From 872de8ff04922e4ad95c5af39131ae9fbefe6ac5 Mon Sep 17 00:00:00 2001 From: Jussi Kivilinna Date: Sun, 17 Mar 2013 11:59:13 +0200 Subject: [PATCH] rtlwifi: usb: use usb_alloc_coherent for RX buffers 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 Signed-off-by: John W. Linville --- 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 b5c80b5d57ef..22f29d75947e 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 fb986f98d1df..22d7c68258ec 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 *); -- 2.20.1