2011-07-14 08:50:34

by Shahar Levi

[permalink] [raw]
Subject: [PATCH] wl12xx: Add support to RX packets payload alignment

In case of QoS packets the packet payload isn't aligned to
4 bytes. In that case the mac80211 layer take care of that
via memmove() in ieee80211_deliver_skb().
Add support of copy packets from aggregation buffer to the
skbs with packet payload aligned care. In case of QoS packets
copy the packets in offset of 2 bytes guarantee payload aligned
to 4 bytes.

Signed-off-by: Shahar Levi <[email protected]>
---
drivers/net/wireless/wl12xx/rx.c | 39 ++++++++++++++++++++++++++++++-------
drivers/net/wireless/wl12xx/rx.h | 8 ++++--
2 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/wl12xx/rx.c b/drivers/net/wireless/wl12xx/rx.c
index 0450fb4..46f4af6 100644
--- a/drivers/net/wireless/wl12xx/rx.c
+++ b/drivers/net/wireless/wl12xx/rx.c
@@ -38,12 +38,20 @@ static u8 wl1271_rx_get_mem_block(struct wl1271_fw_common_status *status,
}

static u32 wl1271_rx_get_buf_size(struct wl1271_fw_common_status *status,
- u32 drv_rx_counter)
+ u32 drv_rx_counter)
{
return (le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]) &
RX_BUF_SIZE_MASK) >> RX_BUF_SIZE_SHIFT_DIV;
}

+static bool wl1271_rx_get_unaligned(struct wl1271_fw_common_status *status,
+ u32 drv_rx_counter)
+{
+ /* Convert the value to bool */
+ return !!(le32_to_cpu(status->rx_pkt_descs[drv_rx_counter]) &
+ RX_BUF_UNALIGNED_PAYLOAD);
+}
+
static void wl1271_rx_status(struct wl1271 *wl,
struct wl1271_rx_descriptor *desc,
struct ieee80211_rx_status *status,
@@ -89,7 +97,8 @@ static void wl1271_rx_status(struct wl1271 *wl,
}
}

-static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length)
+static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length,
+ bool unaligned)
{
struct wl1271_rx_descriptor *desc;
struct sk_buff *skb;
@@ -97,6 +106,7 @@ static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length)
u8 *buf;
u8 beacon = 0;
u8 is_data = 0;
+ u8 reserved = unaligned ? NET_IP_ALIGN : 0;

/*
* In PLT mode we seem to get frames and mac80211 warns about them,
@@ -131,17 +141,25 @@ static int wl1271_rx_handle_data(struct wl1271 *wl, u8 *data, u32 length)
return -EINVAL;
}

- skb = __dev_alloc_skb(length, GFP_KERNEL);
+ /* skb length not included rx descriptor */
+ skb = __dev_alloc_skb(length + reserved - sizeof(*desc), GFP_KERNEL);
if (!skb) {
wl1271_error("Couldn't allocate RX frame");
return -ENOMEM;
}

- buf = skb_put(skb, length);
- memcpy(buf, data, length);
+ /* reserve the unaligned payload(if any) */
+ skb_reserve(skb, reserved);
+
+ buf = skb_put(skb, length - sizeof(*desc));

- /* now we pull the descriptor out of the buffer */
- skb_pull(skb, sizeof(*desc));
+ /*
+ * Copy packets from aggregation buffer to the skbs without rx
+ * descriptor and with packet payload aligned care. In case of unaligned
+ * packets copy the packets in offset of 2 bytes guarantee IP header
+ * payload aligned to 4 bytes.
+ */
+ memcpy(buf, data + sizeof(*desc), length - sizeof(*desc));

hdr = (struct ieee80211_hdr *)skb->data;
if (ieee80211_is_beacon(hdr->frame_control))
@@ -175,6 +193,7 @@ void wl1271_rx(struct wl1271 *wl, struct wl1271_fw_common_status *status)
u32 pkt_offset;
bool is_ap = (wl->bss_type == BSS_TYPE_AP_BSS);
bool had_data = false;
+ bool unaligned = false;

while (drv_rx_counter != fw_rx_counter) {
buf_size = 0;
@@ -222,6 +241,10 @@ void wl1271_rx(struct wl1271 *wl, struct wl1271_fw_common_status *status)
while (pkt_offset < buf_size) {
pkt_length = wl1271_rx_get_buf_size(status,
drv_rx_counter);
+
+ unaligned = wl1271_rx_get_unaligned(status,
+ drv_rx_counter);
+
/*
* the handle data call can only fail in memory-outage
* conditions, in that case the received frame will just
@@ -229,7 +252,7 @@ void wl1271_rx(struct wl1271 *wl, struct wl1271_fw_common_status *status)
*/
if (wl1271_rx_handle_data(wl,
wl->aggr_buf + pkt_offset,
- pkt_length) == 1)
+ pkt_length, unaligned) == 1)
had_data = true;

wl->rx_counter++;
diff --git a/drivers/net/wireless/wl12xx/rx.h b/drivers/net/wireless/wl12xx/rx.h
index c88e3fa..68b64eb 100644
--- a/drivers/net/wireless/wl12xx/rx.h
+++ b/drivers/net/wireless/wl12xx/rx.h
@@ -93,9 +93,11 @@
#define WL1271_RX_DESC_MIC_FAIL 0x02
#define WL1271_RX_DESC_DRIVER_RX_Q_FAIL 0x03

-#define RX_MEM_BLOCK_MASK 0xFF
-#define RX_BUF_SIZE_MASK 0xFFF00
-#define RX_BUF_SIZE_SHIFT_DIV 6
+#define RX_MEM_BLOCK_MASK 0xFF
+#define RX_BUF_SIZE_MASK 0xFFF00
+#define RX_BUF_SIZE_SHIFT_DIV 6
+/* If set, the start of IP payload is not 4 bytes aligned */
+#define RX_BUF_UNALIGNED_PAYLOAD BIT(20)

enum {
WL12XX_RX_CLASS_UNKNOWN,
--
1.7.1



2011-08-12 07:34:23

by Luciano Coelho

[permalink] [raw]
Subject: Re: [PATCH] wl12xx: Add support to RX packets payload alignment

On Thu, 2011-07-14 at 11:50 +0300, Shahar Levi wrote:
> In case of QoS packets the packet payload isn't aligned to
> 4 bytes. In that case the mac80211 layer take care of that
> via memmove() in ieee80211_deliver_skb().
> Add support of copy packets from aggregation buffer to the
> skbs with packet payload aligned care. In case of QoS packets
> copy the packets in offset of 2 bytes guarantee payload aligned
> to 4 bytes.
>
> Signed-off-by: Shahar Levi <[email protected]>
> ---

Applied and pushed, thanks!

--
Cheers,
Luca.