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Diffstat (limited to 'drivers/uwb/i1480/i1480u-wlp/rx.c')
-rw-r--r--drivers/uwb/i1480/i1480u-wlp/rx.c486
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 0000000..9fc0353
--- /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;
+}
+
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