usb-uhci.c

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// mode: 0: unlink but no deletion mark (step 1 of async_unlink)
//       1: regular (unlink/delete-mark)
//       2: deletion mark for QH (step 2 of async_unlink)
// looks a bit complicated because of all the bulk queueing goodies

_static void uhci_clean_transfer (uhci_t *s, urb_t *urb, uhci_desc_t *qh, int mode)
{
	uhci_desc_t *bqh, *nqh, *prevqh, *prevtd;
	int now;
	urb_priv_t *priv=(urb_priv_t*)urb->hcpriv;

	now=UHCI_GET_CURRENT_FRAME(s);

	bqh=priv->bottom_qh;	
	
	if (!priv->next_queued_urb)  { // no more appended bulk queues

		queue_dbg("uhci_clean_transfer: No more bulks for urb %p, qh %p, bqh %p, nqh %p",urb, qh, bqh, priv->next_qh);	
	
		if (priv->prev_queued_urb) {  // qh not top of the queue
			urb_priv_t* ppriv=(urb_priv_t*)priv->prev_queued_urb->hcpriv;

			if (mode != 2) {
				unsigned long flags;
				
				spin_lock_irqsave (&s->qh_lock, flags);
				prevqh = list_entry (ppriv->desc_list.next, uhci_desc_t, desc_list);
				prevtd = list_entry (prevqh->vertical.prev, uhci_desc_t, vertical);
				prevtd->hw.td.link = virt_to_bus(priv->bottom_qh) | UHCI_PTR_QH; // skip current qh
				mb();
				queue_dbg("uhci_clean_transfer: relink pqh %p, ptd %p",prevqh, prevtd);
				spin_unlock_irqrestore (&s->qh_lock, flags);

				ppriv->bottom_qh = priv->bottom_qh;
				ppriv->next_queued_urb = NULL;
			}
		}
		else {   // queue is dead, qh is top of the queue
			
			if (mode!=2)
				unlink_qh(s, qh); // remove qh from horizontal chain

			if (bqh) {  // remove remainings of bulk queue
				nqh=priv->next_qh;

				if (mode != 2) 
					unlink_qh(s, nqh);  // remove nqh from horizontal chain
				
				if (mode) {
					nqh->last_used = bqh->last_used = now;
					list_add_tail (&nqh->horizontal, &s->free_desc);
					list_add_tail (&bqh->horizontal, &s->free_desc);
				}			
			}
		}
	}
	else { // there are queued urbs following
	
	  queue_dbg("uhci_clean_transfer: urb %p, prevurb %p, nexturb %p, qh %p, bqh %p, nqh %p",
		       urb, priv->prev_queued_urb,  priv->next_queued_urb, qh, bqh, priv->next_qh);	
       	
		if (mode !=2) {	// no work for cleanup at unlink-completion
			urb_t *nurb;
			unsigned long flags;

			nurb = priv->next_queued_urb;
			spin_lock_irqsave (&s->qh_lock, flags);		

			if (!priv->prev_queued_urb) { // top QH
				
				prevqh = list_entry (qh->horizontal.prev, uhci_desc_t, horizontal);
				prevqh->hw.qh.head = virt_to_bus(bqh) | UHCI_PTR_QH;
				list_del (&qh->horizontal);  // remove this qh form horizontal chain
				list_add (&bqh->horizontal, &prevqh->horizontal); // insert next bqh in horizontal chain
			}
			else {		// intermediate QH
				urb_priv_t* ppriv=(urb_priv_t*)priv->prev_queued_urb->hcpriv;
				urb_priv_t* npriv=(urb_priv_t*)nurb->hcpriv;
				uhci_desc_t * bnqh;
				
				bnqh = list_entry (npriv->desc_list.next, uhci_desc_t, desc_list);
				ppriv->bottom_qh = bnqh;
				ppriv->next_queued_urb = nurb;				
				prevqh = list_entry (ppriv->desc_list.next, uhci_desc_t, desc_list);
				prevqh->hw.qh.head = virt_to_bus(bqh) | UHCI_PTR_QH;
			}

			mb();
			spin_unlock_irqrestore (&s->qh_lock, flags);
			((urb_priv_t*)nurb->hcpriv)->prev_queued_urb=priv->prev_queued_urb;
		}		
	}

	if (mode) {
		qh->last_used = now;	
		list_add_tail (&qh->horizontal, &s->free_desc); // mark for later deletion/kfree
	}
}
/*-------------------------------------------------------------------*/
// Release bandwidth for Interrupt or Isoc. transfers 
_static void uhci_release_bandwidth(urb_t *urb)
{       
	if (urb->bandwidth) {
		switch (usb_pipetype(urb->pipe)) {
		case PIPE_INTERRUPT:
			usb_release_bandwidth (urb->dev, urb, 0);
			break;
		case PIPE_ISOCHRONOUS:
			usb_release_bandwidth (urb->dev, urb, 1);
			break;
		default:
			break;
		}
	}	
}
/*-------------------------------------------------------------------*/
// unlinks an urb by dequeuing its qh, waits some frames and forgets it
_static int uhci_unlink_urb_sync (uhci_t *s, urb_t *urb)
{
	uhci_desc_t *qh;
	urb_priv_t *urb_priv;
	unsigned long flags=0;
	struct usb_device *usb_dev;

	spin_lock_irqsave (&s->urb_list_lock, flags);

	if (!in_interrupt())		// shouldn't be called from interrupt at all...
		spin_lock(&urb->lock); 
	
	if (urb->status == -EINPROGRESS) {
		// URB probably still in work
		dequeue_urb (s, urb);
		uhci_switch_timer_int(s);
		s->unlink_urb_done=1;

		uhci_release_bandwidth(urb);
		urb->status = -ENOENT;	// mark urb as killed		

		if (!in_interrupt())	
			spin_unlock(&urb->lock); 

		spin_unlock_irqrestore (&s->urb_list_lock, flags);		
		
		urb_priv = urb->hcpriv;

		switch (usb_pipetype (urb->pipe)) {

		case PIPE_INTERRUPT:
			usb_dotoggle (urb->dev, usb_pipeendpoint (urb->pipe), usb_pipeout (urb->pipe));

		case PIPE_ISOCHRONOUS:
			uhci_clean_iso_step1(s, urb_priv);
			uhci_wait_ms(1);
			uhci_clean_iso_step2(s, urb_priv);
			break;

		case PIPE_BULK:
		case PIPE_CONTROL:
			spin_lock_irqsave (&s->urb_list_lock, flags);
			qh = list_entry (urb_priv->desc_list.next, uhci_desc_t, desc_list);
			uhci_clean_transfer(s, urb, qh, 1);
			spin_unlock_irqrestore (&s->urb_list_lock, flags);
			uhci_wait_ms(1);
		}
		
#ifdef DEBUG_SLAB
		kmem_cache_free (urb_priv_kmem, urb->hcpriv);
#else
		kfree (urb->hcpriv);
#endif
		usb_dev = urb->dev;
		if (urb->complete) {
			dbg("unlink_urb: calling completion");
			urb->dev = NULL;
			urb->complete ((struct urb *) urb);
		}
		usb_dec_dev_use (usb_dev);
	}
	else {
		if (!in_interrupt())	
			spin_unlock(&urb->lock); 
		spin_unlock_irqrestore (&s->urb_list_lock, flags);
	}

	return 0;
}
/*-------------------------------------------------------------------*/
// async unlink_urb completion/cleanup work
// has to be protected by urb_list_lock!
// features: if set in transfer_flags, the resulting status of the killed
// transaction is not overwritten

_static void uhci_cleanup_unlink(uhci_t *s, int force)
{
	struct list_head *q;
	urb_t *urb;
	struct usb_device *dev;
	int pipe,now;
	urb_priv_t *urb_priv;

	q=s->urb_unlinked.next;
	now=UHCI_GET_CURRENT_FRAME(s);

	while (q != &s->urb_unlinked) {

		urb = list_entry (q, urb_t, urb_list);

		urb_priv = (urb_priv_t*)urb->hcpriv;
		q = urb->urb_list.next;
		
		if (force ||
 		    ((urb_priv->started != 0xffffffff) && (urb_priv->started != now))) {
			async_dbg("async cleanup %p",urb);
			switch (usb_pipetype (urb->pipe)) { // process descriptors
			case PIPE_CONTROL:
				process_transfer (s, urb, 2);  // 2: don't unlink (already done)
				break;
			case PIPE_BULK:
				if (!s->avoid_bulk.counter)
					process_transfer (s, urb, 2); // don't unlink (already done)
				else
					continue;
				break;
			case PIPE_ISOCHRONOUS:
				process_iso (s, urb, 1); // force, don't unlink
				break;
			case PIPE_INTERRUPT:
				process_interrupt (s, urb);
				break;
			}

			if (!(urb->transfer_flags & USB_TIMEOUT_KILLED))
		  		urb->status = -ECONNRESET; // mark as asynchronously killed

			pipe = urb->pipe;		// completion may destroy all...
			dev = urb->dev;
			urb_priv = urb->hcpriv;

			if (urb->complete) {
				spin_unlock(&s->urb_list_lock);
				urb->dev = NULL;
				urb->complete ((struct urb *) urb);
				spin_lock(&s->urb_list_lock);
			}

			if (!(urb->transfer_flags & USB_TIMEOUT_KILLED))
				urb->status = -ENOENT;  // now the urb is really dead
			switch (usb_pipetype (pipe)) {
			case PIPE_ISOCHRONOUS:
			case PIPE_INTERRUPT:
				uhci_clean_iso_step2(s, urb_priv);
				break;
			}
	
			usb_dec_dev_use (dev);
#ifdef DEBUG_SLAB
			kmem_cache_free (urb_priv_kmem, urb_priv);
#else
			kfree (urb_priv);
#endif

			list_del (&urb->urb_list);
		}
	}
}

/*-------------------------------------------------------------------*/
// needs urb_list_lock!
_static int uhci_unlink_urb_async (uhci_t *s,urb_t *urb)
{
	uhci_desc_t *qh;
	urb_priv_t *urb_priv;
	
	async_dbg("unlink_urb_async called %p",urb);

	if ((urb->status == -EINPROGRESS) ||
	    ((usb_pipetype (urb->pipe) ==  PIPE_INTERRUPT) && ((urb_priv_t*)urb->hcpriv)->flags))
	{
		((urb_priv_t*)urb->hcpriv)->started = ~0;

		dequeue_urb (s, urb);
		list_add_tail (&urb->urb_list, &s->urb_unlinked); // store urb
		uhci_switch_timer_int(s);
			
		s->unlink_urb_done = 1;
		
		urb->status = -ECONNABORTED;	// mark urb as "waiting to be killed"	
		urb_priv = (urb_priv_t*)urb->hcpriv;

		switch (usb_pipetype (urb->pipe)) {
		case PIPE_INTERRUPT:
			usb_dotoggle (urb->dev, usb_pipeendpoint (urb->pipe), usb_pipeout (urb->pipe));		

		case PIPE_ISOCHRONOUS:
			uhci_clean_iso_step1 (s, urb_priv);
			break;

		case PIPE_BULK:
		case PIPE_CONTROL:
			qh = list_entry (urb_priv->desc_list.next, uhci_desc_t, desc_list);
			uhci_clean_transfer (s, urb, qh, 0);
			break;
		}
		((urb_priv_t*)urb->hcpriv)->started = UHCI_GET_CURRENT_FRAME(s);
		return -EINPROGRESS;  // completion will follow
	}		

	return 0;    // URB already dead
}
/*-------------------------------------------------------------------*/
_static int uhci_unlink_urb (urb_t *urb)
{
	uhci_t *s;
	unsigned long flags=0;
	dbg("uhci_unlink_urb called for %p",urb);
	if (!urb || !urb->dev)		// you never know...
		return -EINVAL;
	
	s = (uhci_t*) urb->dev->bus->hcpriv;

	if (usb_pipedevice (urb->pipe) == s->rh.devnum)
		return rh_unlink_urb (urb);

	if (!urb->hcpriv)
		return -EINVAL;

	if (urb->transfer_flags & USB_ASYNC_UNLINK) {
		int ret;

       		spin_lock_irqsave (&s->urb_list_lock, flags);

		// The URB needs to be locked if called outside completion context

		if (!in_interrupt())
			spin_lock(&urb->lock);

		uhci_release_bandwidth(urb);
		ret = uhci_unlink_urb_async(s, urb);

		if (!in_interrupt())
			spin_unlock(&urb->lock);

		spin_unlock_irqrestore (&s->urb_list_lock, flags);	

		return ret;
	}
	else
		return uhci_unlink_urb_sync(s, urb);
}
/*-------------------------------------------------------------------*/
// In case of ASAP iso transfer, search the URB-list for already queued URBs
// for this EP and calculate the earliest start frame for the new
// URB (easy seamless URB continuation!)
_static int find_iso_limits (urb_t *urb, unsigned int *start, unsigned int *end)
{
	urb_t *u, *last_urb = NULL;
	uhci_t *s = (uhci_t*) urb->dev->bus->hcpriv;
	struct list_head *p;
	int ret=-1;
	unsigned long flags;
	
	spin_lock_irqsave (&s->urb_list_lock, flags);
	p=s->urb_list.prev;

	for (; p != &s->urb_list; p = p->prev) {
		u = list_entry (p, urb_t, urb_list);
		// look for pending URBs with identical pipe handle
		// works only because iso doesn't toggle the data bit!
		if ((urb->pipe == u->pipe) && (urb->dev == u->dev) && (u->status == -EINPROGRESS)) {
			if (!last_urb)
				*start = u->start_frame;
			last_urb = u;
		}
	}
	
	if (last_urb) {
		*end = (last_urb->start_frame + last_urb->number_of_packets) & 1023;
		ret=0;
	}
	
	spin_unlock_irqrestore(&s->urb_list_lock, flags);
	
	return ret;
}
/*-------------------------------------------------------------------*/
// adjust start_frame according to scheduling constraints (ASAP etc)

_static int iso_find_start (urb_t *urb)
{
	uhci_t *s = (uhci_t*) urb->dev->bus->hcpriv;
	unsigned int now;
	unsigned int start_limit = 0, stop_limit = 0, queued_size;
	int limits;

	now = UHCI_GET_CURRENT_FRAME (s) & 1023;

	if ((unsigned) urb->number_of_packets > 900)
		return -EFBIG;
	
	limits = find_iso_limits (urb, &start_limit, &stop_limit);
	queued_size = (stop_limit - start_limit) & 1023;

	if (urb->transfer_flags & USB_ISO_ASAP) {
		// first iso
		if (limits) {
			// 10ms setup should be enough //FIXME!
			urb->start_frame = (now + 10) & 1023;
		}
		else {
			urb->start_frame = stop_limit;		//seamless linkage

			if (((now - urb->start_frame) & 1023) <= (unsigned) urb->number_of_packets) {
				info("iso_find_start: gap in seamless isochronous scheduling");
				dbg("iso_find_start: now %u start_frame %u number_of_packets %u pipe 0x%08x",
					now, urb->start_frame, urb->number_of_packets, urb->pipe);
				urb->start_frame = (now + 5) & 1023;	// 5ms setup should be enough //FIXME!
			}
		}
	}
	else {
		urb->start_frame &= 1023;
		if (((now - urb->start_frame) & 1023) < (unsigned) urb->number_of_packets) {
			dbg("iso_find_start: now between start_frame and end");
			return -EAGAIN;
		}
	}

	/* check if either start_frame or start_frame+number_of_packets-1 lies between start_limit and stop_limit */
	if (limits)
		return 0;

	if (((urb->start_frame - start_limit) & 1023) < queued_size ||
	    ((urb->start_frame + urb->number_of_packets - 1 - start_limit) & 1023) < queued_size) {
		dbg("iso_find_start: start_frame %u number_of_packets %u start_limit %u stop_limit %u",
			urb->start_frame, urb->number_of_packets, start_limit, stop_limit);
		return -EAGAIN;
	}

	return 0;
}
/*-------------------------------------------------------------------*/
// submits USB interrupt (ie. polling ;-) 
// ASAP-flag set implicitely
// if period==0, the the transfer is only done once

_static int uhci_submit_int_urb (urb_t *urb)
{
	uhci_t *s = (uhci_t*) urb->dev->bus->hcpriv;
	urb_priv_t *urb_priv = urb->hcpriv;
	int nint, n, ret;
	uhci_desc_t *td;
	int status, destination;
	int info;
	unsigned int pipe = urb->pipe;

	if (urb->interval < 0 || urb->interval >= 256)
		return -EINVAL;

	if (urb->interval == 0)
		nint = 0;
	else {
		for (nint = 0, n = 1; nint <= 8; nint++, n += n)	// round interval down to 2^n
		 {
			if (urb->interval < n) {
				urb->interval = n / 2;
				break;
			}
		}
		nint--;
	}

	dbg("Rounded interval to %i, chain  %i", urb->interval, nint);

	urb->start_frame = UHCI_GET_CURRENT_FRAME (s) & 1023;	// remember start frame, just in case...

	urb->number_of_packets = 1;

	// INT allows only one packet
	if (urb->transfer_buffer_length > usb_maxpacket (urb->dev, pipe, usb_pipeout (pipe)))
		return -EINVAL;

	ret = alloc_td (&td, UHCI_PTR_DEPTH);

	if (ret)
		return -ENOMEM;