Instead of sending one packet at a time to the firmware, try to
send all available packets at once.
This optimization decreases the number of transactions, which saves
CPU cycles and increases network throughput.
Signed-off-by: Ido Yariv <ido@xxxxxxxxxx>
---
drivers/net/wireless/wl12xx/wl1271_tx.c | 99 ++++++++++++-------------------
1 files changed, 37 insertions(+), 62 deletions(-)
diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.c b/drivers/net/wireless/wl12xx/wl1271_tx.c
index 1b8295c..e3dc13c 100644
--- a/drivers/net/wireless/wl12xx/wl1271_tx.c
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.c
@@ -43,13 +43,17 @@ static int wl1271_tx_id(struct wl1271 *wl, struct sk_buff *skb)
return -EBUSY;
}
-static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
+static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra,
+ u32 buf_offset)
{
struct wl1271_tx_hw_descr *desc;
u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
u32 total_blocks;
int id, ret = -EBUSY;
+ if (buf_offset + total_len > WL1271_AGGR_BUFFER_SIZE)
+ return -EBUSY;
+
/* allocate free identifier for the packet */
id = wl1271_tx_id(wl, skb);
if (id < 0)
@@ -82,7 +86,7 @@ static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
return ret;
}
-static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
+static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
u32 extra, struct ieee80211_tx_info *control)
{
struct timespec ts;
@@ -133,59 +137,17 @@ static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
desc->tx_attr = cpu_to_le16(tx_attr);
wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
- return 0;
-}
-
-static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
- struct ieee80211_tx_info *control)
-{
-
- struct wl1271_tx_hw_descr *desc;
- int len;
-
- /* FIXME: This is a workaround for getting non-aligned packets.
- This happens at least with EAPOL packets from the user space.
- Our DMA requires packets to be aligned on a 4-byte boundary.
- */
- if (unlikely((long)skb->data & 0x03)) {
- int offset = (4 - (long)skb->data) & 0x03;
- wl1271_debug(DEBUG_TX, "skb offset %d", offset);
-
- /* check whether the current skb can be used */
- if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
- unsigned char *src = skb->data;
-
- /* align the buffer on a 4-byte boundary */
- skb_reserve(skb, offset);
- memmove(skb->data, src, skb->len);
- } else {
- wl1271_info("No handler, fixme!");
- return -EINVAL;
- }
- }
-
- len = WL1271_TX_ALIGN(skb->len);
-
- /* perform a fixed address block write with the packet */
- wl1271_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
-
- /* write packet new counter into the write access register */
- wl->tx_packets_count++;
-
- desc = (struct wl1271_tx_hw_descr *) skb->data;
- wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
- desc->id, skb, len, desc->length);
-
- return 0;
}
/* caller must hold wl->mutex */
-static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
+static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb,
+ u32 buf_offset)
{
struct ieee80211_tx_info *info;
u32 extra = 0;
int ret = 0;
u8 idx;
+ u32 total_len;
if (!skb)
return -EINVAL;
@@ -208,19 +170,22 @@ static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
}
}
- ret = wl1271_tx_allocate(wl, skb, extra);
+ ret = wl1271_tx_allocate(wl, skb, extra, buf_offset);
if (ret < 0)
return ret;
- ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
- if (ret < 0)
- return ret;
+ wl1271_tx_fill_hdr(wl, skb, extra, info);
- ret = wl1271_tx_send_packet(wl, skb, info);
- if (ret < 0)
- return ret;
+ /*
+ * The length of each packet is stored in terms of words. Thus, we must
+ * pad the skb data to make sure its length is aligned.
+ * The number of padding bytes is computed and set in wl1271_tx_fill_hdr
+ */
+ total_len = WL1271_TX_ALIGN(skb->len);
+ memcpy(wl->aggr_buf + buf_offset, skb->data, skb->len);
+ memset(wl->aggr_buf + buf_offset + skb->len, 0, total_len - skb->len);
- return ret;
+ return total_len;
}
u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
@@ -245,7 +210,7 @@ void wl1271_tx_work(struct work_struct *work)
struct sk_buff *skb;
bool woken_up = false;
u32 sta_rates = 0;
- u32 prev_tx_packets_count;
+ u32 buf_offset;
int ret;
/* check if the rates supported by the AP have changed */
@@ -262,14 +227,15 @@ void wl1271_tx_work(struct work_struct *work)
if (unlikely(wl->state == WL1271_STATE_OFF))
goto out;
- prev_tx_packets_count = wl->tx_packets_count;
-
/* if rates have changed, re-configure the rate policy */
if (unlikely(sta_rates)) {
wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates);
wl1271_acx_rate_policies(wl);
}
+ /* Prepare the transfer buffer, by aggregating all
+ * available packets */
+ buf_offset = 0;
while ((skb = skb_dequeue(&wl->tx_queue))) {
if (!woken_up) {
ret = wl1271_ps_elp_wakeup(wl, false);
@@ -278,21 +244,30 @@ void wl1271_tx_work(struct work_struct *work)
woken_up = true;
}
- ret = wl1271_tx_frame(wl, skb);
+ ret = wl1271_prepare_tx_frame(wl, skb, buf_offset);
if (ret == -EBUSY) {
- /* firmware buffer is full, lets stop transmitting. */
+ /*
+ * Either the firmware buffer is full, or the
+ * aggregation buffer is.
+ * Queue back last skb, and stop aggregating.
+ */
skb_queue_head(&wl->tx_queue, skb);
goto out_ack;
} else if (ret < 0) {
dev_kfree_skb(skb);
goto out_ack;
}
+ buf_offset += ret;
+ wl->tx_packets_count++;
}
out_ack:
- /* interrupt the firmware with the new packets */
- if (prev_tx_packets_count != wl->tx_packets_count)
+ if (buf_offset) {
+ wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
+ buf_offset, true);
+ /* interrupt the firmware with the new packets */
wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
+ }
out:
if (woken_up)
--
1.7.0.4
--
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