Return-path: Received: from sabertooth02.qualcomm.com ([65.197.215.38]:64722 "EHLO sabertooth02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752309AbbCOOAz (ORCPT ); Sun, 15 Mar 2015 10:00:55 -0400 From: Vladimir Kondratiev Cc: Vladimir Kondratiev , linux-wireless@vger.kernel.org, wil6210@qca.qualcomm.com To: Kalle Valo Subject: [PATCH 3/7] wil6210: Align Rx frames on 4*n+2 by having SNAP Date: Sun, 15 Mar 2015 16:00:19 +0200 Message-Id: <1426428024-4538-6-git-send-email-qca_vkondrat@qca.qualcomm.com> (sfid-20150315_150058_786682_539F241F) In-Reply-To: <1426428024-4538-1-git-send-email-qca_vkondrat@qca.qualcomm.com> References: <1426428024-4538-1-git-send-email-qca_vkondrat@qca.qualcomm.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: For the networking code and for hardware network accelerators, it is better to have IP header 4*n aligned. On the other side, DMA on Rx path require buffer to be aligned on 4*n as well. Having 14 bytes of Ethernet header, these 2 alignment requests are in contradiction. To solve this, order hardware offload block to not remove SNAP header. This adds extra 6 bytes between addresses and ethertype, making it 20 bytes total. This way, both buffer and IP header are 4*n aligned. Remaining is only to remove SNAP by shifting addresses 6 bytes. This involves data copying, so this feature should be disabled unless required by the platform. Module parameter "rx_align_2" (bool, default - false) introduced to control this feature. Feature is completely disabled when parameter is false. Signed-off-by: Vladimir Kondratiev --- drivers/net/wireless/ath/wil6210/txrx.c | 27 ++++++++++++++++++++++++--- drivers/net/wireless/ath/wil6210/wil6210.h | 1 + drivers/net/wireless/ath/wil6210/wmi.c | 5 +++++ drivers/net/wireless/ath/wil6210/wmi.h | 3 +++ 4 files changed, 33 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c index 3feb86c4..2453470 100644 --- a/drivers/net/wireless/ath/wil6210/txrx.c +++ b/drivers/net/wireless/ath/wil6210/txrx.c @@ -33,6 +33,15 @@ module_param(rtap_include_phy_info, bool, S_IRUGO); MODULE_PARM_DESC(rtap_include_phy_info, " Include PHY info in the radiotap header, default - no"); +bool rx_align_2; +module_param(rx_align_2, bool, S_IRUGO); +MODULE_PARM_DESC(rx_align_2, " align Rx buffers on 4*n+2, default - no"); + +static inline uint wil_rx_snaplen(void) +{ + return rx_align_2 ? 6 : 0; +} + static inline int wil_vring_is_empty(struct vring *vring) { return vring->swhead == vring->swtail; @@ -209,7 +218,7 @@ static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring, u32 i, int headroom) { struct device *dev = wil_to_dev(wil); - unsigned int sz = mtu_max + ETH_HLEN; + unsigned int sz = mtu_max + ETH_HLEN + wil_rx_snaplen(); struct vring_rx_desc dd, *d = ⅆ volatile struct vring_rx_desc *_d = &vring->va[i].rx; dma_addr_t pa; @@ -365,7 +374,8 @@ static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil, struct vring_rx_desc *d; struct sk_buff *skb; dma_addr_t pa; - unsigned int sz = mtu_max + ETH_HLEN; + unsigned int snaplen = wil_rx_snaplen(); + unsigned int sz = mtu_max + ETH_HLEN + snaplen; u16 dmalen; u8 ftype; int cid; @@ -438,7 +448,7 @@ static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil, return NULL; } - if (unlikely(skb->len < ETH_HLEN)) { + if (unlikely(skb->len < ETH_HLEN + snaplen)) { wil_err(wil, "Short frame, len = %d\n", skb->len); /* TODO: process it (i.e. BAR) */ kfree_skb(skb); @@ -460,6 +470,17 @@ static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil, */ } + if (snaplen) { + /* Packet layout + * +-------+-------+---------+------------+------+ + * | SA(6) | DA(6) | SNAP(6) | ETHTYPE(2) | DATA | + * +-------+-------+---------+------------+------+ + * Need to remove SNAP, shifting SA and DA forward + */ + memmove(skb->data + snaplen, skb->data, 2 * ETH_ALEN); + skb_pull(skb, snaplen); + } + return skb; } diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h index c1a71ab..a6b096e 100644 --- a/drivers/net/wireless/ath/wil6210/wil6210.h +++ b/drivers/net/wireless/ath/wil6210/wil6210.h @@ -28,6 +28,7 @@ extern unsigned int mtu_max; extern unsigned short rx_ring_overflow_thrsh; extern int agg_wsize; extern u32 vring_idle_trsh; +extern bool rx_align_2; #define WIL_NAME "wil6210" #define WIL_FW_NAME "wil6210.fw" /* code */ diff --git a/drivers/net/wireless/ath/wil6210/wmi.c b/drivers/net/wireless/ath/wil6210/wmi.c index 0213135..8c18a46 100644 --- a/drivers/net/wireless/ath/wil6210/wmi.c +++ b/drivers/net/wireless/ath/wil6210/wmi.c @@ -1109,6 +1109,11 @@ int wmi_rx_chain_add(struct wil6210_priv *wil, struct vring *vring) */ cmd.l3_l4_ctrl |= (1 << L3_L4_CTRL_TCPIP_CHECKSUM_EN_POS); } + + if (rx_align_2) + cmd.l2_802_3_offload_ctrl |= + L2_802_3_OFFLOAD_CTRL_SNAP_KEEP_MSK; + /* typical time for secure PCP is 840ms */ rc = wmi_call(wil, WMI_CFG_RX_CHAIN_CMDID, &cmd, sizeof(cmd), WMI_CFG_RX_CHAIN_DONE_EVENTID, &evt, sizeof(evt), 2000); diff --git a/drivers/net/wireless/ath/wil6210/wmi.h b/drivers/net/wireless/ath/wil6210/wmi.h index 8a4af61..0979650 100644 --- a/drivers/net/wireless/ath/wil6210/wmi.h +++ b/drivers/net/wireless/ath/wil6210/wmi.h @@ -687,6 +687,9 @@ struct wmi_cfg_rx_chain_cmd { #define L2_802_3_OFFLOAD_CTRL_VLAN_TAG_INSERTION_POS (0) #define L2_802_3_OFFLOAD_CTRL_VLAN_TAG_INSERTION_LEN (1) #define L2_802_3_OFFLOAD_CTRL_VLAN_TAG_INSERTION_MSK (0x1) + #define L2_802_3_OFFLOAD_CTRL_SNAP_KEEP_POS (1) + #define L2_802_3_OFFLOAD_CTRL_SNAP_KEEP_LEN (1) + #define L2_802_3_OFFLOAD_CTRL_SNAP_KEEP_MSK (0x2) u8 l2_802_3_offload_ctrl; #define L2_NWIFI_OFFLOAD_CTRL_REMOVE_QOS_POS (0) -- 2.1.0