rt2x00: Optimize TX descriptor handling

HT and no-HT rt2x00 devices use a partly different TX descriptor.
Optimize the tx desciptor memory layout by putting the PLCP and HT
substructs into a union and introduce a new driver flag to decide which
TX desciptor format is used by the device.

This saves us the expensive PLCP calculation fOr HT devices and the HT
descriptor setup on no-HT devices.

Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

12 files changed, 79 insertions, 55 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index d38acf4b65e1..60d75962b805 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1131,19 +1131,21 @@ static void rt2400pci_write_tx_desc(struct queue_entry *entry,
 	rt2x00_desc_write(txd, 2, word);
 
 	rt2x00_desc_read(txd, 3, &word);
-	rt2x00_set_field32(&word, TXD_W3_PLCP_SIGNAL, txdesc->signal);
+	rt2x00_set_field32(&word, TXD_W3_PLCP_SIGNAL, txdesc->u.plcp.signal);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_SIGNAL_REGNUM, 5);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_SIGNAL_BUSY, 1);
-	rt2x00_set_field32(&word, TXD_W3_PLCP_SERVICE, txdesc->service);
+	rt2x00_set_field32(&word, TXD_W3_PLCP_SERVICE, txdesc->u.plcp.service);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_SERVICE_REGNUM, 6);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_SERVICE_BUSY, 1);
 	rt2x00_desc_write(txd, 3, word);
 
 	rt2x00_desc_read(txd, 4, &word);
-	rt2x00_set_field32(&word, TXD_W4_PLCP_LENGTH_LOW, txdesc->length_low);
+	rt2x00_set_field32(&word, TXD_W4_PLCP_LENGTH_LOW,
+			   txdesc->u.plcp.length_low);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_LOW_REGNUM, 8);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_LOW_BUSY, 1);
-	rt2x00_set_field32(&word, TXD_W4_PLCP_LENGTH_HIGH, txdesc->length_high);
+	rt2x00_set_field32(&word, TXD_W4_PLCP_LENGTH_HIGH,
+			   txdesc->u.plcp.length_high);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_HIGH_REGNUM, 7);
 	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_HIGH_BUSY, 1);
 	rt2x00_desc_write(txd, 4, word);
diff --git a/drivers/net/wireless/rt2x00/rt2500pci.c b/drivers/net/wireless/rt2x00/rt2500pci.c
index b00e4d483c58..53ff64e19648 100644
--- a/drivers/net/wireless/rt2x00/rt2500pci.c
+++ b/drivers/net/wireless/rt2x00/rt2500pci.c
@@ -1287,10 +1287,12 @@ static void rt2500pci_write_tx_desc(struct queue_entry *entry,
 	rt2x00_desc_write(txd, 2, word);
 
 	rt2x00_desc_read(txd, 3, &word);
-	rt2x00_set_field32(&word, TXD_W3_PLCP_SIGNAL, txdesc->signal);
-	rt2x00_set_field32(&word, TXD_W3_PLCP_SERVICE, txdesc->service);
-	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_LOW, txdesc->length_low);
-	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_HIGH, txdesc->length_high);
+	rt2x00_set_field32(&word, TXD_W3_PLCP_SIGNAL, txdesc->u.plcp.signal);
+	rt2x00_set_field32(&word, TXD_W3_PLCP_SERVICE, txdesc->u.plcp.service);
+	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_LOW,
+			   txdesc->u.plcp.length_low);
+	rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_HIGH,
+			   txdesc->u.plcp.length_high);
 	rt2x00_desc_write(txd, 3, word);
 
 	rt2x00_desc_read(txd, 10, &word);
diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index b71df29436e7..ed5bc9c6224f 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1114,10 +1114,12 @@ static void rt2500usb_write_tx_desc(struct queue_entry *entry,
 	rt2x00_desc_write(txd, 1, word);
 
 	rt2x00_desc_read(txd, 2, &word);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_SIGNAL, txdesc->signal);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_SERVICE, txdesc->service);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_LOW, txdesc->length_low);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_HIGH, txdesc->length_high);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_SIGNAL, txdesc->u.plcp.signal);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_SERVICE, txdesc->u.plcp.service);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_LOW,
+			   txdesc->u.plcp.length_low);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_HIGH,
+			   txdesc->u.plcp.length_high);
 	rt2x00_desc_write(txd, 2, word);
 
 	if (test_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags)) {
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index ad90c86810d7..553d4d01a439 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -472,14 +472,15 @@ void rt2800_write_tx_data(struct queue_entry *entry,
 			   test_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags));
 	rt2x00_set_field32(&word, TXWI_W0_AMPDU,
 			   test_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags));
-	rt2x00_set_field32(&word, TXWI_W0_MPDU_DENSITY, txdesc->mpdu_density);
-	rt2x00_set_field32(&word, TXWI_W0_TX_OP, txdesc->txop);
-	rt2x00_set_field32(&word, TXWI_W0_MCS, txdesc->mcs);
+	rt2x00_set_field32(&word, TXWI_W0_MPDU_DENSITY,
+			   txdesc->u.ht.mpdu_density);
+	rt2x00_set_field32(&word, TXWI_W0_TX_OP, txdesc->u.ht.txop);
+	rt2x00_set_field32(&word, TXWI_W0_MCS, txdesc->u.ht.mcs);
 	rt2x00_set_field32(&word, TXWI_W0_BW,
 			   test_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags));
 	rt2x00_set_field32(&word, TXWI_W0_SHORT_GI,
 			   test_bit(ENTRY_TXD_HT_SHORT_GI, &txdesc->flags));
-	rt2x00_set_field32(&word, TXWI_W0_STBC, txdesc->stbc);
+	rt2x00_set_field32(&word, TXWI_W0_STBC, txdesc->u.ht.stbc);
 	rt2x00_set_field32(&word, TXWI_W0_PHYMODE, txdesc->rate_mode);
 	rt2x00_desc_write(txwi, 0, word);
 
@@ -488,7 +489,7 @@ void rt2800_write_tx_data(struct queue_entry *entry,
 			   test_bit(ENTRY_TXD_ACK, &txdesc->flags));
 	rt2x00_set_field32(&word, TXWI_W1_NSEQ,
 			   test_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags));
-	rt2x00_set_field32(&word, TXWI_W1_BW_WIN_SIZE, txdesc->ba_size);
+	rt2x00_set_field32(&word, TXWI_W1_BW_WIN_SIZE, txdesc->u.ht.ba_size);
 	rt2x00_set_field32(&word, TXWI_W1_WIRELESS_CLI_ID,
 			   test_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags) ?
 			   txdesc->key_idx : 0xff);
diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c
index 046a7b7d1241..49ea189c9821 100644
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -979,6 +979,7 @@ static int rt2800pci_probe_hw(struct rt2x00_dev *rt2x00dev)
 	if (!modparam_nohwcrypt)
 		__set_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags);
 	__set_bit(DRIVER_SUPPORT_LINK_TUNING, &rt2x00dev->flags);
+	__set_bit(DRIVER_REQUIRE_HT_TX_DESC, &rt2x00dev->flags);
 
 	/*
 	 * Set the rssi offset.
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index 5d91561e0de7..f1a92144996f 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -565,6 +565,7 @@ static int rt2800usb_probe_hw(struct rt2x00_dev *rt2x00dev)
 		__set_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags);
 	__set_bit(DRIVER_SUPPORT_LINK_TUNING, &rt2x00dev->flags);
 	__set_bit(DRIVER_SUPPORT_WATCHDOG, &rt2x00dev->flags);
+	__set_bit(DRIVER_REQUIRE_HT_TX_DESC, &rt2x00dev->flags);
 
 	/*
 	 * Set the rssi offset.
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 9067c917c659..81a0f8bed6ae 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -663,6 +663,7 @@ enum rt2x00_flags {
 	DRIVER_REQUIRE_TXSTATUS_FIFO,
 	DRIVER_REQUIRE_TASKLET_CONTEXT,
 	DRIVER_REQUIRE_SW_SEQNO,
+	DRIVER_REQUIRE_HT_TX_DESC,
 
 	/*
 	 * Driver features
diff --git a/drivers/net/wireless/rt2x00/rt2x00ht.c b/drivers/net/wireless/rt2x00/rt2x00ht.c
index 03d9579da681..78a0e7386a78 100644
--- a/drivers/net/wireless/rt2x00/rt2x00ht.c
+++ b/drivers/net/wireless/rt2x00/rt2x00ht.c
@@ -38,12 +38,12 @@ void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
 
 	if (tx_info->control.sta)
-		txdesc->mpdu_density =
+		txdesc->u.ht.mpdu_density =
 		    tx_info->control.sta->ht_cap.ampdu_density;
 
-	txdesc->ba_size = 7;	/* FIXME: What value is needed? */
+	txdesc->u.ht.ba_size = 7;	/* FIXME: What value is needed? */
 
-	txdesc->stbc =
+	txdesc->u.ht.stbc =
 	    (tx_info->flags & IEEE80211_TX_CTL_STBC) >> IEEE80211_TX_CTL_STBC_SHIFT;
 
 	/*
@@ -51,22 +51,22 @@ void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
 	 * mcs rate to be used
 	 */
 	if (txrate->flags & IEEE80211_TX_RC_MCS) {
-		txdesc->mcs = txrate->idx;
+		txdesc->u.ht.mcs = txrate->idx;
 
 		/*
 		 * MIMO PS should be set to 1 for STA's using dynamic SM PS
 		 * when using more then one tx stream (>MCS7).
 		 */
-		if (tx_info->control.sta && txdesc->mcs > 7 &&
+		if (tx_info->control.sta && txdesc->u.ht.mcs > 7 &&
 		    ((tx_info->control.sta->ht_cap.cap &
 		      IEEE80211_HT_CAP_SM_PS) >>
 		     IEEE80211_HT_CAP_SM_PS_SHIFT) ==
 		    WLAN_HT_CAP_SM_PS_DYNAMIC)
 			__set_bit(ENTRY_TXD_HT_MIMO_PS, &txdesc->flags);
 	} else {
-		txdesc->mcs = rt2x00_get_rate_mcs(hwrate->mcs);
+		txdesc->u.ht.mcs = rt2x00_get_rate_mcs(hwrate->mcs);
 		if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
-			txdesc->mcs |= 0x08;
+			txdesc->u.ht.mcs |= 0x08;
 	}
 
 	/*
@@ -105,11 +105,11 @@ void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
 	 * for frames not transmitted with TXOP_HTTXOP
 	 */
 	if (ieee80211_is_mgmt(hdr->frame_control))
-		txdesc->txop = TXOP_BACKOFF;
+		txdesc->u.ht.txop = TXOP_BACKOFF;
 	else if (!(tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT))
-		txdesc->txop = TXOP_SIFS;
+		txdesc->u.ht.txop = TXOP_SIFS;
 	else
-		txdesc->txop = TXOP_HTTXOP;
+		txdesc->u.ht.txop = TXOP_HTTXOP;
 }
 
 u16 rt2x00ht_center_channel(struct rt2x00_dev *rt2x00dev,
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index eebb564ee4da..7816c1c39d6e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -270,12 +270,12 @@ static void rt2x00queue_create_tx_descriptor_plcp(struct queue_entry *entry,
 	 * PLCP setup
 	 * Length calculation depends on OFDM/CCK rate.
 	 */
-	txdesc->signal = hwrate->plcp;
-	txdesc->service = 0x04;
+	txdesc->u.plcp.signal = hwrate->plcp;
+	txdesc->u.plcp.service = 0x04;
 
 	if (hwrate->flags & DEV_RATE_OFDM) {
-		txdesc->length_high = (data_length >> 6) & 0x3f;
-		txdesc->length_low = data_length & 0x3f;
+		txdesc->u.plcp.length_high = (data_length >> 6) & 0x3f;
+		txdesc->u.plcp.length_low = data_length & 0x3f;
 	} else {
 		/*
 		 * Convert length to microseconds.
@@ -290,18 +290,18 @@ static void rt2x00queue_create_tx_descriptor_plcp(struct queue_entry *entry,
 			 * Check if we need to set the Length Extension
 			 */
 			if (hwrate->bitrate == 110 && residual <= 30)
-				txdesc->service |= 0x80;
+				txdesc->u.plcp.service |= 0x80;
 		}
 
-		txdesc->length_high = (duration >> 8) & 0xff;
-		txdesc->length_low = duration & 0xff;
+		txdesc->u.plcp.length_high = (duration >> 8) & 0xff;
+		txdesc->u.plcp.length_low = duration & 0xff;
 
 		/*
 		 * When preamble is enabled we should set the
 		 * preamble bit for the signal.
 		 */
 		if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
-			txdesc->signal |= 0x08;
+			txdesc->u.plcp.signal |= 0x08;
 	}
 }
 
@@ -397,9 +397,12 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
 	 * Apply TX descriptor handling by components
 	 */
 	rt2x00crypto_create_tx_descriptor(entry, txdesc);
-	rt2x00ht_create_tx_descriptor(entry, txdesc, hwrate);
 	rt2x00queue_create_tx_descriptor_seq(entry, txdesc);
-	rt2x00queue_create_tx_descriptor_plcp(entry, txdesc, hwrate);
+
+	if (test_bit(DRIVER_REQUIRE_HT_TX_DESC, &rt2x00dev->flags))
+		rt2x00ht_create_tx_descriptor(entry, txdesc, hwrate);
+	else
+		rt2x00queue_create_tx_descriptor_plcp(entry, txdesc, hwrate);
 }
 
 static int rt2x00queue_write_tx_data(struct queue_entry *entry,
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index fab8e2687f29..330552046440 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -305,20 +305,27 @@ struct txentry_desc {
 	u16 length;
 	u16 header_length;
 
-	u16 length_high;
-	u16 length_low;
-	u16 signal;
-	u16 service;
-
-	u16 mcs;
-	u16 stbc;
-	u16 ba_size;
+	union {
+		struct {
+			u16 length_high;
+			u16 length_low;
+			u16 signal;
+			u16 service;
+		} plcp;
+
+		struct {
+			u16 mcs;
+			u16 stbc;
+			u16 ba_size;
+			u16 mpdu_density;
+			short txop;
+		} ht;
+	} u;
+
 	u16 rate_mode;
-	u16 mpdu_density;
 
 	short retry_limit;
 	short ifs;
-	short txop;
 
 	enum cipher cipher;
 	u16 key_idx;
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 2ed845b1ea3c..c01b811a50d5 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -1898,10 +1898,12 @@ static void rt61pci_write_tx_desc(struct queue_entry *entry,
 	rt2x00_desc_write(txd, 1, word);
 
 	rt2x00_desc_read(txd, 2, &word);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_SIGNAL, txdesc->signal);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_SERVICE, txdesc->service);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_LOW, txdesc->length_low);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_HIGH, txdesc->length_high);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_SIGNAL, txdesc->u.plcp.signal);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_SERVICE, txdesc->u.plcp.service);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_LOW,
+			   txdesc->u.plcp.length_low);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_HIGH,
+			   txdesc->u.plcp.length_high);
 	rt2x00_desc_write(txd, 2, word);
 
 	if (test_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags)) {
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index a799c262c1db..a4c9a3e20ec4 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -1499,10 +1499,12 @@ static void rt73usb_write_tx_desc(struct queue_entry *entry,
 	rt2x00_desc_write(txd, 1, word);
 
 	rt2x00_desc_read(txd, 2, &word);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_SIGNAL, txdesc->signal);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_SERVICE, txdesc->service);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_LOW, txdesc->length_low);
-	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_HIGH, txdesc->length_high);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_SIGNAL, txdesc->u.plcp.signal);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_SERVICE, txdesc->u.plcp.service);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_LOW,
+			   txdesc->u.plcp.length_low);
+	rt2x00_set_field32(&word, TXD_W2_PLCP_LENGTH_HIGH,
+			   txdesc->u.plcp.length_high);
 	rt2x00_desc_write(txd, 2, word);
 
 	if (test_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags)) {