// SPDX-License-Identifier: GPL-2.0
/******************************************************************************
 * rtl8712_recv.c
 *
 * Copyright(c) 2007 - 2010 Realtek Corporation. All rights reserved.
 * Linux device driver for RTL8192SU
 *
 * Modifications for inclusion into the Linux staging tree are
 * Copyright(c) 2010 Larry Finger. All rights reserved.
 *
 * Contact information:
 * WLAN FAE <wlanfae@realtek.com>
 * Larry Finger <Larry.Finger@lwfinger.net>
 *
 ******************************************************************************/

#define _RTL8712_RECV_C_

#include <linux/if_ether.h>
#include <linux/ip.h>

#include "osdep_service.h"
#include "drv_types.h"
#include "recv_osdep.h"
#include "mlme_osdep.h"
#include "ethernet.h"
#include "usb_ops.h"
#include "wifi.h"

/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
static u8 bridge_tunnel_header[] = {0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8};

/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
static u8 rfc1042_header[] = {0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00};

static void recv_tasklet(unsigned long priv);

void r8712_init_recv_priv(struct recv_priv *precvpriv,
                          struct _adapter *padapter)
{
        int i;
        struct recv_buf *precvbuf;
        addr_t tmpaddr = 0;
        int alignment = 0;
        struct sk_buff *pskb = NULL;

        /*init recv_buf*/
        _init_queue(&precvpriv->free_recv_buf_queue);
        precvpriv->pallocated_recv_buf =
                kzalloc(NR_RECVBUFF * sizeof(struct recv_buf) + 4, GFP_ATOMIC);
        if (!precvpriv->pallocated_recv_buf)
                return;
        precvpriv->precv_buf = precvpriv->pallocated_recv_buf + 4 -
                              ((addr_t)(precvpriv->pallocated_recv_buf) & 3);
        precvbuf = (struct recv_buf *)precvpriv->precv_buf;
        for (i = 0; i < NR_RECVBUFF; i++) {
                INIT_LIST_HEAD(&precvbuf->list);
                spin_lock_init(&precvbuf->recvbuf_lock);
                if (r8712_os_recvbuf_resource_alloc(padapter, precvbuf))
                        break;
                precvbuf->ref_cnt = 0;
                precvbuf->adapter = padapter;
                list_add_tail(&precvbuf->list,
                              &(precvpriv->free_recv_buf_queue.queue));
                precvbuf++;
        }
        precvpriv->free_recv_buf_queue_cnt = NR_RECVBUFF;
        tasklet_init(&precvpriv->recv_tasklet, recv_tasklet,
                     (unsigned long)padapter);
        skb_queue_head_init(&precvpriv->rx_skb_queue);

        skb_queue_head_init(&precvpriv->free_recv_skb_queue);
        for (i = 0; i < NR_PREALLOC_RECV_SKB; i++) {
                pskb = netdev_alloc_skb(padapter->pnetdev, MAX_RECVBUF_SZ +
                       RECVBUFF_ALIGN_SZ);
                if (pskb) {
                        tmpaddr = (addr_t)pskb->data;
                        alignment = tmpaddr & (RECVBUFF_ALIGN_SZ - 1);
                        skb_reserve(pskb, (RECVBUFF_ALIGN_SZ - alignment));
                        skb_queue_tail(&precvpriv->free_recv_skb_queue, pskb);
                }
                pskb = NULL;
        }
}

void r8712_free_recv_priv(struct recv_priv *precvpriv)
{
        int i;
        struct recv_buf *precvbuf;
        struct _adapter *padapter = precvpriv->adapter;

        precvbuf = (struct recv_buf *)precvpriv->precv_buf;
        for (i = 0; i < NR_RECVBUFF; i++) {
                r8712_os_recvbuf_resource_free(padapter, precvbuf);
                precvbuf++;
        }
        kfree(precvpriv->pallocated_recv_buf);
        skb_queue_purge(&precvpriv->rx_skb_queue);
        if (skb_queue_len(&precvpriv->rx_skb_queue))
                netdev_warn(padapter->pnetdev, "r8712u: rx_skb_queue not empty\n");
        skb_queue_purge(&precvpriv->free_recv_skb_queue);
        if (skb_queue_len(&precvpriv->free_recv_skb_queue))
                netdev_warn(padapter->pnetdev, "r8712u: free_recv_skb_queue not empty %d\n",
                            skb_queue_len(&precvpriv->free_recv_skb_queue));
}

void r8712_init_recvbuf(struct _adapter *padapter, struct recv_buf *precvbuf)
{
        precvbuf->transfer_len = 0;
        precvbuf->len = 0;
        precvbuf->ref_cnt = 0;
        if (precvbuf->pbuf) {
                precvbuf->pdata = precvbuf->pbuf;
                precvbuf->phead = precvbuf->pbuf;
                precvbuf->ptail = precvbuf->pbuf;
                precvbuf->pend = precvbuf->pdata + MAX_RECVBUF_SZ;
        }
}

void r8712_free_recvframe(union recv_frame *precvframe,
                          struct  __queue *pfree_recv_queue)
{
        unsigned long irqL;
        struct _adapter *padapter = precvframe->u.hdr.adapter;
        struct recv_priv *precvpriv = &padapter->recvpriv;

        if (precvframe->u.hdr.pkt) {
                dev_kfree_skb_any(precvframe->u.hdr.pkt);/*free skb by driver*/
                precvframe->u.hdr.pkt = NULL;
        }
        spin_lock_irqsave(&pfree_recv_queue->lock, irqL);
        list_del_init(&(precvframe->u.hdr.list));
        list_add_tail(&(precvframe->u.hdr.list), &pfree_recv_queue->queue);
        if (padapter) {
                if (pfree_recv_queue == &precvpriv->free_recv_queue)
                        precvpriv->free_recvframe_cnt++;
        }
        spin_unlock_irqrestore(&pfree_recv_queue->lock, irqL);
}

static void update_recvframe_attrib_from_recvstat(struct rx_pkt_attrib *pattrib,
                                                  struct recv_stat *prxstat)
{
        u16 drvinfo_sz;

        drvinfo_sz = (le32_to_cpu(prxstat->rxdw0) & 0x000f0000) >> 16;
        drvinfo_sz <<= 3;
        /*TODO:
         * Offset 0
         */
        pattrib->bdecrypted = ((le32_to_cpu(prxstat->rxdw0) & BIT(27)) >> 27)
                                 ? 0 : 1;
        pattrib->crc_err = (le32_to_cpu(prxstat->rxdw0) & BIT(14)) >> 14;
        /*Offset 4*/
        /*Offset 8*/
        /*Offset 12*/
        if (le32_to_cpu(prxstat->rxdw3) & BIT(13)) {
                pattrib->tcpchk_valid = 1; /* valid */
                if (le32_to_cpu(prxstat->rxdw3) & BIT(11))
                        pattrib->tcp_chkrpt = 1; /* correct */
                else
                        pattrib->tcp_chkrpt = 0; /* incorrect */
                if (le32_to_cpu(prxstat->rxdw3) & BIT(12))
                        pattrib->ip_chkrpt = 1; /* correct */
                else
                        pattrib->ip_chkrpt = 0; /* incorrect */
        } else {
                pattrib->tcpchk_valid = 0; /* invalid */
        }
        pattrib->mcs_rate = (u8)((le32_to_cpu(prxstat->rxdw3)) & 0x3f);
        pattrib->htc = (u8)((le32_to_cpu(prxstat->rxdw3) >> 14) & 0x1);
        /*Offset 16*/
        /*Offset 20*/
        /*phy_info*/
}

/*perform defrag*/
static union recv_frame *recvframe_defrag(struct _adapter *adapter,
                                          struct  __queue *defrag_q)
{
        struct list_head *plist, *phead;
        u8 wlanhdr_offset;
        u8      curfragnum;
        struct recv_frame_hdr *pfhdr, *pnfhdr;
        union recv_frame *prframe, *pnextrframe;
        struct  __queue *pfree_recv_queue;

        pfree_recv_queue = &adapter->recvpriv.free_recv_queue;
        phead = &defrag_q->queue;
        plist = phead->next;
        prframe = container_of(plist, union recv_frame, u.list);
        list_del_init(&prframe->u.list);
        pfhdr = &prframe->u.hdr;
        curfragnum = 0;
        if (curfragnum != pfhdr->attrib.frag_num) {
                /*the first fragment number must be 0
                 *free the whole queue
                 */
                r8712_free_recvframe(prframe, pfree_recv_queue);
                r8712_free_recvframe_queue(defrag_q, pfree_recv_queue);
                return NULL;
        }
        curfragnum++;
        plist = &defrag_q->queue;
        plist = plist->next;
        while (!end_of_queue_search(phead, plist)) {
                pnextrframe = container_of(plist, union recv_frame, u.list);
                pnfhdr = &pnextrframe->u.hdr;
                /*check the fragment sequence  (2nd ~n fragment frame) */
                if (curfragnum != pnfhdr->attrib.frag_num) {
                        /* the fragment number must increase  (after decache)
                         * release the defrag_q & prframe
                         */
                        r8712_free_recvframe(prframe, pfree_recv_queue);
                        r8712_free_recvframe_queue(defrag_q, pfree_recv_queue);
                        return NULL;
                }
                curfragnum++;
                /* copy the 2nd~n fragment frame's payload to the first fragment
                 * get the 2nd~last fragment frame's payload
                 */
                wlanhdr_offset = pnfhdr->attrib.hdrlen + pnfhdr->attrib.iv_len;
                recvframe_pull(pnextrframe, wlanhdr_offset);
                /* append  to first fragment frame's tail (if privacy frame,
                 * pull the ICV)
                 */
                recvframe_pull_tail(prframe, pfhdr->attrib.icv_len);
                memcpy(pfhdr->rx_tail, pnfhdr->rx_data, pnfhdr->len);
                recvframe_put(prframe, pnfhdr->len);
                pfhdr->attrib.icv_len = pnfhdr->attrib.icv_len;
                plist = plist->next;
        }
        /* free the defrag_q queue and return the prframe */
        r8712_free_recvframe_queue(defrag_q, pfree_recv_queue);
        return prframe;
}

/* check if need to defrag, if needed queue the frame to defrag_q */
union recv_frame *r8712_recvframe_chk_defrag(struct _adapter *padapter,
                                             union recv_frame *precv_frame)
{
        u8      ismfrag;
        u8      fragnum;
        u8   *psta_addr;
        struct recv_frame_hdr *pfhdr;
        struct sta_info *psta;
        struct  sta_priv *pstapriv;
        struct list_head *phead;
        union recv_frame *prtnframe = NULL;
        struct  __queue *pfree_recv_queue, *pdefrag_q;

        pstapriv = &padapter->stapriv;
        pfhdr = &precv_frame->u.hdr;
        pfree_recv_queue = &padapter->recvpriv.free_recv_queue;
        /* need to define struct of wlan header frame ctrl */
        ismfrag = pfhdr->attrib.mfrag;
        fragnum = pfhdr->attrib.frag_num;
        psta_addr = pfhdr->attrib.ta;
        psta = r8712_get_stainfo(pstapriv, psta_addr);
        if (!psta)
                pdefrag_q = NULL;
        else
                pdefrag_q = &psta->sta_recvpriv.defrag_q;

        if ((ismfrag == 0) && (fragnum == 0))
                prtnframe = precv_frame;/*isn't a fragment frame*/
        if (ismfrag == 1) {
                /* 0~(n-1) fragment frame
                 * enqueue to defraf_g
                 */
                if (pdefrag_q) {
                        if (fragnum == 0) {
                                /*the first fragment*/
                                if (!list_empty(&pdefrag_q->queue)) {
                                        /*free current defrag_q */
                                        r8712_free_recvframe_queue(pdefrag_q,
                                                             pfree_recv_queue);
                                }
                        }
                        /* Then enqueue the 0~(n-1) fragment to the defrag_q */
                        phead = &pdefrag_q->queue;
                        list_add_tail(&pfhdr->list, phead);
                        prtnframe = NULL;
                } else {
                        /* can't find this ta's defrag_queue, so free this
                         * recv_frame
                         */
                        r8712_free_recvframe(precv_frame, pfree_recv_queue);
                        prtnframe = NULL;
                }
        }
        if ((ismfrag == 0) && (fragnum != 0)) {
                /* the last fragment frame
                 * enqueue the last fragment
                 */
                if (pdefrag_q) {
                        phead = &pdefrag_q->queue;
                        list_add_tail(&pfhdr->list, phead);
                        /*call recvframe_defrag to defrag*/
                        precv_frame = recvframe_defrag(padapter, pdefrag_q);
                        prtnframe = precv_frame;
                } else {
                        /* can't find this ta's defrag_queue, so free this
                         *  recv_frame
                         */
                        r8712_free_recvframe(precv_frame, pfree_recv_queue);
                        prtnframe = NULL;
                }
        }
        if (prtnframe && (prtnframe->u.hdr.attrib.privacy)) {
                /* after defrag we must check tkip mic code */
                if (r8712_recvframe_chkmic(padapter, prtnframe) == _FAIL) {
                        r8712_free_recvframe(prtnframe, pfree_recv_queue);
                        prtnframe = NULL;
                }
        }
        return prtnframe;
}

static void amsdu_to_msdu(struct _adapter *padapter, union recv_frame *prframe)
{
        int     a_len, padding_len;
        u16     eth_type, nSubframe_Length;
        u8      nr_subframes, i;
        unsigned char *pdata;
        struct rx_pkt_attrib *pattrib;
        _pkt *sub_skb, *subframes[MAX_SUBFRAME_COUNT];
        struct recv_priv *precvpriv = &padapter->recvpriv;
        struct  __queue *pfree_recv_queue = &(precvpriv->free_recv_queue);

        nr_subframes = 0;
        pattrib = &prframe->u.hdr.attrib;
        recvframe_pull(prframe, prframe->u.hdr.attrib.hdrlen);
        if (prframe->u.hdr.attrib.iv_len > 0)
                recvframe_pull(prframe, prframe->u.hdr.attrib.iv_len);
        a_len = prframe->u.hdr.len;
        pdata = prframe->u.hdr.rx_data;
        while (a_len > ETH_HLEN) {
                /* Offset 12 denote 2 mac address */
                nSubframe_Length = *((u16 *)(pdata + 12));
                /*==m==>change the length order*/
                nSubframe_Length = (nSubframe_Length >> 8) +
                                   (nSubframe_Length << 8);
                if (a_len < (ETHERNET_HEADER_SIZE + nSubframe_Length)) {
                        netdev_warn(padapter->pnetdev, "r8712u: nRemain_Length is %d and nSubframe_Length is: %d\n",
                                    a_len, nSubframe_Length);
                        goto exit;
                }
                /* move the data point to data content */
                pdata += ETH_HLEN;
                a_len -= ETH_HLEN;
                /* Allocate new skb for releasing to upper layer */
                sub_skb = dev_alloc_skb(nSubframe_Length + 12);
                if (!sub_skb)
                        break;
                skb_reserve(sub_skb, 12);
                skb_put_data(sub_skb, pdata, nSubframe_Length);
                subframes[nr_subframes++] = sub_skb;
                if (nr_subframes >= MAX_SUBFRAME_COUNT) {
                        netdev_warn(padapter->pnetdev, "r8712u: ParseSubframe(): Too many Subframes! Packets dropped!\n");
                        break;
                }
                pdata += nSubframe_Length;
                a_len -= nSubframe_Length;
                if (a_len != 0) {
                        padding_len = 4 - ((nSubframe_Length + ETH_HLEN) & 3);
                        if (padding_len == 4)
                                padding_len = 0;
                        if (a_len < padding_len)
                                goto exit;
                        pdata += padding_len;
                        a_len -= padding_len;
                }
        }
        for (i = 0; i < nr_subframes; i++) {
                sub_skb = subframes[i];
                /* convert hdr + possible LLC headers into Ethernet header */
                eth_type = (sub_skb->data[6] << 8) | sub_skb->data[7];
                if (sub_skb->len >= 8 &&
                    ((!memcmp(sub_skb->data, rfc1042_header, SNAP_SIZE) &&
                      eth_type != ETH_P_AARP && eth_type != ETH_P_IPX) ||
                     !memcmp(sub_skb->data, bridge_tunnel_header, SNAP_SIZE))) {
                        /* remove RFC1042 or Bridge-Tunnel encapsulation and
                         * replace EtherType
                         */
                        skb_pull(sub_skb, SNAP_SIZE);
                        memcpy(skb_push(sub_skb, ETH_ALEN), pattrib->src,
                               ETH_ALEN);
                        memcpy(skb_push(sub_skb, ETH_ALEN), pattrib->dst,
                               ETH_ALEN);
                } else {
                        __be16 len;
                        /* Leave Ethernet header part of hdr and full payload */
                        len = htons(sub_skb->len);
                        memcpy(skb_push(sub_skb, 2), &len, 2);
                        memcpy(skb_push(sub_skb, ETH_ALEN), pattrib->src,
                               ETH_ALEN);
                        memcpy(skb_push(sub_skb, ETH_ALEN), pattrib->dst,
                               ETH_ALEN);
                }
                /* Indicate the packets to upper layer */
                if (sub_skb) {
                        sub_skb->protocol =
                                 eth_type_trans(sub_skb, padapter->pnetdev);
                        sub_skb->dev = padapter->pnetdev;
                        if ((pattrib->tcpchk_valid == 1) &&
                            (pattrib->tcp_chkrpt == 1)) {
                                sub_skb->ip_summed = CHECKSUM_UNNECESSARY;
                        } else {
                                sub_skb->ip_summed = CHECKSUM_NONE;
                        }
                        netif_rx(sub_skb);
                }
        }
exit:
        prframe->u.hdr.len = 0;
        r8712_free_recvframe(prframe, pfree_recv_queue);
}

void r8712_rxcmd_event_hdl(struct _adapter *padapter, void *prxcmdbuf)
{
        __le32 voffset;
        u8 *poffset;
        u16 cmd_len, drvinfo_sz;
        struct recv_stat *prxstat;

        poffset = prxcmdbuf;
        voffset = *(__le32 *)poffset;
        prxstat = prxcmdbuf;
        drvinfo_sz = (le32_to_cpu(prxstat->rxdw0) & 0x000f0000) >> 16;
        drvinfo_sz <<= 3;
        poffset += RXDESC_SIZE + drvinfo_sz;
        do {
                voffset  = *(__le32 *)poffset;
                cmd_len = (u16)(le32_to_cpu(voffset) & 0xffff);
                r8712_event_handle(padapter, (__le32 *)poffset);
                poffset += (cmd_len + 8);/*8 bytes alignment*/
        } while (le32_to_cpu(voffset) & BIT(31));
}

static int check_indicate_seq(struct recv_reorder_ctrl *preorder_ctrl,
                              u16 seq_num)
{
        u8 wsize = preorder_ctrl->wsize_b;
        u16 wend = (preorder_ctrl->indicate_seq + wsize - 1) % 4096;

        /* Rx Reorder initialize condition.*/
        if (preorder_ctrl->indicate_seq == 0xffff)
                preorder_ctrl->indicate_seq = seq_num;
        /* Drop out the packet which SeqNum is smaller than WinStart */
        if (SN_LESS(seq_num, preorder_ctrl->indicate_seq))
                return false;
        /*
         * Sliding window manipulation. Conditions includes:
         * 1. Incoming SeqNum is equal to WinStart =>Window shift 1
         * 2. Incoming SeqNum is larger than the WinEnd => Window shift N
         */
        if (SN_EQUAL(seq_num, preorder_ctrl->indicate_seq))
                preorder_ctrl->indicate_seq = (preorder_ctrl->indicate_seq +
                                              1) % 4096;
        else if (SN_LESS(wend, seq_num)) {
                if (seq_num >= (wsize - 1))
                        preorder_ctrl->indicate_seq = seq_num + 1 - wsize;
                else
                        preorder_ctrl->indicate_seq = 4095 - (wsize -
                                                      (seq_num + 1)) + 1;
        }
        return true;
}

static int enqueue_reorder_recvframe(struct recv_reorder_ctrl *preorder_ctrl,
                                     union recv_frame *prframe)
{
        struct list_head *phead, *plist;
        union recv_frame *pnextrframe;
        struct rx_pkt_attrib *pnextattrib;
        struct  __queue *ppending_recvframe_queue =
                                        &preorder_ctrl->pending_recvframe_queue;
        struct rx_pkt_attrib *pattrib = &prframe->u.hdr.attrib;

        phead = &ppending_recvframe_queue->queue;
        plist = phead->next;
        while (!end_of_queue_search(phead, plist)) {
                pnextrframe = container_of(plist, union recv_frame, u.list);
                pnextattrib = &pnextrframe->u.hdr.attrib;
                if (SN_LESS(pnextattrib->seq_num, pattrib->seq_num))
                        plist = plist->next;
                else if (SN_EQUAL(pnextattrib->seq_num, pattrib->seq_num))
                        return false;
                else
                        break;
        }
        list_del_init(&(prframe->u.hdr.list));
        list_add_tail(&(prframe->u.hdr.list), plist);
        return true;
}

int r8712_recv_indicatepkts_in_order(struct _adapter *padapter,
                                     struct recv_reorder_ctrl *preorder_ctrl,
                                     int bforced)
{
        struct list_head *phead, *plist;
        union recv_frame *prframe;
        struct rx_pkt_attrib *pattrib;
        int bPktInBuf = false;
        struct  __queue *ppending_recvframe_queue =
                         &preorder_ctrl->pending_recvframe_queue;

        phead = &ppending_recvframe_queue->queue;
        plist = phead->next;
        /* Handling some condition for forced indicate case.*/
        if (bforced) {
                if (list_empty(phead))
                        return true;

                prframe = container_of(plist, union recv_frame, u.list);
                pattrib = &prframe->u.hdr.attrib;
                preorder_ctrl->indicate_seq = pattrib->seq_num;
        }
        /* Prepare indication list and indication.
         * Check if there is any packet need indicate.
         */
        while (!list_empty(phead)) {
                prframe = container_of(plist, union recv_frame, u.list);
                pattrib = &prframe->u.hdr.attrib;
                if (!SN_LESS(preorder_ctrl->indicate_seq, pattrib->seq_num)) {
                        plist = plist->next;
                        list_del_init(&(prframe->u.hdr.list));
                        if (SN_EQUAL(preorder_ctrl->indicate_seq,
                                     pattrib->seq_num))
                                preorder_ctrl->indicate_seq =
                                  (preorder_ctrl->indicate_seq + 1) % 4096;
                        /*indicate this recv_frame*/
                        if (!pattrib->amsdu) {
                                if (!padapter->driver_stopped &&
                                    !padapter->surprise_removed) {
                                        /* indicate this recv_frame */
                                        r8712_recv_indicatepkt(padapter,
                                                               prframe);
                                }
                        } else if (pattrib->amsdu == 1) {
                                amsdu_to_msdu(padapter, prframe);
                        }
                        /* Update local variables. */
                        bPktInBuf = false;
                } else {
                        bPktInBuf = true;
                        break;
                }
        }
        return bPktInBuf;
}

static int recv_indicatepkt_reorder(struct _adapter *padapter,
                                    union recv_frame *prframe)
{
        unsigned long irql;
        struct rx_pkt_attrib *pattrib = &prframe->u.hdr.attrib;
        struct recv_reorder_ctrl *preorder_ctrl = prframe->u.hdr.preorder_ctrl;
        struct  __queue *ppending_recvframe_queue =
                         &preorder_ctrl->pending_recvframe_queue;

        if (!pattrib->amsdu) {
                /* s1. */
                r8712_wlanhdr_to_ethhdr(prframe);
                if (pattrib->qos != 1) {
                        if (!padapter->driver_stopped &&
                            !padapter->surprise_removed) {
                                r8712_recv_indicatepkt(padapter, prframe);
                                return 0;
                        } else {
                                return -EINVAL;
                        }
                }
        }
        spin_lock_irqsave(&ppending_recvframe_queue->lock, irql);
        /*s2. check if winstart_b(indicate_seq) needs to be updated*/
        if (!check_indicate_seq(preorder_ctrl, pattrib->seq_num))
                goto _err_exit;
        /*s3. Insert all packet into Reorder Queue to maintain its ordering.*/
        if (!enqueue_reorder_recvframe(preorder_ctrl, prframe))
                goto _err_exit;
        /*s4.
         * Indication process.
         * After Packet dropping and Sliding Window shifting as above, we can
         * now just indicate the packets with the SeqNum smaller than latest
         * WinStart and buffer other packets.
         *
         * For Rx Reorder condition:
         * 1. All packets with SeqNum smaller than WinStart => Indicate
         * 2. All packets with SeqNum larger than or equal to
         * WinStart => Buffer it.
         */
        if (r8712_recv_indicatepkts_in_order(padapter, preorder_ctrl, false)) {
                mod_timer(&preorder_ctrl->reordering_ctrl_timer,
                          jiffies + msecs_to_jiffies(REORDER_WAIT_TIME));
                spin_unlock_irqrestore(&ppending_recvframe_queue->lock, irql);
        } else {
                spin_unlock_irqrestore(&ppending_recvframe_queue->lock, irql);
                del_timer(&preorder_ctrl->reordering_ctrl_timer);
        }
        return 0;
_err_exit:
        spin_unlock_irqrestore(&ppending_recvframe_queue->lock, irql);
        return -ENOMEM;
}

void r8712_reordering_ctrl_timeout_handler(void *pcontext)
{
        unsigned long irql;
        struct recv_reorder_ctrl *preorder_ctrl = pcontext;
        struct _adapter *padapter = preorder_ctrl->padapter;
        struct  __queue *ppending_recvframe_queue =
                                 &preorder_ctrl->pending_recvframe_queue;

        if (padapter->driver_stopped || padapter->surprise_removed)
                return;
        spin_lock_irqsave(&ppending_recvframe_queue->lock, irql);
        r8712_recv_indicatepkts_in_order(padapter, preorder_ctrl, true);
        spin_unlock_irqrestore(&ppending_recvframe_queue->lock, irql);
}

static int r8712_process_recv_indicatepkts(struct _adapter *padapter,
                                           union recv_frame *prframe)
{
        int retval = _SUCCESS;
        struct mlme_priv *pmlmepriv = &padapter->mlmepriv;
        struct ht_priv  *phtpriv = &pmlmepriv->htpriv;

        if (phtpriv->ht_option == 1) { /*B/G/N Mode*/
                if (recv_indicatepkt_reorder(padapter, prframe)) {
                        /* including perform A-MPDU Rx Ordering Buffer Control*/
                        if (!padapter->driver_stopped &&
                            !padapter->surprise_removed)
                                return _FAIL;
                }
        } else { /*B/G mode*/
                retval = r8712_wlanhdr_to_ethhdr(prframe);
                if (retval)
                        return _FAIL;
                if (!padapter->driver_stopped && !padapter->surprise_removed) {
                        /* indicate this recv_frame */
                        r8712_recv_indicatepkt(padapter, prframe);
                } else {
                        return _FAIL;
                }
        }
        return retval;
}

static u8 query_rx_pwr_percentage(s8 antpower)
{
        if ((antpower <= -100) || (antpower >= 20))
                return  0;
        else if (antpower >= 0)
                return  100;
        else
                return 100 + antpower;
}

static u8 evm_db2percentage(s8 value)
{
        /*
         * -33dB~0dB to 0%~99%
         */
        s8 ret_val = clamp(-value, 0, 33) * 3;

        if (ret_val == 99)
                ret_val = 100;

        return ret_val;
}

s32 r8712_signal_scale_mapping(s32 cur_sig)
{
        s32 ret_sig;

        if (cur_sig >= 51 && cur_sig <= 100)
                ret_sig = 100;
        else if (cur_sig >= 41 && cur_sig <= 50)
                ret_sig = 80 + ((cur_sig - 40) * 2);
        else if (cur_sig >= 31 && cur_sig <= 40)
                ret_sig = 66 + (cur_sig - 30);
        else if (cur_sig >= 21 && cur_sig <= 30)
                ret_sig = 54 + (cur_sig - 20);
        else if (cur_sig >= 10 && cur_sig <= 20)
                ret_sig = 42 + (((cur_sig - 10) * 2) / 3);
        else if (cur_sig >= 5 && cur_sig <= 9)
                ret_sig = 22 + (((cur_sig - 5) * 3) / 2);
        else if (cur_sig >= 1 && cur_sig <= 4)
                ret_sig = 6 + (((cur_sig - 1) * 3) / 2);
        else
                ret_sig = cur_sig;
        return ret_sig;
}

static s32  translate2dbm(struct _adapter *padapter, u8 signal_strength_idx)
{
        s32 signal_power; /* in dBm.*/
        /* Translate to dBm (x=0.5y-95).*/
        signal_power = (s32)((signal_strength_idx + 1) >> 1);
        signal_power -= 95;
        return signal_power;
}

static void query_rx_phy_status(struct _adapter *padapter,
                                union recv_frame *prframe)
{
        u8 i, max_spatial_stream, evm;
        struct recv_stat *prxstat = (struct recv_stat *)prframe->u.hdr.rx_head;
        struct phy_stat *pphy_stat = (struct phy_stat *)(prxstat + 1);
        u8 *pphy_head = (u8 *)(prxstat + 1);
        s8 rx_pwr[4], rx_pwr_all;
        u8 pwdb_all;
        u32 rssi, total_rssi = 0;
        u8 bcck_rate = 0, rf_rx_num = 0, cck_highpwr = 0;
        struct phy_cck_rx_status *pcck_buf;
        u8 sq;

        /* Record it for next packet processing*/
        bcck_rate = (prframe->u.hdr.attrib.mcs_rate <= 3 ? 1 : 0);
        if (bcck_rate) {
                u8 report;

                /* CCK Driver info Structure is not the same as OFDM packet.*/
                pcck_buf = (struct phy_cck_rx_status *)pphy_stat;
                /* (1)Hardware does not provide RSSI for CCK
                 * (2)PWDB, Average PWDB calculated by hardware
                 * (for rate adaptive)
                 */
                if (!cck_highpwr) {
                        report = pcck_buf->cck_agc_rpt & 0xc0;
                        report >>= 6;
                        switch (report) {
                        /* Modify the RF RNA gain value to -40, -20,
                         * -2, 14 by Jenyu's suggestion
                         * Note: different RF with the different
                         * RNA gain.
                         */
                        case 0x3:
                                rx_pwr_all = -40 - (pcck_buf->cck_agc_rpt &
                                             0x3e);
                                break;
                        case 0x2:
                                rx_pwr_all = -20 - (pcck_buf->cck_agc_rpt &
                                             0x3e);
                                break;
                        case 0x1:
                                rx_pwr_all = -2 - (pcck_buf->cck_agc_rpt &
                                             0x3e);
                                break;
                        case 0x0:
                                rx_pwr_all = 14 - (pcck_buf->cck_agc_rpt &
                                             0x3e);
                                break;
                        }
                } else {
                        report = ((u8)(le32_to_cpu(pphy_stat->phydw1) >> 8)) &
                                 0x60;
                        report >>= 5;
                        switch (report) {
                        case 0x3:
                                rx_pwr_all = -40 - ((pcck_buf->cck_agc_rpt &
                                             0x1f) << 1);
                                break;
                        case 0x2:
                                rx_pwr_all = -20 - ((pcck_buf->cck_agc_rpt &
                                             0x1f) << 1);
                                break;
                        case 0x1:
                                rx_pwr_all = -2 - ((pcck_buf->cck_agc_rpt &
                                             0x1f) << 1);
                                break;
                        case 0x0:
                                rx_pwr_all = 14 - ((pcck_buf->cck_agc_rpt &
                                             0x1f) << 1);
                                break;
                        }
                }
                pwdb_all = query_rx_pwr_percentage(rx_pwr_all);
                /* CCK gain is smaller than OFDM/MCS gain,*/
                /* so we add gain diff by experiences, the val is 6 */
                pwdb_all += 6;
                if (pwdb_all > 100)
                        pwdb_all = 100;
                /* modify the offset to make the same gain index with OFDM.*/
                if (pwdb_all > 34 && pwdb_all <= 42)
                        pwdb_all -= 2;
                else if (pwdb_all > 26 && pwdb_all <= 34)
                        pwdb_all -= 6;
                else if (pwdb_all > 14 && pwdb_all <= 26)
                        pwdb_all -= 8;
                else if (pwdb_all > 4 && pwdb_all <= 14)
                        pwdb_all -= 4;
                /*
                 * (3) Get Signal Quality (EVM)
                 */
                if (pwdb_all > 40) {
                        sq = 100;
                } else {
                        sq = pcck_buf->sq_rpt;
                        if (pcck_buf->sq_rpt > 64)
                                sq = 0;
                        else if (pcck_buf->sq_rpt < 20)
                                sq = 100;
                        else
                                sq = ((64 - sq) * 100) / 44;
                }
                prframe->u.hdr.attrib.signal_qual = sq;
                prframe->u.hdr.attrib.rx_mimo_signal_qual[0] = sq;
                prframe->u.hdr.attrib.rx_mimo_signal_qual[1] = -1;
        } else {
                /* (1)Get RSSI for HT rate */
                for (i = 0; i < ((padapter->registrypriv.rf_config) &
                            0x0f); i++) {
                        rf_rx_num++;
                        rx_pwr[i] = ((pphy_head[PHY_STAT_GAIN_TRSW_SHT + i]
                                    & 0x3F) * 2) - 110;
                        /* Translate DBM to percentage. */
                        rssi = query_rx_pwr_percentage(rx_pwr[i]);
                        total_rssi += rssi;
                }
                /* (2)PWDB, Average PWDB calculated by hardware (for
                 * rate adaptive)
                 */
                rx_pwr_all = (((pphy_head[PHY_STAT_PWDB_ALL_SHT]) >> 1) & 0x7f)
                             - 106;
                pwdb_all = query_rx_pwr_percentage(rx_pwr_all);

                {
                        /* (3)EVM of HT rate */
                        if (prframe->u.hdr.attrib.htc &&
                            prframe->u.hdr.attrib.mcs_rate >= 20 &&
                            prframe->u.hdr.attrib.mcs_rate <= 27) {
                                /* both spatial stream make sense */
                                max_spatial_stream = 2;
                        } else {
                                /* only spatial stream 1 makes sense */
                                max_spatial_stream = 1;
                        }
                        for (i = 0; i < max_spatial_stream; i++) {
                                evm = evm_db2percentage((pphy_head
                                      [PHY_STAT_RXEVM_SHT + i]));/*dbm*/
                                prframe->u.hdr.attrib.signal_qual =
                                         (u8)(evm & 0xff);
                                prframe->u.hdr.attrib.rx_mimo_signal_qual[i] =
                                         (u8)(evm & 0xff);
                        }
                }
        }
        /* UI BSS List signal strength(in percentage), make it good looking,
         * from 0~100. It is assigned to the BSS List in
         * GetValueFromBeaconOrProbeRsp().
         */
        if (bcck_rate) {
                prframe->u.hdr.attrib.signal_strength =
                         (u8)r8712_signal_scale_mapping(pwdb_all);
        } else {
                if (rf_rx_num != 0)
                        prframe->u.hdr.attrib.signal_strength =
                                 (u8)(r8712_signal_scale_mapping(total_rssi /=
                                 rf_rx_num));
        }
}

static void process_link_qual(struct _adapter *padapter,
                              union recv_frame *prframe)
{
        u32     last_evm = 0, tmpVal;
        struct rx_pkt_attrib *pattrib;
        struct smooth_rssi_data *sqd = &padapter->recvpriv.signal_qual_data;

        if (!prframe || !padapter)
                return;
        pattrib = &prframe->u.hdr.attrib;
        if (pattrib->signal_qual != 0) {
                /*
                 * 1. Record the general EVM to the sliding window.
                 */
                if (sqd->total_num++ >= PHY_LINKQUALITY_SLID_WIN_MAX) {
                        sqd->total_num = PHY_LINKQUALITY_SLID_WIN_MAX;
                        last_evm = sqd->elements[sqd->index];
                        sqd->total_val -= last_evm;
                }
                sqd->total_val += pattrib->signal_qual;
                sqd->elements[sqd->index++] = pattrib->signal_qual;
                if (sqd->index >= PHY_LINKQUALITY_SLID_WIN_MAX)
                        sqd->index = 0;

                /* <1> Showed on UI for user, in percentage. */
                tmpVal = sqd->total_val / sqd->total_num;
                padapter->recvpriv.signal = (u8)tmpVal;
        }
}

static void process_rssi(struct _adapter *padapter, union recv_frame *prframe)
{
        u32 last_rssi, tmp_val;
        struct rx_pkt_attrib *pattrib = &prframe->u.hdr.attrib;
        struct smooth_rssi_data *ssd = &padapter->recvpriv.signal_strength_data;

        if (ssd->total_num++ >= PHY_RSSI_SLID_WIN_MAX) {
                ssd->total_num = PHY_RSSI_SLID_WIN_MAX;
                last_rssi = ssd->elements[ssd->index];
                ssd->total_val -= last_rssi;
        }
        ssd->total_val += pattrib->signal_strength;
        ssd->elements[ssd->index++] = pattrib->signal_strength;
        if (ssd->index >= PHY_RSSI_SLID_WIN_MAX)
                ssd->index = 0;
        tmp_val = ssd->total_val / ssd->total_num;
        padapter->recvpriv.rssi = (s8)translate2dbm(padapter, (u8)tmp_val);
}

static void process_phy_info(struct _adapter *padapter,
                             union recv_frame *prframe)
{
        query_rx_phy_status(padapter, prframe);
        process_rssi(padapter, prframe);
        process_link_qual(padapter,  prframe);
}

int recv_func(struct _adapter *padapter, void *pcontext)
{
        struct rx_pkt_attrib *pattrib;
        union recv_frame *prframe, *orig_prframe;
        int retval = _SUCCESS;
        struct  __queue *pfree_recv_queue = &padapter->recvpriv.free_recv_queue;
        struct  mlme_priv       *pmlmepriv = &padapter->mlmepriv;

        prframe = pcontext;
        orig_prframe = prframe;
        pattrib = &prframe->u.hdr.attrib;
        if (check_fwstate(pmlmepriv, WIFI_MP_STATE)) {
                if (pattrib->crc_err == 1)
                        padapter->mppriv.rx_crcerrpktcount++;
                else
                        padapter->mppriv.rx_pktcount++;
                if (!check_fwstate(pmlmepriv, WIFI_MP_LPBK_STATE)) {
                        /* free this recv_frame */
                        r8712_free_recvframe(orig_prframe, pfree_recv_queue);
                        goto _exit_recv_func;
                }
        }
        /* check the frame crtl field and decache */
        retval = r8712_validate_recv_frame(padapter, prframe);
        if (retval != _SUCCESS) {
                /* free this recv_frame */
                r8712_free_recvframe(orig_prframe, pfree_recv_queue);
                goto _exit_recv_func;
        }
        process_phy_info(padapter, prframe);
        prframe = r8712_decryptor(padapter, prframe);
        if (!prframe) {
                retval = _FAIL;
                goto _exit_recv_func;
        }
        prframe = r8712_recvframe_chk_defrag(padapter, prframe);
        if (!prframe)
                goto _exit_recv_func;
        prframe = r8712_portctrl(padapter, prframe);
        if (!prframe) {
                retval = _FAIL;
                goto _exit_recv_func;
        }
        retval = r8712_process_recv_indicatepkts(padapter, prframe);
        if (retval != _SUCCESS) {
                r8712_free_recvframe(orig_prframe, pfree_recv_queue);
                goto _exit_recv_func;
        }
_exit_recv_func:
        return retval;
}

static void recvbuf2recvframe(struct _adapter *padapter, struct sk_buff *pskb)
{
        u8 *pbuf, shift_sz = 0;
        u8      frag, mf;
        uint    pkt_len;
        u32 transfer_len;
        struct recv_stat *prxstat;
        u16     pkt_cnt, drvinfo_sz, pkt_offset, tmp_len, alloc_sz;
        struct  __queue *pfree_recv_queue;
        _pkt  *pkt_copy = NULL;
        union recv_frame *precvframe = NULL;
        struct recv_priv *precvpriv = &padapter->recvpriv;

        pfree_recv_queue = &(precvpriv->free_recv_queue);
        pbuf = pskb->data;
        prxstat = (struct recv_stat *)pbuf;
        pkt_cnt = (le32_to_cpu(prxstat->rxdw2) >> 16) & 0xff;
        pkt_len =  le32_to_cpu(prxstat->rxdw0) & 0x00003fff;
        transfer_len = pskb->len;
        /* Test throughput with Netgear 3700 (No security) with Chariot 3T3R
         * pairs. The packet count will be a big number so that the containing
         * packet will effect the Rx reordering.
         */
        if (transfer_len < pkt_len) {
                /* In this case, it means the MAX_RECVBUF_SZ is too small to
                 * get the data from 8712u.

                 */
                return;
        }
        do {
                prxstat = (struct recv_stat *)pbuf;
                pkt_len =  le32_to_cpu(prxstat->rxdw0) & 0x00003fff;
                /* more fragment bit */
                mf = (le32_to_cpu(prxstat->rxdw1) >> 27) & 0x1;
                /* ragmentation number */
                frag = (le32_to_cpu(prxstat->rxdw2) >> 12) & 0xf;
                /* uint 2^3 = 8 bytes */
                drvinfo_sz = (le32_to_cpu(prxstat->rxdw0) & 0x000f0000) >> 16;
                drvinfo_sz <<= 3;
                if (pkt_len <= 0)
                        return;
                /* Qos data, wireless lan header length is 26 */
                if ((le32_to_cpu(prxstat->rxdw0) >> 23) & 0x01)
                        shift_sz = 2;
                precvframe = r8712_alloc_recvframe(pfree_recv_queue);
                if (!precvframe)
                        return;
                INIT_LIST_HEAD(&precvframe->u.hdr.list);
                precvframe->u.hdr.precvbuf = NULL; /*can't access the precvbuf*/
                precvframe->u.hdr.len = 0;
                tmp_len = pkt_len + drvinfo_sz + RXDESC_SIZE;
                pkt_offset = (u16)round_up(tmp_len, 128);
                /* for first fragment packet, driver need allocate 1536 +
                 * drvinfo_sz + RXDESC_SIZE to defrag packet.
                 */
                if ((mf == 1) && (frag == 0))
                        /*1658+6=1664, 1664 is 128 alignment.*/
                        alloc_sz = max_t(u16, tmp_len, 1658);
                else
                        alloc_sz = tmp_len;
                /* 2 is for IP header 4 bytes alignment in QoS packet case.
                 * 4 is for skb->data 4 bytes alignment.
                 */
                alloc_sz += 6;
                pkt_copy = netdev_alloc_skb(padapter->pnetdev, alloc_sz);
                if (pkt_copy) {
                        precvframe->u.hdr.pkt = pkt_copy;
                        skb_reserve(pkt_copy, 4 - ((addr_t)(pkt_copy->data)
                                    % 4));
                        skb_reserve(pkt_copy, shift_sz);
                        memcpy(pkt_copy->data, pbuf, tmp_len);
                        precvframe->u.hdr.rx_head = precvframe->u.hdr.rx_data =
                                 precvframe->u.hdr.rx_tail = pkt_copy->data;
                        precvframe->u.hdr.rx_end = pkt_copy->data + alloc_sz;
                } else {
                        precvframe->u.hdr.pkt = skb_clone(pskb, GFP_ATOMIC);
                        if (!precvframe->u.hdr.pkt)
                                return;
                        precvframe->u.hdr.rx_head = pbuf;
                        precvframe->u.hdr.rx_data = pbuf;
                        precvframe->u.hdr.rx_tail = pbuf;
                        precvframe->u.hdr.rx_end = pbuf + alloc_sz;
                }
                recvframe_put(precvframe, tmp_len);
                recvframe_pull(precvframe, drvinfo_sz + RXDESC_SIZE);
                /* because the endian issue, driver avoid reference to the
                 * rxstat after calling update_recvframe_attrib_from_recvstat();
                 */
                update_recvframe_attrib_from_recvstat(&precvframe->u.hdr.attrib,
                                                      prxstat);
                r8712_recv_entry(precvframe);
                transfer_len -= pkt_offset;
                pbuf += pkt_offset;
                pkt_cnt--;
                precvframe = NULL;
                pkt_copy = NULL;
        } while ((transfer_len > 0) && pkt_cnt > 0);
}

static void recv_tasklet(unsigned long priv)
{
        struct sk_buff *pskb;
        struct _adapter *padapter = (struct _adapter *)priv;
        struct recv_priv *precvpriv = &padapter->recvpriv;

        while (NULL != (pskb = skb_dequeue(&precvpriv->rx_skb_queue))) {
                recvbuf2recvframe(padapter, pskb);
                skb_reset_tail_pointer(pskb);
                pskb->len = 0;
                if (!skb_cloned(pskb))
                        skb_queue_tail(&precvpriv->free_recv_skb_queue, pskb);
                else
                        consume_skb(pskb);
        }
}