2014-12-17 09:23:59

by Avinash Patil

[permalink] [raw]
Subject: [PATCH 3/4] mwifiex: make tx packet 64 byte DMA aligned

From: Xinming Hu <[email protected]>

This patch adds support for DMA alignment of 64 bytes for TX packets.

Signed-off-by: Xinming Hu <[email protected]>
Signed-off-by: Avinash Patil <[email protected]>
---
drivers/net/wireless/mwifiex/11n_aggr.c | 15 ++++++++++++---
drivers/net/wireless/mwifiex/decl.h | 6 ++++--
drivers/net/wireless/mwifiex/sta_tx.c | 19 ++++++++++---------
drivers/net/wireless/mwifiex/uap_txrx.c | 28 +++++++++++++++-------------
4 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/11n_aggr.c b/drivers/net/wireless/mwifiex/11n_aggr.c
index 8720a3d..20b7ff7 100644
--- a/drivers/net/wireless/mwifiex/11n_aggr.c
+++ b/drivers/net/wireless/mwifiex/11n_aggr.c
@@ -101,6 +101,13 @@ mwifiex_11n_form_amsdu_txpd(struct mwifiex_private *priv,
{
struct txpd *local_tx_pd;
struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
+ u8 pad;
+ int headroom = (priv->adapter->iface_type ==
+ MWIFIEX_USB) ? 0 : INTF_HEADER_LEN;
+
+ pad = ((void *)skb->data - sizeof(*local_tx_pd) -
+ headroom - NULL) & (MWIFIEX_DMA_ALIGN_SZ - 1);
+ skb_push(skb, pad);

skb_push(skb, sizeof(*local_tx_pd));

@@ -114,10 +121,12 @@ mwifiex_11n_form_amsdu_txpd(struct mwifiex_private *priv,
local_tx_pd->bss_num = priv->bss_num;
local_tx_pd->bss_type = priv->bss_type;
/* Always zero as the data is followed by struct txpd */
- local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd));
+ local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd) +
+ pad);
local_tx_pd->tx_pkt_type = cpu_to_le16(PKT_TYPE_AMSDU);
local_tx_pd->tx_pkt_length = cpu_to_le16(skb->len -
- sizeof(*local_tx_pd));
+ sizeof(*local_tx_pd) -
+ pad);

if (tx_info->flags & MWIFIEX_BUF_FLAG_TDLS_PKT)
local_tx_pd->flags |= MWIFIEX_TXPD_FLAGS_TDLS_PACKET;
@@ -182,7 +191,7 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
ra_list_flags);
return -1;
}
- skb_reserve(skb_aggr, headroom + sizeof(struct txpd));
+ skb_reserve(skb_aggr, MWIFIEX_MIN_DATA_HEADER_LEN);
tx_info_aggr = MWIFIEX_SKB_TXCB(skb_aggr);

memset(tx_info_aggr, 0, sizeof(*tx_info_aggr));
diff --git a/drivers/net/wireless/mwifiex/decl.h b/drivers/net/wireless/mwifiex/decl.h
index 2269acf..12addae 100644
--- a/drivers/net/wireless/mwifiex/decl.h
+++ b/drivers/net/wireless/mwifiex/decl.h
@@ -32,8 +32,10 @@

#define MWIFIEX_MAX_BSS_NUM (3)

-#define MWIFIEX_MIN_DATA_HEADER_LEN 36 /* sizeof(mwifiex_txpd)
- * + 4 byte alignment
+#define MWIFIEX_DMA_ALIGN_SZ 64
+#define MWIFIEX_MIN_DATA_HEADER_LEN 100 /* sizeof(mwifiex_txpd)
+ * + 4 byte interface header alignment
+ * + 64 byte dma alignment
*/
#define MWIFIEX_MGMT_FRAME_HEADER_SIZE 8 /* sizeof(pkt_type)
* + sizeof(tx_control)
diff --git a/drivers/net/wireless/mwifiex/sta_tx.c b/drivers/net/wireless/mwifiex/sta_tx.c
index b896d73..9796334 100644
--- a/drivers/net/wireless/mwifiex/sta_tx.c
+++ b/drivers/net/wireless/mwifiex/sta_tx.c
@@ -47,8 +47,10 @@ void *mwifiex_process_sta_txpd(struct mwifiex_private *priv,
struct mwifiex_adapter *adapter = priv->adapter;
struct txpd *local_tx_pd;
struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
- u8 pad;
+ int pad;
u16 pkt_type, pkt_offset;
+ int hroom = (priv->adapter->iface_type == MWIFIEX_USB) ? 0 :
+ INTF_HEADER_LEN;

if (!skb->len) {
dev_err(adapter->dev, "Tx: bad packet length: %d\n", skb->len);
@@ -56,13 +58,12 @@ void *mwifiex_process_sta_txpd(struct mwifiex_private *priv,
return skb->data;
}

- pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;
+ BUG_ON(skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN);

- /* If skb->data is not aligned; add padding */
- pad = (4 - (((void *)skb->data - NULL) & 0x3)) % 4;
+ pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;

- BUG_ON(skb_headroom(skb) < (sizeof(*local_tx_pd) + INTF_HEADER_LEN
- + pad));
+ pad = ((void *)skb->data - (sizeof(*local_tx_pd) + hroom)-
+ NULL) & (MWIFIEX_DMA_ALIGN_SZ - 1);
skb_push(skb, sizeof(*local_tx_pd) + pad);

local_tx_pd = (struct txpd *) skb->data;
@@ -70,8 +71,8 @@ void *mwifiex_process_sta_txpd(struct mwifiex_private *priv,
local_tx_pd->bss_num = priv->bss_num;
local_tx_pd->bss_type = priv->bss_type;
local_tx_pd->tx_pkt_length = cpu_to_le16((u16)(skb->len -
- (sizeof(struct txpd)
- + pad)));
+ (sizeof(struct txpd) +
+ pad)));

local_tx_pd->priority = (u8) skb->priority;
local_tx_pd->pkt_delay_2ms =
@@ -115,7 +116,7 @@ void *mwifiex_process_sta_txpd(struct mwifiex_private *priv,
local_tx_pd->tx_pkt_offset = cpu_to_le16(pkt_offset);

/* make space for INTF_HEADER_LEN */
- skb_push(skb, INTF_HEADER_LEN);
+ skb_push(skb, hroom);

if (!local_tx_pd->tx_control)
/* TxCtrl set by user or default */
diff --git a/drivers/net/wireless/mwifiex/uap_txrx.c b/drivers/net/wireless/mwifiex/uap_txrx.c
index be3a203..38ac4d7 100644
--- a/drivers/net/wireless/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/mwifiex/uap_txrx.c
@@ -348,8 +348,10 @@ void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
struct mwifiex_adapter *adapter = priv->adapter;
struct uap_txpd *txpd;
struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
- int pad, len;
- u16 pkt_type;
+ int pad;
+ u16 pkt_type, pkt_offset;
+ int hroom = (priv->adapter->iface_type == MWIFIEX_USB) ? 0 :
+ INTF_HEADER_LEN;

if (!skb->len) {
dev_err(adapter->dev, "Tx: bad packet length: %d\n", skb->len);
@@ -357,22 +359,21 @@ void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
return skb->data;
}

- pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;
-
- /* If skb->data is not aligned, add padding */
- pad = (4 - (((void *)skb->data - NULL) & 0x3)) % 4;
+ BUG_ON(skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN);

- len = sizeof(*txpd) + pad;
+ pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;

- BUG_ON(skb_headroom(skb) < len + INTF_HEADER_LEN);
+ pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
+ (MWIFIEX_DMA_ALIGN_SZ - 1);

- skb_push(skb, len);
+ skb_push(skb, sizeof(*txpd) + pad);

txpd = (struct uap_txpd *)skb->data;
memset(txpd, 0, sizeof(*txpd));
txpd->bss_num = priv->bss_num;
txpd->bss_type = priv->bss_type;
- txpd->tx_pkt_length = cpu_to_le16((u16)(skb->len - len));
+ txpd->tx_pkt_length = cpu_to_le16((u16)(skb->len - (sizeof(*txpd) +
+ pad)));
txpd->priority = (u8)skb->priority;

txpd->pkt_delay_2ms = mwifiex_wmm_compute_drv_pkt_delay(priv, skb);
@@ -392,16 +393,17 @@ void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
cpu_to_le32(priv->wmm.user_pri_pkt_tx_ctrl[txpd->priority]);

/* Offset of actual data */
+ pkt_offset = sizeof(*txpd) + pad;
if (pkt_type == PKT_TYPE_MGMT) {
/* Set the packet type and add header for management frame */
txpd->tx_pkt_type = cpu_to_le16(pkt_type);
- len += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
+ pkt_offset += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
}

- txpd->tx_pkt_offset = cpu_to_le16(len);
+ txpd->tx_pkt_offset = cpu_to_le16(pkt_offset);

/* make space for INTF_HEADER_LEN */
- skb_push(skb, INTF_HEADER_LEN);
+ skb_push(skb, hroom);

if (!txpd->tx_control)
/* TxCtrl set by user or default */
--
1.8.1.4