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         INIT_LIST_HEAD(&ohci->eds_in_use);
  32 }
  33
  34 /*-------------------------------------------------------------------------*/
  35
  36 static 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
  57 static 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 */
  72 static inline struct td *
  73 dma_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 ... */
  85 static struct td *
  86 td_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
 102 static void
 103 td_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 ... */
 119 static struct ed *
 120 ed_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
 134 static void
 135 ed_free (struct ohci_hcd *hc, struct ed *ed)
 136 {
 137         dma_pool_free (hc->ed_cache, ed, ed->dma);
 138 }
 139