/*      $OpenBSD: if_rtwn.c,v 1.6 2015/08/28 00:03:53 deraadt Exp $     */

/*-
 * Copyright (c) 2010 Damien Bergamini <damien.bergamini@free.fr>
 * Copyright (c) 2015 Stefan Sperling <stsp@openbsd.org>
 * Copyright (c) 2016 Andriy Voskoboinyk <avos@FreeBSD.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/cdefs.h>
#include "opt_wlan.h"

#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/taskqueue.h>
#include <sys/bus.h>
#include <sys/endian.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <net/if_media.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_radiotap.h>

#include <dev/rtwn/if_rtwnreg.h>
#include <dev/rtwn/if_rtwnvar.h>
#include <dev/rtwn/if_rtwn_debug.h>

#include <dev/rtwn/pci/rtwn_pci_var.h>
#include <dev/rtwn/pci/rtwn_pci_tx.h>

#include <dev/rtwn/rtl8192c/pci/r92ce_reg.h>

static struct mbuf *
rtwn_mbuf_defrag(struct mbuf *m0, int how)
{
        struct mbuf *m = NULL;

        KASSERT(m0->m_flags & M_PKTHDR,
            ("M_PKTHDR flag is absent (m %p)!", m0));

        /* NB: we need _exactly_ one mbuf (no less, no more). */
        if (m0->m_pkthdr.len > MJUMPAGESIZE) {
                /* XXX MJUM9BYTES? */
                return (NULL);
        } else if (m0->m_pkthdr.len > MCLBYTES) {
                m = m_getjcl(how, MT_DATA, M_PKTHDR, MJUMPAGESIZE);
                if (m == NULL)
                        return (NULL);

                if (m_dup_pkthdr(m, m0, how) == 0) {
                        m_freem(m);
                        return (NULL);
                }

                m_copydata(m0, 0, m0->m_pkthdr.len, mtod(m, caddr_t));
                m->m_len = m->m_pkthdr.len;
                m_freem(m0);

                return (m);
        } else
                return (m_defrag(m0, how));
}

static int
rtwn_pci_tx_start_frame(struct rtwn_softc *sc, struct ieee80211_node *ni,
    struct mbuf *m, uint8_t *tx_desc, uint8_t type)
{
        struct rtwn_pci_softc *pc = RTWN_PCI_SOFTC(sc);
        struct rtwn_tx_ring *ring;
        struct rtwn_tx_data *data;
        struct rtwn_tx_desc_common *txd;
        bus_dma_segment_t segs[1];
        uint8_t qid;
        int nsegs, error;

        RTWN_ASSERT_LOCKED(sc);

        switch (type) {
        case IEEE80211_FC0_TYPE_CTL:
        case IEEE80211_FC0_TYPE_MGT:
                qid = RTWN_PCI_MGNT_QUEUE;
                break;
        default:
                qid = M_WME_GETAC(m);
                break;
        }

        ring = &pc->tx_ring[qid];
        data = &ring->tx_data[ring->cur];
        if (data->m != NULL) {
                RTWN_DPRINTF(sc, RTWN_DEBUG_XMIT,
                    "%s: ring #%u is full (m %p)\n", __func__, qid, data->m);
                return (ENOBUFS);
        }

        txd = (struct rtwn_tx_desc_common *)
            ((uint8_t *)ring->desc + sc->txdesc_len * ring->cur);
        if (txd->flags0 & RTWN_FLAGS0_OWN) {
                device_printf(sc->sc_dev,
                    "%s: OWN bit is set (tx desc %d, ring %u)!\n",
                    __func__, ring->cur, qid);
                return (ENOBUFS);
        }

        /* Copy Tx descriptor. */
        rtwn_pci_copy_tx_desc(pc, txd, tx_desc);
        txd->pktlen = htole16(m->m_pkthdr.len);
        txd->offset = sc->txdesc_len;

        error = bus_dmamap_load_mbuf_sg(ring->data_dmat, data->map, m, segs,
            &nsegs, BUS_DMA_NOWAIT);
        if (error != 0 && error != EFBIG) {
                device_printf(sc->sc_dev, "can't map mbuf (error %d)\n",
                    error);
                return (error);
        }
        if (error != 0) {
                struct mbuf *mnew;

                mnew = rtwn_mbuf_defrag(m, M_NOWAIT);
                if (mnew == NULL) {
                        device_printf(sc->sc_dev, "can't defragment mbuf\n");
                        return (ENOBUFS);
                }
                m = mnew;

                error = bus_dmamap_load_mbuf_sg(ring->data_dmat, data->map, m,
                    segs, &nsegs, BUS_DMA_NOWAIT);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "can't map mbuf (error %d)\n", error);
                        if (ni != NULL) {
                                if_inc_counter(ni->ni_vap->iv_ifp,
                                    IFCOUNTER_OERRORS, 1);
                                ieee80211_free_node(ni);
                        }
                        m_freem(m);
                        return (0);     /* XXX */
                }
        }

        rtwn_pci_tx_postsetup(pc, txd, segs);
        txd->flags0 |= RTWN_FLAGS0_OWN;

        /* Dump Tx descriptor. */
        rtwn_dump_tx_desc(sc, txd);

        bus_dmamap_sync(ring->desc_dmat, ring->desc_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        bus_dmamap_sync(ring->data_dmat, data->map, BUS_DMASYNC_PREWRITE);

        data->m = m;
        data->ni = ni;

        ring->cur = (ring->cur + 1) % RTWN_PCI_TX_LIST_COUNT;

        ring->queued++;
        if (ring->queued >= (RTWN_PCI_TX_LIST_COUNT - 1))
                sc->qfullmsk |= (1 << qid);

#ifndef D4054
        sc->sc_tx_timer = 5;
#endif

        /* Kick TX. */
        rtwn_write_2(sc, R92C_PCIE_CTRL_REG, (1 << qid));

        return (0);
}

static int
rtwn_pci_tx_start_beacon(struct rtwn_softc *sc, struct mbuf *m,
    uint8_t *tx_desc, int id)
{
        struct rtwn_pci_softc *pc = RTWN_PCI_SOFTC(sc);
        struct rtwn_tx_ring *ring;
        struct rtwn_tx_data *data;
        struct rtwn_tx_desc_common *txd;
        bus_dma_segment_t segs[1];
        int nsegs, error, own;

        RTWN_ASSERT_LOCKED(sc);

        KASSERT(id == 0 || id == 1, ("bogus vap id %d\n", id));

        ring = &pc->tx_ring[RTWN_PCI_BEACON_QUEUE];
        data = &ring->tx_data[id];
        txd = (struct rtwn_tx_desc_common *)
            ((uint8_t *)ring->desc + id * sc->txdesc_len);

        bus_dmamap_sync(ring->desc_dmat, ring->desc_map,
            BUS_DMASYNC_POSTREAD);
        own = !!(txd->flags0 & RTWN_FLAGS0_OWN);
        error = 0;
        if (!own || txd->pktlen != htole16(m->m_pkthdr.len)) {
                if (!own) {
                        /* Copy Tx descriptor. */
                        rtwn_pci_copy_tx_desc(pc, txd, tx_desc);
                        txd->offset = sc->txdesc_len;
                } else {
                        /* Reload mbuf. */
                        bus_dmamap_unload(ring->data_dmat, data->map);
                }

                error = bus_dmamap_load_mbuf_sg(ring->data_dmat,
                    data->map, m, segs, &nsegs, BUS_DMA_NOWAIT);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "can't map beacon (error %d)\n", error);
                        txd->flags0 &= ~RTWN_FLAGS0_OWN;
                        goto end;
                }

                txd->pktlen = htole16(m->m_pkthdr.len);
                rtwn_pci_tx_postsetup(pc, txd, segs);
                txd->flags0 |= RTWN_FLAGS0_OWN;
end:
                bus_dmamap_sync(ring->desc_dmat, ring->desc_map,
                    BUS_DMASYNC_PREWRITE);
        }

        /* Dump Tx descriptor. */
        rtwn_dump_tx_desc(sc, txd);

        bus_dmamap_sync(ring->data_dmat, data->map, BUS_DMASYNC_PREWRITE);

        return (0);
}

int
rtwn_pci_tx_start(struct rtwn_softc *sc, struct ieee80211_node *ni,
    struct mbuf *m, uint8_t *tx_desc, uint8_t type, int id)
{
        int error = 0;

        RTWN_ASSERT_LOCKED(sc);

        if (ni == NULL)         /* beacon frame */
                error = rtwn_pci_tx_start_beacon(sc, m, tx_desc, id);
        else
                error = rtwn_pci_tx_start_frame(sc, ni, m, tx_desc, type);

        return (error);
}