* 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]
return;
error_waiter_cancelled:
- if (ack_skb)
- kfree_skb(ack_skb);
+ kfree_skb(ack_skb);
error_no_waiter:
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
return;
}
-
-
/*
* 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 */
projects / mv-sheeva.git / blobdiff