src/system/kernel/device_manager/io_resources.cpp

   1 /*
   2  * Copyright 2004-2008, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
   3  * Copyright 2002-2004, Thomas Kurschel. All rights reserved.
   4  *
   5  * Distributed under the terms of the MIT License.
   6  */
   7
   8
   9 #include "io_resources.h"
  10
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14
  15 //#define TRACE_IO_RESOURCES
  16 #ifdef TRACE_IO_RESOURCES
  17 #       define TRACE(x) dprintf x
  18 #else
  19 #       define TRACE(x) ;
  20 #endif
  21
  22
  23 typedef DoublyLinkedList<io_resource_private,
  24         DoublyLinkedListMemberGetLink<io_resource_private,
  25                 &io_resource_private::fTypeLink> > ResourceTypeList;
  26
  27
  28 static ResourceTypeList sMemoryList;
  29 static ResourceTypeList sPortList;
  30 static ResourceTypeList sDMAChannelList;
  31
  32
  33 io_resource_private::io_resource_private()
  34 {
  35         _Init();
  36 }
  37
  38
  39 io_resource_private::~io_resource_private()
  40 {
  41         Release();
  42 }
  43
  44
  45 void
  46 io_resource_private::_Init()
  47 {
  48         type = 0;
  49         base = 0;
  50         length = 0;
  51 }
  52
  53
  54 status_t
  55 io_resource_private::Acquire(const io_resource& resource)
  56 {
  57         if (!_IsValid(resource))
  58                 return B_BAD_VALUE;
  59
  60         type = resource.type;
  61         base = resource.base;
  62
  63         if (type != B_ISA_DMA_CHANNEL)
  64                 length = resource.length;
  65         else
  66                 length = 1;
  67
  68         ResourceTypeList* list = NULL;
  69
  70         switch (type) {
  71                 case B_IO_MEMORY:
  72                         list = &sMemoryList;
  73                         break;
  74                 case B_IO_PORT:
  75                         list = &sPortList;
  76                         break;
  77                 case B_ISA_DMA_CHANNEL:
  78                         list = &sDMAChannelList;
  79                         break;
  80         }
  81
  82         ResourceTypeList::Iterator iterator = list->GetIterator();
  83         while (iterator.HasNext()) {
  84                 io_resource* resource = iterator.Next();
  85
  86                 // we need the "base + length - 1" trick to avoid wrap around at 4 GB
  87                 if (resource->base >= base
  88                         && resource->base + length - 1 <= base + length - 1) {
  89                         // This range is already covered by someone else
  90                         // TODO: we might want to ignore resources that belong to
  91                         // a node that isn't used.
  92                         _Init();
  93                         return B_RESOURCE_UNAVAILABLE;
  94                 }
  95         }
  96
  97         list->Add(this);
  98         return B_OK;
  99 }
 100
 101
 102 void
 103 io_resource_private::Release()
 104 {
 105         if (type == 0)
 106                 return;
 107
 108         switch (type) {
 109                 case B_IO_MEMORY:
 110                         sMemoryList.Remove(this);
 111                         break;
 112                 case B_IO_PORT:
 113                         sPortList.Remove(this);
 114                         break;
 115                 case B_ISA_DMA_CHANNEL:
 116                         sDMAChannelList.Remove(this);
 117                         break;
 118         }
 119
 120         _Init();
 121 }
 122
 123
 124 /*static*/ bool
 125 io_resource_private::_IsValid(const io_resource& resource)
 126 {
 127         switch (resource.type) {
 128                 case B_IO_MEMORY:
 129                         return resource.base + resource.length > resource.base;
 130                 case B_IO_PORT:
 131                         return (uint16)resource.base == resource.base
 132                                 && (uint16)resource.length == resource.length
 133                                 && resource.base + resource.length > resource.base;
 134                 case B_ISA_DMA_CHANNEL:
 135                         return resource.base <= 8;
 136
 137                 default:
 138                         return false;
 139         }
 140 }
 141
 142
 143 //      #pragma mark -
 144
 145
 146 void
 147 dm_init_io_resources(void)
 148 {
 149         new(&sMemoryList) ResourceTypeList;
 150         new(&sPortList) ResourceTypeList;
 151         new(&sDMAChannelList) ResourceTypeList;
 152 }