system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-10-21 10:49:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

wil6210: Align Rx frames on 4*n+2 by having SNAP

Browse source 
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 <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Vladimir Kondratiev 2015-03-15 16:00:19 +02:00 committed by Kalle Valo
parent cec94d8cf5
commit c406ea7c74
4 changed files with 33 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
drivers/net/wireless/ath/wil6210/txrx.c
View file

@ -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 = &dd;
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;
}

1
drivers/net/wireless/ath/wil6210/wil6210.h
View file

@ -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 */

5
drivers/net/wireless/ath/wil6210/wmi.c
View file

@ -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);

3
drivers/net/wireless/ath/wil6210/wmi.h
View file

@ -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)