/*
   * OHCI HCD (Host Controller Driver) for USB.

   *

   * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
   * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>

   *

   * This file is licenced under the GPL.
   */
  
  /*-------------------------------------------------------------------------*/
  
  /*

   * OHCI deals with three types of memory:

   *	- data used only by the HCD ... kmalloc is fine
   *	- async and periodic schedules, shared by HC and HCD ... these
   *	  need to use dma_pool or dma_alloc_coherent
   *	- driver buffers, read/written by HC ... the hcd glue or the
   *	  device driver provides us with dma addresses
   *

   * There's also "register" data, which is memory mapped.
   * No memory seen by this driver (or any HCD) may be paged out.

   */
  
  /*-------------------------------------------------------------------------*/
  
  static void ohci_hcd_init (struct ohci_hcd *ohci)
  {
  	ohci->next_statechange = jiffies;
  	spin_lock_init (&ohci->lock);
  	INIT_LIST_HEAD (&ohci->pending);

  }
  
  /*-------------------------------------------------------------------------*/
  
  static int ohci_mem_init (struct ohci_hcd *ohci)
  {
  	ohci->td_cache = dma_pool_create ("ohci_td",
  		ohci_to_hcd(ohci)->self.controller,
  		sizeof (struct td),
  		32 /* byte alignment */,
  		0 /* no page-crossing issues */);
  	if (!ohci->td_cache)
  		return -ENOMEM;
  	ohci->ed_cache = dma_pool_create ("ohci_ed",
  		ohci_to_hcd(ohci)->self.controller,
  		sizeof (struct ed),
  		16 /* byte alignment */,
  		0 /* no page-crossing issues */);
  	if (!ohci->ed_cache) {
  		dma_pool_destroy (ohci->td_cache);
  		return -ENOMEM;
  	}
  	return 0;
  }
  
  static void ohci_mem_cleanup (struct ohci_hcd *ohci)
  {
  	if (ohci->td_cache) {
  		dma_pool_destroy (ohci->td_cache);
  		ohci->td_cache = NULL;
  	}
  	if (ohci->ed_cache) {
  		dma_pool_destroy (ohci->ed_cache);
  		ohci->ed_cache = NULL;
  	}
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* ohci "done list" processing needs this mapping */
  static inline struct td *
  dma_to_td (struct ohci_hcd *hc, dma_addr_t td_dma)
  {
  	struct td *td;
  
  	td_dma &= TD_MASK;
  	td = hc->td_hash [TD_HASH_FUNC(td_dma)];
  	while (td && td->td_dma != td_dma)
  		td = td->td_hash;
  	return td;
  }
  
  /* TDs ... */
  static struct td *

  td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)

  {
  	dma_addr_t	dma;
  	struct td	*td;
  
  	td = dma_pool_alloc (hc->td_cache, mem_flags, &dma);
  	if (td) {
  		/* in case hc fetches it, make it look dead */
  		memset (td, 0, sizeof *td);
  		td->hwNextTD = cpu_to_hc32 (hc, dma);
  		td->td_dma = dma;
  		/* hashed in td_fill */
  	}
  	return td;
  }
  
  static void
  td_free (struct ohci_hcd *hc, struct td *td)
  {
  	struct td	**prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];
  
  	while (*prev && *prev != td)
  		prev = &(*prev)->td_hash;
  	if (*prev)
  		*prev = td->td_hash;
  	else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
  		ohci_dbg (hc, "no hash for td %p
  ", td);
  	dma_pool_free (hc->td_cache, td, td->td_dma);
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* EDs ... */
  static struct ed *

  ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)

  {
  	dma_addr_t	dma;
  	struct ed	*ed;
  
  	ed = dma_pool_alloc (hc->ed_cache, mem_flags, &dma);
  	if (ed) {
  		memset (ed, 0, sizeof (*ed));
  		INIT_LIST_HEAD (&ed->td_list);
  		ed->dma = dma;
  	}
  	return ed;
  }
  
  static void
  ed_free (struct ohci_hcd *hc, struct ed *ed)
  {
  	dma_pool_free (hc->ed_cache, ed, ed->dma);
  }