diff options
Diffstat (limited to 'drivers/uwb/i1480/i1480u-wlp/rx.c')
| -rw-r--r-- | drivers/uwb/i1480/i1480u-wlp/rx.c | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/drivers/uwb/i1480/i1480u-wlp/rx.c b/drivers/uwb/i1480/i1480u-wlp/rx.c new file mode 100644 index 000000000000..9fc035354a76 --- /dev/null +++ b/drivers/uwb/i1480/i1480u-wlp/rx.c @@ -0,0 +1,486 @@ +/* + * WUSB Wire Adapter: WLP interface + * Driver for the Linux Network stack. + * + * Copyright (C) 2005-2006 Intel Corporation + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * + * i1480u's RX handling is simple. i1480u will send the received + * network packets broken up in fragments; 1 to N fragments make a + * packet, we assemble them together and deliver the packet with netif_rx(). + * + * Beacuse each USB transfer is a *single* fragment (except when the + * transfer contains a first fragment), each URB called thus + * back contains one or two fragments. So we queue N URBs, each with its own + * fragment buffer. When a URB is done, we process it (adding to the + * current skb from the fragment buffer until complete). Once + * processed, we requeue the URB. There is always a bunch of URBs + * ready to take data, so the intergap should be minimal. + * + * An URB's transfer buffer is the data field of a socket buffer. This + * reduces copying as data can be passed directly to network layer. If a + * complete packet or 1st fragment is received the URB's transfer buffer is + * taken away from it and used to send data to the network layer. In this + * case a new transfer buffer is allocated to the URB before being requeued. + * If a "NEXT" or "LAST" fragment is received, the fragment contents is + * appended to the RX packet under construction and the transfer buffer + * is reused. To be able to use this buffer to assemble complete packets + * we set each buffer's size to that of the MAX ethernet packet that can + * be received. There is thus room for improvement in memory usage. + * + * When the max tx fragment size increases, we should be able to read + * data into the skbs directly with very simple code. + * + * ROADMAP: + * + * ENTRY POINTS: + * + * i1480u_rx_setup(): setup RX context [from i1480u_open()] + * + * i1480u_rx_release(): release RX context [from i1480u_stop()] + * + * i1480u_rx_cb(): called when the RX USB URB receives a + * packet. It removes the header and pushes it up + * the Linux netdev stack with netif_rx(). + * + * i1480u_rx_buffer() + * i1480u_drop() and i1480u_fix() + * i1480u_skb_deliver + * + */ + +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include "i1480u-wlp.h" + +#define D_LOCAL 0 +#include <linux/uwb/debug.h> + + +/** + * Setup the RX context + * + * Each URB is provided with a transfer_buffer that is the data field + * of a new socket buffer. + */ +int i1480u_rx_setup(struct i1480u *i1480u) +{ + int result, cnt; + struct device *dev = &i1480u->usb_iface->dev; + struct net_device *net_dev = i1480u->net_dev; + struct usb_endpoint_descriptor *epd; + struct sk_buff *skb; + + /* Alloc RX stuff */ + i1480u->rx_skb = NULL; /* not in process of receiving packet */ + result = -ENOMEM; + epd = &i1480u->usb_iface->cur_altsetting->endpoint[1].desc; + for (cnt = 0; cnt < i1480u_RX_BUFS; cnt++) { + struct i1480u_rx_buf *rx_buf = &i1480u->rx_buf[cnt]; + rx_buf->i1480u = i1480u; + skb = dev_alloc_skb(i1480u_MAX_RX_PKT_SIZE); + if (!skb) { + dev_err(dev, + "RX: cannot allocate RX buffer %d\n", cnt); + result = -ENOMEM; + goto error; + } + skb->dev = net_dev; + skb->ip_summed = CHECKSUM_NONE; + skb_reserve(skb, 2); + rx_buf->data = skb; + rx_buf->urb = usb_alloc_urb(0, GFP_KERNEL); + if (unlikely(rx_buf->urb == NULL)) { + dev_err(dev, "RX: cannot allocate URB %d\n", cnt); + result = -ENOMEM; + goto error; + } + usb_fill_bulk_urb(rx_buf->urb, i1480u->usb_dev, + usb_rcvbulkpipe(i1480u->usb_dev, epd->bEndpointAddress), + rx_buf->data->data, i1480u_MAX_RX_PKT_SIZE - 2, + i1480u_rx_cb, rx_buf); + result = usb_submit_urb(rx_buf->urb, GFP_NOIO); + if (unlikely(result < 0)) { + dev_err(dev, "RX: cannot submit URB %d: %d\n", + cnt, result); + goto error; + } + } + return 0; + +error: + i1480u_rx_release(i1480u); + return result; +} + + +/** Release resources associated to the rx context */ +void i1480u_rx_release(struct i1480u *i1480u) +{ + int cnt; + for (cnt = 0; cnt < i1480u_RX_BUFS; cnt++) { + if (i1480u->rx_buf[cnt].data) + dev_kfree_skb(i1480u->rx_buf[cnt].data); + if (i1480u->rx_buf[cnt].urb) { + usb_kill_urb(i1480u->rx_buf[cnt].urb); + usb_free_urb(i1480u->rx_buf[cnt].urb); + } + } + if (i1480u->rx_skb != NULL) + dev_kfree_skb(i1480u->rx_skb); +} + +static +void i1480u_rx_unlink_urbs(struct i1480u *i1480u) +{ + int cnt; + for (cnt = 0; cnt < i1480u_RX_BUFS; cnt++) { + if (i1480u->rx_buf[cnt].urb) + usb_unlink_urb(i1480u->rx_buf[cnt].urb); + } +} + +/** Fix an out-of-sequence packet */ +#define i1480u_fix(i1480u, msg...) \ +do { \ + if (printk_ratelimit()) \ + dev_err(&i1480u->usb_iface->dev, msg); \ + dev_kfree_skb_irq(i1480u->rx_skb); \ + i1480u->rx_skb = NULL; \ + i1480u->rx_untd_pkt_size = 0; \ +} while (0) + + +/** Drop an out-of-sequence packet */ +#define i1480u_drop(i1480u, msg...) \ +do { \ + if (printk_ratelimit()) \ + dev_err(&i1480u->usb_iface->dev, msg); \ + i1480u->stats.rx_dropped++; \ +} while (0) + + + + +/** Finalizes setting up the SKB and delivers it + * + * We first pass the incoming frame to WLP substack for verification. It + * may also be a WLP association frame in which case WLP will take over the + * processing. If WLP does not take it over it will still verify it, if the + * frame is invalid the skb will be freed by WLP and we will not continue + * parsing. + * */ +static +void i1480u_skb_deliver(struct i1480u *i1480u) +{ + int should_parse; + struct net_device *net_dev = i1480u->net_dev; + struct device *dev = &i1480u->usb_iface->dev; + + d_printf(6, dev, "RX delivered pre skb(%p), %u bytes\n", + i1480u->rx_skb, i1480u->rx_skb->len); + d_dump(7, dev, i1480u->rx_skb->data, i1480u->rx_skb->len); + should_parse = wlp_receive_frame(dev, &i1480u->wlp, i1480u->rx_skb, + &i1480u->rx_srcaddr); + if (!should_parse) + goto out; + i1480u->rx_skb->protocol = eth_type_trans(i1480u->rx_skb, net_dev); + d_printf(5, dev, "RX delivered skb(%p), %u bytes\n", + i1480u->rx_skb, i1480u->rx_skb->len); + d_dump(7, dev, i1480u->rx_skb->data, + i1480u->rx_skb->len > 72 ? 72 : i1480u->rx_skb->len); + i1480u->stats.rx_packets++; + i1480u->stats.rx_bytes += i1480u->rx_untd_pkt_size; + net_dev->last_rx = jiffies; + /* FIXME: flow control: check netif_rx() retval */ + + netif_rx(i1480u->rx_skb); /* deliver */ +out: + i1480u->rx_skb = NULL; + i1480u->rx_untd_pkt_size = 0; +} + + +/** + * Process a buffer of data received from the USB RX endpoint + * + * First fragment arrives with next or last fragment. All other fragments + * arrive alone. + * + * /me hates long functions. + */ +static +void i1480u_rx_buffer(struct i1480u_rx_buf *rx_buf) +{ + unsigned pkt_completed = 0; /* !0 when we got all pkt fragments */ + size_t untd_hdr_size, untd_frg_size; + size_t i1480u_hdr_size; + struct wlp_rx_hdr *i1480u_hdr = NULL; + + struct i1480u *i1480u = rx_buf->i1480u; + struct sk_buff *skb = rx_buf->data; + int size_left = rx_buf->urb->actual_length; + void *ptr = rx_buf->urb->transfer_buffer; /* also rx_buf->data->data */ + struct untd_hdr *untd_hdr; + + struct net_device *net_dev = i1480u->net_dev; + struct device *dev = &i1480u->usb_iface->dev; + struct sk_buff *new_skb; + +#if 0 + dev_fnstart(dev, + "(i1480u %p ptr %p size_left %zu)\n", i1480u, ptr, size_left); + dev_err(dev, "RX packet, %zu bytes\n", size_left); + dump_bytes(dev, ptr, size_left); +#endif + i1480u_hdr_size = sizeof(struct wlp_rx_hdr); + + while (size_left > 0) { + if (pkt_completed) { + i1480u_drop(i1480u, "RX: fragment follows completed" + "packet in same buffer. Dropping\n"); + break; + } + untd_hdr = ptr; + if (size_left < sizeof(*untd_hdr)) { /* Check the UNTD header */ + i1480u_drop(i1480u, "RX: short UNTD header! Dropping\n"); + goto out; + } + if (unlikely(untd_hdr_rx_tx(untd_hdr) == 0)) { /* Paranoia: TX set? */ + i1480u_drop(i1480u, "RX: TX bit set! Dropping\n"); + goto out; + } + switch (untd_hdr_type(untd_hdr)) { /* Check the UNTD header type */ + case i1480u_PKT_FRAG_1ST: { + struct untd_hdr_1st *untd_hdr_1st = (void *) untd_hdr; + dev_dbg(dev, "1st fragment\n"); + untd_hdr_size = sizeof(struct untd_hdr_1st); + if (i1480u->rx_skb != NULL) + i1480u_fix(i1480u, "RX: 1st fragment out of " + "sequence! Fixing\n"); + if (size_left < untd_hdr_size + i1480u_hdr_size) { + i1480u_drop(i1480u, "RX: short 1st fragment! " + "Dropping\n"); + goto out; + } + i1480u->rx_untd_pkt_size = le16_to_cpu(untd_hdr->len) + - i1480u_hdr_size; + untd_frg_size = le16_to_cpu(untd_hdr_1st->fragment_len); + if (size_left < untd_hdr_size + untd_frg_size) { + i1480u_drop(i1480u, + "RX: short payload! Dropping\n"); + goto out; + } + i1480u->rx_skb = skb; + i1480u_hdr = (void *) untd_hdr_1st + untd_hdr_size; + i1480u->rx_srcaddr = i1480u_hdr->srcaddr; + skb_put(i1480u->rx_skb, untd_hdr_size + untd_frg_size); + skb_pull(i1480u->rx_skb, untd_hdr_size + i1480u_hdr_size); + stats_add_sample(&i1480u->lqe_stats, (s8) i1480u_hdr->LQI - 7); + stats_add_sample(&i1480u->rssi_stats, i1480u_hdr->RSSI + 18); + rx_buf->data = NULL; /* need to create new buffer */ + break; + } + case i1480u_PKT_FRAG_NXT: { + dev_dbg(dev, "nxt fragment\n"); + untd_hdr_size = sizeof(struct untd_hdr_rst); + if (i1480u->rx_skb == NULL) { + i1480u_drop(i1480u, "RX: next fragment out of " + "sequence! Dropping\n"); + goto out; + } + if (size_left < untd_hdr_size) { + i1480u_drop(i1480u, "RX: short NXT fragment! " + "Dropping\n"); + goto out; + } + untd_frg_size = le16_to_cpu(untd_hdr->len); + if (size_left < untd_hdr_size + untd_frg_size) { + i1480u_drop(i1480u, + "RX: short payload! Dropping\n"); + goto out; + } + memmove(skb_put(i1480u->rx_skb, untd_frg_size), + ptr + untd_hdr_size, untd_frg_size); + break; + } + case i1480u_PKT_FRAG_LST: { + dev_dbg(dev, "Lst fragment\n"); + untd_hdr_size = sizeof(struct untd_hdr_rst); + if (i1480u->rx_skb == NULL) { + i1480u_drop(i1480u, "RX: last fragment out of " + "sequence! Dropping\n"); + goto out; + } + if (size_left < untd_hdr_size) { + i1480u_drop(i1480u, "RX: short LST fragment! " + "Dropping\n"); + goto out; + } + untd_frg_size = le16_to_cpu(untd_hdr->len); + if (size_left < untd_frg_size + untd_hdr_size) { + i1480u_drop(i1480u, + "RX: short payload! Dropping\n"); + goto out; + } + memmove(skb_put(i1480u->rx_skb, untd_frg_size), + ptr + untd_hdr_size, untd_frg_size); + pkt_completed = 1; + break; + } + case i1480u_PKT_FRAG_CMP: { + dev_dbg(dev, "cmp fragment\n"); + untd_hdr_size = sizeof(struct untd_hdr_cmp); + if (i1480u->rx_skb != NULL) + i1480u_fix(i1480u, "RX: fix out-of-sequence CMP" + " fragment!\n"); + if (size_left < untd_hdr_size + i1480u_hdr_size) { + i1480u_drop(i1480u, "RX: short CMP fragment! " + "Dropping\n"); + goto out; + } + i1480u->rx_untd_pkt_size = le16_to_cpu(untd_hdr->len); + untd_frg_size = i1480u->rx_untd_pkt_size; + if (size_left < i1480u->rx_untd_pkt_size + untd_hdr_size) { + i1480u_drop(i1480u, + "RX: short payload! Dropping\n"); + goto out; + } + i1480u->rx_skb = skb; + i1480u_hdr = (void *) untd_hdr + untd_hdr_size; + i1480u->rx_srcaddr = i1480u_hdr->srcaddr; + stats_add_sample(&i1480u->lqe_stats, (s8) i1480u_hdr->LQI - 7); + stats_add_sample(&i1480u->rssi_stats, i1480u_hdr->RSSI + 18); + skb_put(i1480u->rx_skb, untd_hdr_size + i1480u->rx_untd_pkt_size); + skb_pull(i1480u->rx_skb, untd_hdr_size + i1480u_hdr_size); + rx_buf->data = NULL; /* for hand off skb to network stack */ + pkt_completed = 1; + i1480u->rx_untd_pkt_size -= i1480u_hdr_size; /* accurate stat */ + break; + } + default: + i1480u_drop(i1480u, "RX: unknown packet type %u! " + "Dropping\n", untd_hdr_type(untd_hdr)); + goto out; + } + size_left -= untd_hdr_size + untd_frg_size; + if (size_left > 0) + ptr += untd_hdr_size + untd_frg_size; + } + if (pkt_completed) + i1480u_skb_deliver(i1480u); +out: + /* recreate needed RX buffers*/ + if (rx_buf->data == NULL) { + /* buffer is being used to receive packet, create new */ + new_skb = dev_alloc_skb(i1480u_MAX_RX_PKT_SIZE); + if (!new_skb) { + if (printk_ratelimit()) + dev_err(dev, + "RX: cannot allocate RX buffer\n"); + } else { + new_skb->dev = net_dev; + new_skb->ip_summed = CHECKSUM_NONE; + skb_reserve(new_skb, 2); + rx_buf->data = new_skb; + } + } + return; +} + + +/** + * Called when an RX URB has finished receiving or has found some kind + * of error condition. + * + * LIMITATIONS: + * + * - We read USB-transfers, each transfer contains a SINGLE fragment + * (can contain a complete packet, or a 1st, next, or last fragment + * of a packet). + * Looks like a transfer can contain more than one fragment (07/18/06) + * + * - Each transfer buffer is the size of the maximum packet size (minus + * headroom), i1480u_MAX_PKT_SIZE - 2 + * + * - We always read the full USB-transfer, no partials. + * + * - Each transfer is read directly into a skb. This skb will be used to + * send data to the upper layers if it is the first fragment or a complete + * packet. In the other cases the data will be copied from the skb to + * another skb that is being prepared for the upper layers from a prev + * first fragment. + * + * It is simply too much of a pain. Gosh, there should be a unified + * SG infrastructure for *everything* [so that I could declare a SG + * buffer, pass it to USB for receiving, append some space to it if + * I wish, receive more until I have the whole chunk, adapt + * pointers on each fragment to remove hardware headers and then + * attach that to an skbuff and netif_rx()]. + */ +void i1480u_rx_cb(struct urb *urb) +{ + int result; + int do_parse_buffer = 1; + struct i1480u_rx_buf *rx_buf = urb->context; + struct i1480u *i1480u = rx_buf->i1480u; + struct device *dev = &i1480u->usb_iface->dev; + unsigned long flags; + u8 rx_buf_idx = rx_buf - i1480u->rx_buf; + + switch (urb->status) { + case 0: + break; + case -ECONNRESET: /* Not an error, but a controlled situation; */ + case -ENOENT: /* (we killed the URB)...so, no broadcast */ + case -ESHUTDOWN: /* going away! */ + dev_err(dev, "RX URB[%u]: goind down %d\n", + rx_buf_idx, urb->status); + goto error; + default: + dev_err(dev, "RX URB[%u]: unknown status %d\n", + rx_buf_idx, urb->status); + if (edc_inc(&i1480u->rx_errors, EDC_MAX_ERRORS, + EDC_ERROR_TIMEFRAME)) { + dev_err(dev, "RX: max acceptable errors exceeded," + " resetting device.\n"); + i1480u_rx_unlink_urbs(i1480u); + wlp_reset_all(&i1480u->wlp); + goto error; + } + do_parse_buffer = 0; + break; + } + spin_lock_irqsave(&i1480u->lock, flags); + /* chew the data fragments, extract network packets */ + if (do_parse_buffer) { + i1480u_rx_buffer(rx_buf); + if (rx_buf->data) { + rx_buf->urb->transfer_buffer = rx_buf->data->data; + result = usb_submit_urb(rx_buf->urb, GFP_ATOMIC); + if (result < 0) { + dev_err(dev, "RX URB[%u]: cannot submit %d\n", + rx_buf_idx, result); + } + } + } + spin_unlock_irqrestore(&i1480u->lock, flags); +error: + return; +} + |