diff options
Diffstat (limited to 'drivers/net/wimax/i2400m/rx.c')
| -rw-r--r-- | drivers/net/wimax/i2400m/rx.c | 117 |
1 files changed, 109 insertions, 8 deletions
diff --git a/drivers/net/wimax/i2400m/rx.c b/drivers/net/wimax/i2400m/rx.c index c62b8c5..cd52506 100644 --- a/drivers/net/wimax/i2400m/rx.c +++ b/drivers/net/wimax/i2400m/rx.c @@ -69,6 +69,22 @@ * 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 @@ -76,6 +92,8 @@ * 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 @@ error_check: } - - /* * Receive and send up a trace * @@ -314,32 +330,112 @@ error_check: 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); @@ -347,6 +443,10 @@ void i2400m_rx_payload(struct i2400m *i2400m, struct sk_buff *skb_rx, 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 */ |