Use dedicated DMA coherent buffers for RX urbs, to avoid allocation of large
skbuffs in hard-irq context and improve performance.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@xxxxxx>
---
drivers/net/wireless/rtlwifi/usb.c | 114 +++++++++++++++++++++---------------
drivers/net/wireless/rtlwifi/usb.h | 1
2 files changed, 68 insertions(+), 47 deletions(-)
diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c
index 41dce83..146d2b4 100644
--- a/drivers/net/wireless/rtlwifi/usb.c
+++ b/drivers/net/wireless/rtlwifi/usb.c
@@ -324,6 +324,7 @@ static int _rtl_usb_init_rx(struct ieee80211_hw *hw)
pr_info("rx_max_size %d, rx_urb_num %d, in_ep %d\n",
rtlusb->rx_max_size, rtlusb->rx_urb_num, rtlusb->in_ep);
init_usb_anchor(&rtlusb->rx_submitted);
+ init_usb_anchor(&rtlusb->rx_cleanup_urbs);
return 0;
}
@@ -405,40 +406,30 @@ static void rtl_usb_init_sw(struct ieee80211_hw *hw)
rtlusb->disableHWSM = true;
}
-#define __RADIO_TAP_SIZE_RSV 32
-
static void _rtl_rx_completed(struct urb *urb);
-static struct sk_buff *_rtl_prep_rx_urb(struct ieee80211_hw *hw,
- struct rtl_usb *rtlusb,
- struct urb *urb,
- gfp_t gfp_mask)
+static int _rtl_prep_rx_urb(struct ieee80211_hw *hw, struct rtl_usb *rtlusb,
+ struct urb *urb, gfp_t gfp_mask)
{
- struct sk_buff *skb;
struct rtl_priv *rtlpriv = rtl_priv(hw);
+ void *buf;
- skb = __dev_alloc_skb((rtlusb->rx_max_size + __RADIO_TAP_SIZE_RSV),
- gfp_mask);
- if (!skb) {
+ buf = usb_alloc_coherent(rtlusb->udev, rtlusb->rx_max_size, gfp_mask,
+ &urb->transfer_dma);
+ if (!buf) {
RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
- "Failed to __dev_alloc_skb!!\n");
- return ERR_PTR(-ENOMEM);
+ "Failed to usb_alloc_coherent!!\n");
+ return -ENOMEM;
}
- /* reserve some space for mac80211's radiotap */
- skb_reserve(skb, __RADIO_TAP_SIZE_RSV);
usb_fill_bulk_urb(urb, rtlusb->udev,
usb_rcvbulkpipe(rtlusb->udev, rtlusb->in_ep),
- skb->data, min(skb_tailroom(skb),
- (int)rtlusb->rx_max_size),
- _rtl_rx_completed, skb);
+ buf, rtlusb->rx_max_size, _rtl_rx_completed, rtlusb);
+ urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
- _rtl_install_trx_info(rtlusb, skb, rtlusb->in_ep);
- return skb;
+ return 0;
}
-#undef __RADIO_TAP_SIZE_RSV
-
static void _rtl_usb_rx_process_agg(struct ieee80211_hw *hw,
struct sk_buff *skb)
{
@@ -558,11 +549,11 @@ static void _rtl_rx_pre_process(struct ieee80211_hw *hw, struct sk_buff *skb)
}
}
+#define __RADIO_TAP_SIZE_RSV 32
+
static void _rtl_rx_completed(struct urb *_urb)
{
- struct sk_buff *skb = (struct sk_buff *)_urb->context;
- struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
- struct rtl_usb *rtlusb = (struct rtl_usb *)info->rate_driver_data[0];
+ struct rtl_usb *rtlusb = (struct rtl_usb *)_urb->context;
struct ieee80211_hw *hw = usb_get_intfdata(rtlusb->intf);
struct rtl_priv *rtlpriv = rtl_priv(hw);
int err = 0;
@@ -571,28 +562,42 @@ static void _rtl_rx_completed(struct urb *_urb)
goto free;
if (likely(0 == _urb->status)) {
- /* If this code were moved to work queue, would CPU
- * utilization be improved? NOTE: We shall allocate another skb
- * and reuse the original one.
+ struct sk_buff *skb;
+ unsigned int size = _urb->actual_length;
+
+ if (size < RTL_RX_DESC_SIZE + sizeof(struct ieee80211_hdr)) {
+ RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
+ "Too short packet from bulk IN! (len: %d)\n",
+ size);
+ goto resubmit;
+ }
+
+ skb = dev_alloc_skb(size + __RADIO_TAP_SIZE_RSV);
+ if (!skb) {
+ RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
+ "Can't allocate skb for bulk IN!\n");
+ goto resubmit;
+ }
+
+ _rtl_install_trx_info(rtlusb, skb, rtlusb->in_ep);
+
+ /* reserve some space for mac80211's radiotap */
+ skb_reserve(skb, __RADIO_TAP_SIZE_RSV);
+
+ memcpy(skb_put(skb, size), _urb->transfer_buffer, size);
+
+ /* TODO: Do further processing in tasklet (queue skbs,
+ * schedule tasklet)
*/
- skb_put(skb, _urb->actual_length);
if (likely(!rtlusb->usb_rx_segregate_hdl)) {
- struct sk_buff *_skb;
_rtl_usb_rx_process_noagg(hw, skb);
- _skb = _rtl_prep_rx_urb(hw, rtlusb, _urb, GFP_ATOMIC);
- if (IS_ERR(_skb)) {
- err = PTR_ERR(_skb);
- RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
- "Can't allocate skb for bulk IN!\n");
- return;
- }
- skb = _skb;
- } else{
+ } else {
/* TO DO */
_rtl_rx_pre_process(hw, skb);
pr_err("rx agg not supported\n");
}
+
goto resubmit;
}
@@ -608,9 +613,6 @@ static void _rtl_rx_completed(struct urb *_urb)
}
resubmit:
- skb_reset_tail_pointer(skb);
- skb_trim(skb, 0);
-
usb_anchor_urb(_urb, &rtlusb->rx_submitted);
err = usb_submit_urb(_urb, GFP_ATOMIC);
if (unlikely(err)) {
@@ -620,13 +622,31 @@ resubmit:
return;
free:
- dev_kfree_skb_irq(skb);
+ /* On some architectures, usb_free_coherent must not be called from
+ * hardirq context. Queue urb to cleanup list.
+ */
+ usb_anchor_urb(_urb, &rtlusb->rx_cleanup_urbs);
+}
+
+#undef __RADIO_TAP_SIZE_RSV
+
+static void _rtl_usb_cleanup_rx(struct ieee80211_hw *hw)
+{
+ struct rtl_usb *rtlusb = rtl_usbdev(rtl_usbpriv(hw));
+ struct urb *urb;
+
+ usb_kill_anchored_urbs(&rtlusb->rx_submitted);
+
+ while ((urb = usb_get_from_anchor(&rtlusb->rx_cleanup_urbs))) {
+ usb_free_coherent(urb->dev, urb->transfer_buffer_length,
+ urb->transfer_buffer, urb->transfer_dma);
+ usb_free_urb(urb);
+ }
}
static int _rtl_usb_receive(struct ieee80211_hw *hw)
{
struct urb *urb;
- struct sk_buff *skb;
int err;
int i;
struct rtl_priv *rtlpriv = rtl_priv(hw);
@@ -645,11 +665,10 @@ static int _rtl_usb_receive(struct ieee80211_hw *hw)
goto err_out;
}
- skb = _rtl_prep_rx_urb(hw, rtlusb, urb, GFP_KERNEL);
- if (IS_ERR(skb)) {
+ err = _rtl_prep_rx_urb(hw, rtlusb, urb, GFP_KERNEL);
+ if (err < 0) {
RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG,
"Failed to prep_rx_urb!!\n");
- err = PTR_ERR(skb);
usb_free_urb(urb);
goto err_out;
}
@@ -664,6 +683,7 @@ static int _rtl_usb_receive(struct ieee80211_hw *hw)
err_out:
usb_kill_anchored_urbs(&rtlusb->rx_submitted);
+ _rtl_usb_cleanup_rx(hw);
return err;
}
@@ -705,7 +725,7 @@ static void rtl_usb_cleanup(struct ieee80211_hw *hw)
SET_USB_STOP(rtlusb);
/* clean up rx stuff. */
- usb_kill_anchored_urbs(&rtlusb->rx_submitted);
+ _rtl_usb_cleanup_rx(hw);
/* clean up tx stuff */
for (i = 0; i < RTL_USB_MAX_EP_NUM; i++) {
diff --git a/drivers/net/wireless/rtlwifi/usb.h b/drivers/net/wireless/rtlwifi/usb.h
index fb986f9..22d7c68 100644
--- a/drivers/net/wireless/rtlwifi/usb.h
+++ b/drivers/net/wireless/rtlwifi/usb.h
@@ -141,6 +141,7 @@ struct rtl_usb {
u32 rx_max_size; /* Bulk IN max buffer size */
u32 rx_urb_num; /* How many Bulk INs are submitted to host. */
struct usb_anchor rx_submitted;
+ struct usb_anchor rx_cleanup_urbs;
void (*usb_rx_segregate_hdl)(struct ieee80211_hw *, struct sk_buff *,
struct sk_buff_head *);
void (*usb_rx_hdl)(struct ieee80211_hw *, struct sk_buff *);
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
