tools/kvm/net/uip/buf.c

   1 #include "kvm/uip.h"
   2
   3 #include <linux/kernel.h>
   4 #include <linux/list.h>
   5
   6 struct uip_buf *uip_buf_get_used(struct uip_info *info)
   7 {
   8         struct uip_buf *buf;
   9         bool found = false;
  10
  11         mutex_lock(&info->buf_lock);
  12
  13         while (!(info->buf_used_nr > 0))
  14                 pthread_cond_wait(&info->buf_used_cond, &info->buf_lock);
  15
  16         list_for_each_entry(buf, &info->buf_head, list) {
  17                 if (buf->status == UIP_BUF_STATUS_USED) {
  18                         /*
  19                          * Set status to INUSE immediately to prevent
  20                          * someone from using this buf until we free it
  21                          */
  22                         buf->status = UIP_BUF_STATUS_INUSE;
  23                         info->buf_used_nr--;
  24                         found = true;
  25                         break;
  26                 }
  27         }
  28
  29         mutex_unlock(&info->buf_lock);
  30
  31         return found ? buf : NULL;
  32 }
  33
  34 struct uip_buf *uip_buf_get_free(struct uip_info *info)
  35 {
  36         struct uip_buf *buf;
  37         bool found = false;
  38
  39         mutex_lock(&info->buf_lock);
  40
  41         while (!(info->buf_free_nr > 0))
  42                 pthread_cond_wait(&info->buf_free_cond, &info->buf_lock);
  43
  44         list_for_each_entry(buf, &info->buf_head, list) {
  45                 if (buf->status == UIP_BUF_STATUS_FREE) {
  46                         /*
  47                          * Set status to INUSE immediately to prevent
  48                          * someone from using this buf until we free it
  49                          */
  50                         buf->status = UIP_BUF_STATUS_INUSE;
  51                         info->buf_free_nr--;
  52                         found = true;
  53                         break;
  54                 }
  55         }
  56
  57         mutex_unlock(&info->buf_lock);
  58
  59         return found ? buf : NULL;
  60 }
  61
  62 struct uip_buf *uip_buf_set_used(struct uip_info *info, struct uip_buf *buf)
  63 {
  64         mutex_lock(&info->buf_lock);
  65
  66         buf->status = UIP_BUF_STATUS_USED;
  67         info->buf_used_nr++;
  68         pthread_cond_signal(&info->buf_used_cond);
  69
  70         mutex_unlock(&info->buf_lock);
  71
  72         return buf;
  73 }
  74
  75 struct uip_buf *uip_buf_set_free(struct uip_info *info, struct uip_buf *buf)
  76 {
  77         mutex_lock(&info->buf_lock);
  78
  79         buf->status = UIP_BUF_STATUS_FREE;
  80         info->buf_free_nr++;
  81         pthread_cond_signal(&info->buf_free_cond);
  82
  83         mutex_unlock(&info->buf_lock);
  84
  85         return buf;
  86 }
  87
  88 struct uip_buf *uip_buf_clone(struct uip_tx_arg *arg)
  89 {
  90         struct uip_buf *buf;
  91         struct uip_eth *eth2;
  92         struct uip_info *info;
  93
  94         info = arg->info;
  95
  96         /*
  97          * Get buffer from device to guest
  98          */
  99         buf = uip_buf_get_free(info);
 100
 101         /*
 102          * Clone buffer
 103          */
 104         memcpy(buf->vnet, arg->vnet, arg->vnet_len);
 105         memcpy(buf->eth, arg->eth, arg->eth_len);
 106         buf->vnet_len   = arg->vnet_len;
 107         buf->eth_len    = arg->eth_len;
 108
 109         eth2            = (struct uip_eth *)buf->eth;
 110         eth2->src       = info->host_mac;
 111         eth2->dst       = arg->eth->src;
 112
 113         return buf;
 114 }