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
  26 static 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 }
  32
  33 /*-------------------------------------------------------------------------*/
  34
  35 static int ohci_mem_init (struct ohci_hcd *ohci)
  36 {
  37         ohci->td_cache = dma_pool_create ("ohci_td",
  38                 ohci_to_hcd(ohci)->self.controller,
  39                 sizeof (struct td),
  40                 32 /* byte alignment */,
  41                 0 /* no page-crossing issues */);
  42         if (!ohci->td_cache)
  43                 return -ENOMEM;
  44         ohci->ed_cache = dma_pool_create ("ohci_ed",
  45                 ohci_to_hcd(ohci)->self.controller,
  46                 sizeof (struct ed),
  47                 16 /* byte alignment */,
  48                 0 /* no page-crossing issues */);
  49         if (!ohci->ed_cache) {
  50                 dma_pool_destroy (ohci->td_cache);
  51                 return -ENOMEM;
  52         }
  53         return 0;
  54 }
  55
  56 static void ohci_mem_cleanup (struct ohci_hcd *ohci)
  57 {
  58         if (ohci->td_cache) {
  59                 dma_pool_destroy (ohci->td_cache);
  60                 ohci->td_cache = NULL;
  61         }
  62         if (ohci->ed_cache) {
  63                 dma_pool_destroy (ohci->ed_cache);
  64                 ohci->ed_cache = NULL;
  65         }
  66 }
  67
  68 /*-------------------------------------------------------------------------*/
  69
  70 /* ohci "done list" processing needs this mapping */
  71 static inline struct td *
  72 dma_to_td (struct ohci_hcd *hc, dma_addr_t td_dma)
  73 {
  74         struct td *td;
  75
  76         td_dma &= TD_MASK;
  77         td = hc->td_hash [TD_HASH_FUNC(td_dma)];
  78         while (td && td->td_dma != td_dma)
  79                 td = td->td_hash;
  80         return td;
  81 }
  82
  83 /* TDs ... */
  84 static struct td *
  85 td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
  86 {
  87         dma_addr_t      dma;
  88         struct td       *td;
  89
  90         td = dma_pool_alloc (hc->td_cache, mem_flags, &dma);
  91         if (td) {
  92                 /* in case hc fetches it, make it look dead */
  93                 memset (td, 0, sizeof *td);
  94                 td->hwNextTD = cpu_to_hc32 (hc, dma);
  95                 td->td_dma = dma;
  96                 /* hashed in td_fill */
  97         }
  98         return td;
  99 }
 100
 101 static void
 102 td_free (struct ohci_hcd *hc, struct td *td)
 103 {
 104         struct td       **prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];
 105
 106         while (*prev && *prev != td)
 107                 prev = &(*prev)->td_hash;
 108         if (*prev)
 109                 *prev = td->td_hash;
 110         else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
 111                 ohci_dbg (hc, "no hash for td %p\n", td);
 112         dma_pool_free (hc->td_cache, td, td->td_dma);
 113 }
 114
 115 /*-------------------------------------------------------------------------*/
 116
 117 /* EDs ... */
 118 static struct ed *
 119 ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
 120 {
 121         dma_addr_t      dma;
 122         struct ed       *ed;
 123
 124         ed = dma_pool_alloc (hc->ed_cache, mem_flags, &dma);
 125         if (ed) {
 126                 memset (ed, 0, sizeof (*ed));
 127                 INIT_LIST_HEAD (&ed->td_list);
 128                 ed->dma = dma;
 129         }
 130         return ed;
 131 }
 132
 133 static void
 134 ed_free (struct ohci_hcd *hc, struct ed *ed)
 135 {
 136         dma_pool_free (hc->ed_cache, ed, ed->dma);
 137 }
 138