arch/m68k-amiga/hidd/pci-mediator/pci_resource.c

   1 /*
   2  * Copyright (C) 2012, The AROS Development Team
   3  * All right reserved.
   4  * Author: Jason S. McMullan <jason.mcmullan@gmail.com>
   5  *
   6  * Licensed under the AROS PUBLIC LICENSE (APL) Version 1.1
   7  */
   8
   9 #include <proto/exec.h>
  10
  11 #include "pci_resource.h"
  12
  13 struct MinList *CreatePCIResourceList(IPTR start, IPTR size)
  14 {
  15     struct MinList *ml;
  16     struct PCIResource *node;
  17
  18     if ((node = AllocMem(sizeof(*node), MEMF_ANY))) {
  19         if ((ml = AllocMem(sizeof(*ml), MEMF_ANY))) {
  20             NEWLIST((struct List *)ml);
  21
  22             node->pr_Start = start;
  23             node->pr_End = start + size - 1;
  24             AddTail((struct List *)ml, (struct Node *)node);
  25             return ml;
  26         }
  27         FreeMem(node, sizeof(*node));
  28     }
  29
  30     return NULL;
  31 }
  32
  33 /* Dispose of a resource list */
  34 VOID DeletePCIResourceList(struct MinList *reslist)
  35 {
  36     struct PCIResource *node;
  37     struct Node *tmp;
  38
  39     ForeachNodeSafe((struct List *)reslist, node, tmp) {
  40         FreeMem(node, sizeof(*node));
  41     }
  42
  43     FreeMem(reslist, sizeof(*reslist));
  44 }
  45
  46 /* Allocates some size aligned space from the resource
  47  * list. Modifies the list (by removing the allocated chunk),
  48  * and returns the new start.
  49  *
  50  * 'size' must be a power of 2!
  51  *
  52  * Returns ~0 if no allocation was available.
  53  */
  54 IPTR AllocPCIResource(struct MinList *reslist, IPTR size)
  55 {
  56     struct PCIResource *node;
  57     IPTR alloc = ~0;
  58     IPTR start, end;
  59
  60     ForeachNode((struct List *)reslist, node) {
  61         /* Aligned start to size */
  62         start = (node->pr_Start + size - 1) & ~(size - 1);
  63         end   = start + size - 1;
  64         if (end <= node->pr_End) {
  65             alloc = start;
  66             break;
  67         }
  68     }
  69
  70     if (alloc == ~0)
  71         return alloc;
  72
  73     if (node->pr_Start == start && end == node->pr_End) {
  74         /* Delete the node */
  75         Remove((struct Node *)node);
  76         FreeMem(node, sizeof(*node));
  77     } else if (node->pr_Start < start && end < node->pr_End) {
  78         struct PCIResource *tmp;
  79
  80         /* Split the node? */
  81         tmp = AllocMem(sizeof(*tmp), MEMF_ANY);
  82         if (tmp == NULL)
  83             return ~0;
  84
  85         tmp->pr_Start = end + 1;
  86         tmp->pr_End   = node->pr_End;
  87
  88         node->pr_End = start - 1;
  89         Insert((struct List *)reslist, (struct Node *)tmp, (struct Node *)node);
  90     } else if (start == node->pr_Start) {
  91         /* Trim from front? */
  92         node->pr_Start = end + 1;
  93     } else if (end == node->pr_End) {
  94         /* Trim from end? */
  95         node->pr_End = start - 1;
  96     }
  97
  98     return alloc;
  99 }