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iwlagn: move Tx datapath to transport layer
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Split the Tx datapath in two parts:
* the first deals with the Tx cmd composition
* the second attaches the skb + Tx cmd to the queues

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
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Emmanuel Grumbach authored and Wey-Yi Guy committed Jul 16, 2011
1 parent 94f9b97 commit 47c1b49
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Showing 5 changed files with 189 additions and 146 deletions.
158 changes: 12 additions & 146 deletions drivers/net/wireless/iwlwifi/iwl-agn-tx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@
#include "iwl-helpers.h"
#include "iwl-agn-hw.h"
#include "iwl-agn.h"
#include "iwl-trans.h"

/*
* mac80211 queues, ACs, hardware queues, FIFOs.
Expand Down Expand Up @@ -98,7 +99,7 @@ static inline int get_fifo_from_tid(struct iwl_rxon_context *ctx, u16 tid)
/**
* iwlagn_txq_update_byte_cnt_tbl - Set up entry in Tx byte-count array
*/
static void iwlagn_txq_update_byte_cnt_tbl(struct iwl_priv *priv,
void iwlagn_txq_update_byte_cnt_tbl(struct iwl_priv *priv,
struct iwl_tx_queue *txq,
u16 byte_cnt)
{
Expand Down Expand Up @@ -547,26 +548,17 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_sta *sta = info->control.sta;
struct iwl_station_priv *sta_priv = NULL;
struct iwl_tx_queue *txq;
struct iwl_queue *q;
struct iwl_device_cmd *out_cmd;
struct iwl_cmd_meta *out_meta;
struct iwl_tx_cmd *tx_cmd;
struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
struct iwl_tx_cmd *tx_cmd;
int txq_id;
dma_addr_t phys_addr = 0;
dma_addr_t txcmd_phys;
dma_addr_t scratch_phys;
u16 len, firstlen, secondlen;

u16 seq_number = 0;
__le16 fc;
u8 hdr_len;
u16 len;
u8 sta_id;
u8 wait_write_ptr = 0;
u8 tid = 0;
u8 *qc = NULL;
unsigned long flags;
bool is_agg = false;

Expand Down Expand Up @@ -614,8 +606,8 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)

IWL_DEBUG_TX(priv, "station Id %d\n", sta_id);

if (sta)
sta_priv = (void *)sta->drv_priv;
if (info->control.sta)
sta_priv = (void *)info->control.sta->drv_priv;

if (sta_priv && sta_priv->asleep &&
(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE)) {
Expand Down Expand Up @@ -650,6 +642,7 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
spin_lock(&priv->sta_lock);

if (ieee80211_is_data_qos(fc)) {
u8 *qc = NULL;
qc = ieee80211_get_qos_ctl(hdr);
tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;

Expand All @@ -670,38 +663,13 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
}
}

txq = &priv->txq[txq_id];
q = &txq->q;

if (unlikely(iwl_queue_space(q) < q->high_mark))
tx_cmd = trans_get_tx_cmd(priv, txq_id);
if (unlikely(!tx_cmd))
goto drop_unlock_sta;

/* Set up driver data for this TFD */
memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl_tx_info));
txq->txb[q->write_ptr].skb = skb;
txq->txb[q->write_ptr].ctx = ctx;

/* Set up first empty entry in queue's array of Tx/cmd buffers */
out_cmd = txq->cmd[q->write_ptr];
out_meta = &txq->meta[q->write_ptr];
tx_cmd = &out_cmd->cmd.tx;
memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
memset(tx_cmd, 0, sizeof(struct iwl_tx_cmd));

/*
* Set up the Tx-command (not MAC!) header.
* Store the chosen Tx queue and TFD index within the sequence field;
* after Tx, uCode's Tx response will return this value so driver can
* locate the frame within the tx queue and do post-tx processing.
*/
out_cmd->hdr.cmd = REPLY_TX;
out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
INDEX_TO_SEQ(q->write_ptr)));

/* Copy MAC header from skb into command buffer */
memcpy(tx_cmd->hdr, hdr, hdr_len);


/* Total # bytes to be transmitted */
len = (u16)skb->len;
tx_cmd->len = cpu_to_le16(len);
Expand All @@ -716,54 +684,9 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
iwlagn_tx_cmd_build_rate(priv, tx_cmd, info, fc);

iwl_update_stats(priv, true, fc, len);
/*
* Use the first empty entry in this queue's command buffer array
* to contain the Tx command and MAC header concatenated together
* (payload data will be in another buffer).
* Size of this varies, due to varying MAC header length.
* If end is not dword aligned, we'll have 2 extra bytes at the end
* of the MAC header (device reads on dword boundaries).
* We'll tell device about this padding later.
*/
len = sizeof(struct iwl_tx_cmd) +
sizeof(struct iwl_cmd_header) + hdr_len;
firstlen = (len + 3) & ~3;

/* Tell NIC about any 2-byte padding after MAC header */
if (firstlen != len)
tx_cmd->tx_flags |= TX_CMD_FLG_MH_PAD_MSK;

/* Physical address of this Tx command's header (not MAC header!),
* within command buffer array. */
txcmd_phys = dma_map_single(priv->bus.dev,
&out_cmd->hdr, firstlen,
DMA_BIDIRECTIONAL);
if (unlikely(dma_mapping_error(priv->bus.dev, txcmd_phys)))
goto drop_unlock_sta;
dma_unmap_addr_set(out_meta, mapping, txcmd_phys);
dma_unmap_len_set(out_meta, len, firstlen);

if (!ieee80211_has_morefrags(hdr->frame_control)) {
txq->need_update = 1;
} else {
wait_write_ptr = 1;
txq->need_update = 0;
}

/* Set up TFD's 2nd entry to point directly to remainder of skb,
* if any (802.11 null frames have no payload). */
secondlen = skb->len - hdr_len;
if (secondlen > 0) {
phys_addr = dma_map_single(priv->bus.dev, skb->data + hdr_len,
secondlen, DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(priv->bus.dev, phys_addr))) {
dma_unmap_single(priv->bus.dev,
dma_unmap_addr(out_meta, mapping),
dma_unmap_len(out_meta, len),
DMA_BIDIRECTIONAL);
goto drop_unlock_sta;
}
}
if (trans_tx(priv, skb, tx_cmd, txq_id, fc, is_agg, ctx))
goto drop_unlock_sta;

if (ieee80211_is_data_qos(fc)) {
priv->stations[sta_id].tid[tid].tfds_in_queue++;
Expand All @@ -772,54 +695,8 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
}

spin_unlock(&priv->sta_lock);

/* Attach buffers to TFD */
iwlagn_txq_attach_buf_to_tfd(priv, txq, txcmd_phys, firstlen, 1);
if (secondlen > 0)
iwlagn_txq_attach_buf_to_tfd(priv, txq, phys_addr,
secondlen, 0);

scratch_phys = txcmd_phys + sizeof(struct iwl_cmd_header) +
offsetof(struct iwl_tx_cmd, scratch);

/* take back ownership of DMA buffer to enable update */
dma_sync_single_for_cpu(priv->bus.dev, txcmd_phys, firstlen,
DMA_BIDIRECTIONAL);
tx_cmd->dram_lsb_ptr = cpu_to_le32(scratch_phys);
tx_cmd->dram_msb_ptr = iwl_get_dma_hi_addr(scratch_phys);

IWL_DEBUG_TX(priv, "sequence nr = 0X%x\n",
le16_to_cpu(out_cmd->hdr.sequence));
IWL_DEBUG_TX(priv, "tx_flags = 0X%x\n", le32_to_cpu(tx_cmd->tx_flags));
iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd, sizeof(*tx_cmd));
iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd->hdr, hdr_len);

/* Set up entry for this TFD in Tx byte-count array */
if (info->flags & IEEE80211_TX_CTL_AMPDU)
iwlagn_txq_update_byte_cnt_tbl(priv, txq,
le16_to_cpu(tx_cmd->len));

dma_sync_single_for_device(priv->bus.dev, txcmd_phys, firstlen,
DMA_BIDIRECTIONAL);

trace_iwlwifi_dev_tx(priv,
&((struct iwl_tfd *)txq->tfds)[txq->q.write_ptr],
sizeof(struct iwl_tfd),
&out_cmd->hdr, firstlen,
skb->data + hdr_len, secondlen);

/* Tell device the write index *just past* this latest filled TFD */
q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
iwl_txq_update_write_ptr(priv, txq);
spin_unlock_irqrestore(&priv->lock, flags);

/*
* At this point the frame is "transmitted" successfully
* and we will get a TX status notification eventually,
* regardless of the value of ret. "ret" only indicates
* whether or not we should update the write pointer.
*/

/*
* Avoid atomic ops if it isn't an associated client.
* Also, if this is a packet for aggregation, don't
Expand All @@ -830,17 +707,6 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
if (sta_priv && sta_priv->client && !is_agg)
atomic_inc(&sta_priv->pending_frames);

if ((iwl_queue_space(q) < q->high_mark) && priv->mac80211_registered) {
if (wait_write_ptr) {
spin_lock_irqsave(&priv->lock, flags);
txq->need_update = 1;
iwl_txq_update_write_ptr(priv, txq);
spin_unlock_irqrestore(&priv->lock, flags);
} else {
iwl_stop_queue(priv, txq);
}
}

return 0;

drop_unlock_sta:
Expand Down
4 changes: 4 additions & 0 deletions drivers/net/wireless/iwlwifi/iwl-agn.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -142,6 +142,10 @@ void iwlagn_stop_device(struct iwl_priv *priv);
/* tx queue */
void iwlagn_set_wr_ptrs(struct iwl_priv *priv,
int txq_id, u32 index);
void iwlagn_txq_update_byte_cnt_tbl(struct iwl_priv *priv,
struct iwl_tx_queue *txq,
u16 byte_cnt);

void iwlagn_tx_queue_set_status(struct iwl_priv *priv,
struct iwl_tx_queue *txq,
int tx_fifo_id, int scd_retry);
Expand Down
4 changes: 4 additions & 0 deletions drivers/net/wireless/iwlwifi/iwl-dev.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1257,6 +1257,10 @@ struct iwl_trans_ops {

int (*send_cmd_pdu)(struct iwl_priv *priv, u8 id, u32 flags, u16 len,
const void *data);
struct iwl_tx_cmd * (*get_tx_cmd)(struct iwl_priv *priv, int txq_id);
int (*tx)(struct iwl_priv *priv, struct sk_buff *skb,
struct iwl_tx_cmd *tx_cmd, int txq_id, __le16 fc, bool ampdu,
struct iwl_rxon_context *ctx);
};

struct iwl_trans {
Expand Down
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