/*
* Copyright (c) 2008 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.
*/
/*
* Implementation of receive path.
*/
#include "core.h"
/*
* 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.
*
* NOTE: Caller should hold the rxbuf lock.
*/
static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
{
struct ath_hal *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;
/* XXX For RADAR?
* virtual addr of the beginning of the buffer. */
skb = bf->bf_mpdu;
ASSERT(skb != NULL);
ds->ds_vdata = skb->data;
/* setup rx descriptors */
ath9k_hw_setuprxdesc(ah,
ds,
skb_tailroom(skb), /* buffer size */
0);
if (sc->sc_rxlink == NULL)
ath9k_hw_putrxbuf(ah, bf->bf_daddr);
else
*sc->sc_rxlink = bf->bf_daddr;
sc->sc_rxlink = &ds->ds_link;
ath9k_hw_rxena(ah);
}
/* Process received BAR frame */
static int ath_bar_rx(struct ath_softc *sc,
struct ath_node *an,
struct sk_buff *skb)
{
struct ieee80211_bar *bar;
struct ath_arx_tid *rxtid;
struct sk_buff *tskb;
struct ath_recv_status *rx_status;
int tidno, index, cindex;
u16 seqno;
/* look at BAR contents */
bar = (struct ieee80211_bar *)skb->data;
tidno = (le16_to_cpu(bar->control) & IEEE80211_BAR_CTL_TID_M)
>> IEEE80211_BAR_CTL_TID_S;
seqno = le16_to_cpu(bar->start_seq_num) >> IEEE80211_SEQ_SEQ_SHIFT;
/* process BAR - indicate all pending RX frames till the BAR seqno */
rxtid = &an->an_aggr.rx.tid[tidno];
spin_lock_bh(&rxtid->tidlock);
/* get relative index */
index = ATH_BA_INDEX(rxtid->seq_next, seqno);
/* drop BAR if old sequence (index is too large) */
if ((index > rxtid->baw_size) &&
(index > (IEEE80211_SEQ_MAX - (rxtid->baw_size << 2))))
/* discard frame, ieee layer may not treat frame as a dup */
goto unlock_and_free;
/* complete receive processing for all pending frames upto BAR seqno */
cindex = (rxtid->baw_head + index) & (ATH_TID_MAX_BUFS - 1);
while ((rxtid->baw_head != rxtid->baw_tail) &&
(rxtid->baw_head != cindex)) {
tskb = rxtid->rxbuf[rxtid->baw_head].rx_wbuf;
rx_status = &rxtid->rxbuf[rxtid->baw_head].rx_status;
rxtid->rxbuf[rxtid->baw_head].rx_wbuf = NULL;
if (tskb != NULL)
ath_rx_subframe(an, tskb, rx_status);
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
}
/* ... and indicate rest of the frames in-order */
while (rxtid->baw_head != rxtid->baw_tail &&
rxtid->rxbuf[rxtid->baw_head].rx_wbuf != NULL) {
tskb = rxtid->rxbuf[rxtid->baw_head].rx_wbuf;
rx_status = &rxtid->rxbuf[rxtid->baw_head].rx_status;
rxtid->rxbuf[rxtid->baw_head].rx_wbuf = NULL;
ath_rx_subframe(an, tskb, rx_status);
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
}
unlock_and_free:
spin_unlock_bh(&rxtid->tidlock);
/* free bar itself */
dev_kfree_skb(skb);
return IEEE80211_FTYPE_CTL;
}
/* Function to handle a subframe of aggregation when HT is enabled */
static int ath_ampdu_input(struct ath_softc *sc,
struct ath_node *an,
struct sk_buff *skb,
struct ath_recv_status *rx_status)
{
struct ieee80211_hdr *hdr;
struct ath_arx_tid *rxtid;
struct ath_rxbuf *rxbuf;
u8 type, subtype;
u16 rxseq;
int tid = 0, index, cindex, rxdiff;
__le16 fc;
u8 *qc;
hdr = (struct ieee80211_hdr *)skb->data;
fc = hdr->frame_control;
/* collect stats of frames with non-zero version */
if ((le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_VERS) != 0) {
dev_kfree_skb(skb);
return -1;
}
type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;
subtype = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_STYPE;
if (ieee80211_is_back_req(fc))
return ath_bar_rx(sc, an, skb);
/* special aggregate processing only for qos unicast data frames */
if (!ieee80211_is_data(fc) ||
!ieee80211_is_data_qos(fc) ||
is_multicast_ether_addr(hdr->addr1))
return ath_rx_subframe(an, skb, rx_status);
/* lookup rx tid state */
if (ieee80211_is_data_qos(fc)) {
qc = ieee80211_get_qos_ctl(hdr);
tid = qc[0] & 0xf;
}
if (sc->sc_opmode == ATH9K_M_STA) {
/* Drop the frame not belonging to me. */
if (memcmp(hdr->addr1, sc->sc_myaddr, ETH_ALEN)) {
dev_kfree_skb(skb);
return -1;
}
}
rxtid = &an->an_aggr.rx.tid[tid];
spin_lock(&rxtid->tidlock);
rxdiff = (rxtid->baw_tail - rxtid->baw_head) &
(ATH_TID_MAX_BUFS - 1);
/*
* If the ADDBA exchange has not been completed by the source,
* process via legacy path (i.e. no reordering buffer is needed)
*/
if (!rxtid->addba_exchangecomplete) {
spin_unlock(&rxtid->tidlock);
return ath_rx_subframe(an, skb, rx_status);
}
/* extract sequence number from recvd frame */
rxseq = le16_to_cpu(hdr->seq_ctrl) >> IEEE80211_SEQ_SEQ_SHIFT;
if (rxtid->seq_reset) {
rxtid->seq_reset = 0;
rxtid->seq_next = rxseq;
}
index = ATH_BA_INDEX(rxtid->seq_next, rxseq);
/* drop frame if old sequence (index is too large) */
if (index > (IEEE80211_SEQ_MAX - (rxtid->baw_size << 2))) {
/* discard frame, ieee layer may not treat frame as a dup */
spin_unlock(&rxtid->tidlock);
dev_kfree_skb(skb);
return IEEE80211_FTYPE_DATA;
}
/* sequence number is beyond block-ack window */
if (index >= rxtid->baw_size) {
/* complete receive processing for all pending frames */
while (index >= rxtid->baw_size) {
rxbuf = rxtid->rxbuf + rxtid->baw_head;
if (rxbuf->rx_wbuf != NULL) {
ath_rx_subframe(an, rxbuf->rx_wbuf,
&rxbuf->rx_status);
rxbuf->rx_wbuf = NULL;
}
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
index--;
}
}
/* add buffer to the recv ba window */
cindex = (rxtid->baw_head + index) & (ATH_TID_MAX_BUFS - 1);
rxbuf = rxtid->rxbuf + cindex;
if (rxbuf->rx_wbuf != NULL) {
spin_unlock(&rxtid->tidlock);
/* duplicate frame */
dev_kfree_skb(skb);
return IEEE80211_FTYPE_DATA;
}
rxbuf->rx_wbuf = skb;
rxbuf->rx_time = get_timestamp();
rxbuf->rx_status = *rx_status;
/* advance tail if sequence received is newer
* than any received so far */
if (index >= rxdiff) {
rxtid->baw_tail = cindex;
INCR(rxtid->baw_tail, ATH_TID_MAX_BUFS);
}
/* indicate all in-order received frames */
while (rxtid->baw_head != rxtid->baw_tail) {
rxbuf = rxtid->rxbuf + rxtid->baw_head;
if (!rxbuf->rx_wbuf)
break;
ath_rx_subframe(an, rxbuf->rx_wbuf, &rxbuf->rx_status);
rxbuf->rx_wbuf = NULL;
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
}
/*
* start a timer to flush all received frames if there are pending
* receive frames
*/
if (rxtid->baw_head != rxtid->baw_tail)
mod_timer(&rxtid->timer, ATH_RX_TIMEOUT);
else
del_timer_sync(&rxtid->timer);
spin_unlock(&rxtid->tidlock);
return IEEE80211_FTYPE_DATA;
}
/* Timer to flush all received sub-frames */
static void ath_rx_timer(unsigned long data)
{
struct ath_arx_tid *rxtid = (struct ath_arx_tid *)data;
struct ath_node *an = rxtid->an;
struct ath_rxbuf *rxbuf;
int nosched;
spin_lock_bh(&rxtid->tidlock);
while (rxtid->baw_head != rxtid->baw_tail) {
rxbuf = rxtid->rxbuf + rxtid->baw_head;
if (!rxbuf->rx_wbuf) {
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
continue;
}
/*
* Stop if the next one is a very recent frame.
*
* Call get_timestamp in every iteration to protect against the
* case in which a new frame is received while we are executing
* this function. Using a timestamp obtained before entering
* the loop could lead to a very large time interval
* (a negative value typecast to unsigned), breaking the
* function's logic.
*/
if ((get_timestamp() - rxbuf->rx_time) <
(ATH_RX_TIMEOUT * HZ / 1000))
break;
ath_rx_subframe(an, rxbuf->rx_wbuf,
&rxbuf->rx_status);
rxbuf->rx_wbuf = NULL;
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
}
/*
* start a timer to flush all received frames if there are pending
* receive frames
*/
if (rxtid->baw_head != rxtid->baw_tail)
nosched = 0;
else
nosched = 1; /* no need to re-arm the timer again */
spin_unlock_bh(&rxtid->tidlock);
}
/* Free all pending sub-frames in the re-ordering buffer */
static void ath_rx_flush_tid(struct ath_softc *sc,
struct ath_arx_tid *rxtid, int drop)
{
struct ath_rxbuf *rxbuf;
spin_lock_bh(&rxtid->tidlock);
while (rxtid->baw_head != rxtid->baw_tail) {
rxbuf = rxtid->rxbuf + rxtid->baw_head;
if (!rxbuf->rx_wbuf) {
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
continue;
}
if (drop)
dev_kfree_skb(rxbuf->rx_wbuf);
else
ath_rx_subframe(rxtid->an,
rxbuf->rx_wbuf,
&rxbuf->rx_status);
rxbuf->rx_wbuf = NULL;
INCR(rxtid->baw_head, ATH_TID_MAX_BUFS);
INCR(rxtid->seq_next, IEEE80211_SEQ_MAX);
}
spin_unlock_bh(&rxtid->tidlock);
}
static struct sk_buff *ath_rxbuf_alloc(struct ath_softc *sc,
u32 len)
{
struct sk_buff *skb;
u32 off;
/*
* Cache-line-align. This is important (for the
* 5210 at least) as not doing so causes bogus data
* in rx'd frames.
*/
skb = dev_alloc_skb(len + sc->sc_cachelsz - 1);
if (skb != NULL) {
off = ((unsigned long) skb->data) % sc->sc_cachelsz;
if (off != 0)
skb_reserve(skb, sc->sc_cachelsz - off);
} else {
DPRINTF(sc, ATH_DBG_FATAL,
"%s: skbuff alloc of size %u failed\n",
__func__, len);
return NULL;
}
return skb;
}
static void ath_rx_requeue(struct ath_softc *sc, struct sk_buff *skb)
{
struct ath_buf *bf = ATH_RX_CONTEXT(skb)->ctx_rxbuf;
ASSERT(bf != NULL);
spin_lock_bh(&sc->sc_rxbuflock);
if (bf->bf_status & ATH_BUFSTATUS_STALE) {
/*
* This buffer is still held for hw acess.
* Mark it as free to be re-queued it later.
*/
bf->bf_status |= ATH_BUFSTATUS_FREE;
} else {
/* XXX: we probably never enter here, remove after
* verification */
list_add_tail(&bf->list, &sc->sc_rxbuf);
ath_rx_buf_link(sc, bf);
}
spin_unlock_bh(&sc->sc_rxbuflock);
}
/*
* The skb indicated to upper stack won't be returned to us.
* So we have to allocate a new one and queue it by ourselves.
*/
static int ath_rx_indicate(struct ath_softc *sc,
struct sk_buff *skb,
struct ath_recv_status *status,
u16 keyix)
{
struct ath_buf *bf = ATH_RX_CONTEXT(skb)->ctx_rxbuf;
struct sk_buff *nskb;
int type;
/* indicate frame to the stack, which will free the old skb. */
type = ath__rx_indicate(sc, skb, status, keyix);
/* allocate a new skb and queue it to for H/W processing */
nskb = ath_rxbuf_alloc(sc, sc->sc_rxbufsize);
if (nskb != NULL) {
bf->bf_mpdu = nskb;
bf->bf_buf_addr = ath_skb_map_single(sc,
nskb,
PCI_DMA_FROMDEVICE,
/* XXX: Remove get_dma_mem_context() */
get_dma_mem_context(bf, bf_dmacontext));
ATH_RX_CONTEXT(nskb)->ctx_rxbuf = bf;
/* queue the new wbuf to H/W */
ath_rx_requeue(sc, nskb);
}
return type;
}
static void ath_opmode_init(struct ath_softc *sc)
{
struct ath_hal *ah = sc->sc_ah;
u32 rfilt, mfilt[2];
/* configure rx filter */
rfilt = ath_calcrxfilter(sc);
ath9k_hw_setrxfilter(ah, rfilt);
/* configure bssid mask */
if (ah->ah_caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
ath9k_hw_setbssidmask(ah, sc->sc_bssidmask);
/* configure operational mode */
ath9k_hw_setopmode(ah);
/* Handle any link-level address change. */
ath9k_hw_setmac(ah, sc->sc_myaddr);
/* calculate and install multicast filter */
mfilt[0] = mfilt[1] = ~0;
ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
DPRINTF(sc, ATH_DBG_CONFIG ,
"%s: RX filter 0x%x, MC filter %08x:%08x\n",
__func__, rfilt, mfilt[0], mfilt[1]);
}
int ath_rx_init(struct ath_softc *sc, int nbufs)
{
struct sk_buff *skb;
struct ath_buf *bf;
int error = 0;
do {
spin_lock_init(&sc->sc_rxflushlock);
sc->sc_rxflush = 0;
spin_lock_init(&sc->sc_rxbuflock);
/*
* Cisco's VPN software requires that drivers be able to
* receive encapsulated frames that are larger than the MTU.
* Since we can't be sure how large a frame we'll get, setup
* to handle the larges on possible.
*/
sc->sc_rxbufsize = roundup(IEEE80211_MAX_MPDU_LEN,
min(sc->sc_cachelsz,
(u16)64));
DPRINTF(sc, ATH_DBG_CONFIG, "%s: cachelsz %u rxbufsize %u\n",
__func__, sc->sc_cachelsz, sc->sc_rxbufsize);
/* Initialize rx descriptors */
error = ath_descdma_setup(sc, &sc->sc_rxdma, &sc->sc_rxbuf,
"rx", nbufs, 1);
if (error != 0) {
DPRINTF(sc, ATH_DBG_FATAL,
"%s: failed to allocate rx descriptors: %d\n",
__func__, error);
break;
}
/* Pre-allocate a wbuf for each rx buffer */
list_for_each_entry(bf, &sc->sc_rxbuf, list) {
skb = ath_rxbuf_alloc(sc, sc->sc_rxbufsize);
if (skb == NULL) {
error = -ENOMEM;
break;
}
bf->bf_mpdu = skb;
bf->bf_buf_addr =
ath_skb_map_single(sc, skb, PCI_DMA_FROMDEVICE,
get_dma_mem_context(bf, bf_dmacontext));
ATH_RX_CONTEXT(skb)->ctx_rxbuf = bf;
}
sc->sc_rxlink = NULL;
} while (0);
if (error)
ath_rx_cleanup(sc);
return error;
}
/* Reclaim all rx queue resources */
void ath_rx_cleanup(struct ath_softc *sc)
{
struct sk_buff *skb;
struct ath_buf *bf;
list_for_each_entry(bf, &sc->sc_rxbuf, list) {
skb = bf->bf_mpdu;
if (skb)
dev_kfree_skb(skb);
}
/* cleanup rx descriptors */
if (sc->sc_rxdma.dd_desc_len != 0)
ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_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_opmode != ATH9K_M_STA)
rfilt |= ATH9K_RX_FILTER_PROBEREQ;
/* Can't set HOSTAP into promiscous mode */
if (sc->sc_opmode == ATH9K_M_MONITOR) {
rfilt |= ATH9K_RX_FILTER_PROM;
/* ??? To prevent from sending ACK */
rfilt &= ~ATH9K_RX_FILTER_UCAST;
}
if (sc->sc_opmode == ATH9K_M_STA || sc->sc_opmode == ATH9K_M_IBSS ||
sc->sc_scanning)
rfilt |= ATH9K_RX_FILTER_BEACON;
/* If in HOSTAP mode, want to enable reception of PSPOLL frames
& beacon frames */
if (sc->sc_opmode == ATH9K_M_HOSTAP)
rfilt |= (ATH9K_RX_FILTER_BEACON | ATH9K_RX_FILTER_PSPOLL);
return rfilt;
#undef RX_FILTER_PRESERVE
}
/* Enable the receive h/w following a reset. */
int ath_startrecv(struct ath_softc *sc)
{
struct ath_hal *ah = sc->sc_ah;
struct ath_buf *bf, *tbf;
spin_lock_bh(&sc->sc_rxbuflock);
if (list_empty(&sc->sc_rxbuf))
goto start_recv;
sc->sc_rxlink = NULL;
list_for_each_entry_safe(bf, tbf, &sc->sc_rxbuf, list) {
if (bf->bf_status & ATH_BUFSTATUS_STALE) {
/* restarting h/w, no need for holding descriptors */
bf->bf_status &= ~ATH_BUFSTATUS_STALE;
/*
* Upper layer may not be done with the frame yet so
* we can't just re-queue it to hardware. Remove it
* from h/w queue. It'll be re-queued when upper layer
* returns the frame and ath_rx_requeue_mpdu is called.
*/
if (!(bf->bf_status & ATH_BUFSTATUS_FREE)) {
list_del(&bf->list);
continue;
}
}
/* chain descriptors */
ath_rx_buf_link(sc, bf);
}
/* We could have deleted elements so the list may be empty now */
if (list_empty(&sc->sc_rxbuf))
goto start_recv;
bf = list_first_entry(&sc->sc_rxbuf, struct ath_buf, list);
ath9k_hw_putrxbuf(ah, bf->bf_daddr);
ath9k_hw_rxena(ah); /* enable recv descriptors */
start_recv:
spin_unlock_bh(&sc->sc_rxbuflock);
ath_opmode_init(sc); /* set filters, etc. */
ath9k_hw_startpcureceive(ah); /* re-enable PCU/DMA engine */
return 0;
}
/* Disable the receive h/w in preparation for a reset. */
bool ath_stoprecv(struct ath_softc *sc)
{
struct ath_hal *ah = sc->sc_ah;
u64 tsf;
bool stopped;
ath9k_hw_stoppcurecv(ah); /* disable PCU */
ath9k_hw_setrxfilter(ah, 0); /* clear recv filter */
stopped = ath9k_hw_stopdmarecv(ah); /* disable DMA engine */
mdelay(3); /* 3ms is long enough for 1 frame */
tsf = ath9k_hw_gettsf64(ah);
sc->sc_rxlink = NULL; /* just in case */
return stopped;
}
/* Flush receive queue */
void ath_flushrecv(struct ath_softc *sc)
{
/*
* ath_rx_tasklet may be used to handle rx interrupt and flush receive
* queue at the same time. Use a lock to serialize the access of rx
* queue.
* ath_rx_tasklet cannot hold the spinlock while indicating packets.
* Instead, do not claim the spinlock but check for a flush in
* progress (see references to sc_rxflush)
*/
spin_lock_bh(&sc->sc_rxflushlock);
sc->sc_rxflush = 1;
ath_rx_tasklet(sc, 1);
sc->sc_rxflush = 0;
spin_unlock_bh(&sc->sc_rxflushlock);
}
/* Process an individual frame */
int ath_rx_input(struct ath_softc *sc,
struct ath_node *an,
int is_ampdu,
struct sk_buff *skb,
struct ath_recv_status *rx_status,
enum ATH_RX_TYPE *status)
{
if (is_ampdu && sc->sc_rxaggr) {
*status = ATH_RX_CONSUMED;
return ath_ampdu_input(sc, an, skb, rx_status);
} else {
*status = ATH_RX_NON_CONSUMED;
return -1;
}
}
/* Process receive queue, as well as LED, etc. */
int ath_rx_tasklet(struct ath_softc *sc, int flush)
{
#define PA2DESC(_sc, _pa) \
((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
struct ath_buf *bf, *bf_held = NULL;
struct ath_desc *ds;
struct ieee80211_hdr *hdr;
struct sk_buff *skb = NULL;
struct ath_recv_status rx_status;
struct ath_hal *ah = sc->sc_ah;
int type, rx_processed = 0;
u32 phyerr;
u8 chainreset = 0;
int retval;
__le16 fc;
do {
/* If handling rx interrupt and flush is in progress => exit */
if (sc->sc_rxflush && (flush == 0))
break;
spin_lock_bh(&sc->sc_rxbuflock);
if (list_empty(&sc->sc_rxbuf)) {
sc->sc_rxlink = NULL;
spin_unlock_bh(&sc->sc_rxbuflock);
break;
}
bf = list_first_entry(&sc->sc_rxbuf, struct ath_buf, list);
/*
* There is a race condition that BH gets scheduled after sw
* writes RxE and before hw re-load the last descriptor to get
* the newly chained one. Software must keep the last DONE
* descriptor as a holding descriptor - software does so by
* marking it with the STALE flag.
*/
if (bf->bf_status & ATH_BUFSTATUS_STALE) {
bf_held = bf;
if (list_is_last(&bf_held->list, &sc->sc_rxbuf)) {
/*
* The holding descriptor is the last
* descriptor in queue. It's safe to
* remove the last holding descriptor
* in BH context.
*/
list_del(&bf_held->list);
bf_held->bf_status &= ~ATH_BUFSTATUS_STALE;
sc->sc_rxlink = NULL;
if (bf_held->bf_status & ATH_BUFSTATUS_FREE) {
list_add_tail(&bf_held->list,
&sc->sc_rxbuf);
ath_rx_buf_link(sc, bf_held);
}
spin_unlock_bh(&sc->sc_rxbuflock);
break;
}
bf = list_entry(bf->list.next, struct ath_buf, list);
}
ds = bf->bf_desc;
++rx_processed;
/*
* 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->sc_rxbuf)) {
spin_unlock_bh(&sc->sc_rxbuflock);
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) {
spin_unlock_bh(&sc->sc_rxbuflock);
break;
}
}
/* XXX: we do not support frames spanning
* multiple descriptors */
bf->bf_status |= ATH_BUFSTATUS_DONE;
skb = bf->bf_mpdu;
if (skb == NULL) { /* XXX ??? can this happen */
spin_unlock_bh(&sc->sc_rxbuflock);
continue;
}
/*
* Now we know it's a completed frame, we can indicate the
* frame. Remove the previous holding descriptor and leave
* this one in the queue as the new holding descriptor.
*/
if (bf_held) {
list_del(&bf_held->list);
bf_held->bf_status &= ~ATH_BUFSTATUS_STALE;
if (bf_held->bf_status & ATH_BUFSTATUS_FREE) {
list_add_tail(&bf_held->list, &sc->sc_rxbuf);
/* try to requeue this descriptor */
ath_rx_buf_link(sc, bf_held);
}
}
bf->bf_status |= ATH_BUFSTATUS_STALE;
bf_held = bf;
/*
* Release the lock here in case ieee80211_input() return
* the frame immediately by calling ath_rx_mpdu_requeue().
*/
spin_unlock_bh(&sc->sc_rxbuflock);
if (flush) {
/*
* If we're asked to flush receive queue, directly
* chain it back at the queue without processing it.
*/
goto rx_next;
}
hdr = (struct ieee80211_hdr *)skb->data;
fc = hdr->frame_control;
memzero(&rx_status, sizeof(struct ath_recv_status));
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.
*/
#ifndef ERROR_FRAMES
/*
* Enable this if you want to see
* error frames in Monitor mode.
*/
if (sc->sc_opmode != ATH9K_M_MONITOR)
goto rx_next;
#endif
/* fall thru for monitor mode handling... */
} else if (ds->ds_rxstat.rs_status != 0) {
if (ds->ds_rxstat.rs_status & ATH9K_RXERR_CRC)
rx_status.flags |= ATH_RX_FCS_ERROR;
if (ds->ds_rxstat.rs_status & ATH9K_RXERR_PHY) {
phyerr = ds->ds_rxstat.rs_phyerr & 0x1f;
goto rx_next;
}
if (ds->ds_rxstat.rs_status & ATH9K_RXERR_DECRYPT) {
/*
* Decrypt error. 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.
*/
rx_status.flags |= ATH_RX_DECRYPT_ERROR;
} else if (ds->ds_rxstat.rs_status & ATH9K_RXERR_MIC) {
/*
* Demic error. We only mark frame status here
* and always push up the frame up to let
* mac80211 handle the actual error case. This
* let us keep statistics there. Hardware may
* post a false-positive MIC error.
*/
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.flags |= ATH_RX_MIC_ERROR;
}
/*
* Reject error frames with the exception of
* decryption and MIC failures. For monitor mode,
* we also ignore the CRC error.
*/
if (sc->sc_opmode == ATH9K_M_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;
}
}
}
/*
* The status portion of the descriptor could get corrupted.
*/
if (sc->sc_rxbufsize < ds->ds_rxstat.rs_datalen)
goto rx_next;
/*
* Sync and unmap the frame. At this point we're
* committed to passing the sk_buff somewhere so
* clear buf_skb; this means a new sk_buff must be
* allocated when the rx descriptor is setup again
* to receive another frame.
*/
skb_put(skb, ds->ds_rxstat.rs_datalen);
skb->protocol = cpu_to_be16(ETH_P_CONTROL);
rx_status.tsf = ath_extend_tsf(sc, ds->ds_rxstat.rs_tstamp);
rx_status.rateieee =
sc->sc_hwmap[ds->ds_rxstat.rs_rate].ieeerate;
rx_status.rateKbps =
sc->sc_hwmap[ds->ds_rxstat.rs_rate].rateKbps;
rx_status.ratecode = ds->ds_rxstat.rs_rate;
/* HT rate */
if (rx_status.ratecode & 0x80) {
/* TODO - add table to avoid division */
if (ds->ds_rxstat.rs_flags & ATH9K_RX_2040) {
rx_status.flags |= ATH_RX_40MHZ;
rx_status.rateKbps =
(rx_status.rateKbps * 27) / 13;
}
if (ds->ds_rxstat.rs_flags & ATH9K_RX_GI)
rx_status.rateKbps =
(rx_status.rateKbps * 10) / 9;
else
rx_status.flags |= ATH_RX_SHORT_GI;
}
/* sc->sc_noise_floor is only available when the station
attaches to an AP, so we use a default value
if we are not yet attached. */
/* XXX we should use either sc->sc_noise_floor or
* ath_hal_getChanNoise(ah, &sc->sc_curchan)
* to calculate the noise floor.
* However, the value returned by ath_hal_getChanNoise
* seems to be incorrect (-31dBm on the last test),
* so we will use a hard-coded value until we
* figure out what is going on.
*/
rx_status.abs_rssi =
ds->ds_rxstat.rs_rssi + ATH_DEFAULT_NOISE_FLOOR;
pci_dma_sync_single_for_cpu(sc->pdev,
bf->bf_buf_addr,
skb_tailroom(skb),
PCI_DMA_FROMDEVICE);
pci_unmap_single(sc->pdev,
bf->bf_buf_addr,
sc->sc_rxbufsize,
PCI_DMA_FROMDEVICE);
/* XXX: Ah! make me more readable, use a helper */
if (ah->ah_caps.hw_caps & ATH9K_HW_CAP_HT) {
if (ds->ds_rxstat.rs_moreaggr == 0) {
rx_status.rssictl[0] =
ds->ds_rxstat.rs_rssi_ctl0;
rx_status.rssictl[1] =
ds->ds_rxstat.rs_rssi_ctl1;
rx_status.rssictl[2] =
ds->ds_rxstat.rs_rssi_ctl2;
rx_status.rssi = ds->ds_rxstat.rs_rssi;
if (ds->ds_rxstat.rs_flags & ATH9K_RX_2040) {
rx_status.rssiextn[0] =
ds->ds_rxstat.rs_rssi_ext0;
rx_status.rssiextn[1] =
ds->ds_rxstat.rs_rssi_ext1;
rx_status.rssiextn[2] =
ds->ds_rxstat.rs_rssi_ext2;
rx_status.flags |=
ATH_RX_RSSI_EXTN_VALID;
}
rx_status.flags |= ATH_RX_RSSI_VALID |
ATH_RX_CHAIN_RSSI_VALID;
}
} else {
/*
* Need to insert the "combined" rssi into the
* status structure for upper layer processing
*/
rx_status.rssi = ds->ds_rxstat.rs_rssi;
rx_status.flags |= ATH_RX_RSSI_VALID;
}
/* Pass frames up to the stack. */
type = ath_rx_indicate(sc, skb,
&rx_status, ds->ds_rxstat.rs_keyix);
/*
* change the default rx antenna if rx diversity chooses the
* other antenna 3 times in a row.
*/
if (sc->sc_defant != ds->ds_rxstat.rs_antenna) {
if (++sc->sc_rxotherant >= 3)
ath_setdefantenna(sc,
ds->ds_rxstat.rs_antenna);
} else {
sc->sc_rxotherant = 0;
}
#ifdef CONFIG_SLOW_ANT_DIV
if ((rx_status.flags & ATH_RX_RSSI_VALID) &&
ieee80211_is_beacon(fc)) {
ath_slow_ant_div(&sc->sc_antdiv, hdr, &ds->ds_rxstat);
}
#endif
/*
* For frames successfully indicated, the buffer will be
* returned to us by upper layers by calling
* ath_rx_mpdu_requeue, either synchronusly or asynchronously.
* So we don't want to do it here in this loop.
*/
continue;
rx_next:
bf->bf_status |= ATH_BUFSTATUS_FREE;
} while (TRUE);
if (chainreset) {
DPRINTF(sc, ATH_DBG_CONFIG,
"%s: Reset rx chain mask. "
"Do internal reset\n", __func__);
ASSERT(flush == 0);
ath_internal_reset(sc);
}
return 0;
#undef PA2DESC
}
/* Process ADDBA request in per-TID data structure */
int ath_rx_aggr_start(struct ath_softc *sc,
const u8 *addr,
u16 tid,
u16 *ssn)
{
struct ath_arx_tid *rxtid;
struct ath_node *an;
struct ieee80211_hw *hw = sc->hw;
struct ieee80211_supported_band *sband;
u16 buffersize = 0;
spin_lock_bh(&sc->node_lock);
an = ath_node_find(sc, (u8 *) addr);
spin_unlock_bh(&sc->node_lock);
if (!an) {
DPRINTF(sc, ATH_DBG_AGGR,
"%s: Node not found to initialize RX aggregation\n",
__func__);
return -1;
}
sband = hw->wiphy->bands[hw->conf.channel->band];
buffersize = IEEE80211_MIN_AMPDU_BUF <<
sband->ht_info.ampdu_factor; /* FIXME */
rxtid = &an->an_aggr.rx.tid[tid];
spin_lock_bh(&rxtid->tidlock);
if (sc->sc_rxaggr) {
/* Allow aggregation reception
* Adjust rx BA window size. Peer might indicate a
* zero buffer size for a _dont_care_ condition.
*/
if (buffersize)
rxtid->baw_size = min(buffersize, rxtid->baw_size);
/* set rx sequence number */
rxtid->seq_next = *ssn;
/* Allocate the receive buffers for this TID */
DPRINTF(sc, ATH_DBG_AGGR,
"%s: Allcating rxbuffer for TID %d\n", __func__, tid);
if (rxtid->rxbuf == NULL) {
/*
* If the rxbuff is not NULL at this point, we *probably*
* already allocated the buffer on a previous ADDBA,
* and this is a subsequent ADDBA that got through.
* Don't allocate, but use the value in the pointer,
* we zero it out when we de-allocate.
*/
rxtid->rxbuf = kmalloc(ATH_TID_MAX_BUFS *
sizeof(struct ath_rxbuf), GFP_ATOMIC);
}
if (rxtid->rxbuf == NULL) {
DPRINTF(sc, ATH_DBG_AGGR,
"%s: Unable to allocate RX buffer, "
"refusing ADDBA\n", __func__);
} else {
/* Ensure the memory is zeroed out (all internal
* pointers are null) */
memzero(rxtid->rxbuf, ATH_TID_MAX_BUFS *
sizeof(struct ath_rxbuf));
DPRINTF(sc, ATH_DBG_AGGR,
"%s: Allocated @%p\n", __func__, rxtid->rxbuf);
/* Allow aggregation reception */
rxtid->addba_exchangecomplete = 1;
}
}
spin_unlock_bh(&rxtid->tidlock);
return 0;
}
/* Process DELBA */
int ath_rx_aggr_stop(struct ath_softc *sc,
const u8 *addr,
u16 tid)
{
struct ath_node *an;
spin_lock_bh(&sc->node_lock);
an = ath_node_find(sc, (u8 *) addr);
spin_unlock_bh(&sc->node_lock);
if (!an) {
DPRINTF(sc, ATH_DBG_AGGR,
"%s: RX aggr stop for non-existent node\n", __func__);
return -1;
}
ath_rx_aggr_teardown(sc, an, tid);
return 0;
}
/* Rx aggregation tear down */
void ath_rx_aggr_teardown(struct ath_softc *sc,
struct ath_node *an, u8 tid)
{
struct ath_arx_tid *rxtid = &an->an_aggr.rx.tid[tid];
if (!rxtid->addba_exchangecomplete)
return;
del_timer_sync(&rxtid->timer);
ath_rx_flush_tid(sc, rxtid, 0);
rxtid->addba_exchangecomplete = 0;
/* De-allocate the receive buffer array allocated when addba started */
if (rxtid->rxbuf) {
DPRINTF(sc, ATH_DBG_AGGR,
"%s: Deallocating TID %d rxbuff @%p\n",
__func__, tid, rxtid->rxbuf);
kfree(rxtid->rxbuf);
/* Set pointer to null to avoid reuse*/
rxtid->rxbuf = NULL;
}
}
/* Initialize per-node receive state */
void ath_rx_node_init(struct ath_softc *sc, struct ath_node *an)
{
if (sc->sc_rxaggr) {
struct ath_arx_tid *rxtid;
int tidno;
/* Init per tid rx state */
for (tidno = 0, rxtid = &an->an_aggr.rx.tid[tidno];
tidno < WME_NUM_TID;
tidno++, rxtid++) {
rxtid->an = an;
rxtid->seq_reset = 1;
rxtid->seq_next = 0;
rxtid->baw_size = WME_MAX_BA;
rxtid->baw_head = rxtid->baw_tail = 0;
/*
* Ensure the buffer pointer is null at this point
* (needs to be allocated when addba is received)
*/
rxtid->rxbuf = NULL;
setup_timer(&rxtid->timer, ath_rx_timer,
(unsigned long)rxtid);
spin_lock_init(&rxtid->tidlock);
/* ADDBA state */
rxtid->addba_exchangecomplete = 0;
}
}
}
void ath_rx_node_cleanup(struct ath_softc *sc, struct ath_node *an)
{
if (sc->sc_rxaggr) {
struct ath_arx_tid *rxtid;
int tidno, i;
/* Init per tid rx state */
for (tidno = 0, rxtid = &an->an_aggr.rx.tid[tidno];
tidno < WME_NUM_TID;
tidno++, rxtid++) {
if (!rxtid->addba_exchangecomplete)
continue;
/* must cancel timer first */
del_timer_sync(&rxtid->timer);
/* drop any pending sub-frames */
ath_rx_flush_tid(sc, rxtid, 1);
for (i = 0; i < ATH_TID_MAX_BUFS; i++)
ASSERT(rxtid->rxbuf[i].rx_wbuf == NULL);
rxtid->addba_exchangecomplete = 0;
}
}
}
/* Cleanup per-node receive state */
void ath_rx_node_free(struct ath_softc *sc, struct ath_node *an)
{
ath_rx_node_cleanup(sc, an);
}
dma_addr_t ath_skb_map_single(struct ath_softc *sc,
struct sk_buff *skb,
int direction,
dma_addr_t *pa)
{
/*
* NB: do NOT use skb->len, which is 0 on initialization.
* Use skb's entire data area instead.
*/
*pa = pci_map_single(sc->pdev, skb->data,
skb_end_pointer(skb) - skb->head, direction);
return *pa;
}
void ath_skb_unmap_single(struct ath_softc *sc,
struct sk_buff *skb,
int direction,
dma_addr_t *pa)
{
/* Unmap skb's entire data area */
pci_unmap_single(sc->pdev, *pa,
skb_end_pointer(skb) - skb->head, direction);
}
