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;
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;
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);
* 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
* 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.
*/
* 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);
}
* @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.
*
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);
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,
* 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_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]
}
-
-
/*
* Receive and send up a trace
*
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);
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",
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",
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 */
I2400M_PT_TRACE, /* For device debug */
I2400M_PT_RESET_WARM, /* device reset */
I2400M_PT_RESET_COLD, /* USB[transport] reset, like reconnect */
+ I2400M_PT_EDATA, /* Extended RX data */
I2400M_PT_ILLEGAL
};
} __attribute__((packed));
+/*
+ * Payload for an extended data packet
+ *
+ * New in v1.4
+ *
+ * @cs: the type of data in the packet, as defined per (802.16e
+ * T11.13.19.1). Currently only 2 (IPv4 packet) supported.
+ *
+ * This is prefixed to each and every INCOMING DATA packet.
+ */
+struct i2400m_pl_edata_hdr {
+ __le32 reorder;
+ __u8 cs;
+ __u8 reserved[11];
+} __attribute__((packed));
+
+enum i2400m_cs {
+ I2400M_CS_IPV4_0 = 0,
+ I2400M_CS_IPV4 = 2,
+};
+
+enum i2400m_reorder {
+ I2400M_REORDER_NEEDED = 0x01,
+};
+
+
/* Misc constants */
enum {
I2400M_PL_PAD = 16, /* Payload data size alignment */
I2400M_TLV_DEVICE_RESET_TYPE = 132,
I2400M_TLV_CONFIG_IDLE_PARAMETERS = 601,
I2400M_TLV_CONFIG_IDLE_TIMEOUT = 611,
+ I2400M_TLV_CONFIG_D2H_DATA_FORMAT = 614,
};
* 0 disabled */
} __attribute__((packed));
+/* New in v1.4 -- for backward compat, will be removed */
+struct i2400m_tlv_config_d2h_data_format {
+ struct i2400m_tlv_hdr hdr;
+ __u8 format; /* 0 old format, 1 enhanced */
+ __u8 reserved[3];
+} __attribute__((packed));
+
#endif /* #ifndef __LINUX__WIMAX__I2400M_H__ */