/*
* Copyright (c) 2008-2009 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 "ath9k.h"
static struct ieee80211_hw * ath_get_virt_hw(struct ath_softc *sc,
struct ieee80211_hdr *hdr)
{
struct ieee80211_hw *hw = sc->pri_wiphy->hw;
int i;
spin_lock_bh(&sc->wiphy_lock);
for (i = 0; i < sc->num_sec_wiphy; i++) {
struct ath_wiphy *aphy = sc->sec_wiphy[i];
if (aphy == NULL)
continue;
if (compare_ether_addr(hdr->addr1, aphy->hw->wiphy->perm_addr)
== 0) {
hw = aphy->hw;
break;
}
}
spin_unlock_bh(&sc->wiphy_lock);
return hw;
}
/*
* 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_buf *bf)
{
struct ath_hw *ah = sc->sc_ah;
struct ath_desc *ds;
struct sk_buff *skb;
ATH_RXBUF_RESET(bf);
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;
ASSERT(skb != NULL);
ds->ds_vdata = skb->data;
/* setup rx descriptors. The rx.bufsize here tells the harware
* how much data it can DMA to us and that we are prepared
* to process */
ath9k_hw_setuprxdesc(ah, ds,
sc->rx.bufsize,
0);
if (sc->rx.rxlink == NULL)
ath9k_hw_putrxbuf(ah, bf->bf_daddr);
else
*sc->rx.rxlink = bf->bf_daddr;
sc->rx.rxlink = &ds->ds_link;
ath9k_hw_rxena(ah);
}
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;
}
/*
* Extend 15-bit time stamp from rx descriptor to
* a full 64-bit TSF using the current h/w TSF.
*/
static u64 ath_extend_tsf(struct ath_softc *sc, u32 rstamp)
{
u64 tsf;
tsf = ath9k_hw_gettsf64(sc->sc_ah);
if ((tsf & 0x7fff) < rstamp)
tsf -= 0x8000;
return (tsf & ~0x7fff) | rstamp;
}
/*
* 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 ath_rx_prepare(struct sk_buff *skb, struct ath_desc *ds,
struct ieee80211_rx_status *rx_status, bool *decrypt_error,
struct ath_softc *sc)
{
struct ieee80211_hdr *hdr;
u8 ratecode;
__le16 fc;
struct ieee80211_hw *hw;
struct ieee80211_sta *sta;
struct ath_node *an;
int last_rssi = ATH_RSSI_DUMMY_MARKER;
hdr = (struct ieee80211_hdr *)skb->data;
fc = hdr->frame_control;
memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
hw = ath_get_virt_hw(sc, hdr);
if (ds->ds_rxstat.rs_more) {
/*
* Frame spans multiple descriptors; this cannot happen yet
* as we don't support jumbograms. If not in monitor mode,
* discard the frame. Enable this if you want to see
* error frames in Monitor mode.
*/
if (sc->sc_ah->opmode != NL80211_IFTYPE_MONITOR)
goto rx_next;
} else if (ds->ds_rxstat.rs_status != 0) {
if (ds->ds_rxstat.rs_status & ATH9K_RXERR_CRC)
rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
if (ds->ds_rxstat.rs_status & ATH9K_RXERR_PHY)
goto rx_next;
if (ds->ds_rxstat.rs_status & ATH9K_RXERR_DECRYPT) {
*decrypt_error = true;
} else if (ds->ds_rxstat.rs_status & ATH9K_RXERR_MIC) {
if (ieee80211_is_ctl(fc))
/*
* Sometimes, we get invalid
* MIC failures on valid control frames.
* Remove these mic errors.
*/
ds->ds_rxstat.rs_status &= ~ATH9K_RXERR_MIC;
else
rx_status->flag |= RX_FLAG_MMIC_ERROR;
}
/*
* Reject error frames with the exception of
* decryption and MIC failures. For monitor mode,
* we also ignore the CRC error.
*/
if (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR) {
if (ds->ds_rxstat.rs_status &
~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
ATH9K_RXERR_CRC))
goto rx_next;
} else {
if (ds->ds_rxstat.rs_status &
~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
goto rx_next;
}
}
}
ratecode = ds->ds_rxstat.rs_rate;
if (ratecode & 0x80) {
/* HT rate */
rx_status->flag |= RX_FLAG_HT;
if (ds->ds_rxstat.rs_flags & ATH9K_RX_2040)
rx_status->flag |= RX_FLAG_40MHZ;
if (ds->ds_rxstat.rs_flags & ATH9K_RX_GI)
rx_status->flag |= RX_FLAG_SHORT_GI;
rx_status->rate_idx = ratecode & 0x7f;
} else {
int i = 0, cur_band, n_rates;
cur_band = hw->conf.channel->band;
n_rates = sc->sbands[cur_band].n_bitrates;
for (i = 0; i < n_rates; i++) {
if (sc->sbands[cur_band].bitrates[i].hw_value ==
ratecode) {
rx_status->rate_idx = i;
break;
}
if (sc->sbands[cur_band].bitrates[i].hw_value_short ==
ratecode) {
rx_status->rate_idx = i;
rx_status->flag |= RX_FLAG_SHORTPRE;
break;
}
}
}
rcu_read_lock();
sta = ieee80211_find_sta(sc->hw, hdr->addr2);
if (sta) {
an = (struct ath_node *) sta->drv_priv;
if (ds->ds_rxstat.rs_rssi != ATH9K_RSSI_BAD &&
!ds->ds_rxstat.rs_moreaggr)
ATH_RSSI_LPF(an->last_rssi, ds->ds_rxstat.rs_rssi);
last_rssi = an->last_rssi;
}
rcu_read_unlock();
if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
ds->ds_rxstat.rs_rssi = ATH_EP_RND(last_rssi,
ATH_RSSI_EP_MULTIPLIER);
if (ds->ds_rxstat.rs_rssi < 0)
ds->ds_rxstat.rs_rssi = 0;
else if (ds->ds_rxstat.rs_rssi > 127)
ds->ds_rxstat.rs_rssi = 127;
/* Update Beacon RSSI, this is used by ANI. */
if (ieee80211_is_beacon(fc))
sc->sc_ah->stats.avgbrssi = ds->ds_rxstat.rs_rssi;
rx_status->mactime = ath_extend_tsf(sc, ds->ds_rxstat.rs_tstamp);
rx_status->band = hw->conf.channel->band;
rx_status->freq = hw->conf.channel->center_freq;
rx_status->noise = sc->ani.noise_floor;
rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + ds->ds_rxstat.rs_rssi;
rx_status->antenna = ds->ds_rxstat.rs_antenna;
/*
* Theory for reporting quality:
*
* At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
* At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
* At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
*
* MCS 7 is the highets MCS index usable by a 1-stream device.
* MCS 15 is the highest MCS index usable by a 2-stream device.
*
* All ath9k devices are either 1-stream or 2-stream.
*
* How many bars you see is derived from the qual reporting.
*
* A more elaborate scheme can be used here but it requires tables
* of SNR/throughput for each possible mode used. For the MCS table
* you can refer to the wireless wiki:
*
* http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
*
*/
if (conf_is_ht(&hw->conf))
rx_status->qual = ds->ds_rxstat.rs_rssi * 100 / 45;
else
rx_status->qual = ds->ds_rxstat.rs_rssi * 100 / 35;
/* rssi can be more than 45 though, anything above that
* should be considered at 100% */
if (rx_status->qual > 100)
rx_status->qual = 100;
rx_status->flag |= RX_FLAG_TSFT;
return 1;
rx_next:
return 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 */
if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
ath_hw_setbssidmask(common);
/* configure operational mode */
ath9k_hw_setopmode(ah);
/* Handle any link-level address change. */
ath9k_hw_setmac(ah, common->macaddr);
/* calculate and install multicast filter */
mfilt[0] = mfilt[1] = ~0;
ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
}
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_buf *bf;
int error = 0;
spin_lock_init(&sc->rx.rxflushlock);
sc->sc_flags &= ~SC_OP_RXFLUSH;
spin_lock_init(&sc->rx.rxbuflock);
sc->rx.bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
min(common->cachelsz, (u16)64));
ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
common->cachelsz, sc->rx.bufsize);
/* Initialize rx descriptors */
error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
"rx", nbufs, 1);
if (error != 0) {
ath_print(common, ATH_DBG_FATAL,
"failed to allocate rx descriptors: %d\n", error);
goto err;
}
list_for_each_entry(bf, &sc->rx.rxbuf, list) {
skb = ath_rxbuf_alloc(common, sc->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,
sc->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;
ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error() on RX init\n");
error = -ENOMEM;
goto err;
}
bf->bf_dmacontext = bf->bf_buf_addr;
}
sc->rx.rxlink = NULL;
err:
if (error)
ath_rx_cleanup(sc);
return error;
}
void ath_rx_cleanup(struct ath_softc *sc)
{
struct sk_buff *skb;
struct ath_buf *bf;
list_for_each_entry(bf, &sc->rx.rxbuf, list) {
skb = bf->bf_mpdu;
if (skb) {
dma_unmap_single(sc->dev, bf->bf_buf_addr,
sc->rx.bufsize, DMA_FROM_DEVICE);
dev_kfree_skb(skb);
}
}
if (sc->rx.rxdma.dd_desc_len != 0)
ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
}
/*
* 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)
{
#define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
u32 rfilt;
rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
| ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
| ATH9K_RX_FILTER_MCAST;
/* If not a STA, enable processing of Probe Requests */
if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
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->opmode != NL80211_IFTYPE_AP) &&
(sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
(sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
rfilt |= ATH9K_RX_FILTER_PROM;
if (sc->rx.rxfilter & FIF_CONTROL)
rfilt |= ATH9K_RX_FILTER_CONTROL;
if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
!(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
rfilt |= ATH9K_RX_FILTER_MYBEACON;
else
rfilt |= ATH9K_RX_FILTER_BEACON;
if (sc->rx.rxfilter & FIF_PSPOLL)
rfilt |= ATH9K_RX_FILTER_PSPOLL;
if (conf_is_ht(&sc->hw->conf))
rfilt |= ATH9K_RX_FILTER_COMP_BAR;
if (sc->sec_wiphy || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
/* TODO: only needed if more than one BSSID is in use in
* station/adhoc mode */
/* The following may also be needed for other 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;
}
return rfilt;
#undef RX_FILTER_PRESERVE
}
int ath_startrecv(struct ath_softc *sc)
{
struct ath_hw *ah = sc->sc_ah;
struct ath_buf *bf, *tbf;
spin_lock_bh(&sc->rx.rxbuflock);
if (list_empty(&sc->rx.rxbuf))
goto start_recv;
sc->rx.rxlink = NULL;
list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
ath_rx_buf_link(sc, bf);
}
/* 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_buf, list);
ath9k_hw_putrxbuf(ah, bf->bf_daddr);
ath9k_hw_rxena(ah);
start_recv:
spin_unlock_bh(&sc->rx.rxbuflock);
ath_opmode_init(sc);
ath9k_hw_startpcureceive(ah);
return 0;
}
bool ath_stoprecv(struct ath_softc *sc)
{
struct ath_hw *ah = sc->sc_ah;
bool stopped;
ath9k_hw_stoppcurecv(ah);
ath9k_hw_setrxfilter(ah, 0);
stopped = ath9k_hw_stopdmarecv(ah);
sc->rx.rxlink = NULL;
return stopped;
}
void ath_flushrecv(struct ath_softc *sc)
{
spin_lock_bh(&sc->rx.rxflushlock);
sc->sc_flags |= SC_OP_RXFLUSH;
ath_rx_tasklet(sc, 1);
sc->sc_flags &= ~SC_OP_RXFLUSH;
spin_unlock_bh(&sc->rx.rxflushlock);
}
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 ieee80211_mgmt *mgmt;
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
if (skb->len < 24 + 8 + 2 + 2)
return;
mgmt = (struct ieee80211_mgmt *)skb->data;
if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
return; /* not from our current AP */
sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
if (sc->sc_flags & SC_OP_BEACON_SYNC) {
sc->sc_flags &= ~SC_OP_BEACON_SYNC;
ath_print(common, ATH_DBG_PS,
"Reconfigure Beacon timers based on "
"timestamp from the AP\n");
ath_beacon_config(sc, NULL);
}
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_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
"buffered broadcast/multicast frame(s)\n");
sc->sc_flags |= SC_OP_WAIT_FOR_CAB | SC_OP_WAIT_FOR_BEACON;
return;
}
if (sc->sc_flags & SC_OP_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->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
ath_print(common, ATH_DBG_PS,
"PS wait for CAB frames timed out\n");
}
}
static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
{
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->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
ieee80211_is_beacon(hdr->frame_control))
ath_rx_ps_beacon(sc, skb);
else if ((sc->sc_flags & SC_OP_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->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
ath_print(common, ATH_DBG_PS,
"All PS CAB frames received, back to sleep\n");
} else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
!is_multicast_ether_addr(hdr->addr1) &&
!ieee80211_has_morefrags(hdr->frame_control)) {
sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
ath_print(common, ATH_DBG_PS,
"Going back to sleep after having received "
"PS-Poll data (0x%x)\n",
sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
SC_OP_WAIT_FOR_CAB |
SC_OP_WAIT_FOR_PSPOLL_DATA |
SC_OP_WAIT_FOR_TX_ACK));
}
}
static void ath_rx_send_to_mac80211(struct ath_softc *sc, struct sk_buff *skb,
struct ieee80211_rx_status *rx_status)
{
struct ieee80211_hdr *hdr;
hdr = (struct ieee80211_hdr *)skb->data;
/* Send the frame to mac80211 */
if (is_multicast_ether_addr(hdr->addr1)) {
int i;
/*
* Deliver broadcast/multicast frames to all suitable
* virtual wiphys.
*/
/* TODO: filter based on channel configuration */
for (i = 0; i < sc->num_sec_wiphy; i++) {
struct ath_wiphy *aphy = sc->sec_wiphy[i];
struct sk_buff *nskb;
if (aphy == NULL)
continue;
nskb = skb_copy(skb, GFP_ATOMIC);
if (nskb) {
memcpy(IEEE80211_SKB_RXCB(nskb), rx_status,
sizeof(*rx_status));
ieee80211_rx(aphy->hw, nskb);
}
}
memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
ieee80211_rx(sc->hw, skb);
} else {
/* Deliver unicast frames based on receiver address */
memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
ieee80211_rx(ath_get_virt_hw(sc, hdr), skb);
}
}
int ath_rx_tasklet(struct ath_softc *sc, int flush)
{
#define PA2DESC(_sc, _pa) \
((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc + \
((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
struct ath_buf *bf;
struct ath_desc *ds;
struct sk_buff *skb = NULL, *requeue_skb;
struct ieee80211_rx_status rx_status;
struct ath_hw *ah = sc->sc_ah;
struct ath_common *common = ath9k_hw_common(ah);
struct ieee80211_hdr *hdr;
int hdrlen, padsize, retval;
bool decrypt_error = false;
u8 keyix;
__le16 fc;
spin_lock_bh(&sc->rx.rxbuflock);
do {
/* If handling rx interrupt and flush is in progress => exit */
if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
break;
if (list_empty(&sc->rx.rxbuf)) {
sc->rx.rxlink = NULL;
break;
}
bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
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.
*/
retval = ath9k_hw_rxprocdesc(ah, ds,
bf->bf_daddr,
PA2DESC(sc, ds->ds_link),
0);
if (retval == -EINPROGRESS) {
struct ath_buf *tbf;
struct ath_desc *tds;
if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
sc->rx.rxlink = NULL;
break;
}
tbf = list_entry(bf->list.next, struct ath_buf, 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;
retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
PA2DESC(sc, tds->ds_link), 0);
if (retval == -EINPROGRESS) {
break;
}
}
skb = bf->bf_mpdu;
if (!skb)
continue;
/*
* 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,
sc->rx.bufsize,
DMA_FROM_DEVICE);
/*
* If we're asked to flush receive queue, directly
* chain it back at the queue without processing it.
*/
if (flush)
goto requeue;
if (!ds->ds_rxstat.rs_datalen)
goto requeue;
/* The status portion of the descriptor could get corrupted. */
if (sc->rx.bufsize < ds->ds_rxstat.rs_datalen)
goto requeue;
if (!ath_rx_prepare(skb, ds, &rx_status, &decrypt_error, sc))
goto requeue;
/* Ensure we always have an skb to requeue once we are done
* processing the current buffer's skb */
requeue_skb = ath_rxbuf_alloc(common, sc->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)
goto requeue;
/* Unmap the frame */
dma_unmap_single(sc->dev, bf->bf_buf_addr,
sc->rx.bufsize,
DMA_FROM_DEVICE);
skb_put(skb, ds->ds_rxstat.rs_datalen);
/* see if any padding is done by the hw and remove it */
hdr = (struct ieee80211_hdr *)skb->data;
hdrlen = ieee80211_get_hdrlen_from_skb(skb);
fc = hdr->frame_control;
/* The MAC header is padded to have 32-bit boundary if the
* packet payload is non-zero. The general calculation for
* padsize would take into account odd header lengths:
* padsize = (4 - hdrlen % 4) % 4; However, since only
* even-length headers are used, padding can only be 0 or 2
* bytes and we can optimize this a bit. In addition, we must
* not try to remove padding from short control frames that do
* not have payload. */
padsize = hdrlen & 3;
if (padsize && hdrlen >= 24) {
memmove(skb->data + padsize, skb->data, hdrlen);
skb_pull(skb, padsize);
}
keyix = ds->ds_rxstat.rs_keyix;
if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
rx_status.flag |= RX_FLAG_DECRYPTED;
} else if (ieee80211_has_protected(fc)
&& !decrypt_error && skb->len >= hdrlen + 4) {
keyix = skb->data[hdrlen + 3] >> 6;
if (test_bit(keyix, sc->keymap))
rx_status.flag |= RX_FLAG_DECRYPTED;
}
if (ah->sw_mgmt_crypto &&
(rx_status.flag & RX_FLAG_DECRYPTED) &&
ieee80211_is_mgmt(fc)) {
/* Use software decrypt for management frames. */
rx_status.flag &= ~RX_FLAG_DECRYPTED;
}
/* We will now give hardware our shiny new allocated skb */
bf->bf_mpdu = requeue_skb;
bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
sc->rx.bufsize,
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(sc->dev,
bf->bf_buf_addr))) {
dev_kfree_skb_any(requeue_skb);
bf->bf_mpdu = NULL;
ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error() on RX\n");
ath_rx_send_to_mac80211(sc, skb, &rx_status);
break;
}
bf->bf_dmacontext = bf->bf_buf_addr;
/*
* change the default rx antenna if rx diversity chooses the
* other antenna 3 times in a row.
*/
if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
if (++sc->rx.rxotherant >= 3)
ath_setdefantenna(sc, ds->ds_rxstat.rs_antenna);
} else {
sc->rx.rxotherant = 0;
}
if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
SC_OP_WAIT_FOR_CAB |
SC_OP_WAIT_FOR_PSPOLL_DATA)))
ath_rx_ps(sc, skb);
ath_rx_send_to_mac80211(sc, skb, &rx_status);
requeue:
list_move_tail(&bf->list, &sc->rx.rxbuf);
ath_rx_buf_link(sc, bf);
} while (1);
spin_unlock_bh(&sc->rx.rxbuflock);
return 0;
#undef PA2DESC
}
