LXR linux/drivers/usb/host/ohci-mem.c

   1/*
   2 * OHCI HCD (Host Controller Driver) for USB.
   3 *
   4 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
   5 * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
   6 *
   7 * This file is licenced under the GPL.
   8 */
   9
  10/*-------------------------------------------------------------------------*/
  11
  12/*
  13 * OHCI deals with three types of memory:
  14 *      - data used only by the HCD ... kmalloc is fine
  15 *      - async and periodic schedules, shared by HC and HCD ... these
  16 *        need to use dma_pool or dma_alloc_coherent
  17 *      - driver buffers, read/written by HC ... the hcd glue or the
  18 *        device driver provides us with dma addresses
  19 *
  20 * There's also "register" data, which is memory mapped.
  21 * No memory seen by this driver (or any HCD) may be paged out.
  22 */
  23
  24/*-------------------------------------------------------------------------*/
  25
  26static void ohci_hcd_init (struct ohci_hcd *ohci)
  27{
  28        ohci->next_statechange = jiffies;
  29        spin_lock_init (&ohci->lock);
  30        INIT_LIST_HEAD (&ohci->pending);
  31        INIT_LIST_HEAD(&ohci->eds_in_use);
  32}
  33
  34/*-------------------------------------------------------------------------*/
  35
  36static int ohci_mem_init (struct ohci_hcd *ohci)
  37{
  38        ohci->td_cache = dma_pool_create ("ohci_td",
  39                ohci_to_hcd(ohci)->self.controller,
  40                sizeof (struct td),
  41                32 /* byte alignment */,
  42                0 /* no page-crossing issues */);
  43        if (!ohci->td_cache)
  44                return -ENOMEM;
  45        ohci->ed_cache = dma_pool_create ("ohci_ed",
  46                ohci_to_hcd(ohci)->self.controller,
  47                sizeof (struct ed),
  48                16 /* byte alignment */,
  49                0 /* no page-crossing issues */);
  50        if (!ohci->ed_cache) {
  51                dma_pool_destroy (ohci->td_cache);
  52                return -ENOMEM;
  53        }
  54        return 0;
  55}
  56
  57static void ohci_mem_cleanup (struct ohci_hcd *ohci)
  58{
  59        if (ohci->td_cache) {
  60                dma_pool_destroy (ohci->td_cache);
  61                ohci->td_cache = NULL;
  62        }
  63        if (ohci->ed_cache) {
  64                dma_pool_destroy (ohci->ed_cache);
  65                ohci->ed_cache = NULL;
  66        }
  67}
  68
  69/*-------------------------------------------------------------------------*/
  70
  71/* ohci "done list" processing needs this mapping */
  72static inline struct td *
  73dma_to_td (struct ohci_hcd *hc, dma_addr_t td_dma)
  74{
  75        struct td *td;
  76
  77        td_dma &= TD_MASK;
  78        td = hc->td_hash [TD_HASH_FUNC(td_dma)];
  79        while (td && td->td_dma != td_dma)
  80                td = td->td_hash;
  81        return td;
  82}
  83
  84/* TDs ... */
  85static struct td *
  86td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
  87{
  88        dma_addr_t      dma;
  89        struct td       *td;
  90
  91        td = dma_pool_alloc (hc->td_cache, mem_flags, &dma);
  92        if (td) {
  93                /* in case hc fetches it, make it look dead */
  94                memset (td, 0, sizeof *td);
  95                td->hwNextTD = cpu_to_hc32 (hc, dma);
  96                td->td_dma = dma;
  97                /* hashed in td_fill */
  98        }
  99        return td;
 100}
 101
 102static void
 103td_free (struct ohci_hcd *hc, struct td *td)
 104{
 105        struct td       **prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];
 106
 107        while (*prev && *prev != td)
 108                prev = &(*prev)->td_hash;
 109        if (*prev)
 110                *prev = td->td_hash;
 111        else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
 112                ohci_dbg (hc, "no hash for td %p\n", td);
 113        dma_pool_free (hc->td_cache, td, td->td_dma);
 114}
 115
 116/*-------------------------------------------------------------------------*/
 117
 118/* EDs ... */
 119static struct ed *
 120ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
 121{
 122        dma_addr_t      dma;
 123        struct ed       *ed;
 124
 125        ed = dma_pool_alloc (hc->ed_cache, mem_flags, &dma);
 126        if (ed) {
 127                memset (ed, 0, sizeof (*ed));
 128                INIT_LIST_HEAD (&ed->td_list);
 129                ed->dma = dma;
 130        }
 131        return ed;
 132}
 133
 134static void
 135ed_free (struct ohci_hcd *hc, struct ed *ed)
 136{
 137        dma_pool_free (hc->ed_cache, ed, ed->dma);
 138}
 139
 140