/******************************************************************************
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2017 Intel Deutschland GmbH
 * Copyright(c) 2018        Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2017 Intel Deutschland GmbH
 * Copyright(c) 2018        Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/
#include <linux/pm_runtime.h>
#include <net/tso.h>
#include <linux/tcp.h>

#include "iwl-debug.h"
#include "iwl-csr.h"
#include "iwl-io.h"
#include "internal.h"
#include "fw/api/tx.h"

 /*
 * iwl_pcie_gen2_tx_stop - Stop all Tx DMA channels
 */
void iwl_pcie_gen2_tx_stop(struct iwl_trans *trans)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        int txq_id;

        /*
         * This function can be called before the op_mode disabled the
         * queues. This happens when we have an rfkill interrupt.
         * Since we stop Tx altogether - mark the queues as stopped.
         */
        memset(trans_pcie->queue_stopped, 0, sizeof(trans_pcie->queue_stopped));
        memset(trans_pcie->queue_used, 0, sizeof(trans_pcie->queue_used));

        /* Unmap DMA from host system and free skb's */
        for (txq_id = 0; txq_id < ARRAY_SIZE(trans_pcie->txq); txq_id++) {
                if (!trans_pcie->txq[txq_id])
                        continue;
                iwl_pcie_gen2_txq_unmap(trans, txq_id);
        }
}

/*
 * iwl_pcie_txq_update_byte_tbl - Set up entry in Tx byte-count array
 */
static void iwl_pcie_gen2_update_byte_tbl(struct iwl_trans_pcie *trans_pcie,
                                          struct iwl_txq *txq, u16 byte_cnt,
                                          int num_tbs)
{
        struct iwlagn_scd_bc_tbl *scd_bc_tbl = txq->bc_tbl.addr;
        struct iwl_trans *trans = iwl_trans_pcie_get_trans(trans_pcie);
        struct iwl_gen3_bc_tbl *scd_bc_tbl_gen3 = txq->bc_tbl.addr;
        int idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);
        u8 filled_tfd_size, num_fetch_chunks;
        u16 len = byte_cnt;
        __le16 bc_ent;

        if (trans_pcie->bc_table_dword)
                len = DIV_ROUND_UP(len, 4);

        if (WARN_ON(len > 0xFFF || idx >= txq->n_window))
                return;

        filled_tfd_size = offsetof(struct iwl_tfh_tfd, tbs) +
                                   num_tbs * sizeof(struct iwl_tfh_tb);
        /*
         * filled_tfd_size contains the number of filled bytes in the TFD.
         * Dividing it by 64 will give the number of chunks to fetch
         * to SRAM- 0 for one chunk, 1 for 2 and so on.
         * If, for example, TFD contains only 3 TBs then 32 bytes
         * of the TFD are used, and only one chunk of 64 bytes should
         * be fetched
         */
        num_fetch_chunks = DIV_ROUND_UP(filled_tfd_size, 64) - 1;

        bc_ent = cpu_to_le16(len | (num_fetch_chunks << 12));
        if (trans->cfg->device_family >= IWL_DEVICE_FAMILY_22560)
                scd_bc_tbl_gen3->tfd_offset[idx] = bc_ent;
        else
                scd_bc_tbl->tfd_offset[idx] = bc_ent;
}

/*
 * iwl_pcie_gen2_txq_inc_wr_ptr - Send new write index to hardware
 */
static void iwl_pcie_gen2_txq_inc_wr_ptr(struct iwl_trans *trans,
                                         struct iwl_txq *txq)
{
        lockdep_assert_held(&txq->lock);

        IWL_DEBUG_TX(trans, "Q:%d WR: 0x%x\n", txq->id, txq->write_ptr);

        /*
         * if not in power-save mode, uCode will never sleep when we're
         * trying to tx (during RFKILL, we're not trying to tx).
         */
        iwl_write32(trans, HBUS_TARG_WRPTR, txq->write_ptr | (txq->id << 16));
}

static u8 iwl_pcie_gen2_get_num_tbs(struct iwl_trans *trans,
                                    struct iwl_tfh_tfd *tfd)
{
        return le16_to_cpu(tfd->num_tbs) & 0x1f;
}

static void iwl_pcie_gen2_tfd_unmap(struct iwl_trans *trans,
                                    struct iwl_cmd_meta *meta,
                                    struct iwl_tfh_tfd *tfd)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        int i, num_tbs;

        /* Sanity check on number of chunks */
        num_tbs = iwl_pcie_gen2_get_num_tbs(trans, tfd);

        if (num_tbs > trans_pcie->max_tbs) {
                IWL_ERR(trans, "Too many chunks: %i\n", num_tbs);
                return;
        }

        /* first TB is never freed - it's the bidirectional DMA data */
        for (i = 1; i < num_tbs; i++) {
                if (meta->tbs & BIT(i))
                        dma_unmap_page(trans->dev,
                                       le64_to_cpu(tfd->tbs[i].addr),
                                       le16_to_cpu(tfd->tbs[i].tb_len),
                                       DMA_TO_DEVICE);
                else
                        dma_unmap_single(trans->dev,
                                         le64_to_cpu(tfd->tbs[i].addr),
                                         le16_to_cpu(tfd->tbs[i].tb_len),
                                         DMA_TO_DEVICE);
        }

        tfd->num_tbs = 0;
}

static void iwl_pcie_gen2_free_tfd(struct iwl_trans *trans, struct iwl_txq *txq)
{
        /* rd_ptr is bounded by TFD_QUEUE_SIZE_MAX and
         * idx is bounded by n_window
         */
        int idx = iwl_pcie_get_cmd_index(txq, txq->read_ptr);

        lockdep_assert_held(&txq->lock);

        iwl_pcie_gen2_tfd_unmap(trans, &txq->entries[idx].meta,
                                iwl_pcie_get_tfd(trans, txq, idx));

        /* free SKB */
        if (txq->entries) {
                struct sk_buff *skb;

                skb = txq->entries[idx].skb;

                /* Can be called from irqs-disabled context
                 * If skb is not NULL, it means that the whole queue is being
                 * freed and that the queue is not empty - free the skb
                 */
                if (skb) {
                        iwl_op_mode_free_skb(trans->op_mode, skb);
                        txq->entries[idx].skb = NULL;
                }
        }
}

static int iwl_pcie_gen2_set_tb(struct iwl_trans *trans,
                                struct iwl_tfh_tfd *tfd, dma_addr_t addr,
                                u16 len)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        int idx = iwl_pcie_gen2_get_num_tbs(trans, tfd);
        struct iwl_tfh_tb *tb = &tfd->tbs[idx];

        /* Each TFD can point to a maximum max_tbs Tx buffers */
        if (le16_to_cpu(tfd->num_tbs) >= trans_pcie->max_tbs) {
                IWL_ERR(trans, "Error can not send more than %d chunks\n",
                        trans_pcie->max_tbs);
                return -EINVAL;
        }

        put_unaligned_le64(addr, &tb->addr);
        tb->tb_len = cpu_to_le16(len);

        tfd->num_tbs = cpu_to_le16(idx + 1);

        return idx;
}

static int iwl_pcie_gen2_build_amsdu(struct iwl_trans *trans,
                                     struct sk_buff *skb,
                                     struct iwl_tfh_tfd *tfd, int start_len,
                                     u8 hdr_len, struct iwl_device_cmd *dev_cmd)
{
#ifdef CONFIG_INET
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_tx_cmd *tx_cmd = (void *)dev_cmd->payload;
        struct ieee80211_hdr *hdr = (void *)skb->data;
        unsigned int snap_ip_tcp_hdrlen, ip_hdrlen, total_len, hdr_room;
        unsigned int mss = skb_shinfo(skb)->gso_size;
        u16 length, iv_len, amsdu_pad;
        u8 *start_hdr;
        struct iwl_tso_hdr_page *hdr_page;
        struct page **page_ptr;
        struct tso_t tso;

        /* if the packet is protected, then it must be CCMP or GCMP */
        iv_len = ieee80211_has_protected(hdr->frame_control) ?
                IEEE80211_CCMP_HDR_LEN : 0;

        trace_iwlwifi_dev_tx(trans->dev, skb, tfd, sizeof(*tfd),
                             &dev_cmd->hdr, start_len, 0);

        ip_hdrlen = skb_transport_header(skb) - skb_network_header(skb);
        snap_ip_tcp_hdrlen = 8 + ip_hdrlen + tcp_hdrlen(skb);
        total_len = skb->len - snap_ip_tcp_hdrlen - hdr_len - iv_len;
        amsdu_pad = 0;

        /* total amount of header we may need for this A-MSDU */
        hdr_room = DIV_ROUND_UP(total_len, mss) *
                (3 + snap_ip_tcp_hdrlen + sizeof(struct ethhdr)) + iv_len;

        /* Our device supports 9 segments at most, it will fit in 1 page */
        hdr_page = get_page_hdr(trans, hdr_room);
        if (!hdr_page)
                return -ENOMEM;

        get_page(hdr_page->page);
        start_hdr = hdr_page->pos;
        page_ptr = (void *)((u8 *)skb->cb + trans_pcie->page_offs);
        *page_ptr = hdr_page->page;
        memcpy(hdr_page->pos, skb->data + hdr_len, iv_len);
        hdr_page->pos += iv_len;

        /*
         * Pull the ieee80211 header + IV to be able to use TSO core,
         * we will restore it for the tx_status flow.
         */
        skb_pull(skb, hdr_len + iv_len);

        /*
         * Remove the length of all the headers that we don't actually
         * have in the MPDU by themselves, but that we duplicate into
         * all the different MSDUs inside the A-MSDU.
         */
        le16_add_cpu(&tx_cmd->len, -snap_ip_tcp_hdrlen);

        tso_start(skb, &tso);

        while (total_len) {
                /* this is the data left for this subframe */
                unsigned int data_left = min_t(unsigned int, mss, total_len);
                struct sk_buff *csum_skb = NULL;
                unsigned int tb_len;
                dma_addr_t tb_phys;
                u8 *subf_hdrs_start = hdr_page->pos;

                total_len -= data_left;

                memset(hdr_page->pos, 0, amsdu_pad);
                hdr_page->pos += amsdu_pad;
                amsdu_pad = (4 - (sizeof(struct ethhdr) + snap_ip_tcp_hdrlen +
                                  data_left)) & 0x3;
                ether_addr_copy(hdr_page->pos, ieee80211_get_DA(hdr));
                hdr_page->pos += ETH_ALEN;
                ether_addr_copy(hdr_page->pos, ieee80211_get_SA(hdr));
                hdr_page->pos += ETH_ALEN;

                length = snap_ip_tcp_hdrlen + data_left;
                *((__be16 *)hdr_page->pos) = cpu_to_be16(length);
                hdr_page->pos += sizeof(length);

                /*
                 * This will copy the SNAP as well which will be considered
                 * as MAC header.
                 */
                tso_build_hdr(skb, hdr_page->pos, &tso, data_left, !total_len);

                hdr_page->pos += snap_ip_tcp_hdrlen;

                tb_len = hdr_page->pos - start_hdr;
                tb_phys = dma_map_single(trans->dev, start_hdr,
                                         tb_len, DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(trans->dev, tb_phys))) {
                        dev_kfree_skb(csum_skb);
                        goto out_err;
                }
                iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, tb_len);
                trace_iwlwifi_dev_tx_tso_chunk(trans->dev, start_hdr, tb_len);
                /* add this subframe's headers' length to the tx_cmd */
                le16_add_cpu(&tx_cmd->len, hdr_page->pos - subf_hdrs_start);

                /* prepare the start_hdr for the next subframe */
                start_hdr = hdr_page->pos;

                /* put the payload */
                while (data_left) {
                        tb_len = min_t(unsigned int, tso.size, data_left);
                        tb_phys = dma_map_single(trans->dev, tso.data,
                                                 tb_len, DMA_TO_DEVICE);
                        if (unlikely(dma_mapping_error(trans->dev, tb_phys))) {
                                dev_kfree_skb(csum_skb);
                                goto out_err;
                        }
                        iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, tb_len);
                        trace_iwlwifi_dev_tx_tso_chunk(trans->dev, tso.data,
                                                       tb_len);

                        data_left -= tb_len;
                        tso_build_data(skb, &tso, tb_len);
                }
        }

        /* re -add the WiFi header and IV */
        skb_push(skb, hdr_len + iv_len);

        return 0;

out_err:
#endif
        return -EINVAL;
}

static struct
iwl_tfh_tfd *iwl_pcie_gen2_build_tx_amsdu(struct iwl_trans *trans,
                                          struct iwl_txq *txq,
                                          struct iwl_device_cmd *dev_cmd,
                                          struct sk_buff *skb,
                                          struct iwl_cmd_meta *out_meta,
                                          int hdr_len,
                                          int tx_cmd_len)
{
        int idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);
        struct iwl_tfh_tfd *tfd = iwl_pcie_get_tfd(trans, txq, idx);
        dma_addr_t tb_phys;
        int len;
        void *tb1_addr;

        tb_phys = iwl_pcie_get_first_tb_dma(txq, idx);

        iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, IWL_FIRST_TB_SIZE);

        /*
         * The second TB (tb1) points to the remainder of the TX command
         * and the 802.11 header - dword aligned size
         * (This calculation modifies the TX command, so do it before the
         * setup of the first TB)
         */
        len = tx_cmd_len + sizeof(struct iwl_cmd_header) + hdr_len -
              IWL_FIRST_TB_SIZE;

        /* do not align A-MSDU to dword as the subframe header aligns it */

        /* map the data for TB1 */
        tb1_addr = ((u8 *)&dev_cmd->hdr) + IWL_FIRST_TB_SIZE;
        tb_phys = dma_map_single(trans->dev, tb1_addr, len, DMA_TO_DEVICE);
        if (unlikely(dma_mapping_error(trans->dev, tb_phys)))
                goto out_err;
        iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, len);

        if (iwl_pcie_gen2_build_amsdu(trans, skb, tfd,
                                      len + IWL_FIRST_TB_SIZE,
                                      hdr_len, dev_cmd))
                goto out_err;

        /* building the A-MSDU might have changed this data, memcpy it now */
        memcpy(&txq->first_tb_bufs[idx], &dev_cmd->hdr, IWL_FIRST_TB_SIZE);
        return tfd;

out_err:
        iwl_pcie_gen2_tfd_unmap(trans, out_meta, tfd);
        return NULL;
}

static struct
iwl_tfh_tfd *iwl_pcie_gen2_build_tx(struct iwl_trans *trans,
                                    struct iwl_txq *txq,
                                    struct iwl_device_cmd *dev_cmd,
                                    struct sk_buff *skb,
                                    struct iwl_cmd_meta *out_meta,
                                    int hdr_len,
                                    int tx_cmd_len)
{
        int idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);
        struct iwl_tfh_tfd *tfd = iwl_pcie_get_tfd(trans, txq, idx);
        dma_addr_t tb_phys;
        int i, len, tb1_len, tb2_len;
        void *tb1_addr;

        tb_phys = iwl_pcie_get_first_tb_dma(txq, idx);

        /* The first TB points to bi-directional DMA data */
        memcpy(&txq->first_tb_bufs[idx], &dev_cmd->hdr, IWL_FIRST_TB_SIZE);

        iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, IWL_FIRST_TB_SIZE);

        /*
         * The second TB (tb1) points to the remainder of the TX command
         * and the 802.11 header - dword aligned size
         * (This calculation modifies the TX command, so do it before the
         * setup of the first TB)
         */
        len = tx_cmd_len + sizeof(struct iwl_cmd_header) + hdr_len -
              IWL_FIRST_TB_SIZE;

        tb1_len = ALIGN(len, 4);

        /* map the data for TB1 */
        tb1_addr = ((u8 *)&dev_cmd->hdr) + IWL_FIRST_TB_SIZE;
        tb_phys = dma_map_single(trans->dev, tb1_addr, tb1_len, DMA_TO_DEVICE);
        if (unlikely(dma_mapping_error(trans->dev, tb_phys)))
                goto out_err;
        iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, tb1_len);

        /* set up TFD's third entry to point to remainder of skb's head */
        tb2_len = skb_headlen(skb) - hdr_len;

        if (tb2_len > 0) {
                tb_phys = dma_map_single(trans->dev, skb->data + hdr_len,
                                         tb2_len, DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(trans->dev, tb_phys)))
                        goto out_err;
                iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, tb2_len);
        }

        /* set up the remaining entries to point to the data */
        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
                const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
                int tb_idx;

                if (!skb_frag_size(frag))
                        continue;

                tb_phys = skb_frag_dma_map(trans->dev, frag, 0,
                                           skb_frag_size(frag), DMA_TO_DEVICE);

                if (unlikely(dma_mapping_error(trans->dev, tb_phys)))
                        goto out_err;
                tb_idx = iwl_pcie_gen2_set_tb(trans, tfd, tb_phys,
                                              skb_frag_size(frag));

                out_meta->tbs |= BIT(tb_idx);
        }

        trace_iwlwifi_dev_tx(trans->dev, skb, tfd, sizeof(*tfd), &dev_cmd->hdr,
                             IWL_FIRST_TB_SIZE + tb1_len, hdr_len);
        trace_iwlwifi_dev_tx_data(trans->dev, skb, hdr_len);

        return tfd;

out_err:
        iwl_pcie_gen2_tfd_unmap(trans, out_meta, tfd);
        return NULL;
}

static
struct iwl_tfh_tfd *iwl_pcie_gen2_build_tfd(struct iwl_trans *trans,
                                            struct iwl_txq *txq,
                                            struct iwl_device_cmd *dev_cmd,
                                            struct sk_buff *skb,
                                            struct iwl_cmd_meta *out_meta)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        int idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);
        struct iwl_tfh_tfd *tfd = iwl_pcie_get_tfd(trans, txq, idx);
        int len, hdr_len;
        bool amsdu;

        /* There must be data left over for TB1 or this code must be changed */
        BUILD_BUG_ON(sizeof(struct iwl_tx_cmd_gen2) < IWL_FIRST_TB_SIZE);

        memset(tfd, 0, sizeof(*tfd));

        if (trans->cfg->device_family < IWL_DEVICE_FAMILY_22560)
                len = sizeof(struct iwl_tx_cmd_gen2);
        else
                len = sizeof(struct iwl_tx_cmd_gen3);

        amsdu = ieee80211_is_data_qos(hdr->frame_control) &&
                        (*ieee80211_get_qos_ctl(hdr) &
                         IEEE80211_QOS_CTL_A_MSDU_PRESENT);

        hdr_len = ieee80211_hdrlen(hdr->frame_control);

        if (amsdu)
                return iwl_pcie_gen2_build_tx_amsdu(trans, txq, dev_cmd, skb,
                                                    out_meta, hdr_len, len);

        return iwl_pcie_gen2_build_tx(trans, txq, dev_cmd, skb, out_meta,
                                      hdr_len, len);
}

int iwl_trans_pcie_gen2_tx(struct iwl_trans *trans, struct sk_buff *skb,
                           struct iwl_device_cmd *dev_cmd, int txq_id)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_cmd_meta *out_meta;
        struct iwl_txq *txq = trans_pcie->txq[txq_id];
        u16 cmd_len;
        int idx;
        void *tfd;

        if (WARN_ONCE(!test_bit(txq_id, trans_pcie->queue_used),
                      "TX on unused queue %d\n", txq_id))
                return -EINVAL;

        if (skb_is_nonlinear(skb) &&
            skb_shinfo(skb)->nr_frags > IWL_PCIE_MAX_FRAGS(trans_pcie) &&
            __skb_linearize(skb))
                return -ENOMEM;

        spin_lock(&txq->lock);

        if (trans->cfg->device_family >= IWL_DEVICE_FAMILY_22560) {
                struct iwl_tx_cmd_gen3 *tx_cmd_gen3 =
                        (void *)dev_cmd->payload;

                cmd_len = le16_to_cpu(tx_cmd_gen3->len);
        } else {
                struct iwl_tx_cmd_gen2 *tx_cmd_gen2 =
                        (void *)dev_cmd->payload;

                cmd_len = le16_to_cpu(tx_cmd_gen2->len);
        }

        if (iwl_queue_space(trans, txq) < txq->high_mark) {
                iwl_stop_queue(trans, txq);

                /* don't put the packet on the ring, if there is no room */
                if (unlikely(iwl_queue_space(trans, txq) < 3)) {
                        struct iwl_device_cmd **dev_cmd_ptr;

                        dev_cmd_ptr = (void *)((u8 *)skb->cb +
                                               trans_pcie->dev_cmd_offs);

                        *dev_cmd_ptr = dev_cmd;
                        __skb_queue_tail(&txq->overflow_q, skb);
                        spin_unlock(&txq->lock);
                        return 0;
                }
        }

        idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);

        /* Set up driver data for this TFD */
        txq->entries[idx].skb = skb;
        txq->entries[idx].cmd = dev_cmd;

        dev_cmd->hdr.sequence =
                cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
                            INDEX_TO_SEQ(idx)));

        /* Set up first empty entry in queue's array of Tx/cmd buffers */
        out_meta = &txq->entries[idx].meta;
        out_meta->flags = 0;

        tfd = iwl_pcie_gen2_build_tfd(trans, txq, dev_cmd, skb, out_meta);
        if (!tfd) {
                spin_unlock(&txq->lock);
                return -1;
        }

        /* Set up entry for this TFD in Tx byte-count array */
        iwl_pcie_gen2_update_byte_tbl(trans_pcie, txq, cmd_len,
                                      iwl_pcie_gen2_get_num_tbs(trans, tfd));

        /* start timer if queue currently empty */
        if (txq->read_ptr == txq->write_ptr) {
                if (txq->wd_timeout)
                        mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);
                IWL_DEBUG_RPM(trans, "Q: %d first tx - take ref\n", txq->id);
                iwl_trans_ref(trans);
        }

        /* Tell device the write index *just past* this latest filled TFD */
        txq->write_ptr = iwl_queue_inc_wrap(trans, txq->write_ptr);
        iwl_pcie_gen2_txq_inc_wr_ptr(trans, txq);
        /*
         * At this point the frame is "transmitted" successfully
         * and we will get a TX status notification eventually.
         */
        spin_unlock(&txq->lock);
        return 0;
}

/*************** HOST COMMAND QUEUE FUNCTIONS   *****/

/*
 * iwl_pcie_gen2_enqueue_hcmd - enqueue a uCode command
 * @priv: device private data point
 * @cmd: a pointer to the ucode command structure
 *
 * The function returns < 0 values to indicate the operation
 * failed. On success, it returns the index (>= 0) of command in the
 * command queue.
 */
static int iwl_pcie_gen2_enqueue_hcmd(struct iwl_trans *trans,
                                      struct iwl_host_cmd *cmd)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_txq *txq = trans_pcie->txq[trans_pcie->cmd_queue];
        struct iwl_device_cmd *out_cmd;
        struct iwl_cmd_meta *out_meta;
        unsigned long flags;
        void *dup_buf = NULL;
        dma_addr_t phys_addr;
        int i, cmd_pos, idx;
        u16 copy_size, cmd_size, tb0_size;
        bool had_nocopy = false;
        u8 group_id = iwl_cmd_groupid(cmd->id);
        const u8 *cmddata[IWL_MAX_CMD_TBS_PER_TFD];
        u16 cmdlen[IWL_MAX_CMD_TBS_PER_TFD];
        struct iwl_tfh_tfd *tfd;

        copy_size = sizeof(struct iwl_cmd_header_wide);
        cmd_size = sizeof(struct iwl_cmd_header_wide);

        for (i = 0; i < IWL_MAX_CMD_TBS_PER_TFD; i++) {
                cmddata[i] = cmd->data[i];
                cmdlen[i] = cmd->len[i];

                if (!cmd->len[i])
                        continue;

                /* need at least IWL_FIRST_TB_SIZE copied */
                if (copy_size < IWL_FIRST_TB_SIZE) {
                        int copy = IWL_FIRST_TB_SIZE - copy_size;

                        if (copy > cmdlen[i])
                                copy = cmdlen[i];
                        cmdlen[i] -= copy;
                        cmddata[i] += copy;
                        copy_size += copy;
                }

                if (cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY) {
                        had_nocopy = true;
                        if (WARN_ON(cmd->dataflags[i] & IWL_HCMD_DFL_DUP)) {
                                idx = -EINVAL;
                                goto free_dup_buf;
                        }
                } else if (cmd->dataflags[i] & IWL_HCMD_DFL_DUP) {
                        /*
                         * This is also a chunk that isn't copied
                         * to the static buffer so set had_nocopy.
                         */
                        had_nocopy = true;

                        /* only allowed once */
                        if (WARN_ON(dup_buf)) {
                                idx = -EINVAL;
                                goto free_dup_buf;
                        }

                        dup_buf = kmemdup(cmddata[i], cmdlen[i],
                                          GFP_ATOMIC);
                        if (!dup_buf)
                                return -ENOMEM;
                } else {
                        /* NOCOPY must not be followed by normal! */
                        if (WARN_ON(had_nocopy)) {
                                idx = -EINVAL;
                                goto free_dup_buf;
                        }
                        copy_size += cmdlen[i];
                }
                cmd_size += cmd->len[i];
        }

        /*
         * If any of the command structures end up being larger than the
         * TFD_MAX_PAYLOAD_SIZE and they aren't dynamically allocated into
         * separate TFDs, then we will need to increase the size of the buffers
         */
        if (WARN(copy_size > TFD_MAX_PAYLOAD_SIZE,
                 "Command %s (%#x) is too large (%d bytes)\n",
                 iwl_get_cmd_string(trans, cmd->id), cmd->id, copy_size)) {
                idx = -EINVAL;
                goto free_dup_buf;
        }

        spin_lock_bh(&txq->lock);

        idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);
        tfd = iwl_pcie_get_tfd(trans, txq, txq->write_ptr);
        memset(tfd, 0, sizeof(*tfd));

        if (iwl_queue_space(trans, txq) < ((cmd->flags & CMD_ASYNC) ? 2 : 1)) {
                spin_unlock_bh(&txq->lock);

                IWL_ERR(trans, "No space in command queue\n");
                iwl_op_mode_cmd_queue_full(trans->op_mode);
                idx = -ENOSPC;
                goto free_dup_buf;
        }

        out_cmd = txq->entries[idx].cmd;
        out_meta = &txq->entries[idx].meta;

        /* re-initialize to NULL */
        memset(out_meta, 0, sizeof(*out_meta));
        if (cmd->flags & CMD_WANT_SKB)
                out_meta->source = cmd;

        /* set up the header */
        out_cmd->hdr_wide.cmd = iwl_cmd_opcode(cmd->id);
        out_cmd->hdr_wide.group_id = group_id;
        out_cmd->hdr_wide.version = iwl_cmd_version(cmd->id);
        out_cmd->hdr_wide.length =
                cpu_to_le16(cmd_size - sizeof(struct iwl_cmd_header_wide));
        out_cmd->hdr_wide.reserved = 0;
        out_cmd->hdr_wide.sequence =
                cpu_to_le16(QUEUE_TO_SEQ(trans_pcie->cmd_queue) |
                                         INDEX_TO_SEQ(txq->write_ptr));

        cmd_pos = sizeof(struct iwl_cmd_header_wide);
        copy_size = sizeof(struct iwl_cmd_header_wide);

        /* and copy the data that needs to be copied */
        for (i = 0; i < IWL_MAX_CMD_TBS_PER_TFD; i++) {
                int copy;

                if (!cmd->len[i])
                        continue;

                /* copy everything if not nocopy/dup */
                if (!(cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY |
                                           IWL_HCMD_DFL_DUP))) {
                        copy = cmd->len[i];

                        memcpy((u8 *)out_cmd + cmd_pos, cmd->data[i], copy);
                        cmd_pos += copy;
                        copy_size += copy;
                        continue;
                }

                /*
                 * Otherwise we need at least IWL_FIRST_TB_SIZE copied
                 * in total (for bi-directional DMA), but copy up to what
                 * we can fit into the payload for debug dump purposes.
                 */
                copy = min_t(int, TFD_MAX_PAYLOAD_SIZE - cmd_pos, cmd->len[i]);

                memcpy((u8 *)out_cmd + cmd_pos, cmd->data[i], copy);
                cmd_pos += copy;

                /* However, treat copy_size the proper way, we need it below */
                if (copy_size < IWL_FIRST_TB_SIZE) {
                        copy = IWL_FIRST_TB_SIZE - copy_size;

                        if (copy > cmd->len[i])
                                copy = cmd->len[i];
                        copy_size += copy;
                }
        }

        IWL_DEBUG_HC(trans,
                     "Sending command %s (%.2x.%.2x), seq: 0x%04X, %d bytes at %d[%d]:%d\n",
                     iwl_get_cmd_string(trans, cmd->id), group_id,
                     out_cmd->hdr.cmd, le16_to_cpu(out_cmd->hdr.sequence),
                     cmd_size, txq->write_ptr, idx, trans_pcie->cmd_queue);

        /* start the TFD with the minimum copy bytes */
        tb0_size = min_t(int, copy_size, IWL_FIRST_TB_SIZE);
        memcpy(&txq->first_tb_bufs[idx], &out_cmd->hdr, tb0_size);
        iwl_pcie_gen2_set_tb(trans, tfd, iwl_pcie_get_first_tb_dma(txq, idx),
                             tb0_size);

        /* map first command fragment, if any remains */
        if (copy_size > tb0_size) {
                phys_addr = dma_map_single(trans->dev,
                                           ((u8 *)&out_cmd->hdr) + tb0_size,
                                           copy_size - tb0_size,
                                           DMA_TO_DEVICE);
                if (dma_mapping_error(trans->dev, phys_addr)) {
                        idx = -ENOMEM;
                        iwl_pcie_gen2_tfd_unmap(trans, out_meta, tfd);
                        goto out;
                }
                iwl_pcie_gen2_set_tb(trans, tfd, phys_addr,
                                     copy_size - tb0_size);
        }

        /* map the remaining (adjusted) nocopy/dup fragments */
        for (i = 0; i < IWL_MAX_CMD_TBS_PER_TFD; i++) {
                const void *data = cmddata[i];

                if (!cmdlen[i])
                        continue;
                if (!(cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY |
                                           IWL_HCMD_DFL_DUP)))
                        continue;
                if (cmd->dataflags[i] & IWL_HCMD_DFL_DUP)
                        data = dup_buf;
                phys_addr = dma_map_single(trans->dev, (void *)data,
                                           cmdlen[i], DMA_TO_DEVICE);
                if (dma_mapping_error(trans->dev, phys_addr)) {
                        idx = -ENOMEM;
                        iwl_pcie_gen2_tfd_unmap(trans, out_meta, tfd);
                        goto out;
                }
                iwl_pcie_gen2_set_tb(trans, tfd, phys_addr, cmdlen[i]);
        }

        BUILD_BUG_ON(IWL_TFH_NUM_TBS > sizeof(out_meta->tbs) * BITS_PER_BYTE);
        out_meta->flags = cmd->flags;
        if (WARN_ON_ONCE(txq->entries[idx].free_buf))
                kzfree(txq->entries[idx].free_buf);
        txq->entries[idx].free_buf = dup_buf;

        trace_iwlwifi_dev_hcmd(trans->dev, cmd, cmd_size, &out_cmd->hdr_wide);

        /* start timer if queue currently empty */
        if (txq->read_ptr == txq->write_ptr && txq->wd_timeout)
                mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);

        spin_lock_irqsave(&trans_pcie->reg_lock, flags);
        if (!(cmd->flags & CMD_SEND_IN_IDLE) &&
            !trans_pcie->ref_cmd_in_flight) {
                trans_pcie->ref_cmd_in_flight = true;
                IWL_DEBUG_RPM(trans, "set ref_cmd_in_flight - ref\n");
                iwl_trans_ref(trans);
        }
        /* Increment and update queue's write index */
        txq->write_ptr = iwl_queue_inc_wrap(trans, txq->write_ptr);
        iwl_pcie_gen2_txq_inc_wr_ptr(trans, txq);
        spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);

out:
        spin_unlock_bh(&txq->lock);
free_dup_buf:
        if (idx < 0)
                kfree(dup_buf);
        return idx;
}

#define HOST_COMPLETE_TIMEOUT   (2 * HZ)

static int iwl_pcie_gen2_send_hcmd_sync(struct iwl_trans *trans,
                                        struct iwl_host_cmd *cmd)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        const char *cmd_str = iwl_get_cmd_string(trans, cmd->id);
        struct iwl_txq *txq = trans_pcie->txq[trans_pcie->cmd_queue];
        int cmd_idx;
        int ret;

        IWL_DEBUG_INFO(trans, "Attempting to send sync command %s\n", cmd_str);

        if (WARN(test_and_set_bit(STATUS_SYNC_HCMD_ACTIVE,
                                  &trans->status),
                 "Command %s: a command is already active!\n", cmd_str))
                return -EIO;

        IWL_DEBUG_INFO(trans, "Setting HCMD_ACTIVE for command %s\n", cmd_str);

        if (pm_runtime_suspended(&trans_pcie->pci_dev->dev)) {
                ret = wait_event_timeout(trans_pcie->d0i3_waitq,
                                 pm_runtime_active(&trans_pcie->pci_dev->dev),
                                 msecs_to_jiffies(IWL_TRANS_IDLE_TIMEOUT));
                if (!ret) {
                        IWL_ERR(trans, "Timeout exiting D0i3 before hcmd\n");
                        return -ETIMEDOUT;
                }
        }

        cmd_idx = iwl_pcie_gen2_enqueue_hcmd(trans, cmd);
        if (cmd_idx < 0) {
                ret = cmd_idx;
                clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
                IWL_ERR(trans, "Error sending %s: enqueue_hcmd failed: %d\n",
                        cmd_str, ret);
                return ret;
        }

        ret = wait_event_timeout(trans_pcie->wait_command_queue,
                                 !test_bit(STATUS_SYNC_HCMD_ACTIVE,
                                           &trans->status),
                                 HOST_COMPLETE_TIMEOUT);
        if (!ret) {
                IWL_ERR(trans, "Error sending %s: time out after %dms.\n",
                        cmd_str, jiffies_to_msecs(HOST_COMPLETE_TIMEOUT));

                IWL_ERR(trans, "Current CMD queue read_ptr %d write_ptr %d\n",
                        txq->read_ptr, txq->write_ptr);

                clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
                IWL_DEBUG_INFO(trans, "Clearing HCMD_ACTIVE for command %s\n",
                               cmd_str);
                ret = -ETIMEDOUT;

                iwl_force_nmi(trans);
                iwl_trans_fw_error(trans);

                goto cancel;
        }

        if (test_bit(STATUS_FW_ERROR, &trans->status)) {
                IWL_ERR(trans, "FW error in SYNC CMD %s\n", cmd_str);
                dump_stack();
                ret = -EIO;
                goto cancel;
        }

        if (!(cmd->flags & CMD_SEND_IN_RFKILL) &&
            test_bit(STATUS_RFKILL_OPMODE, &trans->status)) {
                IWL_DEBUG_RF_KILL(trans, "RFKILL in SYNC CMD... no rsp\n");
                ret = -ERFKILL;
                goto cancel;
        }

        if ((cmd->flags & CMD_WANT_SKB) && !cmd->resp_pkt) {
                IWL_ERR(trans, "Error: Response NULL in '%s'\n", cmd_str);
                ret = -EIO;
                goto cancel;
        }

        return 0;

cancel:
        if (cmd->flags & CMD_WANT_SKB) {
                /*
                 * Cancel the CMD_WANT_SKB flag for the cmd in the
                 * TX cmd queue. Otherwise in case the cmd comes
                 * in later, it will possibly set an invalid
                 * address (cmd->meta.source).
                 */
                txq->entries[cmd_idx].meta.flags &= ~CMD_WANT_SKB;
        }

        if (cmd->resp_pkt) {
                iwl_free_resp(cmd);
                cmd->resp_pkt = NULL;
        }

        return ret;
}

int iwl_trans_pcie_gen2_send_hcmd(struct iwl_trans *trans,
                                  struct iwl_host_cmd *cmd)
{
        if (!(cmd->flags & CMD_SEND_IN_RFKILL) &&
            test_bit(STATUS_RFKILL_OPMODE, &trans->status)) {
                IWL_DEBUG_RF_KILL(trans, "Dropping CMD 0x%x: RF KILL\n",
                                  cmd->id);
                return -ERFKILL;
        }

        if (cmd->flags & CMD_ASYNC) {
                int ret;

                /* An asynchronous command can not expect an SKB to be set. */
                if (WARN_ON(cmd->flags & CMD_WANT_SKB))
                        return -EINVAL;

                ret = iwl_pcie_gen2_enqueue_hcmd(trans, cmd);

                if (ret < 0) {
                        IWL_ERR(trans,
                                "Error sending %s: enqueue_hcmd failed: %d\n",
                                iwl_get_cmd_string(trans, cmd->id), ret);
                        return ret;
                }
                return 0;
        }

        return iwl_pcie_gen2_send_hcmd_sync(trans, cmd);
}

/*
 * iwl_pcie_gen2_txq_unmap -  Unmap any remaining DMA mappings and free skb's
 */
void iwl_pcie_gen2_txq_unmap(struct iwl_trans *trans, int txq_id)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_txq *txq = trans_pcie->txq[txq_id];

        spin_lock_bh(&txq->lock);
        while (txq->write_ptr != txq->read_ptr) {
                IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n",
                                   txq_id, txq->read_ptr);

                if (txq_id != trans_pcie->cmd_queue) {
                        int idx = iwl_pcie_get_cmd_index(txq, txq->read_ptr);
                        struct sk_buff *skb = txq->entries[idx].skb;

                        if (WARN_ON_ONCE(!skb))
                                continue;

                        iwl_pcie_free_tso_page(trans_pcie, skb);
                }
                iwl_pcie_gen2_free_tfd(trans, txq);
                txq->read_ptr = iwl_queue_inc_wrap(trans, txq->read_ptr);

                if (txq->read_ptr == txq->write_ptr) {
                        unsigned long flags;

                        spin_lock_irqsave(&trans_pcie->reg_lock, flags);
                        if (txq_id != trans_pcie->cmd_queue) {
                                IWL_DEBUG_RPM(trans, "Q %d - last tx freed\n",
                                              txq->id);
                                iwl_trans_unref(trans);
                        } else if (trans_pcie->ref_cmd_in_flight) {
                                trans_pcie->ref_cmd_in_flight = false;
                                IWL_DEBUG_RPM(trans,
                                              "clear ref_cmd_in_flight\n");
                                iwl_trans_unref(trans);
                        }
                        spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
                }
        }

        while (!skb_queue_empty(&txq->overflow_q)) {
                struct sk_buff *skb = __skb_dequeue(&txq->overflow_q);

                iwl_op_mode_free_skb(trans->op_mode, skb);
        }

        spin_unlock_bh(&txq->lock);

        /* just in case - this queue may have been stopped */
        iwl_wake_queue(trans, txq);
}

static void iwl_pcie_gen2_txq_free_memory(struct iwl_trans *trans,
                                          struct iwl_txq *txq)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct device *dev = trans->dev;

        /* De-alloc circular buffer of TFDs */
        if (txq->tfds) {
                dma_free_coherent(dev,
                                  trans_pcie->tfd_size * txq->n_window,
                                  txq->tfds, txq->dma_addr);
                dma_free_coherent(dev,
                                  sizeof(*txq->first_tb_bufs) * txq->n_window,
                                  txq->first_tb_bufs, txq->first_tb_dma);
        }

        kfree(txq->entries);
        iwl_pcie_free_dma_ptr(trans, &txq->bc_tbl);
        kfree(txq);
}

/*
 * iwl_pcie_txq_free - Deallocate DMA queue.
 * @txq: Transmit queue to deallocate.
 *
 * Empty queue by removing and destroying all BD's.
 * Free all buffers.
 * 0-fill, but do not free "txq" descriptor structure.
 */
static void iwl_pcie_gen2_txq_free(struct iwl_trans *trans, int txq_id)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_txq *txq = trans_pcie->txq[txq_id];
        int i;

        if (WARN_ON(!txq))
                return;

        iwl_pcie_gen2_txq_unmap(trans, txq_id);

        /* De-alloc array of command/tx buffers */
        if (txq_id == trans_pcie->cmd_queue)
                for (i = 0; i < txq->n_window; i++) {
                        kzfree(txq->entries[i].cmd);
                        kzfree(txq->entries[i].free_buf);
                }
        del_timer_sync(&txq->stuck_timer);

        iwl_pcie_gen2_txq_free_memory(trans, txq);

        trans_pcie->txq[txq_id] = NULL;

        clear_bit(txq_id, trans_pcie->queue_used);
}

int iwl_trans_pcie_dyn_txq_alloc(struct iwl_trans *trans,
                                 struct iwl_tx_queue_cfg_cmd *cmd,
                                 int cmd_id, int size,
                                 unsigned int timeout)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_tx_queue_cfg_rsp *rsp;
        struct iwl_txq *txq;
        struct iwl_host_cmd hcmd = {
                .id = cmd_id,
                .len = { sizeof(*cmd) },
                .data = { cmd, },
                .flags = CMD_WANT_SKB,
        };
        int ret, qid;
        u32 wr_ptr;

        txq = kzalloc(sizeof(*txq), GFP_KERNEL);
        if (!txq)
                return -ENOMEM;
        ret = iwl_pcie_alloc_dma_ptr(trans, &txq->bc_tbl,
                                     (trans->cfg->device_family >=
                                      IWL_DEVICE_FAMILY_22560) ?
                                     sizeof(struct iwl_gen3_bc_tbl) :
                                     sizeof(struct iwlagn_scd_bc_tbl));
        if (ret) {
                IWL_ERR(trans, "Scheduler BC Table allocation failed\n");
                kfree(txq);
                return -ENOMEM;
        }

        ret = iwl_pcie_txq_alloc(trans, txq, size, false);
        if (ret) {
                IWL_ERR(trans, "Tx queue alloc failed\n");
                goto error;
        }
        ret = iwl_pcie_txq_init(trans, txq, size, false);
        if (ret) {
                IWL_ERR(trans, "Tx queue init failed\n");
                goto error;
        }

        txq->wd_timeout = msecs_to_jiffies(timeout);

        cmd->tfdq_addr = cpu_to_le64(txq->dma_addr);
        cmd->byte_cnt_addr = cpu_to_le64(txq->bc_tbl.dma);
        cmd->cb_size = cpu_to_le32(TFD_QUEUE_CB_SIZE(size));

        ret = iwl_trans_send_cmd(trans, &hcmd);
        if (ret)
                goto error;

        if (WARN_ON(iwl_rx_packet_payload_len(hcmd.resp_pkt) != sizeof(*rsp))) {
                ret = -EINVAL;
                goto error_free_resp;
        }

        rsp = (void *)hcmd.resp_pkt->data;
        qid = le16_to_cpu(rsp->queue_number);
        wr_ptr = le16_to_cpu(rsp->write_pointer);

        if (qid >= ARRAY_SIZE(trans_pcie->txq)) {
                WARN_ONCE(1, "queue index %d unsupported", qid);
                ret = -EIO;
                goto error_free_resp;
        }

        if (test_and_set_bit(qid, trans_pcie->queue_used)) {
                WARN_ONCE(1, "queue %d already used", qid);
                ret = -EIO;
                goto error_free_resp;
        }

        txq->id = qid;
        trans_pcie->txq[qid] = txq;
        wr_ptr &= (trans->cfg->base_params->max_tfd_queue_size - 1);

        /* Place first TFD at index corresponding to start sequence number */
        txq->read_ptr = wr_ptr;
        txq->write_ptr = wr_ptr;
        iwl_write_direct32(trans, HBUS_TARG_WRPTR,
                           (txq->write_ptr) | (qid << 16));
        IWL_DEBUG_TX_QUEUES(trans, "Activate queue %d\n", qid);

        iwl_free_resp(&hcmd);
        return qid;

error_free_resp:
        iwl_free_resp(&hcmd);
error:
        iwl_pcie_gen2_txq_free_memory(trans, txq);
        return ret;
}

void iwl_trans_pcie_dyn_txq_free(struct iwl_trans *trans, int queue)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

        /*
         * Upon HW Rfkill - we stop the device, and then stop the queues
         * in the op_mode. Just for the sake of the simplicity of the op_mode,
         * allow the op_mode to call txq_disable after it already called
         * stop_device.
         */
        if (!test_and_clear_bit(queue, trans_pcie->queue_used)) {
                WARN_ONCE(test_bit(STATUS_DEVICE_ENABLED, &trans->status),
                          "queue %d not used", queue);
                return;
        }

        iwl_pcie_gen2_txq_unmap(trans, queue);

        IWL_DEBUG_TX_QUEUES(trans, "Deactivate queue %d\n", queue);
}

void iwl_pcie_gen2_tx_free(struct iwl_trans *trans)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        int i;

        memset(trans_pcie->queue_used, 0, sizeof(trans_pcie->queue_used));

        /* Free all TX queues */
        for (i = 0; i < ARRAY_SIZE(trans_pcie->txq); i++) {
                if (!trans_pcie->txq[i])
                        continue;

                iwl_pcie_gen2_txq_free(trans, i);
        }
}

int iwl_pcie_gen2_tx_init(struct iwl_trans *trans)
{
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_txq *cmd_queue;
        int txq_id = trans_pcie->cmd_queue, ret;

        /* alloc and init the command queue */
        if (!trans_pcie->txq[txq_id]) {
                cmd_queue = kzalloc(sizeof(*cmd_queue), GFP_KERNEL);
                if (!cmd_queue) {
                        IWL_ERR(trans, "Not enough memory for command queue\n");
                        return -ENOMEM;
                }
                trans_pcie->txq[txq_id] = cmd_queue;
                ret = iwl_pcie_txq_alloc(trans, cmd_queue, TFD_CMD_SLOTS, true);
                if (ret) {
                        IWL_ERR(trans, "Tx %d queue init failed\n", txq_id);
                        goto error;
                }
        } else {
                cmd_queue = trans_pcie->txq[txq_id];
        }

        ret = iwl_pcie_txq_init(trans, cmd_queue, TFD_CMD_SLOTS, true);
        if (ret) {
                IWL_ERR(trans, "Tx %d queue alloc failed\n", txq_id);
                goto error;
        }
        trans_pcie->txq[txq_id]->id = txq_id;
        set_bit(txq_id, trans_pcie->queue_used);

        return 0;

error:
        iwl_pcie_gen2_tx_free(trans);
        return ret;
}