The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/dev/ath/if_ath_rx.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer,
   12  *    without modification.
   13  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
   14  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
   15  *    redistribution must be conditioned upon including a substantially
   16  *    similar Disclaimer requirement for further binary redistribution.
   17  *
   18  * NO WARRANTY
   19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   21  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
   22  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
   23  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
   24  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
   27  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   29  * THE POSSIBILITY OF SUCH DAMAGES.
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD$");
   34 
   35 /*
   36  * Driver for the Atheros Wireless LAN controller.
   37  *
   38  * This software is derived from work of Atsushi Onoe; his contribution
   39  * is greatly appreciated.
   40  */
   41 
   42 #include "opt_inet.h"
   43 #include "opt_ath.h"
   44 /*
   45  * This is needed for register operations which are performed
   46  * by the driver - eg, calls to ath_hal_gettsf32().
   47  *
   48  * It's also required for any AH_DEBUG checks in here, eg the
   49  * module dependencies.
   50  */
   51 #include "opt_ah.h"
   52 #include "opt_wlan.h"
   53 
   54 #include <sys/param.h>
   55 #include <sys/systm.h>
   56 #include <sys/sysctl.h>
   57 #include <sys/mbuf.h>
   58 #include <sys/malloc.h>
   59 #include <sys/lock.h>
   60 #include <sys/mutex.h>
   61 #include <sys/kernel.h>
   62 #include <sys/socket.h>
   63 #include <sys/sockio.h>
   64 #include <sys/errno.h>
   65 #include <sys/callout.h>
   66 #include <sys/bus.h>
   67 #include <sys/endian.h>
   68 #include <sys/kthread.h>
   69 #include <sys/taskqueue.h>
   70 #include <sys/priv.h>
   71 #include <sys/module.h>
   72 #include <sys/ktr.h>
   73 #include <sys/smp.h>    /* for mp_ncpus */
   74 
   75 #include <machine/bus.h>
   76 
   77 #include <net/if.h>
   78 #include <net/if_var.h>
   79 #include <net/if_dl.h>
   80 #include <net/if_media.h>
   81 #include <net/if_types.h>
   82 #include <net/if_arp.h>
   83 #include <net/ethernet.h>
   84 #include <net/if_llc.h>
   85 
   86 #include <net80211/ieee80211_var.h>
   87 #include <net80211/ieee80211_regdomain.h>
   88 #ifdef IEEE80211_SUPPORT_SUPERG
   89 #include <net80211/ieee80211_superg.h>
   90 #endif
   91 #ifdef IEEE80211_SUPPORT_TDMA
   92 #include <net80211/ieee80211_tdma.h>
   93 #endif
   94 
   95 #include <net/bpf.h>
   96 
   97 #ifdef INET
   98 #include <netinet/in.h>
   99 #include <netinet/if_ether.h>
  100 #endif
  101 
  102 #include <dev/ath/if_athvar.h>
  103 #include <dev/ath/ath_hal/ah_devid.h>           /* XXX for softled */
  104 #include <dev/ath/ath_hal/ah_diagcodes.h>
  105 
  106 #include <dev/ath/if_ath_debug.h>
  107 #include <dev/ath/if_ath_misc.h>
  108 #include <dev/ath/if_ath_tsf.h>
  109 #include <dev/ath/if_ath_tx.h>
  110 #include <dev/ath/if_ath_sysctl.h>
  111 #include <dev/ath/if_ath_led.h>
  112 #include <dev/ath/if_ath_keycache.h>
  113 #include <dev/ath/if_ath_rx.h>
  114 #include <dev/ath/if_ath_beacon.h>
  115 #include <dev/ath/if_athdfs.h>
  116 #include <dev/ath/if_ath_descdma.h>
  117 
  118 #ifdef ATH_TX99_DIAG
  119 #include <dev/ath/ath_tx99/ath_tx99.h>
  120 #endif
  121 
  122 #ifdef  ATH_DEBUG_ALQ
  123 #include <dev/ath/if_ath_alq.h>
  124 #endif
  125 
  126 #include <dev/ath/if_ath_lna_div.h>
  127 
  128 /*
  129  * Calculate the receive filter according to the
  130  * operating mode and state:
  131  *
  132  * o always accept unicast, broadcast, and multicast traffic
  133  * o accept PHY error frames when hardware doesn't have MIB support
  134  *   to count and we need them for ANI (sta mode only until recently)
  135  *   and we are not scanning (ANI is disabled)
  136  *   NB: older hal's add rx filter bits out of sight and we need to
  137  *       blindly preserve them
  138  * o probe request frames are accepted only when operating in
  139  *   hostap, adhoc, mesh, or monitor modes
  140  * o enable promiscuous mode
  141  *   - when in monitor mode
  142  *   - if interface marked PROMISC (assumes bridge setting is filtered)
  143  * o accept beacons:
  144  *   - when operating in station mode for collecting rssi data when
  145  *     the station is otherwise quiet, or
  146  *   - when operating in adhoc mode so the 802.11 layer creates
  147  *     node table entries for peers,
  148  *   - when scanning
  149  *   - when doing s/w beacon miss (e.g. for ap+sta)
  150  *   - when operating in ap mode in 11g to detect overlapping bss that
  151  *     require protection
  152  *   - when operating in mesh mode to detect neighbors
  153  * o accept control frames:
  154  *   - when in monitor mode
  155  * XXX HT protection for 11n
  156  */
  157 u_int32_t
  158 ath_calcrxfilter(struct ath_softc *sc)
  159 {
  160         struct ieee80211com *ic = &sc->sc_ic;
  161         u_int32_t rfilt;
  162 
  163         rfilt = HAL_RX_FILTER_UCAST | HAL_RX_FILTER_BCAST | HAL_RX_FILTER_MCAST;
  164         if (!sc->sc_needmib && !sc->sc_scanning)
  165                 rfilt |= HAL_RX_FILTER_PHYERR;
  166         if (ic->ic_opmode != IEEE80211_M_STA)
  167                 rfilt |= HAL_RX_FILTER_PROBEREQ;
  168         /* XXX ic->ic_monvaps != 0? */
  169         if (ic->ic_opmode == IEEE80211_M_MONITOR || ic->ic_promisc > 0)
  170                 rfilt |= HAL_RX_FILTER_PROM;
  171 
  172         /*
  173          * Only listen to all beacons if we're scanning.
  174          *
  175          * Otherwise we only really need to hear beacons from
  176          * our own BSSID.
  177          *
  178          * IBSS? software beacon miss? Just receive all beacons.
  179          * We need to hear beacons/probe requests from everyone so
  180          * we can merge ibss.
  181          */
  182         if (ic->ic_opmode == IEEE80211_M_IBSS || sc->sc_swbmiss) {
  183                 rfilt |= HAL_RX_FILTER_BEACON;
  184         } else if (ic->ic_opmode == IEEE80211_M_STA) {
  185                 if (sc->sc_do_mybeacon && ! sc->sc_scanning) {
  186                         rfilt |= HAL_RX_FILTER_MYBEACON;
  187                 } else { /* scanning, non-mybeacon chips */
  188                         rfilt |= HAL_RX_FILTER_BEACON;
  189                 }
  190         }
  191 
  192         /*
  193          * NB: We don't recalculate the rx filter when
  194          * ic_protmode changes; otherwise we could do
  195          * this only when ic_protmode != NONE.
  196          */
  197         if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
  198             IEEE80211_IS_CHAN_ANYG(ic->ic_curchan))
  199                 rfilt |= HAL_RX_FILTER_BEACON;
  200 
  201         /*
  202          * Enable hardware PS-POLL RX only for hostap mode;
  203          * STA mode sends PS-POLL frames but never
  204          * receives them.
  205          */
  206         if (ath_hal_getcapability(sc->sc_ah, HAL_CAP_PSPOLL,
  207             0, NULL) == HAL_OK &&
  208             ic->ic_opmode == IEEE80211_M_HOSTAP)
  209                 rfilt |= HAL_RX_FILTER_PSPOLL;
  210 
  211         if (sc->sc_nmeshvaps) {
  212                 rfilt |= HAL_RX_FILTER_BEACON;
  213                 if (sc->sc_hasbmatch)
  214                         rfilt |= HAL_RX_FILTER_BSSID;
  215                 else
  216                         rfilt |= HAL_RX_FILTER_PROM;
  217         }
  218         if (ic->ic_opmode == IEEE80211_M_MONITOR)
  219                 rfilt |= HAL_RX_FILTER_CONTROL;
  220 
  221         /*
  222          * Enable RX of compressed BAR frames only when doing
  223          * 802.11n. Required for A-MPDU.
  224          */
  225         if (IEEE80211_IS_CHAN_HT(ic->ic_curchan))
  226                 rfilt |= HAL_RX_FILTER_COMPBAR;
  227 
  228         /*
  229          * Enable radar PHY errors if requested by the
  230          * DFS module.
  231          */
  232         if (sc->sc_dodfs)
  233                 rfilt |= HAL_RX_FILTER_PHYRADAR;
  234 
  235         /*
  236          * Enable spectral PHY errors if requested by the
  237          * spectral module.
  238          */
  239         if (sc->sc_dospectral)
  240                 rfilt |= HAL_RX_FILTER_PHYRADAR;
  241 
  242         DPRINTF(sc, ATH_DEBUG_MODE, "%s: RX filter 0x%x, %s\n",
  243             __func__, rfilt, ieee80211_opmode_name[ic->ic_opmode]);
  244         return rfilt;
  245 }
  246 
  247 static int
  248 ath_legacy_rxbuf_init(struct ath_softc *sc, struct ath_buf *bf)
  249 {
  250         struct ath_hal *ah = sc->sc_ah;
  251         int error;
  252         struct mbuf *m;
  253         struct ath_desc *ds;
  254 
  255         /* XXX TODO: ATH_RX_LOCK_ASSERT(sc); */
  256 
  257         m = bf->bf_m;
  258         if (m == NULL) {
  259                 /*
  260                  * NB: by assigning a page to the rx dma buffer we
  261                  * implicitly satisfy the Atheros requirement that
  262                  * this buffer be cache-line-aligned and sized to be
  263                  * multiple of the cache line size.  Not doing this
  264                  * causes weird stuff to happen (for the 5210 at least).
  265                  */
  266                 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
  267                 if (m == NULL) {
  268                         DPRINTF(sc, ATH_DEBUG_ANY,
  269                                 "%s: no mbuf/cluster\n", __func__);
  270                         sc->sc_stats.ast_rx_nombuf++;
  271                         return ENOMEM;
  272                 }
  273                 m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
  274 
  275                 error = bus_dmamap_load_mbuf_sg(sc->sc_dmat,
  276                                              bf->bf_dmamap, m,
  277                                              bf->bf_segs, &bf->bf_nseg,
  278                                              BUS_DMA_NOWAIT);
  279                 if (error != 0) {
  280                         DPRINTF(sc, ATH_DEBUG_ANY,
  281                             "%s: bus_dmamap_load_mbuf_sg failed; error %d\n",
  282                             __func__, error);
  283                         sc->sc_stats.ast_rx_busdma++;
  284                         m_freem(m);
  285                         return error;
  286                 }
  287                 KASSERT(bf->bf_nseg == 1,
  288                         ("multi-segment packet; nseg %u", bf->bf_nseg));
  289                 bf->bf_m = m;
  290         }
  291         bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREREAD);
  292 
  293         /*
  294          * Setup descriptors.  For receive we always terminate
  295          * the descriptor list with a self-linked entry so we'll
  296          * not get overrun under high load (as can happen with a
  297          * 5212 when ANI processing enables PHY error frames).
  298          *
  299          * To insure the last descriptor is self-linked we create
  300          * each descriptor as self-linked and add it to the end.  As
  301          * each additional descriptor is added the previous self-linked
  302          * entry is ``fixed'' naturally.  This should be safe even
  303          * if DMA is happening.  When processing RX interrupts we
  304          * never remove/process the last, self-linked, entry on the
  305          * descriptor list.  This insures the hardware always has
  306          * someplace to write a new frame.
  307          */
  308         /*
  309          * 11N: we can no longer afford to self link the last descriptor.
  310          * MAC acknowledges BA status as long as it copies frames to host
  311          * buffer (or rx fifo). This can incorrectly acknowledge packets
  312          * to a sender if last desc is self-linked.
  313          */
  314         ds = bf->bf_desc;
  315         if (sc->sc_rxslink)
  316                 ds->ds_link = bf->bf_daddr;     /* link to self */
  317         else
  318                 ds->ds_link = 0;                /* terminate the list */
  319         ds->ds_data = bf->bf_segs[0].ds_addr;
  320         ath_hal_setuprxdesc(ah, ds
  321                 , m->m_len              /* buffer size */
  322                 , 0
  323         );
  324 
  325         if (sc->sc_rxlink != NULL)
  326                 *sc->sc_rxlink = bf->bf_daddr;
  327         sc->sc_rxlink = &ds->ds_link;
  328         return 0;
  329 }
  330 
  331 /*
  332  * Intercept management frames to collect beacon rssi data
  333  * and to do ibss merges.
  334  */
  335 void
  336 ath_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m,
  337         int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
  338 {
  339         struct ieee80211vap *vap = ni->ni_vap;
  340         struct ath_softc *sc = vap->iv_ic->ic_softc;
  341         uint64_t tsf_beacon_old, tsf_beacon;
  342         uint64_t nexttbtt;
  343         int64_t tsf_delta;
  344         int32_t tsf_delta_bmiss;
  345         int32_t tsf_remainder;
  346         uint64_t tsf_beacon_target;
  347         int tsf_intval;
  348 
  349         tsf_beacon_old = ((uint64_t) le32dec(ni->ni_tstamp.data + 4)) << 32;
  350         tsf_beacon_old |= le32dec(ni->ni_tstamp.data);
  351 
  352 #define TU_TO_TSF(_tu)  (((u_int64_t)(_tu)) << 10)
  353         tsf_intval = 1;
  354         if (ni->ni_intval > 0) {
  355                 tsf_intval = TU_TO_TSF(ni->ni_intval);
  356         }
  357 #undef  TU_TO_TSF
  358 
  359         /*
  360          * Call up first so subsequent work can use information
  361          * potentially stored in the node (e.g. for ibss merge).
  362          */
  363         ATH_VAP(vap)->av_recv_mgmt(ni, m, subtype, rxs, rssi, nf);
  364         switch (subtype) {
  365         case IEEE80211_FC0_SUBTYPE_BEACON:
  366                 /*
  367                  * Always update the per-node beacon RSSI if we're hearing
  368                  * beacons from that node.
  369                  */
  370                 ATH_RSSI_LPF(ATH_NODE(ni)->an_node_stats.ns_avgbrssi, rssi);
  371 
  372                 /*
  373                  * Only do the following processing if it's for
  374                  * the current BSS.
  375                  *
  376                  * In scan and IBSS mode we receive all beacons,
  377                  * which means we need to filter out stuff
  378                  * that isn't for us or we'll end up constantly
  379                  * trying to sync / merge to BSSes that aren't
  380                  * actually us.
  381                  */
  382                 if ((vap->iv_opmode != IEEE80211_M_HOSTAP) &&
  383                     IEEE80211_ADDR_EQ(ni->ni_bssid, vap->iv_bss->ni_bssid)) {
  384                         /* update rssi statistics for use by the hal */
  385                         /* XXX unlocked check against vap->iv_bss? */
  386                         ATH_RSSI_LPF(sc->sc_halstats.ns_avgbrssi, rssi);
  387 
  388                         tsf_beacon = ((uint64_t) le32dec(ni->ni_tstamp.data + 4)) << 32;
  389                         tsf_beacon |= le32dec(ni->ni_tstamp.data);
  390 
  391                         nexttbtt = ath_hal_getnexttbtt(sc->sc_ah);
  392 
  393                         /*
  394                          * Let's calculate the delta and remainder, so we can see
  395                          * if the beacon timer from the AP is varying by more than
  396                          * a few TU.  (Which would be a huge, huge problem.)
  397                          */
  398                         tsf_delta = (long long) tsf_beacon - (long long) tsf_beacon_old;
  399 
  400                         tsf_delta_bmiss = tsf_delta / tsf_intval;
  401 
  402                         /*
  403                          * If our delta is greater than half the beacon interval,
  404                          * let's round the bmiss value up to the next beacon
  405                          * interval.  Ie, we're running really, really early
  406                          * on the next beacon.
  407                          */
  408                         if (tsf_delta % tsf_intval > (tsf_intval / 2))
  409                                 tsf_delta_bmiss ++;
  410 
  411                         tsf_beacon_target = tsf_beacon_old +
  412                             (((unsigned long long) tsf_delta_bmiss) * (long long) tsf_intval);
  413 
  414                         /*
  415                          * The remainder using '%' is between 0 .. intval-1.
  416                          * If we're actually running too fast, then the remainder
  417                          * will be some large number just under intval-1.
  418                          * So we need to look at whether we're running
  419                          * before or after the target beacon interval
  420                          * and if we are, modify how we do the remainder
  421                          * calculation.
  422                          */
  423                         if (tsf_beacon < tsf_beacon_target) {
  424                                 tsf_remainder =
  425                                     -(tsf_intval - ((tsf_beacon - tsf_beacon_old) % tsf_intval));
  426                         } else {
  427                                 tsf_remainder = (tsf_beacon - tsf_beacon_old) % tsf_intval;
  428                         }
  429 
  430                         DPRINTF(sc, ATH_DEBUG_BEACON, "%s: %s: old_tsf=%llu (%u), new_tsf=%llu (%u), target_tsf=%llu (%u), delta=%lld, bmiss=%d, remainder=%d\n",
  431                             __func__,
  432                             ieee80211_get_vap_ifname(vap),
  433                             (unsigned long long) tsf_beacon_old,
  434                             (unsigned int) (tsf_beacon_old >> 10),
  435                             (unsigned long long) tsf_beacon,
  436                             (unsigned int ) (tsf_beacon >> 10),
  437                             (unsigned long long) tsf_beacon_target,
  438                             (unsigned int) (tsf_beacon_target >> 10),
  439                             (long long) tsf_delta,
  440                             tsf_delta_bmiss,
  441                             tsf_remainder);
  442 
  443                         DPRINTF(sc, ATH_DEBUG_BEACON, "%s: %s: ni=%6D bssid=%6D tsf=%llu (%u), nexttbtt=%llu (%u), delta=%d\n",
  444                             __func__,
  445                             ieee80211_get_vap_ifname(vap),
  446                             ni->ni_bssid, ":",
  447                             vap->iv_bss->ni_bssid, ":",
  448                             (unsigned long long) tsf_beacon,
  449                             (unsigned int) (tsf_beacon >> 10),
  450                             (unsigned long long) nexttbtt,
  451                             (unsigned int) (nexttbtt >> 10),
  452                             (int32_t) tsf_beacon - (int32_t) nexttbtt + tsf_intval);
  453 
  454                         /*
  455                          * We only do syncbeacon on STA VAPs; not on IBSS;
  456                          * but don't do it with swbmiss enabled or we
  457                          * may end up overwriting AP mode beacon config.
  458                          *
  459                          * The driver (and net80211) should be smarter about
  460                          * this..
  461                          */
  462                         if (vap->iv_opmode == IEEE80211_M_STA &&
  463                             sc->sc_syncbeacon &&
  464                             (!sc->sc_swbmiss) &&
  465                             ni == vap->iv_bss &&
  466                             ((vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) == 0) &&
  467                             (vap->iv_state == IEEE80211_S_RUN || vap->iv_state == IEEE80211_S_SLEEP)) {
  468                                 DPRINTF(sc, ATH_DEBUG_BEACON,
  469                                     "%s: syncbeacon=1; syncing\n",
  470                                     __func__);
  471                                 /*
  472                                  * Resync beacon timers using the tsf of the beacon
  473                                  * frame we just received.
  474                                  */
  475                                 ath_beacon_config(sc, vap);
  476                                 sc->sc_syncbeacon = 0;
  477                         }
  478                 }
  479 
  480                 /* fall thru... */
  481         case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
  482                 if (vap->iv_opmode == IEEE80211_M_IBSS &&
  483                     vap->iv_state == IEEE80211_S_RUN &&
  484                     ieee80211_ibss_merge_check(ni)) {
  485                         uint32_t rstamp = sc->sc_lastrs->rs_tstamp;
  486                         uint64_t tsf = ath_extend_tsf(sc, rstamp,
  487                                 ath_hal_gettsf64(sc->sc_ah));
  488                         /*
  489                          * Handle ibss merge as needed; check the tsf on the
  490                          * frame before attempting the merge.  The 802.11 spec
  491                          * says the station should change it's bssid to match
  492                          * the oldest station with the same ssid, where oldest
  493                          * is determined by the tsf.  Note that hardware
  494                          * reconfiguration happens through callback to
  495                          * ath_newstate as the state machine will go from
  496                          * RUN -> RUN when this happens.
  497                          */
  498                         if (le64toh(ni->ni_tstamp.tsf) >= tsf) {
  499                                 DPRINTF(sc, ATH_DEBUG_STATE,
  500                                     "ibss merge, rstamp %u tsf %ju "
  501                                     "tstamp %ju\n", rstamp, (uintmax_t)tsf,
  502                                     (uintmax_t)ni->ni_tstamp.tsf);
  503                                 (void) ieee80211_ibss_merge(ni);
  504                         }
  505                 }
  506                 break;
  507         }
  508 }
  509 
  510 #ifdef  ATH_ENABLE_RADIOTAP_VENDOR_EXT
  511 static void
  512 ath_rx_tap_vendor(struct ath_softc *sc, struct mbuf *m,
  513     const struct ath_rx_status *rs, u_int64_t tsf, int16_t nf)
  514 {
  515 
  516         /* Fill in the extension bitmap */
  517         sc->sc_rx_th.wr_ext_bitmap = htole32(1 << ATH_RADIOTAP_VENDOR_HEADER);
  518 
  519         /* Fill in the vendor header */
  520         sc->sc_rx_th.wr_vh.vh_oui[0] = 0x7f;
  521         sc->sc_rx_th.wr_vh.vh_oui[1] = 0x03;
  522         sc->sc_rx_th.wr_vh.vh_oui[2] = 0x00;
  523 
  524         /* XXX what should this be? */
  525         sc->sc_rx_th.wr_vh.vh_sub_ns = 0;
  526         sc->sc_rx_th.wr_vh.vh_skip_len =
  527             htole16(sizeof(struct ath_radiotap_vendor_hdr));
  528 
  529         /* General version info */
  530         sc->sc_rx_th.wr_v.vh_version = 1;
  531 
  532         sc->sc_rx_th.wr_v.vh_rx_chainmask = sc->sc_rxchainmask;
  533 
  534         /* rssi */
  535         sc->sc_rx_th.wr_v.rssi_ctl[0] = rs->rs_rssi_ctl[0];
  536         sc->sc_rx_th.wr_v.rssi_ctl[1] = rs->rs_rssi_ctl[1];
  537         sc->sc_rx_th.wr_v.rssi_ctl[2] = rs->rs_rssi_ctl[2];
  538         sc->sc_rx_th.wr_v.rssi_ext[0] = rs->rs_rssi_ext[0];
  539         sc->sc_rx_th.wr_v.rssi_ext[1] = rs->rs_rssi_ext[1];
  540         sc->sc_rx_th.wr_v.rssi_ext[2] = rs->rs_rssi_ext[2];
  541 
  542         /* evm */
  543         sc->sc_rx_th.wr_v.evm[0] = rs->rs_evm0;
  544         sc->sc_rx_th.wr_v.evm[1] = rs->rs_evm1;
  545         sc->sc_rx_th.wr_v.evm[2] = rs->rs_evm2;
  546         /* These are only populated from the AR9300 or later */
  547         sc->sc_rx_th.wr_v.evm[3] = rs->rs_evm3;
  548         sc->sc_rx_th.wr_v.evm[4] = rs->rs_evm4;
  549 
  550         /* direction */
  551         sc->sc_rx_th.wr_v.vh_flags = ATH_VENDOR_PKT_RX;
  552 
  553         /* RX rate */
  554         sc->sc_rx_th.wr_v.vh_rx_hwrate = rs->rs_rate;
  555 
  556         /* RX flags */
  557         sc->sc_rx_th.wr_v.vh_rs_flags = rs->rs_flags;
  558 
  559         if (rs->rs_isaggr)
  560                 sc->sc_rx_th.wr_v.vh_flags |= ATH_VENDOR_PKT_ISAGGR;
  561         if (rs->rs_moreaggr)
  562                 sc->sc_rx_th.wr_v.vh_flags |= ATH_VENDOR_PKT_MOREAGGR;
  563 
  564         /* phyerr info */
  565         if (rs->rs_status & HAL_RXERR_PHY) {
  566                 sc->sc_rx_th.wr_v.vh_phyerr_code = rs->rs_phyerr;
  567                 sc->sc_rx_th.wr_v.vh_flags |= ATH_VENDOR_PKT_RXPHYERR;
  568         } else {
  569                 sc->sc_rx_th.wr_v.vh_phyerr_code = 0xff;
  570         }
  571         sc->sc_rx_th.wr_v.vh_rs_status = rs->rs_status;
  572         sc->sc_rx_th.wr_v.vh_rssi = rs->rs_rssi;
  573 }
  574 #endif  /* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
  575 
  576 static void
  577 ath_rx_tap(struct ath_softc *sc, struct mbuf *m,
  578         const struct ath_rx_status *rs, u_int64_t tsf, int16_t nf)
  579 {
  580 #define CHAN_HT20       htole32(IEEE80211_CHAN_HT20)
  581 #define CHAN_HT40U      htole32(IEEE80211_CHAN_HT40U)
  582 #define CHAN_HT40D      htole32(IEEE80211_CHAN_HT40D)
  583 #define CHAN_HT         (CHAN_HT20|CHAN_HT40U|CHAN_HT40D)
  584         const HAL_RATE_TABLE *rt;
  585         uint8_t rix;
  586 
  587         rt = sc->sc_currates;
  588         KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
  589         rix = rt->rateCodeToIndex[rs->rs_rate];
  590         sc->sc_rx_th.wr_rate = sc->sc_hwmap[rix].ieeerate;
  591         sc->sc_rx_th.wr_flags = sc->sc_hwmap[rix].rxflags;
  592 
  593         /* 802.11 specific flags */
  594         sc->sc_rx_th.wr_chan_flags &= ~CHAN_HT;
  595         if (rs->rs_status & HAL_RXERR_PHY) {
  596                 /*
  597                  * PHY error - make sure the channel flags
  598                  * reflect the actual channel configuration,
  599                  * not the received frame.
  600                  */
  601                 if (IEEE80211_IS_CHAN_HT40U(sc->sc_curchan))
  602                         sc->sc_rx_th.wr_chan_flags |= CHAN_HT40U;
  603                 else if (IEEE80211_IS_CHAN_HT40D(sc->sc_curchan))
  604                         sc->sc_rx_th.wr_chan_flags |= CHAN_HT40D;
  605                 else if (IEEE80211_IS_CHAN_HT20(sc->sc_curchan))
  606                         sc->sc_rx_th.wr_chan_flags |= CHAN_HT20;
  607         } else if (sc->sc_rx_th.wr_rate & IEEE80211_RATE_MCS) { /* HT rate */
  608                 struct ieee80211com *ic = &sc->sc_ic;
  609 
  610                 if ((rs->rs_flags & HAL_RX_2040) == 0)
  611                         sc->sc_rx_th.wr_chan_flags |= CHAN_HT20;
  612                 else if (IEEE80211_IS_CHAN_HT40U(ic->ic_curchan))
  613                         sc->sc_rx_th.wr_chan_flags |= CHAN_HT40U;
  614                 else
  615                         sc->sc_rx_th.wr_chan_flags |= CHAN_HT40D;
  616 
  617                 if (rs->rs_flags & HAL_RX_GI)
  618                         sc->sc_rx_th.wr_flags |= IEEE80211_RADIOTAP_F_SHORTGI;
  619         }
  620 
  621         sc->sc_rx_th.wr_tsf = htole64(ath_extend_tsf(sc, rs->rs_tstamp, tsf));
  622         if (rs->rs_status & HAL_RXERR_CRC)
  623                 sc->sc_rx_th.wr_flags |= IEEE80211_RADIOTAP_F_BADFCS;
  624         /* XXX propagate other error flags from descriptor */
  625         sc->sc_rx_th.wr_antnoise = nf;
  626         sc->sc_rx_th.wr_antsignal = nf + rs->rs_rssi;
  627         sc->sc_rx_th.wr_antenna = rs->rs_antenna;
  628 #undef CHAN_HT
  629 #undef CHAN_HT20
  630 #undef CHAN_HT40U
  631 #undef CHAN_HT40D
  632 }
  633 
  634 static void
  635 ath_handle_micerror(struct ieee80211com *ic,
  636         struct ieee80211_frame *wh, int keyix)
  637 {
  638         struct ieee80211_node *ni;
  639 
  640         /* XXX recheck MIC to deal w/ chips that lie */
  641         /* XXX discard MIC errors on !data frames */
  642         ni = ieee80211_find_rxnode(ic, (const struct ieee80211_frame_min *) wh);
  643         if (ni != NULL) {
  644                 ieee80211_notify_michael_failure(ni->ni_vap, wh, keyix);
  645                 ieee80211_free_node(ni);
  646         }
  647 }
  648 
  649 /*
  650  * Process a single packet.
  651  *
  652  * The mbuf must already be synced, unmapped and removed from bf->bf_m
  653  * by this stage.
  654  *
  655  * The mbuf must be consumed by this routine - either passed up the
  656  * net80211 stack, put on the holding queue, or freed.
  657  */
  658 int
  659 ath_rx_pkt(struct ath_softc *sc, struct ath_rx_status *rs, HAL_STATUS status,
  660     uint64_t tsf, int nf, HAL_RX_QUEUE qtype, struct ath_buf *bf,
  661     struct mbuf *m)
  662 {
  663         uint64_t rstamp;
  664         /* XXX TODO: make this an mbuf tag? */
  665         struct ieee80211_rx_stats rxs;
  666         int len, type, i;
  667         struct ieee80211com *ic = &sc->sc_ic;
  668         struct ieee80211_node *ni;
  669         int is_good = 0;
  670         struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
  671 
  672         NET_EPOCH_ASSERT();
  673 
  674         /*
  675          * Calculate the correct 64 bit TSF given
  676          * the TSF64 register value and rs_tstamp.
  677          */
  678         rstamp = ath_extend_tsf(sc, rs->rs_tstamp, tsf);
  679 
  680         /* 802.11 return codes - These aren't specifically errors */
  681         if (rs->rs_flags & HAL_RX_GI)
  682                 sc->sc_stats.ast_rx_halfgi++;
  683         if (rs->rs_flags & HAL_RX_2040)
  684                 sc->sc_stats.ast_rx_2040++;
  685         if (rs->rs_flags & HAL_RX_DELIM_CRC_PRE)
  686                 sc->sc_stats.ast_rx_pre_crc_err++;
  687         if (rs->rs_flags & HAL_RX_DELIM_CRC_POST)
  688                 sc->sc_stats.ast_rx_post_crc_err++;
  689         if (rs->rs_flags & HAL_RX_DECRYPT_BUSY)
  690                 sc->sc_stats.ast_rx_decrypt_busy_err++;
  691         if (rs->rs_flags & HAL_RX_HI_RX_CHAIN)
  692                 sc->sc_stats.ast_rx_hi_rx_chain++;
  693         if (rs->rs_flags & HAL_RX_STBC)
  694                 sc->sc_stats.ast_rx_stbc++;
  695 
  696         if (rs->rs_status != 0) {
  697                 if (rs->rs_status & HAL_RXERR_CRC)
  698                         sc->sc_stats.ast_rx_crcerr++;
  699                 if (rs->rs_status & HAL_RXERR_FIFO)
  700                         sc->sc_stats.ast_rx_fifoerr++;
  701                 if (rs->rs_status & HAL_RXERR_PHY) {
  702                         sc->sc_stats.ast_rx_phyerr++;
  703                         /* Process DFS radar events */
  704                         if ((rs->rs_phyerr == HAL_PHYERR_RADAR) ||
  705                             (rs->rs_phyerr == HAL_PHYERR_FALSE_RADAR_EXT)) {
  706                                 /* Now pass it to the radar processing code */
  707                                 ath_dfs_process_phy_err(sc, m, rstamp, rs);
  708                         }
  709 
  710                         /*
  711                          * Be suitably paranoid about receiving phy errors
  712                          * out of the stats array bounds
  713                          */
  714                         if (rs->rs_phyerr < ATH_IOCTL_STATS_NUM_RX_PHYERR)
  715                                 sc->sc_stats.ast_rx_phy[rs->rs_phyerr]++;
  716                         goto rx_error;  /* NB: don't count in ierrors */
  717                 }
  718                 if (rs->rs_status & HAL_RXERR_DECRYPT) {
  719                         /*
  720                          * Decrypt error.  If the error occurred
  721                          * because there was no hardware key, then
  722                          * let the frame through so the upper layers
  723                          * can process it.  This is necessary for 5210
  724                          * parts which have no way to setup a ``clear''
  725                          * key cache entry.
  726                          *
  727                          * XXX do key cache faulting
  728                          */
  729                         if (rs->rs_keyix == HAL_RXKEYIX_INVALID)
  730                                 goto rx_accept;
  731                         sc->sc_stats.ast_rx_badcrypt++;
  732                 }
  733                 /*
  734                  * Similar as above - if the failure was a keymiss
  735                  * just punt it up to the upper layers for now.
  736                  */
  737                 if (rs->rs_status & HAL_RXERR_KEYMISS) {
  738                         sc->sc_stats.ast_rx_keymiss++;
  739                         goto rx_accept;
  740                 }
  741                 if (rs->rs_status & HAL_RXERR_MIC) {
  742                         sc->sc_stats.ast_rx_badmic++;
  743                         /*
  744                          * Do minimal work required to hand off
  745                          * the 802.11 header for notification.
  746                          */
  747                         /* XXX frag's and qos frames */
  748                         len = rs->rs_datalen;
  749                         if (len >= sizeof (struct ieee80211_frame)) {
  750                                 ath_handle_micerror(ic,
  751                                     mtod(m, struct ieee80211_frame *),
  752                                     sc->sc_splitmic ?
  753                                         rs->rs_keyix-32 : rs->rs_keyix);
  754                         }
  755                 }
  756                 counter_u64_add(ic->ic_ierrors, 1);
  757 rx_error:
  758                 /*
  759                  * Cleanup any pending partial frame.
  760                  */
  761                 if (re->m_rxpending != NULL) {
  762                         m_freem(re->m_rxpending);
  763                         re->m_rxpending = NULL;
  764                 }
  765                 /*
  766                  * When a tap is present pass error frames
  767                  * that have been requested.  By default we
  768                  * pass decrypt+mic errors but others may be
  769                  * interesting (e.g. crc).
  770                  */
  771                 if (ieee80211_radiotap_active(ic) &&
  772                     (rs->rs_status & sc->sc_monpass)) {
  773                         /* NB: bpf needs the mbuf length setup */
  774                         len = rs->rs_datalen;
  775                         m->m_pkthdr.len = m->m_len = len;
  776                         ath_rx_tap(sc, m, rs, rstamp, nf);
  777 #ifdef  ATH_ENABLE_RADIOTAP_VENDOR_EXT
  778                         ath_rx_tap_vendor(sc, m, rs, rstamp, nf);
  779 #endif  /* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
  780                         ieee80211_radiotap_rx_all(ic, m);
  781                 }
  782                 /* XXX pass MIC errors up for s/w reclaculation */
  783                 m_freem(m); m = NULL;
  784                 goto rx_next;
  785         }
  786 rx_accept:
  787         len = rs->rs_datalen;
  788         m->m_len = len;
  789 
  790         if (rs->rs_more) {
  791                 /*
  792                  * Frame spans multiple descriptors; save
  793                  * it for the next completed descriptor, it
  794                  * will be used to construct a jumbogram.
  795                  */
  796                 if (re->m_rxpending != NULL) {
  797                         /* NB: max frame size is currently 2 clusters */
  798                         sc->sc_stats.ast_rx_toobig++;
  799                         m_freem(re->m_rxpending);
  800                 }
  801                 m->m_pkthdr.len = len;
  802                 re->m_rxpending = m;
  803                 m = NULL;
  804                 goto rx_next;
  805         } else if (re->m_rxpending != NULL) {
  806                 /*
  807                  * This is the second part of a jumbogram,
  808                  * chain it to the first mbuf, adjust the
  809                  * frame length, and clear the rxpending state.
  810                  */
  811                 re->m_rxpending->m_next = m;
  812                 re->m_rxpending->m_pkthdr.len += len;
  813                 m = re->m_rxpending;
  814                 re->m_rxpending = NULL;
  815         } else {
  816                 /*
  817                  * Normal single-descriptor receive; setup packet length.
  818                  */
  819                 m->m_pkthdr.len = len;
  820         }
  821 
  822         /*
  823          * Validate rs->rs_antenna.
  824          *
  825          * Some users w/ AR9285 NICs have reported crashes
  826          * here because rs_antenna field is bogusly large.
  827          * Let's enforce the maximum antenna limit of 8
  828          * (and it shouldn't be hard coded, but that's a
  829          * separate problem) and if there's an issue, print
  830          * out an error and adjust rs_antenna to something
  831          * sensible.
  832          *
  833          * This code should be removed once the actual
  834          * root cause of the issue has been identified.
  835          * For example, it may be that the rs_antenna
  836          * field is only valid for the last frame of
  837          * an aggregate and it just happens that it is
  838          * "mostly" right. (This is a general statement -
  839          * the majority of the statistics are only valid
  840          * for the last frame in an aggregate.
  841          */
  842         if (rs->rs_antenna >= ATH_IOCTL_STATS_NUM_RX_ANTENNA) {
  843                 device_printf(sc->sc_dev, "%s: rs_antenna > 7 (%d)\n",
  844                     __func__, rs->rs_antenna);
  845 #ifdef  ATH_DEBUG
  846                 ath_printrxbuf(sc, bf, 0, status == HAL_OK);
  847 #endif /* ATH_DEBUG */
  848                 rs->rs_antenna = 0;     /* XXX better than nothing */
  849         }
  850 
  851         /*
  852          * If this is an AR9285/AR9485, then the receive and LNA
  853          * configuration is stored in RSSI[2] / EXTRSSI[2].
  854          * We can extract this out to build a much better
  855          * receive antenna profile.
  856          *
  857          * Yes, this just blurts over the above RX antenna field
  858          * for now.  It's fine, the AR9285 doesn't really use
  859          * that.
  860          *
  861          * Later on we should store away the fine grained LNA
  862          * information and keep separate counters just for
  863          * that.  It'll help when debugging the AR9285/AR9485
  864          * combined diversity code.
  865          */
  866         if (sc->sc_rx_lnamixer) {
  867                 rs->rs_antenna = 0;
  868 
  869                 /* Bits 0:1 - the LNA configuration used */
  870                 rs->rs_antenna |=
  871                     ((rs->rs_rssi_ctl[2] & HAL_RX_LNA_CFG_USED)
  872                       >> HAL_RX_LNA_CFG_USED_S);
  873 
  874                 /* Bit 2 - the external RX antenna switch */
  875                 if (rs->rs_rssi_ctl[2] & HAL_RX_LNA_EXTCFG)
  876                         rs->rs_antenna |= 0x4;
  877         }
  878 
  879         sc->sc_stats.ast_ant_rx[rs->rs_antenna]++;
  880 
  881         /*
  882          * Populate the rx status block.  When there are bpf
  883          * listeners we do the additional work to provide
  884          * complete status.  Otherwise we fill in only the
  885          * material required by ieee80211_input.  Note that
  886          * noise setting is filled in above.
  887          */
  888         if (ieee80211_radiotap_active(ic)) {
  889                 ath_rx_tap(sc, m, rs, rstamp, nf);
  890 #ifdef  ATH_ENABLE_RADIOTAP_VENDOR_EXT
  891                 ath_rx_tap_vendor(sc, m, rs, rstamp, nf);
  892 #endif  /* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
  893         }
  894 
  895         /*
  896          * From this point on we assume the frame is at least
  897          * as large as ieee80211_frame_min; verify that.
  898          */
  899         if (len < IEEE80211_MIN_LEN) {
  900                 if (!ieee80211_radiotap_active(ic)) {
  901                         DPRINTF(sc, ATH_DEBUG_RECV,
  902                             "%s: short packet %d\n", __func__, len);
  903                         sc->sc_stats.ast_rx_tooshort++;
  904                 } else {
  905                         /* NB: in particular this captures ack's */
  906                         ieee80211_radiotap_rx_all(ic, m);
  907                 }
  908                 m_freem(m); m = NULL;
  909                 goto rx_next;
  910         }
  911 
  912         if (IFF_DUMPPKTS(sc, ATH_DEBUG_RECV)) {
  913                 const HAL_RATE_TABLE *rt = sc->sc_currates;
  914                 uint8_t rix = rt->rateCodeToIndex[rs->rs_rate];
  915 
  916                 ieee80211_dump_pkt(ic, mtod(m, caddr_t), len,
  917                     sc->sc_hwmap[rix].ieeerate, rs->rs_rssi);
  918         }
  919 
  920         m_adj(m, -IEEE80211_CRC_LEN);
  921 
  922         /*
  923          * Locate the node for sender, track state, and then
  924          * pass the (referenced) node up to the 802.11 layer
  925          * for its use.
  926          */
  927         ni = ieee80211_find_rxnode_withkey(ic,
  928                 mtod(m, const struct ieee80211_frame_min *),
  929                 rs->rs_keyix == HAL_RXKEYIX_INVALID ?
  930                         IEEE80211_KEYIX_NONE : rs->rs_keyix);
  931         sc->sc_lastrs = rs;
  932 
  933         if (rs->rs_isaggr)
  934                 sc->sc_stats.ast_rx_agg++;
  935 
  936         /*
  937          * Populate the per-chain RSSI values where appropriate.
  938          */
  939         bzero(&rxs, sizeof(rxs));
  940         rxs.r_flags |= IEEE80211_R_NF | IEEE80211_R_RSSI |
  941             IEEE80211_R_C_CHAIN |
  942             IEEE80211_R_C_NF |
  943             IEEE80211_R_C_RSSI |
  944             IEEE80211_R_TSF64 |
  945             IEEE80211_R_TSF_START;      /* XXX TODO: validate */
  946         rxs.c_rssi = rs->rs_rssi;
  947         rxs.c_nf = nf;
  948         rxs.c_chain = 3;        /* XXX TODO: check */
  949         rxs.c_rx_tsf = rstamp;
  950 
  951         for (i = 0; i < 3; i++) {
  952                 rxs.c_rssi_ctl[i] = rs->rs_rssi_ctl[i];
  953                 rxs.c_rssi_ext[i] = rs->rs_rssi_ext[i];
  954                 /*
  955                  * XXX note: we currently don't track
  956                  * per-chain noisefloor.
  957                  */
  958                 rxs.c_nf_ctl[i] = nf;
  959                 rxs.c_nf_ext[i] = nf;
  960         }
  961 
  962         if (ni != NULL) {
  963                 /*
  964                  * Only punt packets for ampdu reorder processing for
  965                  * 11n nodes; net80211 enforces that M_AMPDU is only
  966                  * set for 11n nodes.
  967                  */
  968                 if (ni->ni_flags & IEEE80211_NODE_HT)
  969                         m->m_flags |= M_AMPDU;
  970 
  971                 /*
  972                  * Inform rate control about the received RSSI.
  973                  * It can then use this information to potentially drastically
  974                  * alter the available rate based on the RSSI estimate.
  975                  *
  976                  * This is super important when associating to a far away station;
  977                  * you don't want to waste time trying higher rates at some low
  978                  * packet exchange rate (like during DHCP) just to establish
  979                  * that higher MCS rates aren't available.
  980                  */
  981                 ATH_RSSI_LPF(ATH_NODE(ni)->an_node_stats.ns_avgrssi,
  982                     rs->rs_rssi);
  983                 ath_rate_update_rx_rssi(sc, ATH_NODE(ni),
  984                     ATH_RSSI(ATH_NODE(ni)->an_node_stats.ns_avgrssi));
  985 
  986                 /*
  987                  * Sending station is known, dispatch directly.
  988                  */
  989                 (void) ieee80211_add_rx_params(m, &rxs);
  990                 type = ieee80211_input_mimo(ni, m);
  991                 ieee80211_free_node(ni);
  992                 m = NULL;
  993                 /*
  994                  * Arrange to update the last rx timestamp only for
  995                  * frames from our ap when operating in station mode.
  996                  * This assumes the rx key is always setup when
  997                  * associated.
  998                  */
  999                 if (ic->ic_opmode == IEEE80211_M_STA &&
 1000                     rs->rs_keyix != HAL_RXKEYIX_INVALID)
 1001                         is_good = 1;
 1002         } else {
 1003                 (void) ieee80211_add_rx_params(m, &rxs);
 1004                 type = ieee80211_input_mimo_all(ic, m);
 1005                 m = NULL;
 1006         }
 1007 
 1008         /*
 1009          * At this point we have passed the frame up the stack; thus
 1010          * the mbuf is no longer ours.
 1011          */
 1012 
 1013         /*
 1014          * Track legacy station RX rssi and do any rx antenna management.
 1015          */
 1016         ATH_RSSI_LPF(sc->sc_halstats.ns_avgrssi, rs->rs_rssi);
 1017         if (sc->sc_diversity) {
 1018                 /*
 1019                  * When using fast diversity, change the default rx
 1020                  * antenna if diversity chooses the other antenna 3
 1021                  * times in a row.
 1022                  */
 1023                 if (sc->sc_defant != rs->rs_antenna) {
 1024                         if (++sc->sc_rxotherant >= 3)
 1025                                 ath_setdefantenna(sc, rs->rs_antenna);
 1026                 } else
 1027                         sc->sc_rxotherant = 0;
 1028         }
 1029 
 1030         /* Handle slow diversity if enabled */
 1031         if (sc->sc_dolnadiv) {
 1032                 ath_lna_rx_comb_scan(sc, rs, ticks, hz);
 1033         }
 1034 
 1035         if (sc->sc_softled) {
 1036                 /*
 1037                  * Blink for any data frame.  Otherwise do a
 1038                  * heartbeat-style blink when idle.  The latter
 1039                  * is mainly for station mode where we depend on
 1040                  * periodic beacon frames to trigger the poll event.
 1041                  */
 1042                 if (type == IEEE80211_FC0_TYPE_DATA) {
 1043                         const HAL_RATE_TABLE *rt = sc->sc_currates;
 1044                         ath_led_event(sc,
 1045                             rt->rateCodeToIndex[rs->rs_rate]);
 1046                 } else if (ticks - sc->sc_ledevent >= sc->sc_ledidle)
 1047                         ath_led_event(sc, 0);
 1048                 }
 1049 rx_next:
 1050         /*
 1051          * Debugging - complain if we didn't NULL the mbuf pointer
 1052          * here.
 1053          */
 1054         if (m != NULL) {
 1055                 device_printf(sc->sc_dev,
 1056                     "%s: mbuf %p should've been freed!\n",
 1057                     __func__,
 1058                     m);
 1059         }
 1060         return (is_good);
 1061 }
 1062 
 1063 #define ATH_RX_MAX              128
 1064 
 1065 /*
 1066  * XXX TODO: break out the "get buffers" from "call ath_rx_pkt()" like
 1067  * the EDMA code does.
 1068  *
 1069  * XXX TODO: then, do all of the RX list management stuff inside
 1070  * ATH_RX_LOCK() so we don't end up potentially racing.  The EDMA
 1071  * code is doing it right.
 1072  */
 1073 static void
 1074 ath_rx_proc(struct ath_softc *sc, int resched)
 1075 {
 1076 #define PA2DESC(_sc, _pa) \
 1077         ((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
 1078                 ((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
 1079         struct ath_buf *bf;
 1080         struct ath_hal *ah = sc->sc_ah;
 1081 #ifdef IEEE80211_SUPPORT_SUPERG
 1082         struct ieee80211com *ic = &sc->sc_ic;
 1083 #endif
 1084         struct ath_desc *ds;
 1085         struct ath_rx_status *rs;
 1086         struct mbuf *m;
 1087         int ngood;
 1088         HAL_STATUS status;
 1089         int16_t nf;
 1090         u_int64_t tsf;
 1091         int npkts = 0;
 1092         int kickpcu = 0;
 1093         int ret;
 1094 
 1095         NET_EPOCH_ASSERT();
 1096 
 1097         /* XXX we must not hold the ATH_LOCK here */
 1098         ATH_UNLOCK_ASSERT(sc);
 1099         ATH_PCU_UNLOCK_ASSERT(sc);
 1100 
 1101         ATH_PCU_LOCK(sc);
 1102         sc->sc_rxproc_cnt++;
 1103         kickpcu = sc->sc_kickpcu;
 1104         ATH_PCU_UNLOCK(sc);
 1105 
 1106         ATH_LOCK(sc);
 1107         ath_power_set_power_state(sc, HAL_PM_AWAKE);
 1108         ATH_UNLOCK(sc);
 1109 
 1110         DPRINTF(sc, ATH_DEBUG_RX_PROC, "%s: called\n", __func__);
 1111         ngood = 0;
 1112         nf = ath_hal_getchannoise(ah, sc->sc_curchan);
 1113         sc->sc_stats.ast_rx_noise = nf;
 1114         tsf = ath_hal_gettsf64(ah);
 1115         do {
 1116                 /*
 1117                  * Don't process too many packets at a time; give the
 1118                  * TX thread time to also run - otherwise the TX
 1119                  * latency can jump by quite a bit, causing throughput
 1120                  * degredation.
 1121                  */
 1122                 if (!kickpcu && npkts >= ATH_RX_MAX)
 1123                         break;
 1124 
 1125                 bf = TAILQ_FIRST(&sc->sc_rxbuf);
 1126                 if (sc->sc_rxslink && bf == NULL) {     /* NB: shouldn't happen */
 1127                         device_printf(sc->sc_dev, "%s: no buffer!\n", __func__);
 1128                         break;
 1129                 } else if (bf == NULL) {
 1130                         /*
 1131                          * End of List:
 1132                          * this can happen for non-self-linked RX chains
 1133                          */
 1134                         sc->sc_stats.ast_rx_hitqueueend++;
 1135                         break;
 1136                 }
 1137                 m = bf->bf_m;
 1138                 if (m == NULL) {                /* NB: shouldn't happen */
 1139                         /*
 1140                          * If mbuf allocation failed previously there
 1141                          * will be no mbuf; try again to re-populate it.
 1142                          */
 1143                         /* XXX make debug msg */
 1144                         device_printf(sc->sc_dev, "%s: no mbuf!\n", __func__);
 1145                         TAILQ_REMOVE(&sc->sc_rxbuf, bf, bf_list);
 1146                         goto rx_proc_next;
 1147                 }
 1148                 ds = bf->bf_desc;
 1149                 if (ds->ds_link == bf->bf_daddr) {
 1150                         /* NB: never process the self-linked entry at the end */
 1151                         sc->sc_stats.ast_rx_hitqueueend++;
 1152                         break;
 1153                 }
 1154                 /* XXX sync descriptor memory */
 1155                 /*
 1156                  * Must provide the virtual address of the current
 1157                  * descriptor, the physical address, and the virtual
 1158                  * address of the next descriptor in the h/w chain.
 1159                  * This allows the HAL to look ahead to see if the
 1160                  * hardware is done with a descriptor by checking the
 1161                  * done bit in the following descriptor and the address
 1162                  * of the current descriptor the DMA engine is working
 1163                  * on.  All this is necessary because of our use of
 1164                  * a self-linked list to avoid rx overruns.
 1165                  */
 1166                 rs = &bf->bf_status.ds_rxstat;
 1167                 status = ath_hal_rxprocdesc(ah, ds,
 1168                                 bf->bf_daddr, PA2DESC(sc, ds->ds_link), rs);
 1169 #ifdef ATH_DEBUG
 1170                 if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
 1171                         ath_printrxbuf(sc, bf, 0, status == HAL_OK);
 1172 #endif
 1173 
 1174 #ifdef  ATH_DEBUG_ALQ
 1175                 if (if_ath_alq_checkdebug(&sc->sc_alq, ATH_ALQ_EDMA_RXSTATUS))
 1176                     if_ath_alq_post(&sc->sc_alq, ATH_ALQ_EDMA_RXSTATUS,
 1177                     sc->sc_rx_statuslen, (char *) ds);
 1178 #endif  /* ATH_DEBUG_ALQ */
 1179 
 1180                 if (status == HAL_EINPROGRESS)
 1181                         break;
 1182 
 1183                 TAILQ_REMOVE(&sc->sc_rxbuf, bf, bf_list);
 1184                 npkts++;
 1185 
 1186                 /*
 1187                  * Process a single frame.
 1188                  */
 1189                 bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_POSTREAD);
 1190                 bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
 1191                 bf->bf_m = NULL;
 1192                 if (ath_rx_pkt(sc, rs, status, tsf, nf, HAL_RX_QUEUE_HP, bf, m))
 1193                         ngood++;
 1194 rx_proc_next:
 1195                 /*
 1196                  * If there's a holding buffer, insert that onto
 1197                  * the RX list; the hardware is now definitely not pointing
 1198                  * to it now.
 1199                  */
 1200                 ret = 0;
 1201                 if (sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf != NULL) {
 1202                         TAILQ_INSERT_TAIL(&sc->sc_rxbuf,
 1203                             sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf,
 1204                             bf_list);
 1205                         ret = ath_rxbuf_init(sc,
 1206                             sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf);
 1207                 }
 1208                 /*
 1209                  * Next, throw our buffer into the holding entry.  The hardware
 1210                  * may use the descriptor to read the link pointer before
 1211                  * DMAing the next descriptor in to write out a packet.
 1212                  */
 1213                 sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf = bf;
 1214         } while (ret == 0);
 1215 
 1216         /* rx signal state monitoring */
 1217         ath_hal_rxmonitor(ah, &sc->sc_halstats, sc->sc_curchan);
 1218         if (ngood)
 1219                 sc->sc_lastrx = tsf;
 1220 
 1221         ATH_KTR(sc, ATH_KTR_RXPROC, 2, "ath_rx_proc: npkts=%d, ngood=%d", npkts, ngood);
 1222         /* Queue DFS tasklet if needed */
 1223         if (resched && ath_dfs_tasklet_needed(sc, sc->sc_curchan))
 1224                 taskqueue_enqueue(sc->sc_tq, &sc->sc_dfstask);
 1225 
 1226         /*
 1227          * Now that all the RX frames were handled that
 1228          * need to be handled, kick the PCU if there's
 1229          * been an RXEOL condition.
 1230          */
 1231         if (resched && kickpcu) {
 1232                 ATH_PCU_LOCK(sc);
 1233                 ATH_KTR(sc, ATH_KTR_ERROR, 0, "ath_rx_proc: kickpcu");
 1234                 device_printf(sc->sc_dev, "%s: kickpcu; handled %d packets\n",
 1235                     __func__, npkts);
 1236 
 1237                 /*
 1238                  * Go through the process of fully tearing down
 1239                  * the RX buffers and reinitialising them.
 1240                  *
 1241                  * There's a hardware bug that causes the RX FIFO
 1242                  * to get confused under certain conditions and
 1243                  * constantly write over the same frame, leading
 1244                  * the RX driver code here to get heavily confused.
 1245                  */
 1246                 /*
 1247                  * XXX Has RX DMA stopped enough here to just call
 1248                  *     ath_startrecv()?
 1249                  * XXX Do we need to use the holding buffer to restart
 1250                  *     RX DMA by appending entries to the final
 1251                  *     descriptor?  Quite likely.
 1252                  */
 1253 #if 1
 1254                 ath_startrecv(sc);
 1255 #else
 1256                 /*
 1257                  * Disabled for now - it'd be nice to be able to do
 1258                  * this in order to limit the amount of CPU time spent
 1259                  * reinitialising the RX side (and thus minimise RX
 1260                  * drops) however there's a hardware issue that
 1261                  * causes things to get too far out of whack.
 1262                  */
 1263                 /*
 1264                  * XXX can we hold the PCU lock here?
 1265                  * Are there any net80211 buffer calls involved?
 1266                  */
 1267                 bf = TAILQ_FIRST(&sc->sc_rxbuf);
 1268                 ath_hal_putrxbuf(ah, bf->bf_daddr, HAL_RX_QUEUE_HP);
 1269                 ath_hal_rxena(ah);              /* enable recv descriptors */
 1270                 ath_mode_init(sc);              /* set filters, etc. */
 1271                 ath_hal_startpcurecv(ah, (!! sc->sc_scanning)); /* re-enable PCU/DMA engine */
 1272 #endif
 1273 
 1274                 ath_hal_intrset(ah, sc->sc_imask);
 1275                 sc->sc_kickpcu = 0;
 1276                 ATH_PCU_UNLOCK(sc);
 1277         }
 1278 
 1279 #ifdef IEEE80211_SUPPORT_SUPERG
 1280         if (resched)
 1281                 ieee80211_ff_age_all(ic, 100);
 1282 #endif
 1283 
 1284         /*
 1285          * Put the hardware to sleep again if we're done with it.
 1286          */
 1287         ATH_LOCK(sc);
 1288         ath_power_restore_power_state(sc);
 1289         ATH_UNLOCK(sc);
 1290 
 1291         /*
 1292          * If we hit the maximum number of frames in this round,
 1293          * reschedule for another immediate pass.  This gives
 1294          * the TX and TX completion routines time to run, which
 1295          * will reduce latency.
 1296          */
 1297         if (npkts >= ATH_RX_MAX)
 1298                 sc->sc_rx.recv_sched(sc, resched);
 1299 
 1300         ATH_PCU_LOCK(sc);
 1301         sc->sc_rxproc_cnt--;
 1302         ATH_PCU_UNLOCK(sc);
 1303 }
 1304 #undef  PA2DESC
 1305 #undef  ATH_RX_MAX
 1306 
 1307 /*
 1308  * Only run the RX proc if it's not already running.
 1309  * Since this may get run as part of the reset/flush path,
 1310  * the task can't clash with an existing, running tasklet.
 1311  */
 1312 static void
 1313 ath_legacy_rx_tasklet(void *arg, int npending)
 1314 {
 1315         struct ath_softc *sc = arg;
 1316         struct epoch_tracker et;
 1317 
 1318         ATH_KTR(sc, ATH_KTR_RXPROC, 1, "ath_rx_proc: pending=%d", npending);
 1319         DPRINTF(sc, ATH_DEBUG_RX_PROC, "%s: pending %u\n", __func__, npending);
 1320         ATH_PCU_LOCK(sc);
 1321         if (sc->sc_inreset_cnt > 0) {
 1322                 device_printf(sc->sc_dev,
 1323                     "%s: sc_inreset_cnt > 0; skipping\n", __func__);
 1324                 ATH_PCU_UNLOCK(sc);
 1325                 return;
 1326         }
 1327         ATH_PCU_UNLOCK(sc);
 1328 
 1329         NET_EPOCH_ENTER(et);
 1330         ath_rx_proc(sc, 1);
 1331         NET_EPOCH_EXIT(et);
 1332 }
 1333 
 1334 static void
 1335 ath_legacy_flushrecv(struct ath_softc *sc)
 1336 {
 1337         struct epoch_tracker et;
 1338         NET_EPOCH_ENTER(et);
 1339         ath_rx_proc(sc, 0);
 1340         NET_EPOCH_EXIT(et);
 1341 }
 1342 
 1343 static void
 1344 ath_legacy_flush_rxpending(struct ath_softc *sc)
 1345 {
 1346 
 1347         /* XXX ATH_RX_LOCK_ASSERT(sc); */
 1348 
 1349         if (sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending != NULL) {
 1350                 m_freem(sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending);
 1351                 sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending = NULL;
 1352         }
 1353         if (sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending != NULL) {
 1354                 m_freem(sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending);
 1355                 sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending = NULL;
 1356         }
 1357 }
 1358 
 1359 static int
 1360 ath_legacy_flush_rxholdbf(struct ath_softc *sc)
 1361 {
 1362         struct ath_buf *bf;
 1363 
 1364         /* XXX ATH_RX_LOCK_ASSERT(sc); */
 1365         /*
 1366          * If there are RX holding buffers, free them here and return
 1367          * them to the list.
 1368          *
 1369          * XXX should just verify that bf->bf_m is NULL, as it must
 1370          * be at this point!
 1371          */
 1372         bf = sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf;
 1373         if (bf != NULL) {
 1374                 if (bf->bf_m != NULL)
 1375                         m_freem(bf->bf_m);
 1376                 bf->bf_m = NULL;
 1377                 TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
 1378                 (void) ath_rxbuf_init(sc, bf);
 1379         }
 1380         sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf = NULL;
 1381 
 1382         bf = sc->sc_rxedma[HAL_RX_QUEUE_LP].m_holdbf;
 1383         if (bf != NULL) {
 1384                 if (bf->bf_m != NULL)
 1385                         m_freem(bf->bf_m);
 1386                 bf->bf_m = NULL;
 1387                 TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
 1388                 (void) ath_rxbuf_init(sc, bf);
 1389         }
 1390         sc->sc_rxedma[HAL_RX_QUEUE_LP].m_holdbf = NULL;
 1391 
 1392         return (0);
 1393 }
 1394 
 1395 /*
 1396  * Disable the receive h/w in preparation for a reset.
 1397  */
 1398 static void
 1399 ath_legacy_stoprecv(struct ath_softc *sc, int dodelay)
 1400 {
 1401 #define PA2DESC(_sc, _pa) \
 1402         ((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
 1403                 ((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
 1404         struct ath_hal *ah = sc->sc_ah;
 1405 
 1406         ATH_RX_LOCK(sc);
 1407 
 1408         ath_hal_stoppcurecv(ah);        /* disable PCU */
 1409         ath_hal_setrxfilter(ah, 0);     /* clear recv filter */
 1410         ath_hal_stopdmarecv(ah);        /* disable DMA engine */
 1411         /*
 1412          * TODO: see if this particular DELAY() is required; it may be
 1413          * masking some missing FIFO flush or DMA sync.
 1414          */
 1415 #if 0
 1416         if (dodelay)
 1417 #endif
 1418                 DELAY(3000);            /* 3ms is long enough for 1 frame */
 1419 #ifdef ATH_DEBUG
 1420         if (sc->sc_debug & (ATH_DEBUG_RESET | ATH_DEBUG_FATAL)) {
 1421                 struct ath_buf *bf;
 1422                 u_int ix;
 1423 
 1424                 device_printf(sc->sc_dev,
 1425                     "%s: rx queue %p, link %p\n",
 1426                     __func__,
 1427                     (caddr_t)(uintptr_t) ath_hal_getrxbuf(ah, HAL_RX_QUEUE_HP),
 1428                     sc->sc_rxlink);
 1429                 ix = 0;
 1430                 TAILQ_FOREACH(bf, &sc->sc_rxbuf, bf_list) {
 1431                         struct ath_desc *ds = bf->bf_desc;
 1432                         struct ath_rx_status *rs = &bf->bf_status.ds_rxstat;
 1433                         HAL_STATUS status = ath_hal_rxprocdesc(ah, ds,
 1434                                 bf->bf_daddr, PA2DESC(sc, ds->ds_link), rs);
 1435                         if (status == HAL_OK || (sc->sc_debug & ATH_DEBUG_FATAL))
 1436                                 ath_printrxbuf(sc, bf, ix, status == HAL_OK);
 1437                         ix++;
 1438                 }
 1439         }
 1440 #endif
 1441 
 1442         (void) ath_legacy_flush_rxpending(sc);
 1443         (void) ath_legacy_flush_rxholdbf(sc);
 1444 
 1445         sc->sc_rxlink = NULL;           /* just in case */
 1446 
 1447         ATH_RX_UNLOCK(sc);
 1448 #undef PA2DESC
 1449 }
 1450 
 1451 /*
 1452  * XXX TODO: something was calling startrecv without calling
 1453  * stoprecv.  Let's figure out what/why.  It was showing up
 1454  * as a mbuf leak (rxpending) and ath_buf leak (holdbf.)
 1455  */
 1456 
 1457 /*
 1458  * Enable the receive h/w following a reset.
 1459  */
 1460 static int
 1461 ath_legacy_startrecv(struct ath_softc *sc)
 1462 {
 1463         struct ath_hal *ah = sc->sc_ah;
 1464         struct ath_buf *bf;
 1465 
 1466         ATH_RX_LOCK(sc);
 1467 
 1468         /*
 1469          * XXX should verify these are already all NULL!
 1470          */
 1471         sc->sc_rxlink = NULL;
 1472         (void) ath_legacy_flush_rxpending(sc);
 1473         (void) ath_legacy_flush_rxholdbf(sc);
 1474 
 1475         /*
 1476          * Re-chain all of the buffers in the RX buffer list.
 1477          */
 1478         TAILQ_FOREACH(bf, &sc->sc_rxbuf, bf_list) {
 1479                 int error = ath_rxbuf_init(sc, bf);
 1480                 if (error != 0) {
 1481                         DPRINTF(sc, ATH_DEBUG_RECV,
 1482                                 "%s: ath_rxbuf_init failed %d\n",
 1483                                 __func__, error);
 1484                         return error;
 1485                 }
 1486         }
 1487 
 1488         bf = TAILQ_FIRST(&sc->sc_rxbuf);
 1489         ath_hal_putrxbuf(ah, bf->bf_daddr, HAL_RX_QUEUE_HP);
 1490         ath_hal_rxena(ah);              /* enable recv descriptors */
 1491         ath_mode_init(sc);              /* set filters, etc. */
 1492         ath_hal_startpcurecv(ah, (!! sc->sc_scanning)); /* re-enable PCU/DMA engine */
 1493 
 1494         ATH_RX_UNLOCK(sc);
 1495         return 0;
 1496 }
 1497 
 1498 static int
 1499 ath_legacy_dma_rxsetup(struct ath_softc *sc)
 1500 {
 1501         int error;
 1502 
 1503         error = ath_descdma_setup(sc, &sc->sc_rxdma, &sc->sc_rxbuf,
 1504             "rx", sizeof(struct ath_desc), ath_rxbuf, 1);
 1505         if (error != 0)
 1506                 return (error);
 1507 
 1508         return (0);
 1509 }
 1510 
 1511 static int
 1512 ath_legacy_dma_rxteardown(struct ath_softc *sc)
 1513 {
 1514 
 1515         if (sc->sc_rxdma.dd_desc_len != 0)
 1516                 ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
 1517         return (0);
 1518 }
 1519 
 1520 static void
 1521 ath_legacy_recv_sched(struct ath_softc *sc, int dosched)
 1522 {
 1523 
 1524         taskqueue_enqueue(sc->sc_tq, &sc->sc_rxtask);
 1525 }
 1526 
 1527 static void
 1528 ath_legacy_recv_sched_queue(struct ath_softc *sc, HAL_RX_QUEUE q,
 1529     int dosched)
 1530 {
 1531 
 1532         taskqueue_enqueue(sc->sc_tq, &sc->sc_rxtask);
 1533 }
 1534 
 1535 void
 1536 ath_recv_setup_legacy(struct ath_softc *sc)
 1537 {
 1538 
 1539         /* Sensible legacy defaults */
 1540         /*
 1541          * XXX this should be changed to properly support the
 1542          * exact RX descriptor size for each HAL.
 1543          */
 1544         sc->sc_rx_statuslen = sizeof(struct ath_desc);
 1545 
 1546         sc->sc_rx.recv_start = ath_legacy_startrecv;
 1547         sc->sc_rx.recv_stop = ath_legacy_stoprecv;
 1548         sc->sc_rx.recv_flush = ath_legacy_flushrecv;
 1549         sc->sc_rx.recv_tasklet = ath_legacy_rx_tasklet;
 1550         sc->sc_rx.recv_rxbuf_init = ath_legacy_rxbuf_init;
 1551 
 1552         sc->sc_rx.recv_setup = ath_legacy_dma_rxsetup;
 1553         sc->sc_rx.recv_teardown = ath_legacy_dma_rxteardown;
 1554         sc->sc_rx.recv_sched = ath_legacy_recv_sched;
 1555         sc->sc_rx.recv_sched_queue = ath_legacy_recv_sched_queue;
 1556 }

Cache object: 2de123a273ee56e0ed97a04b0e9f9cf7


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.