---

yaml
---
r: 134994
b: refs/heads/master
c: fd5c565
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 347707baa77d273d79258303e00200d40cf3b323
+refs/heads/master: fd5c565c0c04d2716cfdac3f1de3c2261d6a457d

trunk/drivers/net/wimax/i2400m/control.c

@@ -1311,6 +1311,7 @@ int i2400m_dev_initialize(struct i2400m *i2400m)
 	struct device *dev = i2400m_dev(i2400m);
 	struct i2400m_tlv_config_idle_parameters idle_params;
 	struct i2400m_tlv_config_idle_timeout idle_timeout;
+	struct i2400m_tlv_config_d2h_data_format df;
 	const struct i2400m_tlv_hdr *args[9];
 	unsigned argc = 0;
 
@@ -1333,6 +1334,14 @@ int i2400m_dev_initialize(struct i2400m *i2400m)
 			args[argc++] = &idle_timeout.hdr;
 		}
 	}
+	if (i2400m_ge_v1_4(i2400m)) {
+		df.hdr.type =
+			cpu_to_le16(I2400M_TLV_CONFIG_D2H_DATA_FORMAT);
+		df.hdr.length = cpu_to_le16(
+			sizeof(df) - sizeof(df.hdr));
+		df.format = 1;
+		args[argc++] = &df.hdr;
+	}
 	result = i2400m_set_init_config(i2400m, args, argc);
 	if (result < 0)
 		goto error;

trunk/drivers/net/wimax/i2400m/i2400m.h

@@ -593,6 +593,8 @@ extern void i2400m_tx_release(struct i2400m *);
 
 extern void i2400m_net_rx(struct i2400m *, struct sk_buff *, unsigned,
 			  const void *, int);
+extern void i2400m_net_erx(struct i2400m *, struct sk_buff *,
+			   enum i2400m_cs);
 enum i2400m_pt;
 extern int i2400m_tx(struct i2400m *, const void *, size_t, enum i2400m_pt);
 

trunk/drivers/net/wimax/i2400m/netdev.c

@@ -28,13 +28,12 @@
  * space and from the other side. The world is (sadly) configured to
  * take in only Ethernet devices...
  *
- * Because of this, currently there is an copy-each-rxed-packet
- * overhead on the RX path. Each IP packet has to be reallocated to
- * add an ethernet header (as there is no space in what we get from
- * the device). This is a known drawback and coming versions of the
- * device's firmware are being changed to add header space that can be
- * used to insert the ethernet header without having to reallocate and
- * copy.
+ * Because of this, when using firmwares <= v1.3, there is an
+ * copy-each-rxed-packet overhead on the RX path. Each IP packet has
+ * to be reallocated to add an ethernet header (as there is no space
+ * in what we get from the device). This is a known drawback and
+ * firmwares >= 1.4 add header space that can be used to insert the
+ * ethernet header without having to reallocate and copy.
  *
  * TX error handling is tricky; because we have to FIFO/queue the
  * buffers for transmission (as the hardware likes it aggregated), we
@@ -67,7 +66,9 @@
  * i2400m_tx_timeout      Called when the device times out
  *
  * i2400m_net_rx          Called by the RX code when a data frame is
- *                        available.
+ *                        available (firmware <= 1.3)
+ * i2400m_net_erx         Called by the RX code when a data frame is
+ *                        available (firmware >= 1.4).
  * i2400m_netdev_setup    Called to setup all the netdev stuff from
  *                        alloc_netdev.
  */
@@ -396,30 +397,18 @@ void i2400m_tx_timeout(struct net_device *net_dev)
  * Create a fake ethernet header
  *
  * For emulating an ethernet device, every received IP header has to
- * be prefixed with an ethernet header.
- *
- * What we receive has (potentially) many IP packets concatenated with
- * no ETH_HLEN bytes prefixed. Thus there is no space for an eth
- * header.
- *
- * We would have to reallocate or do ugly fragment tricks in order to
- * add it.
- *
- * But what we do is use the header space of the RX transaction
- * (*msg_hdr) as we don't need it anymore; then we'll point all the
- * data skbs there, as they share the same backing store.
- *
- * We only support IPv4 for v3 firmware.
+ * be prefixed with an ethernet header. Fake it with the given
+ * protocol.
  */
 static
 void i2400m_rx_fake_eth_header(struct net_device *net_dev,
-			       void *_eth_hdr)
+			       void *_eth_hdr, int protocol)
 {
 	struct ethhdr *eth_hdr = _eth_hdr;
 
 	memcpy(eth_hdr->h_dest, net_dev->dev_addr, sizeof(eth_hdr->h_dest));
 	memset(eth_hdr->h_source, 0, sizeof(eth_hdr->h_dest));
-	eth_hdr->h_proto = cpu_to_be16(ETH_P_IP);
+	eth_hdr->h_proto = cpu_to_be16(protocol);
 }
 
 
@@ -432,6 +421,13 @@ void i2400m_rx_fake_eth_header(struct net_device *net_dev,
  * @buf: pointer to the buffer containing the data
  * @len: buffer's length
  *
+ * This is only used now for the v1.3 firmware. It will be deprecated
+ * in >= 2.6.31.
+ *
+ * Note that due to firmware limitations, we don't have space to add
+ * an ethernet header, so we need to copy each packet. Firmware
+ * versions >= v1.4 fix this [see i2400m_net_erx()].
+ *
  * We just clone the skb and set it up so that it's skb->data pointer
  * points to "buf" and it's length.
  *
@@ -478,7 +474,7 @@ void i2400m_net_rx(struct i2400m *i2400m, struct sk_buff *skb_rx,
 		memcpy(skb_put(skb, buf_len), buf, buf_len);
 	}
 	i2400m_rx_fake_eth_header(i2400m->wimax_dev.net_dev,
-				  skb->data - ETH_HLEN);
+				  skb->data - ETH_HLEN, ETH_P_IP);
 	skb_set_mac_header(skb, -ETH_HLEN);
 	skb->dev = i2400m->wimax_dev.net_dev;
 	skb->protocol = htons(ETH_P_IP);
@@ -493,6 +489,64 @@ void i2400m_net_rx(struct i2400m *i2400m, struct sk_buff *skb_rx,
 		i2400m, buf, buf_len);
 }
 
+
+/*
+ * i2400m_net_erx - pass a network packet to the stack (extended version)
+ *
+ * @i2400m: device descriptor
+ * @skb: the skb where the packet is - the skb should be set to point
+ *     at the IP packet; this function will add ethernet headers if
+ *     needed.
+ * @cs: packet type
+ *
+ * This is only used now for firmware >= v1.4. Note it is quite
+ * similar to i2400m_net_rx() (used only for v1.3 firmware).
+ *
+ * This function is normally run from a thread context. However, we
+ * still use netif_rx() instead of netif_receive_skb() as was
+ * recommended in the mailing list. Reason is in some stress tests
+ * when sending/receiving a lot of data we seem to hit a softlock in
+ * the kernel's TCP implementation [aroudn tcp_delay_timer()]. Using
+ * netif_rx() took care of the issue.
+ *
+ * This is, of course, still open to do more research on why running
+ * with netif_receive_skb() hits this softlock. FIXME.
+ */
+void i2400m_net_erx(struct i2400m *i2400m, struct sk_buff *skb,
+		    enum i2400m_cs cs)
+{
+	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+	struct device *dev = i2400m_dev(i2400m);
+	int protocol;
+
+	d_fnstart(2, dev, "(i2400m %p skb %p [%zu] cs %d)\n",
+		  i2400m, skb, skb->len, cs);
+	switch(cs) {
+	case I2400M_CS_IPV4_0:
+	case I2400M_CS_IPV4:
+		protocol = ETH_P_IP;
+		i2400m_rx_fake_eth_header(i2400m->wimax_dev.net_dev,
+					  skb->data - ETH_HLEN, ETH_P_IP);
+		skb_set_mac_header(skb, -ETH_HLEN);
+		skb->dev = i2400m->wimax_dev.net_dev;
+		skb->protocol = htons(ETH_P_IP);
+		net_dev->stats.rx_packets++;
+		net_dev->stats.rx_bytes += skb->len;
+		break;
+	default:
+		dev_err(dev, "ERX: BUG? CS type %u unsupported\n", cs);
+		goto error;
+
+	}
+	d_printf(3, dev, "ERX: receiving %d bytes to the network stack\n",
+		 skb->len);
+	d_dump(4, dev, skb->data, skb->len);
+	netif_rx_ni(skb);	/* see notes in function header */
+error:
+	d_fnend(2, dev, "(i2400m %p skb %p [%zu] cs %d) = void\n",
+		i2400m, skb, skb->len, cs);
+}
+
 static const struct net_device_ops i2400m_netdev_ops = {
 	.ndo_open = i2400m_open,
 	.ndo_stop = i2400m_stop,

trunk/drivers/net/wimax/i2400m/rx.c

@@ -69,13 +69,31 @@
  * See tx.c for a deeper description on alignment requirements and
  * other fun facts of it.
  *
+ * DATA PACKETS
+ *
+ * In firmwares <= v1.3, data packets have no header for RX, but they
+ * do for TX (currently unused).
+ *
+ * In firmware >= 1.4, RX packets have an extended header (16
+ * bytes). This header conveys information for management of host
+ * reordering of packets (the device offloads storage of the packets
+ * for reordering to the host).
+ *
+ * Currently this information is not used as the current code doesn't
+ * enable host reordering.
+ *
+ * The header is used as dummy space to emulate an ethernet header and
+ * thus be able to act as an ethernet device without having to reallocate.
+ *
  * ROADMAP
  *
  * i2400m_rx
  *   i2400m_rx_msg_hdr_check
  *   i2400m_rx_pl_descr_check
  *   i2400m_rx_payload
  *     i2400m_net_rx
+ *     i2400m_rx_edata
+ *       i2400m_net_erx
  *     i2400m_rx_ctl
  *       i2400m_msg_size_check
  *       i2400m_report_hook_work    [in a workqueue]
@@ -264,8 +282,6 @@ void i2400m_rx_ctl(struct i2400m *i2400m, struct sk_buff *skb_rx,
 }
 
 
-
-
 /*
  * Receive and send up a trace
  *
@@ -314,39 +330,123 @@ void i2400m_rx_trace(struct i2400m *i2400m,
 	return;
 }
 
+/*
+ * Receive and send up an extended data packet
+ *
+ * @i2400m: device descriptor
+ * @skb_rx: skb that contains the extended data packet
+ * @single_last: 1 if the payload is the only one or the last one of
+ *     the skb.
+ * @payload: pointer to the packet's data inside the skb
+ * @size: size of the payload
+ *
+ * Starting in v1.4 of the i2400m's firmware, the device can send data
+ * packets to the host in an extended format that; this incudes a 16
+ * byte header (struct i2400m_pl_edata_hdr). Using this header's space
+ * we can fake ethernet headers for ethernet device emulation without
+ * having to copy packets around.
+ *
+ * This function handles said path.
+ */
+static
+void i2400m_rx_edata(struct i2400m *i2400m, struct sk_buff *skb_rx,
+		     unsigned single_last, const void *payload, size_t size)
+{
+	struct device *dev = i2400m_dev(i2400m);
+	const struct i2400m_pl_edata_hdr *hdr = payload;
+	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+	struct sk_buff *skb;
+	enum i2400m_cs cs;
+	unsigned reorder_needed;
+
+	d_fnstart(4, dev, "(i2400m %p skb_rx %p single %u payload %p "
+		  "size %zu)\n", i2400m, skb_rx, single_last, payload, size);
+	if (size < sizeof(*hdr)) {
+		dev_err(dev, "ERX: HW BUG? message with short header (%zu "
+			"vs %zu bytes expected)\n", size, sizeof(*hdr));
+		goto error;
+	}
+	reorder_needed = le32_to_cpu(hdr->reorder & I2400M_REORDER_NEEDED);
+	cs = hdr->cs;
+	if (reorder_needed) {
+		dev_err(dev, "ERX: HW BUG? reorder needed, it was disabled\n");
+		goto error;
+	}
+	/* ok, so now decide if we want to clone or reuse the skb,
+	 * pull and trim it so the beginning is the space for the eth
+	 * header and pass it to i2400m_net_erx() for the stack */
+	if (single_last) {
+		skb = skb_get(skb_rx);
+		d_printf(3, dev, "ERX: reusing single payload skb %p\n", skb);
+	} else {
+		skb = skb_clone(skb_rx, GFP_KERNEL);
+		d_printf(3, dev, "ERX: cloning %p\n", skb);
+		if (skb == NULL) {
+			dev_err(dev, "ERX: no memory to clone skb\n");
+			net_dev->stats.rx_dropped++;
+			goto error_skb_clone;
+		}
+	}
+	/* now we have to pull and trim so that the skb points to the
+	 * beginning of the IP packet; the netdev part will add the
+	 * ethernet header as needed. */
+	BUILD_BUG_ON(ETH_HLEN > sizeof(*hdr));
+	skb_pull(skb, payload + sizeof(*hdr) - (void *) skb->data);
+	skb_trim(skb, (void *) skb_end_pointer(skb) - payload + sizeof(*hdr));
+	i2400m_net_erx(i2400m, skb, cs);
+error_skb_clone:
+error:
+	d_fnend(4, dev, "(i2400m %p skb_rx %p single %u payload %p "
+		"size %zu) = void\n", i2400m, skb_rx, single_last, payload, size);
+	return;
+}
+
+
+
 
 /*
  * Act on a received payload
  *
  * @i2400m: device instance
  * @skb_rx: skb where the transaction was received
- * @single: 1 if there is only one payload, 0 otherwise
+ * @single_last: 1 this is the only payload or the last one (so the
+ *     skb can be reused instead of cloned).
  * @pld: payload descriptor
  * @payload: payload data
  *
  * Upon reception of a payload, look at its guts in the payload
- * descriptor and decide what to do with it.
+ * descriptor and decide what to do with it. If it is a single payload
+ * skb or if the last skb is a data packet, the skb will be referenced
+ * and modified (so it doesn't have to be cloned).
  */
 static
 void i2400m_rx_payload(struct i2400m *i2400m, struct sk_buff *skb_rx,
-		       unsigned single, const struct i2400m_pld *pld,
+		       unsigned single_last, const struct i2400m_pld *pld,
 		       const void *payload)
 {
 	struct device *dev = i2400m_dev(i2400m);
 	size_t pl_size = i2400m_pld_size(pld);
 	enum i2400m_pt pl_type = i2400m_pld_type(pld);
 
+	d_printf(7, dev, "RX: received payload type %u, %zu bytes\n",
+		 pl_type, pl_size);
+	d_dump(8, dev, payload, pl_size);
+
 	switch (pl_type) {
 	case I2400M_PT_DATA:
 		d_printf(3, dev, "RX: data payload %zu bytes\n", pl_size);
-		i2400m_net_rx(i2400m, skb_rx, single, payload, pl_size);
+		i2400m_net_rx(i2400m, skb_rx, single_last, payload, pl_size);
 		break;
 	case I2400M_PT_CTRL:
 		i2400m_rx_ctl(i2400m, skb_rx, payload, pl_size);
 		break;
 	case I2400M_PT_TRACE:
 		i2400m_rx_trace(i2400m, payload, pl_size);
 		break;
+	case I2400M_PT_EDATA:
+		d_printf(3, dev, "ERX: data payload %zu bytes\n", pl_size);
+		i2400m_rx_edata(i2400m, skb_rx, single_last, payload, pl_size);
+		break;
 	default:	/* Anything else shouldn't come to the host */
 		if (printk_ratelimit())
 			dev_err(dev, "RX: HW BUG? unexpected payload type %u\n",
@@ -474,7 +574,7 @@ int i2400m_rx(struct i2400m *i2400m, struct sk_buff *skb)
 	const struct i2400m_msg_hdr *msg_hdr;
 	size_t pl_itr, pl_size, skb_len;
 	unsigned long flags;
-	unsigned num_pls;
+	unsigned num_pls, single_last;
 
 	skb_len = skb->len;
 	d_fnstart(4, dev, "(i2400m %p skb %p [size %zu])\n",
@@ -503,7 +603,8 @@ int i2400m_rx(struct i2400m *i2400m, struct sk_buff *skb)
 						  pl_itr, skb->len);
 		if (result < 0)
 			goto error_pl_descr_check;
-		i2400m_rx_payload(i2400m, skb, num_pls == 1, &msg_hdr->pld[i],
+		single_last = num_pls == 1 || i == num_pls - 1;
+		i2400m_rx_payload(i2400m, skb, single_last, &msg_hdr->pld[i],
 				  skb->data + pl_itr);
 		pl_itr += ALIGN(pl_size, I2400M_PL_PAD);
 		cond_resched();		/* Don't monopolize */