbg(DATA, "suppress %s: transit %d\n",
                          entry->name, entry->transit_count);
        }

        entry->generation = genbit;

        brcmf_skb_htod_tag_set_field(skb, GENERATION, genbit);
        brcmf_skbcb(skb)->htod_seq = seq;
        if (brcmf_skb_htod_seq_get_field(skb, FROMFW)) {
                brcmf_skb_htod_seq_set_field(skb, FROMDRV, 1);
                brcmf_skb_htod_seq_set_field(skb, FROMFW, 0);
        } else {
                brcmf_skb_htod_seq_set_field(skb, FROMDRV, 0);
        }
        ret = brcmf_fws_enq(fws, BRCMF_FWS_SKBSTATE_SUPPRESSED, fifo, skb);

        if (ret != 0) {
                /* suppress q is full drop this packet */
                brcmf_fws_hanger_poppkt(&fws->hanger, hslot, &skb, true);
        } else {
                /* Mark suppressed to avoid a double free during wlfc cleanup */
                brcmf_fws_hanger_mark_suppressed(&fws->hanger, hslot);
        }

        return ret;
}

static int
brcmf_fws_txs_process(struct brcmf_fws_info *fws, u8 flags, u32 hslot,
                      u32 genbit, u16 seq)
{
        u32 fifo;
        int ret;
        bool remove_from_hanger = true;
        struct sk_buff *skb;
        struct brcmf_skbuff_cb *skcb;
        struct brcmf_fws_mac_descriptor *entry = NULL;
        u8 ifidx;

        brcmf_dbg(DATA, "flags %d\n", flags);

        if (flags == BRCMF_FWS_TXSTATUS_DISCARD)
                fws->stats.txs_discard++;
        else if (flags == BRCMF_FWS_TXSTATUS_CORE_SUPPRESS) {
                fws->stats.txs_supp_core++;
                remove_from_hanger = false;
        } else if (flags == BRCMF_FWS_TXSTATUS_FW_PS_SUPPRESS) {
                fws->stats.txs_supp_ps++;
                remove_from_hanger = false;
        } else if (flags == BRCMF_FWS_TXSTATUS_FW_TOSSED)
                fws->stats.txs_tossed++;
        else if (flags == BRCMF_FWS_TXSTATUS_HOST_TOSSED)
                fws->stats.txs_host_tossed++;
        else
                brcmf_err("unexpected txstatus\n");

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

        skcb = brcmf_skbcb(skb);
        entry = skcb->mac;
        if (WARN_ON(!entry)) {
                brcmu_pkt_buf_free_skb(skb);
                return -EINVAL;
        }
        entry->transit_count--;
        if (entry->suppressed && entry->suppr_transit_count)
                entry->suppr_transit_count--;

        brcmf_dbg(DATA, "%s flags %d htod %X seq %X\n", entry->name, flags,
                  skcb->htod, seq);

        /* pick up the implicit credit from this packet */
        fifo = brcmf_skb_htod_tag_get_field(skb, FIFO);
        if ((fws->fcmode == BRCMF_FWS_FCMODE_IMPLIED_CREDIT) ||
            (brcmf_skb_if_flags_get_field(skb, REQ_CREDIT)) ||
            (flags == BRCMF_FWS_TXSTATUS_HOST_TOSSED)) {
                brcmf_fws_return_credits(fws, fifo, 1);
                brcmf_fws_schedule_deq(fws);
        }
        brcmf_fws_macdesc_return_req_credit(skb);

        if (brcmf_proto_hdrpull(fws->drvr, false, &ifidx, skb)) {
                brcmu_pkt_buf_free_skb(skb);
                return -EINVAL;
        }
        if (!remove_from_hanger)
                ret = brcmf_fws_txstatus_suppressed(fws, fifo, skb, ifidx,
                                                    genbit, seq);
        if (remove_from_hanger || ret)
                brcmf_txfinalize(fws->drvr, skb, ifidx, true);

        return 0;
}

static int brcmf_fws_fifocreditback_indicate(struct brcmf_fws_info *fws,
                                             u8 *data)
{
        int i;

        if (fws->fcmode != BRCMF_FWS_FCMODE_EXPLICIT_CREDIT) {
                brcmf_dbg(INFO, "ignored\n");
                return BRCMF_FWS_RET_OK_NOSCHEDULE;
        }

        brcmf_dbg(DATA, "enter: data %pM\n", data);
        brcmf_fws_lock(fws);
        for (i = 0; i < BRCMF_FWS_FIFO_COUNT; i++)
                brcmf_fws_return_credits(fws, i, data[i]);

        brcmf_dbg(DATA, "map: credit %x delay %x\n", fws->fifo_credit_map,
                  fws->fifo_delay_map);
        brcmf_fws_unlock(fws);
        return BRCMF_FWS_RET_OK_SCHEDULE;
}

static int brcmf_fws_txstatus_indicate(struct brcmf_fws_info *fws, u8 *data)
{
        __le32 status_le;
        __le16 seq_le;
        u32 status;
        u32 hslot;
        u32 genbit;
        u8 flags;
        u16 seq;

        fws->stats.txs_indicate++;
        memcpy(&status_le, data, sizeof(status_le));
        status = le32_to_cpu(status_le);
        flags = brcmf_txstatus_get_field(status, FLAGS);
        hslot = brcmf_txstatus_get_field(status, HSLOT);
        genbit = brcmf_txstatus_get_field(status, GENERATION);
        if (BRCMF_FWS_MODE_GET_REUSESEQ(fws->mode)) {
                memcpy(&seq_le, &data[BRCMF_FWS_TYPE_PKTTAG_LEN],
                       sizeof(seq_le));
                seq = le16_to_cpu(seq_le);
        } else {
                seq = 0;
        }

        brcmf_fws_lock(fws);
        brcmf_fws_txs_process(fws, flags, hslot, genbit, seq);
        brcmf_fws_unlock(fws);
        return BRCMF_FWS_RET_OK_NOSCHEDULE;
}

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

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

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;
        u8 *credits = data;

        if (e->datalen < BRCMF_FWS_FIFO_COUNT) {
                brcmf_err("event payload too small (%d)\n", e->datalen);
                return -EINVAL;
        }
        if (fws->creditmap_received)
                return 0;

        fws->creditmap_received = true;

        brcmf_dbg(TRACE, "enter: credits %pM\n", credits);
        brcmf_fws_lock(fws);
        for (i = 0; i < ARRAY_SIZE(fws->fifo_credit); i++) {
                if (*credits)
                        fws->fifo_credit_map |= 1 << i;
                else
                        fws->fifo_credit_map &= ~(1 << i);
                fws->fifo_credit[i] = *credits++;
        }
        brcmf_fws_schedule_deq(fws);
        brcmf_fws_unlock(fws);
        return 0;
}

static int brcmf_fws_notify_bcmc_credit_support(struct brcmf_if *ifp,
                                                const struct brcmf_event_msg *e,
                                                void *data)
{
        struct brcmf_fws_info *fws = ifp->drvr->fws;

        brcmf_fws_lock(fws);
        if (fws)
                fws->bcmc_credit_check = true;
        brcmf_fws_unlock(fws);
        return 0;
}

int brcmf_fws_hdrpull(struct brcmf_pub *drvr, int ifidx, s16 signal_len,
                      struct sk_buff *skb)
{
        struct brcmf_skb_reorder_data *rd;
        struct brcmf_fws_info *fws = drvr->fws;
        u8 *signal_data;
        s16 data_len;
        u8 type;
        u8 len;
        u8 *data;
        s32 status;
        s32 err;

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

        WARN_ON(signal_len > skb->len);

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

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

        status = BRCMF_FWS_RET_OK_NOSCHEDULE;
        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(HDRS, "tlv type=%s (%d), len=%d (%d)\n",
                          brcmf_fws_get_tlv_name(type), type, len,
                          brcmf_fws_get_tlv_len(fws, type));

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

                if (len < brcmf_fws_get_tlv_len(fws, type))
                        break;

                err = BRCMF_FWS_RET_OK_NOSCHEDULE;
                switch (type) {
                case BRCMF_FWS_TYPE_COMP_TXSTATUS:
                        break;
                case BRCMF_FWS_TYPE_HOST_REORDER_RXPKTS:
                        rd = (struct brcmf_skb_reorder_data *)skb->cb;
                        rd->reorder = data;
                        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_MAC_OPEN:
                case BRCMF_FWS_TYPE_MAC_CLOSE:
                        err = brcmf_fws_macdesc_state_indicate(fws, type, data);
                        break;
                case BRCMF_FWS_TYPE_INTERFACE_OPEN:
                case BRCMF_FWS_TYPE_INTERFACE_CLOSE:
                        err = brcmf_fws_interface_state_indicate(fws, type,
                                                                 data);
                        break;
                case BRCMF_FWS_TYPE_MAC_REQUEST_CREDIT:
                case BRCMF_FWS_TYPE_MAC_REQUEST_PACKET:
                        err = brcmf_fws_request_indicate(fws, type, data);
                        break;
                case BRCMF_FWS_TYPE_TXSTATUS:
                        brcmf_fws_txstatus_indicate(fws, data);
                        break;
                case BRCMF_FWS_TYPE_FIFO_CREDITBACK:
                        err = brcmf_fws_fifocreditback_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;
                case BRCMF_FWS_TYPE_PKTTAG:
                case BRCMF_FWS_TYPE_PENDING_TRAFFIC_BMP:
                default:
                        fws->stats.tlv_invalid_type++;
                        break;
                }
                if (err == BRCMF_FWS_RET_OK_SCHEDULE)
                        status = BRCMF_FWS_RET_OK_SCHEDULE;
                signal_data += len + 2;
                data_len -= len + 2;
        }

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

        if (status == BRCMF_FWS_RET_OK_SCHEDULE)
                brcmf_fws_schedule_deq(fws);

        /* 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++;

        return 0;
}

static u8 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;
        u8 flags;

        if (skcb->state != BRCMF_FWS_SKBSTATE_SUPPRESSED)
                brcmf_skb_htod_tag_set_field(p, GENERATION, entry->generation);
        flags = BRCMF_FWS_HTOD_FLAG_PKTFROMHOST;
        if (brcmf_skb_if_flags_get_field(p, REQUESTED)) {
                /*
                 * 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);
        return brcmf_fws_hdrpush(fws, p);
}

static void brcmf_fws_rollback_toq(struct brcmf_fws_info *fws,
                                   struct sk_buff *skb, int fifo)
{
        struct brcmf_fws_mac_descriptor *entry;
        struct sk_buff *pktout;
        int qidx, hslot;
        int rc = 0;

        entry = brcmf_skbcb(skb)->mac;
        if (entry->occupied) {
                qidx = 2 * fifo;
                if (brcmf_skbcb(skb)->state == BRCMF_FWS_SKBSTATE_SUPPRESSED)
                        qidx++;

                pktout = brcmu_pktq_penq_head(&entry->psq, qidx, skb);
                if (pktout == NULL) {
                        brcmf_err("%s queue %d full\n", entry->name, qidx);
                        rc = -ENOSPC;
                }
        } else {
                brcmf_err("%s entry removed\n", entry->name);
                rc = -ENOENT;
        }

        if (rc) {
                fws->stats.rollback_failed++;
                hslot = brcmf_skb_htod_tag_get_field(skb, HSLOT);
                brcmf_fws_txs_process(fws, BRCMF_FWS_TXSTATUS_HOST_TOSSED,
                                      hslot, 0, 0);
        } else {
                fws->stats.rollback_success++;
                brcmf_fws_return_credits(fws, fifo, 1);
                brcmf_fws_macdesc_return_req_credit(skb);
        }
}

static int brcmf_fws_borrow_credit(struct brcmf_fws_info *fws)
{
        int lender_ac;

        if (time_after(fws->borrow_defer_timestamp, jiffies)) {
                fws->fifo_credit_map &= ~(1 << BRCMF_FWS_FIFO_AC_BE);
                return -ENAVAIL;
        }

        for (lender_ac = 0; lender_ac <= BRCMF_FWS_FIFO_AC_VO; lender_ac++) {
                if (fws->fifo_credit[lender_ac]) {
                        fws->credits_borrowed[lender_ac]++;
                        fws->fifo_credit[lender_ac]--;
                        if (fws->fifo_credit[lender_ac] == 0)
                                fws->fifo_credit_map &= ~(1 << lender_ac);
                        fws->fifo_credit_map |= (1 << BRCMF_FWS_FIFO_AC_BE);
                        brcmf_dbg(DATA, "borrow credit from: %d\n", lender_ac);
                        return 0;
                }
        }
        fws->fifo_credit_map &= ~(1 << BRCMF_FWS_FIFO_AC_BE);
        return -ENAVAIL;
}

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;
        int rc;
        u8 ifidx;
        u8 data_offset;

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

        data_offset = brcmf_fws_precommit_skb(fws, fifo, skb);
        entry->transit_count++;
        if (entry->suppressed)
                entry->suppr_transit_count++;
        ifidx = brcmf_skb_if_flags_get_field(skb, INDEX);
        brcmf_fws_unlock(fws);
        rc = brcmf_proto_txdata(fws->drvr, ifidx, data_offset, skb);
        brcmf_fws_lock(fws);
        brcmf_dbg(DATA, "%s flags %X htod %X bus_tx %d\n", entry->name,
                  skcb->if_flags, skcb->htod, rc);
        if (rc < 0) {
                entry->transit_count--;
                if (entry->suppressed)
                        entry->suppr_transit_count--;
                brcmf_proto_hdrpull(fws->drvr, false, &ifidx, skb);
                goto rollback;
        }

        fws->stats.pkt2bus++;
        fws->stats.send_pkts[fifo]++;
        if (brcmf_skb_if_flags_get_field(skb, REQUESTED))
                fws->stats.requested_sent[fifo]++;

        return rc;

rollback:
        brcmf_fws_rollback_toq(fws, skb, fifo);
        return rc;
}

static int brcmf_fws_assign_htod(struct brcmf_fws_info *fws, struct sk_buff *p,
                                  int fifo)
{
        struct brcmf_skbuff_cb *skcb = brcmf_skbcb(p);
        int rc, hslot;

        skcb->htod = 0;
        skcb->htod_seq = 0;
        hslot = brcmf_fws_hanger_get_free_slot(&fws->hanger);
        brcmf_skb_htod_tag_set_field(p, HSLOT, hslot);
        brcmf_skb_htod_tag_set_field(p, FREERUN, skcb->mac->seq[fifo]);
        brcmf_skb_htod_tag_set_field(p, FIFO, fifo);
        rc = brcmf_fws_hanger_pushpkt(&fws->hanger, p, hslot);
        if (!rc)
                skcb->mac->seq[fifo]++;
        else
                fws->stats.generic_error++;
        return rc;
}

int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb)
{
        struct brcmf_pub *drvr = ifp->drvr;
        struct brcmf_fws_info *fws = drvr->fws;
        struct brcmf_skbuff_cb *skcb = brcmf_skbcb(skb);
        struct ethhdr *eh = (struct ethhdr *)(skb->data);
        int fifo = BRCMF_FWS_FIFO_BCMC;
        bool multicast = is_multicast_ether_addr(eh->h_dest);
        int rc = 0;

        brcmf_dbg(DATA, "tx proto=0x%X\n", ntohs(eh->h_proto));
        /* determine the priority */
        if (!skb->priority)
                skb->priority = cfg80211_classify8021d(skb, NULL);

        drvr->tx_multicast += !!multicast;

        if (fws->avoid_queueing) {
                rc = brcmf_proto_txdata(drvr, ifp->ifidx, 0, skb);
                if (rc < 0)
                        brcmf_txfinalize(drvr, skb, ifp->ifidx, false);
                return rc;
        }

        /* set control buffer information */
        skcb->if_flags = 0;
        skcb->state = BRCMF_FWS_SKBSTATE_NEW;
        brcmf_skb_if_flags_set_field(skb, INDEX, ifp->ifidx);
        if (!multicast)
                fifo = brcmf_fws_prio2fifo[skb->priority];

        brcmf_fws_lock(fws);
        if (fifo != BRCMF_FWS_FIFO_AC_BE && fifo < BRCMF_FWS_FIFO_BCMC)
                fws->borrow_defer_timestamp = jiffies +
                                              BRCMF_FWS_BORROW_DEFER_PERIOD;

        skcb->mac = brcmf_fws_macdesc_find(fws, ifp, eh->h_dest);
        brcmf_dbg(DATA, "%s mac %pM multi %d fifo %d\n", skcb->mac->name,
                  eh->h_dest, multicast, fifo);
        if (!brcmf_fws_assign_htod(fws, skb, fifo)) {
                brcmf_fws_enq(fws, BRCMF_FWS_SKBSTATE_DELAYED, fifo, skb);
                brcmf_fws_schedule_deq(fws);
        } else {
                brcmf_err("drop skb: no hanger slot\n");
                brcmf_txfinalize(drvr, skb, ifp->ifidx, false);
                rc = -ENOMEM;
        }
        brcmf_fws_unlock(fws);

        return rc;
}

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

void brcmf_fws_add_interface(struct brcmf_if *ifp)
{
        struct brcmf_fws_info *fws = ifp->drvr->fws;
        struct brcmf_fws_mac_descriptor *entry;

        if (!ifp->ndev)
                return;

        entry = &fws->desc.iface[ifp->ifidx];
        ifp->fws_desc = entry;
        brcmf_fws_macdesc_init(entry, ifp->mac_addr, ifp->ifidx);
        brcmf_fws_macdesc_set_name(fws, entry);
        brcmu_pktq_init(&entry->psq, BRCMF_FWS_PSQ_PREC_COUNT,
                        BRCMF_FWS_PSQ_LEN);
        brcmf_dbg(TRACE, "added %s\n", entry->name);
}

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

        if (!entry)
                return;

        brcmf_fws_lock(ifp->drvr->fws);
        ifp->fws_desc = NULL;
        brcmf_dbg(TRACE, "deleting %s\n", entry->name);
        brcmf_fws_macdesc_deinit(entry);
        brcmf_fws_cleanup(ifp->drvr->fws, ifp->ifidx);
        brcmf_fws_unlock(ifp->drvr->fws);
}

static void brcmf_fws_dequeue_worker(struct work_struct *worker)
{
        struct brcmf_fws_info *fws;
        struct brcmf_pub *drvr;
        struct sk_buff *skb;
        int fifo;
        u32 hslot;
        u32 ifidx;
        int ret;

        fws = container_of(worker, struct brcmf_fws_info, fws_dequeue_work);
        drvr = fws->drvr;

        brcmf_fws_lock(fws);
        for (fifo = BRCMF_FWS_FIFO_BCMC; fifo >= 0 && !fws->bus_flow_blocked;
             fifo--) {
                if (!brcmf_fws_fc_active(fws)) {
                        while ((skb = brcmf_fws_deq(fws, fifo)) != NULL) {
                                hslot = brcmf_skb_htod_tag_get_field(skb,

                                                                     HSLOT);
                                brcmf_fws_hanger_poppkt(&fws->hanger, hslot,
                                                        &skb, true);
                                ifidx = brcmf_skb_if_flags_get_field(skb,
                                                                     INDEX);
                                /* Use proto layer to send data frame */
                                brcmf_fws_unlock(fws);
                                ret = brcmf_proto_txdata(drvr, ifidx, 0, skb);
                                brcmf_fws_lock(fws);
                                if (ret < 0)
                                        brcmf_txfinalize(drvr, skb, ifidx,
                                                         false);
                                if (fws->bus_flow_blocked)
                                        break;
                        }
                        continue;
                }
                while ((fws->fifo_credit[fifo]) || ((!fws->bcmc_credit_check) &&
                       (fifo == BRCMF_FWS_FIFO_BCMC))) {
                        skb = brcmf_fws_deq(fws, fifo);
                        if (!skb)
                                break;
                        fws->fifo_credit[fifo]--;
                        if (brcmf_fws_commit_skb(fws, fifo, skb))
                                break;
                        if (fws->bus_flow_blocked)
                                break;
                }
                if ((fifo == BRCMF_FWS_FIFO_AC_BE) &&
                    (fws->fifo_credit[fifo] == 0) &&
                    (!fws->bus_flow_blocked)) {
                        while (brcmf_fws_borrow_credit(fws) == 0) {
                                skb = brcmf_fws_deq(fws, fifo);
                                if (!skb) {
                                        brcmf_fws_return_credits(fws, fifo, 1);
                                        break;
                                }
                                if (brcmf_fws_commit_skb(fws, fifo, skb))
                                        break;
                                if (fws->bus_flow_blocked)
                                        break;
                        }
                }
        }
        brcmf_fws_unlock(fws);
}

#ifdef DEBUG
static int brcmf_debugfs_fws_stats_read(struct seq_file *seq, void *data)
{
        struct brcmf_bus *bus_if = dev_get_drvdata(seq->private);
        struct brcmf_fws_stats *fwstats = &bus_if->drvr->fws->stats;

        seq_printf(seq,
                   "header_pulls:      %u\n"
                   "header_only_pkt:   %u\n"
                   "tlv_parse_failed:  %u\n"
                   "tlv_invalid_type:  %u\n"
                   "mac_update_fails:  %u\n"
                   "ps_update_fails:   %u\n"
                   "if_update_fails:   %u\n"
                   "pkt2bus:           %u\n"
                   "generic_error:     %u\n"
                   "rollback_success:  %u\n"
                   "rollback_failed:   %u\n"
                   "delayq_full:       %u\n"
                   "supprq_full:       %u\n"
                   "txs_indicate:      %u\n"
                   "txs_discard:       %u\n"
                   "txs_suppr_core:    %u\n"
                   "txs_suppr_ps:      %u\n"
                   "txs_tossed:        %u\n"
                   "txs_host_tossed:   %u\n"
                   "bus_flow_block:    %u\n"
                   "fws_flow_block:    %u\n"
                   "send_pkts:         BK:%u BE:%u VO:%u VI:%u BCMC:%u\n"
                   "requested_sent:    BK:%u BE:%u VO:%u VI:%u BCMC:%u\n",
                   fwstats->header_pulls,
                   fwstats->header_only_pkt,
                   fwstats->tlv_parse_failed,
                   fwstats->tlv_invalid_type,
                   fwstats->mac_update_failed,
                   fwstats->mac_ps_update_failed,
                   fwstats->if_update_failed,
                   fwstats->pkt2bus,
                   fwstats->generic_error,
                   fwstats->rollback_success,
                   fwstats->rollback_failed,
                   fwstats->delayq_full_error,
                   fwstats->supprq_full_error,
                   fwstats->txs_indicate,
                   fwstats->txs_discard,
                   fwstats->txs_supp_core,
                   fwstats->txs_supp_ps,
                   fwstats->txs_tossed,
                   fwstats->txs_host_tossed,
                   fwstats->bus_flow_block,
                   fwstats->fws_flow_block,
                   fwstats->send_pkts[0], fwstats->send_pkts[1],
                   fwstats->send_pkts[2], fwstats->send_pkts[3],
                   fwstats->send_pkts[4],
                   fwstats->requested_sent[0],
                   fwstats->requested_sent[1],
                   fwstats->requested_sent[2],
                   fwstats->requested_sent[3],
                   fwstats->requested_sent[4]);

        return 0;
}
#else
static int brcmf_debugfs_fws_stats_read(struct seq_file *seq, void *data)
{
        return 0;
}
#endif

int brcmf_fws_init(struct brcmf_pub *drvr)
{
        struct brcmf_fws_info *fws;
        u32 tlv = BRCMF_FWS_FLAGS_RSSI_SIGNALS;
        int rc;
        u32 mode;

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

        fws = drvr->fws;

        spin_lock_init(&fws->spinlock);

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

        if ((drvr->bus_if->always_use_fws_queue == false) &&
            (fcmode == BRCMF_FWS_FCMODE_NONE)) {
                fws->avoid_queueing = true;
                brcmf_dbg(INFO, "FWS queueing will be avoided\n");
                return 0;
        }

        fws->fws_wq = create_singlethread_workqueue("brcmf_fws_wq");
        if (fws->fws_wq == NULL) {
                brcmf_err("workqueue creation failed\n");
                rc = -EBADF;
                goto fail;
        }
        INIT_WORK(&fws->fws_dequeue_work, brcmf_fws_dequeue_worker);

        /* enable firmware signalling if fcmode active */
        if (fws->fcmode != BRCMF_FWS_FCMODE_NONE)
                tlv |= BRCMF_FWS_FLAGS_XONXOFF_SIGNALS |
                       BRCMF_FWS_FLAGS_CREDIT_STATUS_SIGNALS |
                       BRCMF_FWS_FLAGS_HOST_PROPTXSTATUS_ACTIVE |
                       BRCMF_FWS_FLAGS_HOST_RXREORDER_ACTIVE;

        rc = brcmf_fweh_register(drvr, BRCMF_E_FIFO_CREDIT_MAP,
                                 brcmf_fws_notify_credit_map);
        if (rc < 0) {
                brcmf_err("register credit map handler failed\n");
                goto fail;
        }
        rc = brcmf_fweh_register(drvr, BRCMF_E_BCMC_CREDIT_SUPPORT,
                                 brcmf_fws_notify_bcmc_credit_support);
        if (rc < 0) {
                brcmf_err("register bcmc credit handler failed\n");
                brcmf_fweh_unregister(drvr, BRCMF_E_FIFO_CREDIT_MAP);
                goto fail;
        }

        /* Setting the iovar may fail if feature is unsupported
         * so leave the rc as is so driver initialization can
         * continue. Set mode back to none indicating not enabled.
         */
        fws->fw_signals = true;
        if (brcmf_fil_iovar_int_set(drvr->iflist[0], "tlv", tlv)) {
                brcmf_err("failed to set bdcv2 tlv signaling\n");
                fws->fcmode = BRCMF_FWS_FCMODE_NONE;
                fws->fw_signals = false;
        }

        if (brcmf_fil_iovar_int_set(drvr->iflist[0], "ampdu_hostreorder", 1))
                brcmf_dbg(INFO, "enabling AMPDU host-reorder failed\n");

        /* Enable seq number reuse, if supported */
        if (brcmf_fil_iovar_int_get(drvr->iflist[0], "wlfc_mode", &mode) == 0) {
                if (BRCMF_FWS_MODE_GET_REUSESEQ(mode)) {
                        mode = 0;
                        BRCMF_FWS_MODE_SET_REUSESEQ(mode, 1);
                        if (brcmf_fil_iovar_int_set(drvr->iflist[0],
                                                    "wlfc_mode", mode) == 0) {
                                BRCMF_FWS_MODE_SET_REUSESEQ(fws->mode, 1);
                        }
                }
        }

        brcmf_fws_hanger_init(&fws->hanger);
        brcmf_fws_macdesc_init(&fws->desc.other, NULL, 0);
        brcmf_fws_macdesc_set_name(fws, &fws->desc.other);
        brcmu_pktq_init(&fws->desc.other.psq, BRCMF_FWS_PSQ_PREC_COUNT,
                        BRCMF_FWS_PSQ_LEN);

        /* create debugfs file for statistics */
        brcmf_debugfs_add_entry(drvr, "fws_stats",
                                brcmf_debugfs_fws_stats_read);

        brcmf_dbg(INFO, "%s bdcv2 tlv signaling [%x]\n",
                  fws->fw_signals ? "enabled" : "disabled", tlv);
        return 0;

fail:
        brcmf_fws_deinit(drvr);
        return rc;
}

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

        if (!fws)
                return;

        if (drvr->fws->fws_wq)
                destroy_workqueue(drvr->fws->fws_wq);

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

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

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

        return fws->fcmode != BRCMF_FWS_FCMODE_NONE;
}

void brcmf_fws_bustxfail(struct brcmf_fws_info *fws, struct sk_buff *skb)
{
        u32 hslot;

        if (brcmf_skbcb(skb)->state == BRCMF_FWS_SKBSTATE_TIM) {
                brcmu_pkt_buf_free_skb(skb);
                return;
        }
        brcmf_fws_lock(fws);
        hslot = brcmf_skb_htod_tag_get_field(skb, HSLOT);
        brcmf_fws_txs_process(fws, BRCMF_FWS_TXSTATUS_HOST_TOSSED, hslot, 0, 0);
        brcmf_fws_unlock(fws);
}

void brcmf_fws_bus_blocked(struct brcmf_pub *drvr, bool flow_blocked)
{
        struct brcmf_fws_info *fws = drvr->fws;

        fws->bus_flow_blocked = flow_blocked;
        if (!flow_blocked)
                brcmf_fws_schedule_deq(fws);
        else
                fws->stats.bus_flow_block++;
}