diff options
Diffstat (limited to 'drivers/uwb/i1480/i1480u-wlp/tx.c')
| -rw-r--r-- | drivers/uwb/i1480/i1480u-wlp/tx.c | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/drivers/uwb/i1480/i1480u-wlp/tx.c b/drivers/uwb/i1480/i1480u-wlp/tx.c new file mode 100644 index 00000000000..3426bfb6824 --- /dev/null +++ b/drivers/uwb/i1480/i1480u-wlp/tx.c @@ -0,0 +1,632 @@ +/* + * WUSB Wire Adapter: WLP interface + * Deal with TX (massaging data to transmit, handling it) + * + * 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. + * + * + * Transmission engine. Get an skb, create from that a WLP transmit + * context, add a WLP TX header (which we keep prefilled in the + * device's instance), fill out the target-specific fields and + * fire it. + * + * ROADMAP: + * + * Entry points: + * + * i1480u_tx_release(): called by i1480u_disconnect() to release + * pending tx contexts. + * + * i1480u_tx_cb(): callback for TX contexts (USB URBs) + * i1480u_tx_destroy(): + * + * i1480u_tx_timeout(): called for timeout handling from the + * network stack. + * + * i1480u_hard_start_xmit(): called for transmitting an skb from + * the network stack. Will interact with WLP + * substack to verify and prepare frame. + * i1480u_xmit_frame(): actual transmission on hardware + * + * i1480u_tx_create() Creates TX context + * i1480u_tx_create_1() For packets in 1 fragment + * i1480u_tx_create_n() For packets in >1 fragments + * + * TODO: + * + * - FIXME: rewrite using usb_sg_*(), add asynch support to + * usb_sg_*(). It might not make too much sense as most of + * the times the MTU will be smaller than one page... + */ + +#include "i1480u-wlp.h" +#define D_LOCAL 5 +#include <linux/uwb/debug.h> + +enum { + /* This is only for Next and Last TX packets */ + i1480u_MAX_PL_SIZE = i1480u_MAX_FRG_SIZE + - sizeof(struct untd_hdr_rst), +}; + +/** Free resources allocated to a i1480u tx context. */ +static +void i1480u_tx_free(struct i1480u_tx *wtx) +{ + kfree(wtx->buf); + if (wtx->skb) + dev_kfree_skb_irq(wtx->skb); + usb_free_urb(wtx->urb); + kfree(wtx); +} + +static +void i1480u_tx_destroy(struct i1480u *i1480u, struct i1480u_tx *wtx) +{ + unsigned long flags; + spin_lock_irqsave(&i1480u->tx_list_lock, flags); /* not active any more */ + list_del(&wtx->list_node); + i1480u_tx_free(wtx); + spin_unlock_irqrestore(&i1480u->tx_list_lock, flags); +} + +static +void i1480u_tx_unlink_urbs(struct i1480u *i1480u) +{ + unsigned long flags; + struct i1480u_tx *wtx, *next; + + spin_lock_irqsave(&i1480u->tx_list_lock, flags); + list_for_each_entry_safe(wtx, next, &i1480u->tx_list, list_node) { + usb_unlink_urb(wtx->urb); + } + spin_unlock_irqrestore(&i1480u->tx_list_lock, flags); +} + + +/** + * Callback for a completed tx USB URB. + * + * TODO: + * + * - FIXME: recover errors more gracefully + * - FIXME: handle NAKs (I dont think they come here) for flow ctl + */ +static +void i1480u_tx_cb(struct urb *urb) +{ + struct i1480u_tx *wtx = urb->context; + struct i1480u *i1480u = wtx->i1480u; + struct net_device *net_dev = i1480u->net_dev; + struct device *dev = &i1480u->usb_iface->dev; + unsigned long flags; + + switch (urb->status) { + case 0: + spin_lock_irqsave(&i1480u->lock, flags); + i1480u->stats.tx_packets++; + i1480u->stats.tx_bytes += urb->actual_length; + spin_unlock_irqrestore(&i1480u->lock, flags); + break; + case -ECONNRESET: /* Not an error, but a controlled situation; */ + case -ENOENT: /* (we killed the URB)...so, no broadcast */ + dev_dbg(dev, "notif endp: reset/noent %d\n", urb->status); + netif_stop_queue(net_dev); + break; + case -ESHUTDOWN: /* going away! */ + dev_dbg(dev, "notif endp: down %d\n", urb->status); + netif_stop_queue(net_dev); + break; + default: + dev_err(dev, "TX: unknown URB status %d\n", urb->status); + if (edc_inc(&i1480u->tx_errors, EDC_MAX_ERRORS, + EDC_ERROR_TIMEFRAME)) { + dev_err(dev, "TX: max acceptable errors exceeded." + "Reset device.\n"); + netif_stop_queue(net_dev); + i1480u_tx_unlink_urbs(i1480u); + wlp_reset_all(&i1480u->wlp); + } + break; + } + i1480u_tx_destroy(i1480u, wtx); + if (atomic_dec_return(&i1480u->tx_inflight.count) + <= i1480u->tx_inflight.threshold + && netif_queue_stopped(net_dev) + && i1480u->tx_inflight.threshold != 0) { + if (d_test(2) && printk_ratelimit()) + d_printf(2, dev, "Restart queue. \n"); + netif_start_queue(net_dev); + atomic_inc(&i1480u->tx_inflight.restart_count); + } + return; +} + + +/** + * Given a buffer that doesn't fit in a single fragment, create an + * scatter/gather structure for delivery to the USB pipe. + * + * Implements functionality of i1480u_tx_create(). + * + * @wtx: tx descriptor + * @skb: skb to send + * @gfp_mask: gfp allocation mask + * @returns: Pointer to @wtx if ok, NULL on error. + * + * Sorry, TOO LONG a function, but breaking it up is kind of hard + * + * This will break the buffer in chunks smaller than + * i1480u_MAX_FRG_SIZE (including the header) and add proper headers + * to each: + * + * 1st header \ + * i1480 tx header | fragment 1 + * fragment data / + * nxt header \ fragment 2 + * fragment data / + * .. + * .. + * last header \ fragment 3 + * last fragment data / + * + * This does not fill the i1480 TX header, it is left up to the + * caller to do that; you can get it from @wtx->wlp_tx_hdr. + * + * This function consumes the skb unless there is an error. + */ +static +int i1480u_tx_create_n(struct i1480u_tx *wtx, struct sk_buff *skb, + gfp_t gfp_mask) +{ + int result; + void *pl; + size_t pl_size; + + void *pl_itr, *buf_itr; + size_t pl_size_left, frgs, pl_size_1st, frg_pl_size = 0; + struct untd_hdr_1st *untd_hdr_1st; + struct wlp_tx_hdr *wlp_tx_hdr; + struct untd_hdr_rst *untd_hdr_rst; + + wtx->skb = NULL; + pl = skb->data; + pl_itr = pl; + pl_size = skb->len; + pl_size_left = pl_size; /* payload size */ + /* First fragment; fits as much as i1480u_MAX_FRG_SIZE minus + * the headers */ + pl_size_1st = i1480u_MAX_FRG_SIZE + - sizeof(struct untd_hdr_1st) - sizeof(struct wlp_tx_hdr); + BUG_ON(pl_size_1st > pl_size); + pl_size_left -= pl_size_1st; + /* The rest have an smaller header (no i1480 TX header). We + * need to break up the payload in blocks smaller than + * i1480u_MAX_PL_SIZE (payload excluding header). */ + frgs = (pl_size_left + i1480u_MAX_PL_SIZE - 1) / i1480u_MAX_PL_SIZE; + /* Allocate space for the new buffer. In this new buffer we'll + * place the headers followed by the data fragment, headers, + * data fragments, etc.. + */ + result = -ENOMEM; + wtx->buf_size = sizeof(*untd_hdr_1st) + + sizeof(*wlp_tx_hdr) + + frgs * sizeof(*untd_hdr_rst) + + pl_size; + wtx->buf = kmalloc(wtx->buf_size, gfp_mask); + if (wtx->buf == NULL) + goto error_buf_alloc; + + buf_itr = wtx->buf; /* We got the space, let's fill it up */ + /* Fill 1st fragment */ + untd_hdr_1st = buf_itr; + buf_itr += sizeof(*untd_hdr_1st); + untd_hdr_set_type(&untd_hdr_1st->hdr, i1480u_PKT_FRAG_1ST); + untd_hdr_set_rx_tx(&untd_hdr_1st->hdr, 0); + untd_hdr_1st->hdr.len = cpu_to_le16(pl_size + sizeof(*wlp_tx_hdr)); + untd_hdr_1st->fragment_len = + cpu_to_le16(pl_size_1st + sizeof(*wlp_tx_hdr)); + memset(untd_hdr_1st->padding, 0, sizeof(untd_hdr_1st->padding)); + /* Set up i1480 header info */ + wlp_tx_hdr = wtx->wlp_tx_hdr = buf_itr; + buf_itr += sizeof(*wlp_tx_hdr); + /* Copy the first fragment */ + memcpy(buf_itr, pl_itr, pl_size_1st); + pl_itr += pl_size_1st; + buf_itr += pl_size_1st; + + /* Now do each remaining fragment */ + result = -EINVAL; + while (pl_size_left > 0) { + d_printf(5, NULL, "ITR HDR: pl_size_left %zu buf_itr %zu\n", + pl_size_left, buf_itr - wtx->buf); + if (buf_itr + sizeof(*untd_hdr_rst) - wtx->buf + > wtx->buf_size) { + printk(KERN_ERR "BUG: no space for header\n"); + goto error_bug; + } + d_printf(5, NULL, "ITR HDR 2: pl_size_left %zu buf_itr %zu\n", + pl_size_left, buf_itr - wtx->buf); + untd_hdr_rst = buf_itr; + buf_itr += sizeof(*untd_hdr_rst); + if (pl_size_left > i1480u_MAX_PL_SIZE) { + frg_pl_size = i1480u_MAX_PL_SIZE; + untd_hdr_set_type(&untd_hdr_rst->hdr, i1480u_PKT_FRAG_NXT); + } else { + frg_pl_size = pl_size_left; + untd_hdr_set_type(&untd_hdr_rst->hdr, i1480u_PKT_FRAG_LST); + } + d_printf(5, NULL, + "ITR PL: pl_size_left %zu buf_itr %zu frg_pl_size %zu\n", + pl_size_left, buf_itr - wtx->buf, frg_pl_size); + untd_hdr_set_rx_tx(&untd_hdr_rst->hdr, 0); + untd_hdr_rst->hdr.len = cpu_to_le16(frg_pl_size); + untd_hdr_rst->padding = 0; + if (buf_itr + frg_pl_size - wtx->buf + > wtx->buf_size) { + printk(KERN_ERR "BUG: no space for payload\n"); + goto error_bug; + } + memcpy(buf_itr, pl_itr, frg_pl_size); + buf_itr += frg_pl_size; + pl_itr += frg_pl_size; + pl_size_left -= frg_pl_size; + d_printf(5, NULL, + "ITR PL 2: pl_size_left %zu buf_itr %zu frg_pl_size %zu\n", + pl_size_left, buf_itr - wtx->buf, frg_pl_size); + } + dev_kfree_skb_irq(skb); + return 0; + +error_bug: + printk(KERN_ERR + "BUG: skb %u bytes\n" + "BUG: frg_pl_size %zd i1480u_MAX_FRG_SIZE %u\n" + "BUG: buf_itr %zu buf_size %zu pl_size_left %zu\n", + skb->len, + frg_pl_size, i1480u_MAX_FRG_SIZE, + buf_itr - wtx->buf, wtx->buf_size, pl_size_left); + + kfree(wtx->buf); +error_buf_alloc: + return result; +} + + +/** + * Given a buffer that fits in a single fragment, fill out a @wtx + * struct for transmitting it down the USB pipe. + * + * Uses the fact that we have space reserved in front of the skbuff + * for hardware headers :] + * + * This does not fill the i1480 TX header, it is left up to the + * caller to do that; you can get it from @wtx->wlp_tx_hdr. + * + * @pl: pointer to payload data + * @pl_size: size of the payuload + * + * This function does not consume the @skb. + */ +static +int i1480u_tx_create_1(struct i1480u_tx *wtx, struct sk_buff *skb, + gfp_t gfp_mask) +{ + struct untd_hdr_cmp *untd_hdr_cmp; + struct wlp_tx_hdr *wlp_tx_hdr; + + wtx->buf = NULL; + wtx->skb = skb; + BUG_ON(skb_headroom(skb) < sizeof(*wlp_tx_hdr)); + wlp_tx_hdr = (void *) __skb_push(skb, sizeof(*wlp_tx_hdr)); + wtx->wlp_tx_hdr = wlp_tx_hdr; + BUG_ON(skb_headroom(skb) < sizeof(*untd_hdr_cmp)); + untd_hdr_cmp = (void *) __skb_push(skb, sizeof(*untd_hdr_cmp)); + + untd_hdr_set_type(&untd_hdr_cmp->hdr, i1480u_PKT_FRAG_CMP); + untd_hdr_set_rx_tx(&untd_hdr_cmp->hdr, 0); + untd_hdr_cmp->hdr.len = cpu_to_le16(skb->len - sizeof(*untd_hdr_cmp)); + untd_hdr_cmp->padding = 0; + return 0; +} + + +/** + * Given a skb to transmit, massage it to become palatable for the TX pipe + * + * This will break the buffer in chunks smaller than + * i1480u_MAX_FRG_SIZE and add proper headers to each. + * + * 1st header \ + * i1480 tx header | fragment 1 + * fragment data / + * nxt header \ fragment 2 + * fragment data / + * .. + * .. + * last header \ fragment 3 + * last fragment data / + * + * Each fragment will be always smaller or equal to i1480u_MAX_FRG_SIZE. + * + * If the first fragment is smaller than i1480u_MAX_FRG_SIZE, then the + * following is composed: + * + * complete header \ + * i1480 tx header | single fragment + * packet data / + * + * We were going to use s/g support, but because the interface is + * synch and at the end there is plenty of overhead to do it, it + * didn't seem that worth for data that is going to be smaller than + * one page. + */ +static +struct i1480u_tx *i1480u_tx_create(struct i1480u *i1480u, + struct sk_buff *skb, gfp_t gfp_mask) +{ + int result; + struct usb_endpoint_descriptor *epd; + int usb_pipe; + unsigned long flags; + + struct i1480u_tx *wtx; + const size_t pl_max_size = + i1480u_MAX_FRG_SIZE - sizeof(struct untd_hdr_cmp) + - sizeof(struct wlp_tx_hdr); + + wtx = kmalloc(sizeof(*wtx), gfp_mask); + if (wtx == NULL) + goto error_wtx_alloc; + wtx->urb = usb_alloc_urb(0, gfp_mask); + if (wtx->urb == NULL) + goto error_urb_alloc; + epd = &i1480u->usb_iface->cur_altsetting->endpoint[2].desc; + usb_pipe = usb_sndbulkpipe(i1480u->usb_dev, epd->bEndpointAddress); + /* Fits in a single complete packet or need to split? */ + if (skb->len > pl_max_size) { + result = i1480u_tx_create_n(wtx, skb, gfp_mask); + if (result < 0) + goto error_create; + usb_fill_bulk_urb(wtx->urb, i1480u->usb_dev, usb_pipe, + wtx->buf, wtx->buf_size, i1480u_tx_cb, wtx); + } else { + result = i1480u_tx_create_1(wtx, skb, gfp_mask); + if (result < 0) + goto error_create; + usb_fill_bulk_urb(wtx->urb, i1480u->usb_dev, usb_pipe, + skb->data, skb->len, i1480u_tx_cb, wtx); + } + spin_lock_irqsave(&i1480u->tx_list_lock, flags); + list_add(&wtx->list_node, &i1480u->tx_list); + spin_unlock_irqrestore(&i1480u->tx_list_lock, flags); + return wtx; + +error_create: + kfree(wtx->urb); +error_urb_alloc: + kfree(wtx); +error_wtx_alloc: + return NULL; +} + +/** + * Actual fragmentation and transmission of frame + * + * @wlp: WLP substack data structure + * @skb: To be transmitted + * @dst: Device address of destination + * @returns: 0 on success, <0 on failure + * + * This function can also be called directly (not just from + * hard_start_xmit), so we also check here if the interface is up before + * taking sending anything. + */ +int i1480u_xmit_frame(struct wlp *wlp, struct sk_buff *skb, + struct uwb_dev_addr *dst) +{ + int result = -ENXIO; + struct i1480u *i1480u = container_of(wlp, struct i1480u, wlp); + struct device *dev = &i1480u->usb_iface->dev; + struct net_device *net_dev = i1480u->net_dev; + struct i1480u_tx *wtx; + struct wlp_tx_hdr *wlp_tx_hdr; + static unsigned char dev_bcast[2] = { 0xff, 0xff }; +#if 0 + int lockup = 50; +#endif + + d_fnstart(6, dev, "(skb %p (%u), net_dev %p)\n", skb, skb->len, + net_dev); + BUG_ON(i1480u->wlp.rc == NULL); + if ((net_dev->flags & IFF_UP) == 0) + goto out; + result = -EBUSY; + if (atomic_read(&i1480u->tx_inflight.count) >= i1480u->tx_inflight.max) { + if (d_test(2) && printk_ratelimit()) + d_printf(2, dev, "Max frames in flight " + "stopping queue.\n"); + netif_stop_queue(net_dev); + goto error_max_inflight; + } + result = -ENOMEM; + wtx = i1480u_tx_create(i1480u, skb, GFP_ATOMIC); + if (unlikely(wtx == NULL)) { + if (printk_ratelimit()) + dev_err(dev, "TX: no memory for WLP TX URB," + "dropping packet (in flight %d)\n", + atomic_read(&i1480u->tx_inflight.count)); + netif_stop_queue(net_dev); + goto error_wtx_alloc; + } + wtx->i1480u = i1480u; + /* Fill out the i1480 header; @i1480u->def_tx_hdr read without + * locking. We do so because they are kind of orthogonal to + * each other (and thus not changed in an atomic batch). + * The ETH header is right after the WLP TX header. */ + wlp_tx_hdr = wtx->wlp_tx_hdr; + *wlp_tx_hdr = i1480u->options.def_tx_hdr; + wlp_tx_hdr->dstaddr = *dst; + if (!memcmp(&wlp_tx_hdr->dstaddr, dev_bcast, sizeof(dev_bcast)) + && (wlp_tx_hdr_delivery_id_type(wlp_tx_hdr) & WLP_DRP)) { + /*Broadcast message directed to DRP host. Send as best effort + * on PCA. */ + wlp_tx_hdr_set_delivery_id_type(wlp_tx_hdr, i1480u->options.pca_base_priority); + } + +#if 0 + dev_info(dev, "TX delivering skb -> USB, %zu bytes\n", skb->len); + dump_bytes(dev, skb->data, skb->len > 72 ? 72 : skb->len); +#endif +#if 0 + /* simulates a device lockup after every lockup# packets */ + if (lockup && ((i1480u->stats.tx_packets + 1) % lockup) == 0) { + /* Simulate a dropped transmit interrupt */ + net_dev->trans_start = jiffies; + netif_stop_queue(net_dev); + dev_err(dev, "Simulate lockup at %ld\n", jiffies); + return result; + } +#endif + + result = usb_submit_urb(wtx->urb, GFP_ATOMIC); /* Go baby */ + if (result < 0) { + dev_err(dev, "TX: cannot submit URB: %d\n", result); + /* We leave the freeing of skb to calling function */ + wtx->skb = NULL; + goto error_tx_urb_submit; + } + atomic_inc(&i1480u->tx_inflight.count); + net_dev->trans_start = jiffies; + d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len, + net_dev, result); + return result; + +error_tx_urb_submit: + i1480u_tx_destroy(i1480u, wtx); +error_wtx_alloc: +error_max_inflight: +out: + d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len, + net_dev, result); + return result; +} + + +/** + * Transmit an skb Called when an skbuf has to be transmitted + * + * The skb is first passed to WLP substack to ensure this is a valid + * frame. If valid the device address of destination will be filled and + * the WLP header prepended to the skb. If this step fails we fake sending + * the frame, if we return an error the network stack will just keep trying. + * + * Broadcast frames inside a WSS needs to be treated special as multicast is + * not supported. A broadcast frame is sent as unicast to each member of the + * WSS - this is done by the WLP substack when it finds a broadcast frame. + * So, we test if the WLP substack took over the skb and only transmit it + * if it has not (been taken over). + * + * @net_dev->xmit_lock is held + */ +int i1480u_hard_start_xmit(struct sk_buff *skb, struct net_device *net_dev) +{ + int result; + struct i1480u *i1480u = netdev_priv(net_dev); + struct device *dev = &i1480u->usb_iface->dev; + struct uwb_dev_addr dst; + + d_fnstart(6, dev, "(skb %p (%u), net_dev %p)\n", skb, skb->len, + net_dev); + BUG_ON(i1480u->wlp.rc == NULL); + if ((net_dev->flags & IFF_UP) == 0) + goto error; + result = wlp_prepare_tx_frame(dev, &i1480u->wlp, skb, &dst); + if (result < 0) { + dev_err(dev, "WLP verification of TX frame failed (%d). " + "Dropping packet.\n", result); + goto error; + } else if (result == 1) { + d_printf(6, dev, "WLP will transmit frame. \n"); + /* trans_start time will be set when WLP actually transmits + * the frame */ + goto out; + } + d_printf(6, dev, "Transmitting frame. \n"); + result = i1480u_xmit_frame(&i1480u->wlp, skb, &dst); + if (result < 0) { + dev_err(dev, "Frame TX failed (%d).\n", result); + goto error; + } + d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len, + net_dev, result); + return NETDEV_TX_OK; +error: + dev_kfree_skb_any(skb); + i1480u->stats.tx_dropped++; +out: + d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len, + net_dev, result); + return NETDEV_TX_OK; +} + + +/** + * Called when a pkt transmission doesn't complete in a reasonable period + * Device reset may sleep - do it outside of interrupt context (delayed) + */ +void i1480u_tx_timeout(struct net_device *net_dev) +{ + struct i1480u *i1480u = netdev_priv(net_dev); + + wlp_reset_all(&i1480u->wlp); +} + + +void i1480u_tx_release(struct i1480u *i1480u) +{ + unsigned long flags; + struct i1480u_tx *wtx, *next; + int count = 0, empty; + + spin_lock_irqsave(&i1480u->tx_list_lock, flags); + list_for_each_entry_safe(wtx, next, &i1480u->tx_list, list_node) { + count++; + usb_unlink_urb(wtx->urb); + } + spin_unlock_irqrestore(&i1480u->tx_list_lock, flags); + count = count*10; /* i1480ut 200ms per unlinked urb (intervals of 20ms) */ + /* + * We don't like this sollution too much (dirty as it is), but + * it is cheaper than putting a refcount on each i1480u_tx and + * i1480uting for all of them to go away... + * + * Called when no more packets can be added to tx_list + * so can i1480ut for it to be empty. + */ + while (1) { + spin_lock_irqsave(&i1480u->tx_list_lock, flags); + empty = list_empty(&i1480u->tx_list); + spin_unlock_irqrestore(&i1480u->tx_list_lock, flags); + if (empty) + break; + count--; + BUG_ON(count == 0); + msleep(20); + } +} |