b43legacy: fix upload of beacon packets to the hardware

This fixes uploading of the beacon data and writing of the TIM and DTIM offsets.

The patch by Michael Buesch has been ported to b43legacy.
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43legacy/b43legacy.h

@@ -130,13 +130,19 @@
 #define B43legacy_SHM_SH_HOSTFHI	0x0060 /* Hostflags ucode opts (high) */
 /* SHM_SHARED crypto engine */
 #define B43legacy_SHM_SH_KEYIDXBLOCK	0x05D4 /* Key index/algorithm block */
-/* SHM_SHARED beacon variables */
+/* SHM_SHARED beacon/AP variables */
+#define B43legacy_SHM_SH_DTIMP		0x0012 /* DTIM period */
+#define B43legacy_SHM_SH_BTL0		0x0018 /* Beacon template length 0 */
+#define B43legacy_SHM_SH_BTL1		0x001A /* Beacon template length 1 */
+#define B43legacy_SHM_SH_BTSFOFF	0x001C /* Beacon TSF offset */
+#define B43legacy_SHM_SH_TIMPOS		0x001E /* TIM position in beacon */
 #define B43legacy_SHM_SH_BEACPHYCTL	0x0054 /* Beacon PHY TX control word */
 /* SHM_SHARED ACK/CTS control */
 #define B43legacy_SHM_SH_ACKCTSPHYCTL	0x0022 /* ACK/CTS PHY control word */
 /* SHM_SHARED probe response variables */
-#define B43legacy_SHM_SH_PRPHYCTL	0x0188 /* Probe Resp PHY TX control */
+#define B43legacy_SHM_SH_PRTLEN		0x004A /* Probe Response template length */
 #define B43legacy_SHM_SH_PRMAXTIME	0x0074 /* Probe Response max time */
+#define B43legacy_SHM_SH_PRPHYCTL	0x0188 /* Probe Resp PHY TX control */
 /* SHM_SHARED rate tables */
 /* SHM_SHARED microcode soft registers */
 #define B43legacy_SHM_SH_UCODEREV	0x0000 /* Microcode revision */
@@ -601,6 +607,12 @@ struct b43legacy_wl {
 	u8 nr_devs;
 
 	bool radiotap_enabled;
+
+	/* The beacon we are currently using (AP or IBSS mode).
+	 * This beacon stuff is protected by the irq_lock. */
+	struct sk_buff *current_beacon;
+	bool beacon0_uploaded;
+	bool beacon1_uploaded;
 };
 
 /* Pointers to the firmware data and meta information about it. */
@@ -699,9 +711,6 @@ struct b43legacy_wldev {
 	u8 max_nr_keys;
 	struct b43legacy_key key[58];
 
-	/* Cached beacon template while uploading the template. */
-	struct sk_buff *cached_beacon;
-
 	/* Firmware data */
 	struct b43legacy_firmware fw;
 

drivers/net/wireless/b43legacy/main.c

@@ -962,16 +962,61 @@ static void b43legacy_write_beacon_template(struct b43legacy_wldev *dev,
 					    u16 ram_offset,
 					    u16 shm_size_offset, u8 rate)
 {
-	int len;
-	const u8 *data;
 
-	B43legacy_WARN_ON(!dev->cached_beacon);
-	len = min((size_t)dev->cached_beacon->len,
+	unsigned int i, len, variable_len;
+	const struct ieee80211_mgmt *bcn;
+	const u8 *ie;
+	bool tim_found = 0;
+
+	bcn = (const struct ieee80211_mgmt *)(dev->wl->current_beacon->data);
+	len = min((size_t)dev->wl->current_beacon->len,
 		  0x200 - sizeof(struct b43legacy_plcp_hdr6));
-	data = (const u8 *)(dev->cached_beacon->data);
-	b43legacy_write_template_common(dev, data,
-					len, ram_offset,
+
+	b43legacy_write_template_common(dev, (const u8 *)bcn, len, ram_offset,
 					shm_size_offset, rate);
+
+	/* Find the position of the TIM and the DTIM_period value
+	 * and write them to SHM. */
+	ie = bcn->u.beacon.variable;
+	variable_len = len - offsetof(struct ieee80211_mgmt, u.beacon.variable);
+	for (i = 0; i < variable_len - 2; ) {
+		uint8_t ie_id, ie_len;
+
+		ie_id = ie[i];
+		ie_len = ie[i + 1];
+		if (ie_id == 5) {
+			u16 tim_position;
+			u16 dtim_period;
+			/* This is the TIM Information Element */
+
+			/* Check whether the ie_len is in the beacon data range. */
+			if (variable_len < ie_len + 2 + i)
+				break;
+			/* A valid TIM is at least 4 bytes long. */
+			if (ie_len < 4)
+				break;
+			tim_found = 1;
+
+			tim_position = sizeof(struct b43legacy_plcp_hdr6);
+			tim_position += offsetof(struct ieee80211_mgmt,
+						 u.beacon.variable);
+			tim_position += i;
+
+			dtim_period = ie[i + 3];
+
+			b43legacy_shm_write16(dev, B43legacy_SHM_SHARED,
+					B43legacy_SHM_SH_TIMPOS, tim_position);
+			b43legacy_shm_write16(dev, B43legacy_SHM_SHARED,
+					B43legacy_SHM_SH_DTIMP, dtim_period);
+			break;
+		}
+		i += ie_len + 2;
+	}
+	if (!tim_found) {
+		b43legacywarn(dev->wl, "Did not find a valid TIM IE in the "
+			      "beacon template packet. AP or IBSS operation "
+			      "may be broken.\n");
+	}
 }
 
 static void b43legacy_write_probe_resp_plcp(struct b43legacy_wldev *dev,
@@ -1004,26 +1049,27 @@ static void b43legacy_write_probe_resp_plcp(struct b43legacy_wldev *dev,
  * 2) Patching duration field
  * 3) Stripping TIM
  */
-static u8 *b43legacy_generate_probe_resp(struct b43legacy_wldev *dev,
+static const u8 *b43legacy_generate_probe_resp(struct b43legacy_wldev *dev,
 					       u16 *dest_size,
 					       struct ieee80211_rate *rate)
 {
 	const u8 *src_data;
 	u8 *dest_data;
-	u16 src_size;
-	u16 elem_size;
-	u16 src_pos;
-	u16 dest_pos;
+	u16 src_size, elem_size, src_pos, dest_pos;
 	__le16 dur;
 	struct ieee80211_hdr *hdr;
+	size_t ie_start;
+
+	src_size = dev->wl->current_beacon->len;
+	src_data = (const u8 *)dev->wl->current_beacon->data;
 
-	B43legacy_WARN_ON(!dev->cached_beacon);
-	src_size = dev->cached_beacon->len;
-	src_data = (const u8 *)dev->cached_beacon->data;
+	/* Get the start offset of the variable IEs in the packet. */
+	ie_start = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
+	B43legacy_WARN_ON(ie_start != offsetof(struct ieee80211_mgmt,
+					       u.beacon.variable));
 
-	if (unlikely(src_size < 0x24)) {
-		b43legacydbg(dev->wl, "b43legacy_generate_probe_resp: "
-		       "invalid beacon\n");
+	if (src_size < ie_start) {
+		B43legacy_WARN_ON(1);
 		return NULL;
 	}
 
@@ -1031,19 +1077,18 @@ static u8 *b43legacy_generate_probe_resp(struct b43legacy_wldev *dev,
 	if (unlikely(!dest_data))
 		return NULL;
 
-	/* 0x24 is offset of first variable-len Information-Element
-	 * in beacon frame.
-	 */
-	memcpy(dest_data, src_data, 0x24);
-	src_pos = 0x24;
-	dest_pos = 0x24;
-	for (; src_pos < src_size - 2; src_pos += elem_size) {
+	/* Copy the static data and all Information Elements, except the TIM. */
+	memcpy(dest_data, src_data, ie_start);
+	src_pos = ie_start;
+	dest_pos = ie_start;
+	for ( ; src_pos < src_size - 2; src_pos += elem_size) {
 		elem_size = src_data[src_pos + 1] + 2;
-		if (src_data[src_pos] != 0x05) { /* TIM */
-			memcpy(dest_data + dest_pos, src_data + src_pos,
-			       elem_size);
-			dest_pos += elem_size;
+		if (src_data[src_pos] == 5) {
+			/* This is the TIM. */
+			continue;
 		}
+		memcpy(dest_data + dest_pos, src_data + src_pos, elem_size);
+		dest_pos += elem_size;
 	}
 	*dest_size = dest_pos;
 	hdr = (struct ieee80211_hdr *)dest_data;
@@ -1065,11 +1110,10 @@ static void b43legacy_write_probe_resp_template(struct b43legacy_wldev *dev,
 						u16 shm_size_offset,
 						struct ieee80211_rate *rate)
 {
-	u8 *probe_resp_data;
+	const u8 *probe_resp_data;
 	u16 size;
 
-	B43legacy_WARN_ON(!dev->cached_beacon);
-	size = dev->cached_beacon->len;
+	size = dev->wl->current_beacon->len;
 	probe_resp_data = b43legacy_generate_probe_resp(dev, &size, rate);
 	if (unlikely(!probe_resp_data))
 		return;
@@ -1094,43 +1138,21 @@ static void b43legacy_write_probe_resp_template(struct b43legacy_wldev *dev,
 	kfree(probe_resp_data);
 }
 
-static int b43legacy_refresh_cached_beacon(struct b43legacy_wldev *dev,
+/* Asynchronously update the packet templates in template RAM.
+ * Locking: Requires wl->irq_lock to be locked. */
+static void b43legacy_update_templates(struct b43legacy_wl *wl,
 				       struct sk_buff *beacon)
 {
-	if (dev->cached_beacon)
-		kfree_skb(dev->cached_beacon);
-	dev->cached_beacon = beacon;
-
-	return 0;
-}
-
-static void b43legacy_update_templates(struct b43legacy_wldev *dev)
-{
-	u32 cmd;
-
-	B43legacy_WARN_ON(!dev->cached_beacon);
-
-	b43legacy_write_beacon_template(dev, 0x68, 0x18,
-					B43legacy_CCK_RATE_1MB);
-	b43legacy_write_beacon_template(dev, 0x468, 0x1A,
-					B43legacy_CCK_RATE_1MB);
-	b43legacy_write_probe_resp_template(dev, 0x268, 0x4A,
-					    &b43legacy_b_ratetable[0]);
-
-	cmd = b43legacy_read32(dev, B43legacy_MMIO_MACCMD);
-	cmd |= B43legacy_MACCMD_BEACON0_VALID | B43legacy_MACCMD_BEACON1_VALID;
-	b43legacy_write32(dev, B43legacy_MMIO_MACCMD, cmd);
-}
-
-static void b43legacy_refresh_templates(struct b43legacy_wldev *dev,
-					struct sk_buff *beacon)
-{
-	int err;
+	/* This is the top half of the ansynchronous beacon update. The bottom
+	 * half is the beacon IRQ. Beacon update must be asynchronous to avoid
+	 * sending an invalid beacon. This can happen for example, if the
+	 * firmware transmits a beacon while we are updating it. */
 
-	err = b43legacy_refresh_cached_beacon(dev, beacon);
-	if (unlikely(err))
-		return;
-	b43legacy_update_templates(dev);
+	if (wl->current_beacon)
+		dev_kfree_skb_any(wl->current_beacon);
+	wl->current_beacon = beacon;
+	wl->beacon0_uploaded = 0;
+	wl->beacon1_uploaded = 0;
 }
 
 static void b43legacy_set_ssid(struct b43legacy_wldev *dev,
@@ -1171,38 +1193,37 @@ static void b43legacy_set_beacon_int(struct b43legacy_wldev *dev,
 
 static void handle_irq_beacon(struct b43legacy_wldev *dev)
 {
-	u32 status;
+	struct b43legacy_wl *wl = dev->wl;
+	u32 cmd;
 
-	if (!b43legacy_is_mode(dev->wl, IEEE80211_IF_TYPE_AP))
+	if (!b43legacy_is_mode(wl, IEEE80211_IF_TYPE_AP))
 		return;
 
-	dev->irq_savedstate &= ~B43legacy_IRQ_BEACON;
-	status = b43legacy_read32(dev, B43legacy_MMIO_MACCMD);
+	/* This is the bottom half of the asynchronous beacon update. */
 
-	if (!dev->cached_beacon || ((status & 0x1) && (status & 0x2))) {
-		/* ACK beacon IRQ. */
-		b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_REASON,
-				  B43legacy_IRQ_BEACON);
-		dev->irq_savedstate |= B43legacy_IRQ_BEACON;
-		if (dev->cached_beacon)
-			kfree_skb(dev->cached_beacon);
-		dev->cached_beacon = NULL;
-		return;
-	}
-	if (!(status & 0x1)) {
-		b43legacy_write_beacon_template(dev, 0x68, 0x18,
+	cmd = b43legacy_read32(dev, B43legacy_MMIO_MACCMD);
+	if (!(cmd & B43legacy_MACCMD_BEACON0_VALID)) {
+		if (!wl->beacon0_uploaded) {
+			b43legacy_write_beacon_template(dev, 0x68,
+							B43legacy_SHM_SH_BTL0,
 							B43legacy_CCK_RATE_1MB);
-		status |= 0x1;
-		b43legacy_write32(dev, B43legacy_MMIO_MACCMD,
-				  status);
+			b43legacy_write_probe_resp_template(dev, 0x268,
+							    B43legacy_SHM_SH_PRTLEN,
+							    &__b43legacy_ratetable[3]);
+			wl->beacon0_uploaded = 1;
 		}
-	if (!(status & 0x2)) {
-		b43legacy_write_beacon_template(dev, 0x468, 0x1A,
+		cmd |= B43legacy_MACCMD_BEACON0_VALID;
+	}
+	if (!(cmd & B43legacy_MACCMD_BEACON1_VALID)) {
+		if (!wl->beacon1_uploaded) {
+			b43legacy_write_beacon_template(dev, 0x468,
+							B43legacy_SHM_SH_BTL1,
 							B43legacy_CCK_RATE_1MB);
-		status |= 0x2;
-		b43legacy_write32(dev, B43legacy_MMIO_MACCMD,
-				  status);
+			wl->beacon1_uploaded = 1;
+		}
+		cmd |= B43legacy_MACCMD_BEACON1_VALID;
 	}
+	b43legacy_write32(dev, B43legacy_MMIO_MACCMD, cmd);
 }
 
 static void handle_irq_ucode_debug(struct b43legacy_wldev *dev)
@@ -2709,7 +2730,7 @@ static int b43legacy_op_config_interface(struct ieee80211_hw *hw,
 			B43legacy_WARN_ON(conf->type != IEEE80211_IF_TYPE_AP);
 			b43legacy_set_ssid(dev, conf->ssid, conf->ssid_len);
 			if (conf->beacon)
-				b43legacy_refresh_templates(dev, conf->beacon);
+				b43legacy_update_templates(wl, conf->beacon);
 		}
 		b43legacy_write_mac_bssid_templates(dev);
 	}
@@ -3022,6 +3043,11 @@ static void b43legacy_wireless_core_exit(struct b43legacy_wldev *dev)
 		kfree(phy->tssi2dbm);
 	kfree(phy->lo_control);
 	phy->lo_control = NULL;
+	if (dev->wl->current_beacon) {
+		dev_kfree_skb_any(dev->wl->current_beacon);
+		dev->wl->current_beacon = NULL;
+	}
+
 	ssb_device_disable(dev->dev, 0);
 	ssb_bus_may_powerdown(dev->dev->bus);
 }
@@ -3346,6 +3372,41 @@ static int b43legacy_op_set_retry_limit(struct ieee80211_hw *hw,
 	return err;
 }
 
+static int b43legacy_op_beacon_set_tim(struct ieee80211_hw *hw,
+				       int aid, int set)
+{
+	struct b43legacy_wl *wl = hw_to_b43legacy_wl(hw);
+	struct sk_buff *beacon;
+	unsigned long flags;
+
+	/* We could modify the existing beacon and set the aid bit in the TIM
+	 * field, but that would probably require resizing and moving of data
+	 * within the beacon template. Simply request a new beacon and let
+	 * mac80211 do the hard work. */
+	beacon = ieee80211_beacon_get(hw, wl->vif, NULL);
+	if (unlikely(!beacon))
+		return -ENOMEM;
+	spin_lock_irqsave(&wl->irq_lock, flags);
+	b43legacy_update_templates(wl, beacon);
+	spin_unlock_irqrestore(&wl->irq_lock, flags);
+
+	return 0;
+}
+
+static int b43legacy_op_ibss_beacon_update(struct ieee80211_hw *hw,
+					   struct sk_buff *beacon,
+					   struct ieee80211_tx_control *ctl)
+{
+	struct b43legacy_wl *wl = hw_to_b43legacy_wl(hw);
+	unsigned long flags;
+
+	spin_lock_irqsave(&wl->irq_lock, flags);
+	b43legacy_update_templates(wl, beacon);
+	spin_unlock_irqrestore(&wl->irq_lock, flags);
+
+	return 0;
+}
+
 static const struct ieee80211_ops b43legacy_hw_ops = {
 	.tx			= b43legacy_op_tx,
 	.conf_tx		= b43legacy_op_conf_tx,
@@ -3359,6 +3420,8 @@ static const struct ieee80211_ops b43legacy_hw_ops = {
 	.start			= b43legacy_op_start,
 	.stop			= b43legacy_op_stop,
 	.set_retry_limit	= b43legacy_op_set_retry_limit,
+	.set_tim		= b43legacy_op_beacon_set_tim,
+	.beacon_update		= b43legacy_op_ibss_beacon_update,
 };
 
 /* Hard-reset the chip. Do not call this directly.