include/asm-s390/queue.h

   1 /*
   2  *  include/asm-s390/queue.h
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
   7  *
   8  *  A little set of queue utilies.
   9  */
  10 #ifndef __ASM_QUEUE_H
  11 #define __ASM_QUEUE_H
  12 #include <linux/stddef.h>
  13
  14 typedef struct queue
  15 {
  16         struct queue *next;
  17 } queue;
  18
  19 typedef queue list;
  20
  21 typedef struct
  22 {
  23         queue *head;
  24         queue *tail;
  25 } qheader;
  26
  27 static __inline__ void init_queue(qheader *qhead)
  28 {
  29         memset(qhead,0,sizeof(*qhead));
  30 }
  31
  32 static __inline__ void enqueue_tail(qheader *qhead,queue *member)
  33 {
  34         if(member)
  35         {
  36                 queue *tail=qhead->tail;
  37
  38                 if(tail)
  39                         tail->next=member;
  40                 else
  41
  42                         qhead->head=member;
  43                 qhead->tail=member;
  44                 member->next=NULL;
  45         }
  46 }
  47
  48 static __inline__ queue *dequeue_head(qheader *qhead)
  49 {
  50         queue *head=qhead->head,*next_head;
  51
  52         if(head)
  53         {
  54                 next_head=head->next;
  55                 qhead->head=next_head;
  56                 if(!next_head)
  57                         qhead->tail=NULL;
  58         }
  59         return(head);
  60 }
  61
  62 static __inline__ void init_list(list **lhead)
  63 {
  64         *lhead=NULL;
  65 }
  66
  67 static __inline__ void add_to_list(list **lhead,list *member)
  68 {
  69         member->next=*lhead;
  70         *lhead=member;
  71 }
  72
  73 static __inline__ list *remove_listhead(list **lhead)
  74 {
  75         list *oldhead=*lhead;
  76
  77         if(oldhead)
  78                 *lhead=(*lhead)->next;
  79         return(oldhead);
  80 }
  81
  82 static __inline__ void add_to_list_tail(list **lhead,list *member)
  83 {
  84         list *curr,*prev;
  85         if(*lhead==NULL)
  86                 *lhead=member;
  87         else
  88         {
  89                 prev=*lhead;
  90                 for(curr=(*lhead)->next;curr!=NULL;curr=curr->next)
  91                         prev=curr;
  92                 prev->next=member;
  93         }
  94 }
  95 static __inline__ void add_to_list_tail_null(list **lhead,list *member)
  96 {
  97         member->next=NULL;
  98         add_to_list_tail_null(lhead,member);
  99 }
 100
 101
 102 static __inline__ int is_in_list(list *lhead,list *member)
 103 {
 104         list *curr;
 105
 106         for(curr=lhead;curr!=NULL;curr=curr->next)
 107                 if(curr==member)
 108                         return(1);
 109         return(0);
 110 }
 111
 112 static __inline__ int get_prev(list *lhead,list *member,list **prev)
 113 {
 114         list *curr;
 115
 116         *prev=NULL;
 117         for(curr=lhead;curr!=NULL;curr=curr->next)
 118         {
 119                 if(curr==member)
 120                         return(1);
 121                 *prev=curr;
 122         }
 123         *prev=NULL;
 124         return(0);
 125 }
 126
 127
 128
 129 static __inline__ int remove_from_list(list **lhead,list *member)
 130 {
 131         list *prev;
 132
 133         if(get_prev(*lhead,member,&prev))
 134         {
 135
 136                 if(prev)
 137                         prev->next=member->next;
 138                 else
 139                         *lhead=member->next;
 140                 return(1);
 141         }
 142         return(0);
 143 }
 144
 145 static __inline__ int remove_from_queue(qheader *qhead,queue *member)
 146 {
 147         queue *prev;
 148
 149         if(get_prev(qhead->head,(list *)member,(list **)&prev))
 150         {
 151
 152                 if(prev)
 153                 {
 154                         prev->next=member->next;
 155                         if(prev->next==NULL)
 156                                 qhead->tail=prev;
 157                 }
 158                 else
 159                 {
 160                         if(qhead->head==qhead->tail)
 161                                 qhead->tail=NULL;
 162                         qhead->head=member->next;
 163                 }
 164                 return(1);
 165         }
 166         return(0);
 167 }
 168
 169 #endif /* __ASM_QUEUE_H */
 170