diff options
Diffstat (limited to 'kernel/drivers/net/wireless/ath/ath9k/recv.c')
| -rw-r--r-- | kernel/drivers/net/wireless/ath/ath9k/recv.c | 1176 |
1 files changed, 1176 insertions, 0 deletions
diff --git a/kernel/drivers/net/wireless/ath/ath9k/recv.c b/kernel/drivers/net/wireless/ath/ath9k/recv.c new file mode 100644 index 000000000..6fb40ef86 --- /dev/null +++ b/kernel/drivers/net/wireless/ath/ath9k/recv.c @@ -0,0 +1,1176 @@ +/* + * Copyright (c) 2008-2011 Atheros Communications Inc. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <linux/dma-mapping.h> +#include "ath9k.h" +#include "ar9003_mac.h" + +#define SKB_CB_ATHBUF(__skb) (*((struct ath_rxbuf **)__skb->cb)) + +static inline bool ath9k_check_auto_sleep(struct ath_softc *sc) +{ + return sc->ps_enabled && + (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP); +} + +/* + * Setup and link descriptors. + * + * 11N: we can no longer afford to self link the last descriptor. + * MAC acknowledges BA status as long as it copies frames to host + * buffer (or rx fifo). This can incorrectly acknowledge packets + * to a sender if last desc is self-linked. + */ +static void ath_rx_buf_link(struct ath_softc *sc, struct ath_rxbuf *bf, + bool flush) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ath_desc *ds; + struct sk_buff *skb; + + ds = bf->bf_desc; + ds->ds_link = 0; /* link to null */ + ds->ds_data = bf->bf_buf_addr; + + /* virtual addr of the beginning of the buffer. */ + skb = bf->bf_mpdu; + BUG_ON(skb == NULL); + ds->ds_vdata = skb->data; + + /* + * setup rx descriptors. The rx_bufsize here tells the hardware + * how much data it can DMA to us and that we are prepared + * to process + */ + ath9k_hw_setuprxdesc(ah, ds, + common->rx_bufsize, + 0); + + if (sc->rx.rxlink) + *sc->rx.rxlink = bf->bf_daddr; + else if (!flush) + ath9k_hw_putrxbuf(ah, bf->bf_daddr); + + sc->rx.rxlink = &ds->ds_link; +} + +static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_rxbuf *bf, + bool flush) +{ + if (sc->rx.buf_hold) + ath_rx_buf_link(sc, sc->rx.buf_hold, flush); + + sc->rx.buf_hold = bf; +} + +static void ath_setdefantenna(struct ath_softc *sc, u32 antenna) +{ + /* XXX block beacon interrupts */ + ath9k_hw_setantenna(sc->sc_ah, antenna); + sc->rx.defant = antenna; + sc->rx.rxotherant = 0; +} + +static void ath_opmode_init(struct ath_softc *sc) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + + u32 rfilt, mfilt[2]; + + /* configure rx filter */ + rfilt = ath_calcrxfilter(sc); + ath9k_hw_setrxfilter(ah, rfilt); + + /* configure bssid mask */ + ath_hw_setbssidmask(common); + + /* configure operational mode */ + ath9k_hw_setopmode(ah); + + /* calculate and install multicast filter */ + mfilt[0] = mfilt[1] = ~0; + ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]); +} + +static bool ath_rx_edma_buf_link(struct ath_softc *sc, + enum ath9k_rx_qtype qtype) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_rx_edma *rx_edma; + struct sk_buff *skb; + struct ath_rxbuf *bf; + + rx_edma = &sc->rx.rx_edma[qtype]; + if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize) + return false; + + bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list); + list_del_init(&bf->list); + + skb = bf->bf_mpdu; + + memset(skb->data, 0, ah->caps.rx_status_len); + dma_sync_single_for_device(sc->dev, bf->bf_buf_addr, + ah->caps.rx_status_len, DMA_TO_DEVICE); + + SKB_CB_ATHBUF(skb) = bf; + ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype); + __skb_queue_tail(&rx_edma->rx_fifo, skb); + + return true; +} + +static void ath_rx_addbuffer_edma(struct ath_softc *sc, + enum ath9k_rx_qtype qtype) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + struct ath_rxbuf *bf, *tbf; + + if (list_empty(&sc->rx.rxbuf)) { + ath_dbg(common, QUEUE, "No free rx buf available\n"); + return; + } + + list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) + if (!ath_rx_edma_buf_link(sc, qtype)) + break; + +} + +static void ath_rx_remove_buffer(struct ath_softc *sc, + enum ath9k_rx_qtype qtype) +{ + struct ath_rxbuf *bf; + struct ath_rx_edma *rx_edma; + struct sk_buff *skb; + + rx_edma = &sc->rx.rx_edma[qtype]; + + while ((skb = __skb_dequeue(&rx_edma->rx_fifo)) != NULL) { + bf = SKB_CB_ATHBUF(skb); + BUG_ON(!bf); + list_add_tail(&bf->list, &sc->rx.rxbuf); + } +} + +static void ath_rx_edma_cleanup(struct ath_softc *sc) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ath_rxbuf *bf; + + ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP); + ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP); + + list_for_each_entry(bf, &sc->rx.rxbuf, list) { + if (bf->bf_mpdu) { + dma_unmap_single(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, + DMA_BIDIRECTIONAL); + dev_kfree_skb_any(bf->bf_mpdu); + bf->bf_buf_addr = 0; + bf->bf_mpdu = NULL; + } + } +} + +static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size) +{ + __skb_queue_head_init(&rx_edma->rx_fifo); + rx_edma->rx_fifo_hwsize = size; +} + +static int ath_rx_edma_init(struct ath_softc *sc, int nbufs) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + struct ath_hw *ah = sc->sc_ah; + struct sk_buff *skb; + struct ath_rxbuf *bf; + int error = 0, i; + u32 size; + + ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize - + ah->caps.rx_status_len); + + ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP], + ah->caps.rx_lp_qdepth); + ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP], + ah->caps.rx_hp_qdepth); + + size = sizeof(struct ath_rxbuf) * nbufs; + bf = devm_kzalloc(sc->dev, size, GFP_KERNEL); + if (!bf) + return -ENOMEM; + + INIT_LIST_HEAD(&sc->rx.rxbuf); + + for (i = 0; i < nbufs; i++, bf++) { + skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL); + if (!skb) { + error = -ENOMEM; + goto rx_init_fail; + } + + memset(skb->data, 0, common->rx_bufsize); + bf->bf_mpdu = skb; + + bf->bf_buf_addr = dma_map_single(sc->dev, skb->data, + common->rx_bufsize, + DMA_BIDIRECTIONAL); + if (unlikely(dma_mapping_error(sc->dev, + bf->bf_buf_addr))) { + dev_kfree_skb_any(skb); + bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; + ath_err(common, + "dma_mapping_error() on RX init\n"); + error = -ENOMEM; + goto rx_init_fail; + } + + list_add_tail(&bf->list, &sc->rx.rxbuf); + } + + return 0; + +rx_init_fail: + ath_rx_edma_cleanup(sc); + return error; +} + +static void ath_edma_start_recv(struct ath_softc *sc) +{ + ath9k_hw_rxena(sc->sc_ah); + ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP); + ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP); + ath_opmode_init(sc); + ath9k_hw_startpcureceive(sc->sc_ah, sc->cur_chan->offchannel); +} + +static void ath_edma_stop_recv(struct ath_softc *sc) +{ + ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP); + ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP); +} + +int ath_rx_init(struct ath_softc *sc, int nbufs) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + struct sk_buff *skb; + struct ath_rxbuf *bf; + int error = 0; + + spin_lock_init(&sc->sc_pcu_lock); + + common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 + + sc->sc_ah->caps.rx_status_len; + + if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) + return ath_rx_edma_init(sc, nbufs); + + ath_dbg(common, CONFIG, "cachelsz %u rxbufsize %u\n", + common->cachelsz, common->rx_bufsize); + + /* Initialize rx descriptors */ + + error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf, + "rx", nbufs, 1, 0); + if (error != 0) { + ath_err(common, + "failed to allocate rx descriptors: %d\n", + error); + goto err; + } + + list_for_each_entry(bf, &sc->rx.rxbuf, list) { + skb = ath_rxbuf_alloc(common, common->rx_bufsize, + GFP_KERNEL); + if (skb == NULL) { + error = -ENOMEM; + goto err; + } + + bf->bf_mpdu = skb; + bf->bf_buf_addr = dma_map_single(sc->dev, skb->data, + common->rx_bufsize, + DMA_FROM_DEVICE); + if (unlikely(dma_mapping_error(sc->dev, + bf->bf_buf_addr))) { + dev_kfree_skb_any(skb); + bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; + ath_err(common, + "dma_mapping_error() on RX init\n"); + error = -ENOMEM; + goto err; + } + } + sc->rx.rxlink = NULL; +err: + if (error) + ath_rx_cleanup(sc); + + return error; +} + +void ath_rx_cleanup(struct ath_softc *sc) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct sk_buff *skb; + struct ath_rxbuf *bf; + + if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) { + ath_rx_edma_cleanup(sc); + return; + } + + list_for_each_entry(bf, &sc->rx.rxbuf, list) { + skb = bf->bf_mpdu; + if (skb) { + dma_unmap_single(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, + DMA_FROM_DEVICE); + dev_kfree_skb(skb); + bf->bf_buf_addr = 0; + bf->bf_mpdu = NULL; + } + } +} + +/* + * Calculate the receive filter according to the + * operating mode and state: + * + * o always accept unicast, broadcast, and multicast traffic + * o maintain current state of phy error reception (the hal + * may enable phy error frames for noise immunity work) + * o probe request frames are accepted only when operating in + * hostap, adhoc, or monitor modes + * o enable promiscuous mode according to the interface state + * o accept beacons: + * - when operating in adhoc mode so the 802.11 layer creates + * node table entries for peers, + * - when operating in station mode for collecting rssi data when + * the station is otherwise quiet, or + * - when operating as a repeater so we see repeater-sta beacons + * - when scanning + */ + +u32 ath_calcrxfilter(struct ath_softc *sc) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + u32 rfilt; + + if (config_enabled(CONFIG_ATH9K_TX99)) + return 0; + + rfilt = ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST + | ATH9K_RX_FILTER_MCAST; + + /* if operating on a DFS channel, enable radar pulse detection */ + if (sc->hw->conf.radar_enabled) + rfilt |= ATH9K_RX_FILTER_PHYRADAR | ATH9K_RX_FILTER_PHYERR; + + spin_lock_bh(&sc->chan_lock); + + if (sc->cur_chan->rxfilter & FIF_PROBE_REQ) + rfilt |= ATH9K_RX_FILTER_PROBEREQ; + + /* + * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station + * mode interface or when in monitor mode. AP mode does not need this + * since it receives all in-BSS frames anyway. + */ + if (sc->sc_ah->is_monitoring) + rfilt |= ATH9K_RX_FILTER_PROM; + + if ((sc->cur_chan->rxfilter & FIF_CONTROL) || + sc->sc_ah->dynack.enabled) + rfilt |= ATH9K_RX_FILTER_CONTROL; + + if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) && + (sc->cur_chan->nvifs <= 1) && + !(sc->cur_chan->rxfilter & FIF_BCN_PRBRESP_PROMISC)) + rfilt |= ATH9K_RX_FILTER_MYBEACON; + else + rfilt |= ATH9K_RX_FILTER_BEACON; + + if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) || + (sc->cur_chan->rxfilter & FIF_PSPOLL)) + rfilt |= ATH9K_RX_FILTER_PSPOLL; + + if (sc->cur_chandef.width != NL80211_CHAN_WIDTH_20_NOHT) + rfilt |= ATH9K_RX_FILTER_COMP_BAR; + + if (sc->cur_chan->nvifs > 1 || (sc->cur_chan->rxfilter & FIF_OTHER_BSS)) { + /* This is needed for older chips */ + if (sc->sc_ah->hw_version.macVersion <= AR_SREV_VERSION_9160) + rfilt |= ATH9K_RX_FILTER_PROM; + rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL; + } + + if (AR_SREV_9550(sc->sc_ah) || AR_SREV_9531(sc->sc_ah) || + AR_SREV_9561(sc->sc_ah)) + rfilt |= ATH9K_RX_FILTER_4ADDRESS; + + if (ath9k_is_chanctx_enabled() && + test_bit(ATH_OP_SCANNING, &common->op_flags)) + rfilt |= ATH9K_RX_FILTER_BEACON; + + spin_unlock_bh(&sc->chan_lock); + + return rfilt; + +} + +void ath_startrecv(struct ath_softc *sc) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_rxbuf *bf, *tbf; + + if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) { + ath_edma_start_recv(sc); + return; + } + + if (list_empty(&sc->rx.rxbuf)) + goto start_recv; + + sc->rx.buf_hold = NULL; + sc->rx.rxlink = NULL; + list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) { + ath_rx_buf_link(sc, bf, false); + } + + /* We could have deleted elements so the list may be empty now */ + if (list_empty(&sc->rx.rxbuf)) + goto start_recv; + + bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list); + ath9k_hw_putrxbuf(ah, bf->bf_daddr); + ath9k_hw_rxena(ah); + +start_recv: + ath_opmode_init(sc); + ath9k_hw_startpcureceive(ah, sc->cur_chan->offchannel); +} + +static void ath_flushrecv(struct ath_softc *sc) +{ + if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) + ath_rx_tasklet(sc, 1, true); + ath_rx_tasklet(sc, 1, false); +} + +bool ath_stoprecv(struct ath_softc *sc) +{ + struct ath_hw *ah = sc->sc_ah; + bool stopped, reset = false; + + ath9k_hw_abortpcurecv(ah); + ath9k_hw_setrxfilter(ah, 0); + stopped = ath9k_hw_stopdmarecv(ah, &reset); + + ath_flushrecv(sc); + + if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) + ath_edma_stop_recv(sc); + else + sc->rx.rxlink = NULL; + + if (!(ah->ah_flags & AH_UNPLUGGED) && + unlikely(!stopped)) { + ath_err(ath9k_hw_common(sc->sc_ah), + "Could not stop RX, we could be " + "confusing the DMA engine when we start RX up\n"); + ATH_DBG_WARN_ON_ONCE(!stopped); + } + return stopped && !reset; +} + +static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb) +{ + /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */ + struct ieee80211_mgmt *mgmt; + u8 *pos, *end, id, elen; + struct ieee80211_tim_ie *tim; + + mgmt = (struct ieee80211_mgmt *)skb->data; + pos = mgmt->u.beacon.variable; + end = skb->data + skb->len; + + while (pos + 2 < end) { + id = *pos++; + elen = *pos++; + if (pos + elen > end) + break; + + if (id == WLAN_EID_TIM) { + if (elen < sizeof(*tim)) + break; + tim = (struct ieee80211_tim_ie *) pos; + if (tim->dtim_count != 0) + break; + return tim->bitmap_ctrl & 0x01; + } + + pos += elen; + } + + return false; +} + +static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + bool skip_beacon = false; + + if (skb->len < 24 + 8 + 2 + 2) + return; + + sc->ps_flags &= ~PS_WAIT_FOR_BEACON; + + if (sc->ps_flags & PS_BEACON_SYNC) { + sc->ps_flags &= ~PS_BEACON_SYNC; + ath_dbg(common, PS, + "Reconfigure beacon timers based on synchronized timestamp\n"); + +#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT + if (ath9k_is_chanctx_enabled()) { + if (sc->cur_chan == &sc->offchannel.chan) + skip_beacon = true; + } +#endif + + if (!skip_beacon && + !(WARN_ON_ONCE(sc->cur_chan->beacon.beacon_interval == 0))) + ath9k_set_beacon(sc); + + ath9k_p2p_beacon_sync(sc); + } + + if (ath_beacon_dtim_pending_cab(skb)) { + /* + * Remain awake waiting for buffered broadcast/multicast + * frames. If the last broadcast/multicast frame is not + * received properly, the next beacon frame will work as + * a backup trigger for returning into NETWORK SLEEP state, + * so we are waiting for it as well. + */ + ath_dbg(common, PS, + "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n"); + sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON; + return; + } + + if (sc->ps_flags & PS_WAIT_FOR_CAB) { + /* + * This can happen if a broadcast frame is dropped or the AP + * fails to send a frame indicating that all CAB frames have + * been delivered. + */ + sc->ps_flags &= ~PS_WAIT_FOR_CAB; + ath_dbg(common, PS, "PS wait for CAB frames timed out\n"); + } +} + +static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon) +{ + struct ieee80211_hdr *hdr; + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + + hdr = (struct ieee80211_hdr *)skb->data; + + /* Process Beacon and CAB receive in PS state */ + if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc)) + && mybeacon) { + ath_rx_ps_beacon(sc, skb); + } else if ((sc->ps_flags & PS_WAIT_FOR_CAB) && + (ieee80211_is_data(hdr->frame_control) || + ieee80211_is_action(hdr->frame_control)) && + is_multicast_ether_addr(hdr->addr1) && + !ieee80211_has_moredata(hdr->frame_control)) { + /* + * No more broadcast/multicast frames to be received at this + * point. + */ + sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON); + ath_dbg(common, PS, + "All PS CAB frames received, back to sleep\n"); + } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) && + !is_multicast_ether_addr(hdr->addr1) && + !ieee80211_has_morefrags(hdr->frame_control)) { + sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA; + ath_dbg(common, PS, + "Going back to sleep after having received PS-Poll data (0x%lx)\n", + sc->ps_flags & (PS_WAIT_FOR_BEACON | + PS_WAIT_FOR_CAB | + PS_WAIT_FOR_PSPOLL_DATA | + PS_WAIT_FOR_TX_ACK)); + } +} + +static bool ath_edma_get_buffers(struct ath_softc *sc, + enum ath9k_rx_qtype qtype, + struct ath_rx_status *rs, + struct ath_rxbuf **dest) +{ + struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype]; + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct sk_buff *skb; + struct ath_rxbuf *bf; + int ret; + + skb = skb_peek(&rx_edma->rx_fifo); + if (!skb) + return false; + + bf = SKB_CB_ATHBUF(skb); + BUG_ON(!bf); + + dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, DMA_FROM_DEVICE); + + ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data); + if (ret == -EINPROGRESS) { + /*let device gain the buffer again*/ + dma_sync_single_for_device(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, DMA_FROM_DEVICE); + return false; + } + + __skb_unlink(skb, &rx_edma->rx_fifo); + if (ret == -EINVAL) { + /* corrupt descriptor, skip this one and the following one */ + list_add_tail(&bf->list, &sc->rx.rxbuf); + ath_rx_edma_buf_link(sc, qtype); + + skb = skb_peek(&rx_edma->rx_fifo); + if (skb) { + bf = SKB_CB_ATHBUF(skb); + BUG_ON(!bf); + + __skb_unlink(skb, &rx_edma->rx_fifo); + list_add_tail(&bf->list, &sc->rx.rxbuf); + ath_rx_edma_buf_link(sc, qtype); + } + + bf = NULL; + } + + *dest = bf; + return true; +} + +static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc, + struct ath_rx_status *rs, + enum ath9k_rx_qtype qtype) +{ + struct ath_rxbuf *bf = NULL; + + while (ath_edma_get_buffers(sc, qtype, rs, &bf)) { + if (!bf) + continue; + + return bf; + } + return NULL; +} + +static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc, + struct ath_rx_status *rs) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ath_desc *ds; + struct ath_rxbuf *bf; + int ret; + + if (list_empty(&sc->rx.rxbuf)) { + sc->rx.rxlink = NULL; + return NULL; + } + + bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list); + if (bf == sc->rx.buf_hold) + return NULL; + + ds = bf->bf_desc; + + /* + * Must provide the virtual address of the current + * descriptor, the physical address, and the virtual + * address of the next descriptor in the h/w chain. + * This allows the HAL to look ahead to see if the + * hardware is done with a descriptor by checking the + * done bit in the following descriptor and the address + * of the current descriptor the DMA engine is working + * on. All this is necessary because of our use of + * a self-linked list to avoid rx overruns. + */ + ret = ath9k_hw_rxprocdesc(ah, ds, rs); + if (ret == -EINPROGRESS) { + struct ath_rx_status trs; + struct ath_rxbuf *tbf; + struct ath_desc *tds; + + memset(&trs, 0, sizeof(trs)); + if (list_is_last(&bf->list, &sc->rx.rxbuf)) { + sc->rx.rxlink = NULL; + return NULL; + } + + tbf = list_entry(bf->list.next, struct ath_rxbuf, list); + + /* + * On some hardware the descriptor status words could + * get corrupted, including the done bit. Because of + * this, check if the next descriptor's done bit is + * set or not. + * + * If the next descriptor's done bit is set, the current + * descriptor has been corrupted. Force s/w to discard + * this descriptor and continue... + */ + + tds = tbf->bf_desc; + ret = ath9k_hw_rxprocdesc(ah, tds, &trs); + if (ret == -EINPROGRESS) + return NULL; + + /* + * Re-check previous descriptor, in case it has been filled + * in the mean time. + */ + ret = ath9k_hw_rxprocdesc(ah, ds, rs); + if (ret == -EINPROGRESS) { + /* + * mark descriptor as zero-length and set the 'more' + * flag to ensure that both buffers get discarded + */ + rs->rs_datalen = 0; + rs->rs_more = true; + } + } + + list_del(&bf->list); + if (!bf->bf_mpdu) + return bf; + + /* + * Synchronize the DMA transfer with CPU before + * 1. accessing the frame + * 2. requeueing the same buffer to h/w + */ + dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, + DMA_FROM_DEVICE); + + return bf; +} + +static void ath9k_process_tsf(struct ath_rx_status *rs, + struct ieee80211_rx_status *rxs, + u64 tsf) +{ + u32 tsf_lower = tsf & 0xffffffff; + + rxs->mactime = (tsf & ~0xffffffffULL) | rs->rs_tstamp; + if (rs->rs_tstamp > tsf_lower && + unlikely(rs->rs_tstamp - tsf_lower > 0x10000000)) + rxs->mactime -= 0x100000000ULL; + + if (rs->rs_tstamp < tsf_lower && + unlikely(tsf_lower - rs->rs_tstamp > 0x10000000)) + rxs->mactime += 0x100000000ULL; +} + +/* + * For Decrypt or Demic errors, we only mark packet status here and always push + * up the frame up to let mac80211 handle the actual error case, be it no + * decryption key or real decryption error. This let us keep statistics there. + */ +static int ath9k_rx_skb_preprocess(struct ath_softc *sc, + struct sk_buff *skb, + struct ath_rx_status *rx_stats, + struct ieee80211_rx_status *rx_status, + bool *decrypt_error, u64 tsf) +{ + struct ieee80211_hw *hw = sc->hw; + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ieee80211_hdr *hdr; + bool discard_current = sc->rx.discard_next; + + /* + * Discard corrupt descriptors which are marked in + * ath_get_next_rx_buf(). + */ + if (discard_current) + goto corrupt; + + sc->rx.discard_next = false; + + /* + * Discard zero-length packets. + */ + if (!rx_stats->rs_datalen) { + RX_STAT_INC(rx_len_err); + goto corrupt; + } + + /* + * rs_status follows rs_datalen so if rs_datalen is too large + * we can take a hint that hardware corrupted it, so ignore + * those frames. + */ + if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) { + RX_STAT_INC(rx_len_err); + goto corrupt; + } + + /* Only use status info from the last fragment */ + if (rx_stats->rs_more) + return 0; + + /* + * Return immediately if the RX descriptor has been marked + * as corrupt based on the various error bits. + * + * This is different from the other corrupt descriptor + * condition handled above. + */ + if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC) + goto corrupt; + + hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len); + + ath9k_process_tsf(rx_stats, rx_status, tsf); + ath_debug_stat_rx(sc, rx_stats); + + /* + * Process PHY errors and return so that the packet + * can be dropped. + */ + if (rx_stats->rs_status & ATH9K_RXERR_PHY) { + ath9k_dfs_process_phyerr(sc, hdr, rx_stats, rx_status->mactime); + if (ath_cmn_process_fft(&sc->spec_priv, hdr, rx_stats, rx_status->mactime)) + RX_STAT_INC(rx_spectral); + + return -EINVAL; + } + + /* + * everything but the rate is checked here, the rate check is done + * separately to avoid doing two lookups for a rate for each frame. + */ + spin_lock_bh(&sc->chan_lock); + if (!ath9k_cmn_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error, + sc->cur_chan->rxfilter)) { + spin_unlock_bh(&sc->chan_lock); + return -EINVAL; + } + spin_unlock_bh(&sc->chan_lock); + + if (ath_is_mybeacon(common, hdr)) { + RX_STAT_INC(rx_beacons); + rx_stats->is_mybeacon = true; + } + + /* + * This shouldn't happen, but have a safety check anyway. + */ + if (WARN_ON(!ah->curchan)) + return -EINVAL; + + if (ath9k_cmn_process_rate(common, hw, rx_stats, rx_status)) { + /* + * No valid hardware bitrate found -- we should not get here + * because hardware has already validated this frame as OK. + */ + ath_dbg(common, ANY, "unsupported hw bitrate detected 0x%02x using 1 Mbit\n", + rx_stats->rs_rate); + RX_STAT_INC(rx_rate_err); + return -EINVAL; + } + + if (ath9k_is_chanctx_enabled()) { + if (rx_stats->is_mybeacon) + ath_chanctx_beacon_recv_ev(sc, + ATH_CHANCTX_EVENT_BEACON_RECEIVED); + } + + ath9k_cmn_process_rssi(common, hw, rx_stats, rx_status); + + rx_status->band = ah->curchan->chan->band; + rx_status->freq = ah->curchan->chan->center_freq; + rx_status->antenna = rx_stats->rs_antenna; + rx_status->flag |= RX_FLAG_MACTIME_END; + +#ifdef CONFIG_ATH9K_BTCOEX_SUPPORT + if (ieee80211_is_data_present(hdr->frame_control) && + !ieee80211_is_qos_nullfunc(hdr->frame_control)) + sc->rx.num_pkts++; +#endif + + return 0; + +corrupt: + sc->rx.discard_next = rx_stats->rs_more; + return -EINVAL; +} + +/* + * Run the LNA combining algorithm only in these cases: + * + * Standalone WLAN cards with both LNA/Antenna diversity + * enabled in the EEPROM. + * + * WLAN+BT cards which are in the supported card list + * in ath_pci_id_table and the user has loaded the + * driver with "bt_ant_diversity" set to true. + */ +static void ath9k_antenna_check(struct ath_softc *sc, + struct ath_rx_status *rs) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath9k_hw_capabilities *pCap = &ah->caps; + struct ath_common *common = ath9k_hw_common(ah); + + if (!(ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)) + return; + + /* + * Change the default rx antenna if rx diversity + * chooses the other antenna 3 times in a row. + */ + if (sc->rx.defant != rs->rs_antenna) { + if (++sc->rx.rxotherant >= 3) + ath_setdefantenna(sc, rs->rs_antenna); + } else { + sc->rx.rxotherant = 0; + } + + if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) { + if (common->bt_ant_diversity) + ath_ant_comb_scan(sc, rs); + } else { + ath_ant_comb_scan(sc, rs); + } +} + +static void ath9k_apply_ampdu_details(struct ath_softc *sc, + struct ath_rx_status *rs, struct ieee80211_rx_status *rxs) +{ + if (rs->rs_isaggr) { + rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN; + + rxs->ampdu_reference = sc->rx.ampdu_ref; + + if (!rs->rs_moreaggr) { + rxs->flag |= RX_FLAG_AMPDU_IS_LAST; + sc->rx.ampdu_ref++; + } + + if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE) + rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR; + } +} + +int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) +{ + struct ath_rxbuf *bf; + struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb; + struct ieee80211_rx_status *rxs; + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ieee80211_hw *hw = sc->hw; + int retval; + struct ath_rx_status rs; + enum ath9k_rx_qtype qtype; + bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA); + int dma_type; + u64 tsf = 0; + unsigned long flags; + dma_addr_t new_buf_addr; + unsigned int budget = 512; + struct ieee80211_hdr *hdr; + + if (edma) + dma_type = DMA_BIDIRECTIONAL; + else + dma_type = DMA_FROM_DEVICE; + + qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP; + + tsf = ath9k_hw_gettsf64(ah); + + do { + bool decrypt_error = false; + + memset(&rs, 0, sizeof(rs)); + if (edma) + bf = ath_edma_get_next_rx_buf(sc, &rs, qtype); + else + bf = ath_get_next_rx_buf(sc, &rs); + + if (!bf) + break; + + skb = bf->bf_mpdu; + if (!skb) + continue; + + /* + * Take frame header from the first fragment and RX status from + * the last one. + */ + if (sc->rx.frag) + hdr_skb = sc->rx.frag; + else + hdr_skb = skb; + + rxs = IEEE80211_SKB_RXCB(hdr_skb); + memset(rxs, 0, sizeof(struct ieee80211_rx_status)); + + retval = ath9k_rx_skb_preprocess(sc, hdr_skb, &rs, rxs, + &decrypt_error, tsf); + if (retval) + goto requeue_drop_frag; + + /* Ensure we always have an skb to requeue once we are done + * processing the current buffer's skb */ + requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC); + + /* If there is no memory we ignore the current RX'd frame, + * tell hardware it can give us a new frame using the old + * skb and put it at the tail of the sc->rx.rxbuf list for + * processing. */ + if (!requeue_skb) { + RX_STAT_INC(rx_oom_err); + goto requeue_drop_frag; + } + + /* We will now give hardware our shiny new allocated skb */ + new_buf_addr = dma_map_single(sc->dev, requeue_skb->data, + common->rx_bufsize, dma_type); + if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) { + dev_kfree_skb_any(requeue_skb); + goto requeue_drop_frag; + } + + /* Unmap the frame */ + dma_unmap_single(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, dma_type); + + bf->bf_mpdu = requeue_skb; + bf->bf_buf_addr = new_buf_addr; + + skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len); + if (ah->caps.rx_status_len) + skb_pull(skb, ah->caps.rx_status_len); + + if (!rs.rs_more) + ath9k_cmn_rx_skb_postprocess(common, hdr_skb, &rs, + rxs, decrypt_error); + + if (rs.rs_more) { + RX_STAT_INC(rx_frags); + /* + * rs_more indicates chained descriptors which can be + * used to link buffers together for a sort of + * scatter-gather operation. + */ + if (sc->rx.frag) { + /* too many fragments - cannot handle frame */ + dev_kfree_skb_any(sc->rx.frag); + dev_kfree_skb_any(skb); + RX_STAT_INC(rx_too_many_frags_err); + skb = NULL; + } + sc->rx.frag = skb; + goto requeue; + } + + if (sc->rx.frag) { + int space = skb->len - skb_tailroom(hdr_skb); + + if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) { + dev_kfree_skb(skb); + RX_STAT_INC(rx_oom_err); + goto requeue_drop_frag; + } + + sc->rx.frag = NULL; + + skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len), + skb->len); + dev_kfree_skb_any(skb); + skb = hdr_skb; + } + + if (rxs->flag & RX_FLAG_MMIC_STRIPPED) + skb_trim(skb, skb->len - 8); + + spin_lock_irqsave(&sc->sc_pm_lock, flags); + if ((sc->ps_flags & (PS_WAIT_FOR_BEACON | + PS_WAIT_FOR_CAB | + PS_WAIT_FOR_PSPOLL_DATA)) || + ath9k_check_auto_sleep(sc)) + ath_rx_ps(sc, skb, rs.is_mybeacon); + spin_unlock_irqrestore(&sc->sc_pm_lock, flags); + + ath9k_antenna_check(sc, &rs); + ath9k_apply_ampdu_details(sc, &rs, rxs); + ath_debug_rate_stats(sc, &rs, skb); + + hdr = (struct ieee80211_hdr *)skb->data; + if (ieee80211_is_ack(hdr->frame_control)) + ath_dynack_sample_ack_ts(sc->sc_ah, skb, rs.rs_tstamp); + + ieee80211_rx(hw, skb); + +requeue_drop_frag: + if (sc->rx.frag) { + dev_kfree_skb_any(sc->rx.frag); + sc->rx.frag = NULL; + } +requeue: + list_add_tail(&bf->list, &sc->rx.rxbuf); + + if (!edma) { + ath_rx_buf_relink(sc, bf, flush); + if (!flush) + ath9k_hw_rxena(ah); + } else if (!flush) { + ath_rx_edma_buf_link(sc, qtype); + } + + if (!budget--) + break; + } while (1); + + if (!(ah->imask & ATH9K_INT_RXEOL)) { + ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN); + ath9k_hw_set_interrupts(ah); + } + + return 0; +} |