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iwlagn: reclaim the packets in transport layer
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The reclaim flow is really transport related. Define a simple API to allow the
upper layer to request from the transport layer to reclaim packets until an
index written in the Tx response / BA notification.
The transport layer prepares a list of the packets that are being freed and
passes this list to the upper layer.
Between the two layers, the CB of the skb is used to pass a pointer to the
context (BSS / PAN) in which the skb was sent.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Emmanuel Grumbach authored and John W. Linville committed Aug 29, 2011
1 parent 1f7b617 commit a0eaad7
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Showing 8 changed files with 372 additions and 442 deletions.
271 changes: 3 additions & 268 deletions drivers/net/wireless/iwlwifi/iwl-agn-lib.c
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Original file line number Diff line number Diff line change
Expand Up @@ -42,12 +42,6 @@
#include "iwl-trans.h"
#include "iwl-shared.h"

static inline u32 iwlagn_get_scd_ssn(struct iwlagn_tx_resp *tx_resp)
{
return le32_to_cpup((__le32 *)&tx_resp->status +
tx_resp->frame_count) & MAX_SN;
}

static void iwlagn_count_tx_err_status(struct iwl_priv *priv, u16 status)
{
status &= TX_STATUS_MSK;
Expand Down Expand Up @@ -125,7 +119,7 @@ static void iwlagn_count_tx_err_status(struct iwl_priv *priv, u16 status)
}
}

static void iwlagn_count_agg_tx_err_status(struct iwl_priv *priv, u16 status)
void iwlagn_count_agg_tx_err_status(struct iwl_priv *priv, u16 status)
{
status &= AGG_TX_STATUS_MSK;

Expand Down Expand Up @@ -172,11 +166,10 @@ static void iwlagn_count_agg_tx_err_status(struct iwl_priv *priv, u16 status)
}
}

static void iwlagn_set_tx_status(struct iwl_priv *priv,
void iwlagn_set_tx_status(struct iwl_priv *priv,
struct ieee80211_tx_info *info,
struct iwl_rxon_context *ctx,
struct iwlagn_tx_resp *tx_resp,
int txq_id, bool is_agg)
bool is_agg)
{
u16 status = le16_to_cpu(tx_resp->status.status);

Expand All @@ -188,20 +181,6 @@ static void iwlagn_set_tx_status(struct iwl_priv *priv,
info);
if (!iwl_is_tx_success(status))
iwlagn_count_tx_err_status(priv, status);

if (status == TX_STATUS_FAIL_PASSIVE_NO_RX &&
iwl_is_associated_ctx(ctx) && ctx->vif &&
ctx->vif->type == NL80211_IFTYPE_STATION) {
ctx->last_tx_rejected = true;
iwl_stop_queue(priv, &priv->txq[txq_id]);
}

IWL_DEBUG_TX_REPLY(priv, "TXQ %d status %s (0x%08x) rate_n_flags "
"0x%x retries %d\n",
txq_id,
iwl_get_tx_fail_reason(status), status,
le32_to_cpu(tx_resp->rate_n_flags),
tx_resp->failure_frame);
}

#ifdef CONFIG_IWLWIFI_DEBUG
Expand Down Expand Up @@ -231,157 +210,6 @@ const char *iwl_get_agg_tx_fail_reason(u16 status)
}
#endif /* CONFIG_IWLWIFI_DEBUG */

static int iwlagn_tx_status_reply_tx(struct iwl_priv *priv,
struct iwl_ht_agg *agg,
struct iwlagn_tx_resp *tx_resp,
int txq_id, u16 start_idx)
{
u16 status;
struct agg_tx_status *frame_status = &tx_resp->status;
struct ieee80211_hdr *hdr = NULL;
int i, sh, idx;
u16 seq;

if (agg->wait_for_ba)
IWL_DEBUG_TX_REPLY(priv, "got tx response w/o block-ack\n");

agg->frame_count = tx_resp->frame_count;
agg->start_idx = start_idx;
agg->rate_n_flags = le32_to_cpu(tx_resp->rate_n_flags);
agg->bitmap = 0;

/* # frames attempted by Tx command */
if (agg->frame_count == 1) {
struct iwl_tx_info *txb;

/* Only one frame was attempted; no block-ack will arrive */
idx = start_idx;

IWL_DEBUG_TX_REPLY(priv, "FrameCnt = %d, StartIdx=%d idx=%d\n",
agg->frame_count, agg->start_idx, idx);
txb = &priv->txq[txq_id].txb[idx];
iwlagn_set_tx_status(priv, IEEE80211_SKB_CB(txb->skb),
txb->ctx, tx_resp, txq_id, true);
agg->wait_for_ba = 0;
} else {
/* Two or more frames were attempted; expect block-ack */
u64 bitmap = 0;

/*
* Start is the lowest frame sent. It may not be the first
* frame in the batch; we figure this out dynamically during
* the following loop.
*/
int start = agg->start_idx;

/* Construct bit-map of pending frames within Tx window */
for (i = 0; i < agg->frame_count; i++) {
u16 sc;
status = le16_to_cpu(frame_status[i].status);
seq = le16_to_cpu(frame_status[i].sequence);
idx = SEQ_TO_INDEX(seq);
txq_id = SEQ_TO_QUEUE(seq);

if (status & AGG_TX_STATUS_MSK)
iwlagn_count_agg_tx_err_status(priv, status);

if (status & (AGG_TX_STATE_FEW_BYTES_MSK |
AGG_TX_STATE_ABORT_MSK))
continue;

IWL_DEBUG_TX_REPLY(priv, "FrameCnt = %d, txq_id=%d idx=%d\n",
agg->frame_count, txq_id, idx);
IWL_DEBUG_TX_REPLY(priv, "status %s (0x%08x), "
"try-count (0x%08x)\n",
iwl_get_agg_tx_fail_reason(status),
status & AGG_TX_STATUS_MSK,
status & AGG_TX_TRY_MSK);

hdr = iwl_tx_queue_get_hdr(priv, txq_id, idx);
if (!hdr) {
IWL_ERR(priv,
"BUG_ON idx doesn't point to valid skb"
" idx=%d, txq_id=%d\n", idx, txq_id);
return -1;
}

sc = le16_to_cpu(hdr->seq_ctrl);
if (idx != (SEQ_TO_SN(sc) & 0xff)) {
IWL_ERR(priv,
"BUG_ON idx doesn't match seq control"
" idx=%d, seq_idx=%d, seq=%d\n",
idx, SEQ_TO_SN(sc),
hdr->seq_ctrl);
return -1;
}

IWL_DEBUG_TX_REPLY(priv, "AGG Frame i=%d idx %d seq=%d\n",
i, idx, SEQ_TO_SN(sc));

/*
* sh -> how many frames ahead of the starting frame is
* the current one?
*
* Note that all frames sent in the batch must be in a
* 64-frame window, so this number should be in [0,63].
* If outside of this window, then we've found a new
* "first" frame in the batch and need to change start.
*/
sh = idx - start;

/*
* If >= 64, out of window. start must be at the front
* of the circular buffer, idx must be near the end of
* the buffer, and idx is the new "first" frame. Shift
* the indices around.
*/
if (sh >= 64) {
/* Shift bitmap by start - idx, wrapped */
sh = 0x100 - idx + start;
bitmap = bitmap << sh;
/* Now idx is the new start so sh = 0 */
sh = 0;
start = idx;
/*
* If <= -64 then wraps the 256-pkt circular buffer
* (e.g., start = 255 and idx = 0, sh should be 1)
*/
} else if (sh <= -64) {
sh = 0x100 - start + idx;
/*
* If < 0 but > -64, out of window. idx is before start
* but not wrapped. Shift the indices around.
*/
} else if (sh < 0) {
/* Shift by how far start is ahead of idx */
sh = start - idx;
bitmap = bitmap << sh;
/* Now idx is the new start so sh = 0 */
start = idx;
sh = 0;
}
/* Sequence number start + sh was sent in this batch */
bitmap |= 1ULL << sh;
IWL_DEBUG_TX_REPLY(priv, "start=%d bitmap=0x%llx\n",
start, (unsigned long long)bitmap);
}

/*
* Store the bitmap and possibly the new start, if we wrapped
* the buffer above
*/
agg->bitmap = bitmap;
agg->start_idx = start;
IWL_DEBUG_TX_REPLY(priv, "Frames %d start_idx=%d bitmap=0x%llx\n",
agg->frame_count, agg->start_idx,
(unsigned long long)agg->bitmap);

if (bitmap)
agg->wait_for_ba = 1;
}
return 0;
}

void iwl_check_abort_status(struct iwl_priv *priv,
u8 frame_count, u32 status)
{
Expand All @@ -392,99 +220,6 @@ void iwl_check_abort_status(struct iwl_priv *priv,
}
}

void iwlagn_rx_reply_tx(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = rxb_addr(rxb);
u16 sequence = le16_to_cpu(pkt->hdr.sequence);
int txq_id = SEQ_TO_QUEUE(sequence);
int index = SEQ_TO_INDEX(sequence);
struct iwl_tx_queue *txq = &priv->txq[txq_id];
struct ieee80211_tx_info *info;
struct iwlagn_tx_resp *tx_resp = (void *)&pkt->u.raw[0];
struct ieee80211_hdr *hdr;
struct iwl_tx_info *txb;
u32 status = le16_to_cpu(tx_resp->status.status);
int tid;
int sta_id;
int freed;
unsigned long flags;

if ((index >= txq->q.n_bd) || (iwl_queue_used(&txq->q, index) == 0)) {
IWL_ERR(priv, "%s: Read index for DMA queue txq_id (%d) "
"index %d is out of range [0-%d] %d %d\n", __func__,
txq_id, index, txq->q.n_bd, txq->q.write_ptr,
txq->q.read_ptr);
return;
}

txq->time_stamp = jiffies;
txb = &txq->txb[txq->q.read_ptr];
info = IEEE80211_SKB_CB(txb->skb);
memset(&info->status, 0, sizeof(info->status));

tid = (tx_resp->ra_tid & IWLAGN_TX_RES_TID_MSK) >>
IWLAGN_TX_RES_TID_POS;
sta_id = (tx_resp->ra_tid & IWLAGN_TX_RES_RA_MSK) >>
IWLAGN_TX_RES_RA_POS;

spin_lock_irqsave(&priv->shrd->sta_lock, flags);

hdr = (void *)txb->skb->data;
if (!ieee80211_is_data_qos(hdr->frame_control))
priv->last_seq_ctl = tx_resp->seq_ctl;

if (txq->sched_retry) {
const u32 scd_ssn = iwlagn_get_scd_ssn(tx_resp);
struct iwl_ht_agg *agg;

agg = &priv->stations[sta_id].tid[tid].agg;
/*
* If the BT kill count is non-zero, we'll get this
* notification again.
*/
if (tx_resp->bt_kill_count && tx_resp->frame_count == 1 &&
priv->cfg->bt_params &&
priv->cfg->bt_params->advanced_bt_coexist) {
IWL_DEBUG_COEX(priv, "receive reply tx with bt_kill\n");
}
iwlagn_tx_status_reply_tx(priv, agg, tx_resp, txq_id, index);

/* check if BAR is needed */
if ((tx_resp->frame_count == 1) && !iwl_is_tx_success(status))
info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;

if (txq->q.read_ptr != (scd_ssn & 0xff)) {
index = iwl_queue_dec_wrap(scd_ssn & 0xff, txq->q.n_bd);
IWL_DEBUG_TX_REPLY(priv, "Retry scheduler reclaim "
"scd_ssn=%d idx=%d txq=%d swq=%d\n",
scd_ssn , index, txq_id, txq->swq_id);

freed = iwlagn_tx_queue_reclaim(priv, txq_id, index);
iwl_free_tfds_in_queue(priv, sta_id, tid, freed);

if (priv->mac80211_registered &&
(iwl_queue_space(&txq->q) > txq->q.low_mark) &&
(agg->state != IWL_EMPTYING_HW_QUEUE_DELBA))
iwl_wake_queue(priv, txq);
}
} else {
iwlagn_set_tx_status(priv, info, txb->ctx, tx_resp,
txq_id, false);
freed = iwlagn_tx_queue_reclaim(priv, txq_id, index);
iwl_free_tfds_in_queue(priv, sta_id, tid, freed);

if (priv->mac80211_registered &&
iwl_queue_space(&txq->q) > txq->q.low_mark &&
status != TX_STATUS_FAIL_PASSIVE_NO_RX)
iwl_wake_queue(priv, txq);
}

iwlagn_txq_check_empty(priv, sta_id, tid, txq_id);

iwl_check_abort_status(priv, tx_resp->frame_count, status);
spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);
}

int iwlagn_hw_valid_rtc_data_addr(u32 addr)
{
return (addr >= IWLAGN_RTC_DATA_LOWER_BOUND) &&
Expand Down
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