Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:61850 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756666Ab0I1PH6 (ORCPT ); Tue, 28 Sep 2010 11:07:58 -0400 Received: by wwd20 with SMTP id 20so96229wwd.1 for ; Tue, 28 Sep 2010 08:07:56 -0700 (PDT) From: Ido Yariv To: Luciano Coelho , linux-wireless@vger.kernel.org Cc: Ido Yariv Subject: [PATCH 2/2] wl1271: Support firmware TX packet aggregation Date: Tue, 28 Sep 2010 17:07:44 +0200 Message-Id: <1285686464-8668-3-git-send-email-ido@wizery.com> In-Reply-To: <1285686464-8668-1-git-send-email-ido@wizery.com> References: <1285686464-8668-1-git-send-email-ido@wizery.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- 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