/*
* 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.
*/
#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.
*/
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;
/* 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;
}
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.
*/
/* Note: the kernel can allocate a value greater than
* what we ask it to give us. We really only need 4 KB as that
* is this hardware supports and in fact we need at least 3849
* as that is the MAX AMSDU size this hardware supports.
* Unfortunately this means we may get 8 KB here from the
* kernel... and that is actually what is observed on some
* systems :( */
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,
"skbuff alloc of size %u failed\n", len);
return NULL;
}
return skb;
}
/*
* 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;
hdr = (struct ieee80211_hdr *)skb->data;
fc = hdr->frame_control;
memset(rx_status, 0, sizeof(struct ieee80211_rx_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. Enable this if you want to see
* error frames in Monitor mode.
*/
if (sc->sc_ah->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->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;
struct ieee80211_hw *hw = sc->hw;
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;
}
}
}
rx_status->mactime = ath_extend_tsf(sc, ds->ds_rxstat.rs_tstamp);
rx_status->band = sc->hw->conf.channel->band;
rx_status->freq = sc->hw->conf.channel->center_freq;
rx_status->noise = sc->sc_ani.sc_noise_floor;
rx_status->signal = rx_status->noise + ds->ds_rxstat.rs_rssi;
rx_status->antenna = ds->ds_rxstat.rs_antenna;
/* at 45 you will be able to use MCS 15 reliably. A more elaborate
* scheme can be used here but it requires tables of SNR/throughput for
* each possible mode used. */
rx_status->qual = ds->ds_rxstat.rs_rssi * 100 / 45;
/* 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_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]);
}
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->rx.rxflushlock);
sc->sc_flags &= ~SC_OP_RXFLUSH;
spin_lock_init(&sc->rx.rxbuflock);
sc->rx.bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
min(sc->sc_cachelsz,
(u16)64));
DPRINTF(sc, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
sc->sc_cachelsz, sc->rx.bufsize);
/* Initialize rx descriptors */
error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
"rx", nbufs, 1);
if (error != 0) {
DPRINTF(sc, ATH_DBG_FATAL,
"failed to allocate rx descriptors: %d\n", error);
break;
}
list_for_each_entry(bf, &sc->rx.rxbuf, list) {
skb = ath_rxbuf_alloc(sc, sc->rx.bufsize);
if (skb == NULL) {
error = -ENOMEM;
break;
}
bf->bf_mpdu = skb;
bf->bf_buf_addr = pci_map_single(sc->pdev, skb->data,
sc->rx.bufsize,
PCI_DMA_FROMDEVICE);
if (unlikely(pci_dma_mapping_error(sc->pdev,
bf->bf_buf_addr))) {
dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL;
DPRINTF(sc, ATH_DBG_CONFIG,
"pci_dma_mapping_error() on RX init\n");
error = -ENOMEM;
break;
}
bf->bf_dmacontext = bf->bf_buf_addr;
}
sc->rx.rxlink = NULL;
} while (0);
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)
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->ah_opmode != NL80211_IFTYPE_STATION)
rfilt |= ATH9K_RX_FILTER_PROBEREQ;
/* Can't set HOSTAP into promiscous mode */
if (((sc->sc_ah->ah_opmode != NL80211_IFTYPE_AP) &&
(sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
(sc->sc_ah->ah_opmode == NL80211_IFTYPE_MONITOR)) {
rfilt |= ATH9K_RX_FILTER_PROM;
/* ??? To prevent from sending ACK */
rfilt &= ~ATH9K_RX_FILTER_UCAST;
}
if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_STATION ||
sc->sc_ah->ah_opmode == NL80211_IFTYPE_ADHOC)
rfilt |= ATH9K_RX_FILTER_BEACON;
/* If in HOSTAP mode, want to enable reception of PSPOLL frames
& beacon frames */
if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_AP)
rfilt |= (ATH9K_RX_FILTER_BEACON | ATH9K_RX_FILTER_PSPOLL);
return rfilt;
#undef RX_FILTER_PRESERVE
}
int ath_startrecv(struct ath_softc *sc)
{
struct ath_hal *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_hal *ah = sc->sc_ah;
bool stopped;
ath9k_hw_stoppcurecv(ah);
ath9k_hw_setrxfilter(ah, 0);
stopped = ath9k_hw_stopdmarecv(ah);
mdelay(3); /* 3ms is long enough for 1 frame */
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);
}
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_hal *ah = sc->sc_ah;
struct ieee80211_hdr *hdr;
int hdrlen, padsize, retval;
bool decrypt_error = false;
u8 keyix;
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
*/
pci_dma_sync_single_for_cpu(sc->pdev, bf->bf_buf_addr,
sc->rx.bufsize,
PCI_DMA_FROMDEVICE);
/*
* 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(sc, sc->rx.bufsize);
/* 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 */
pci_unmap_single(sc->pdev, bf->bf_buf_addr,
sc->rx.bufsize,
PCI_DMA_FROMDEVICE);
skb_put(skb, ds->ds_rxstat.rs_datalen);
skb->protocol = cpu_to_be16(ETH_P_CONTROL);
/* 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);
/* 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 ((le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_PROTECTED)
&& !decrypt_error && skb->len >= hdrlen + 4) {
keyix = skb->data[hdrlen + 3] >> 6;
if (test_bit(keyix, sc->sc_keymap))
rx_status.flag |= RX_FLAG_DECRYPTED;
}
/* Send the frame to mac80211 */
__ieee80211_rx(sc->hw, skb, &rx_status);
/* We will now give hardware our shiny new allocated skb */
bf->bf_mpdu = requeue_skb;
bf->bf_buf_addr = pci_map_single(sc->pdev, requeue_skb->data,
sc->rx.bufsize,
PCI_DMA_FROMDEVICE);
if (unlikely(pci_dma_mapping_error(sc->pdev,
bf->bf_buf_addr))) {
dev_kfree_skb_any(requeue_skb);
bf->bf_mpdu = NULL;
DPRINTF(sc, ATH_DBG_CONFIG,
"pci_dma_mapping_error() on RX\n");
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;
}
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
}
