ceph/src/dpdk/lib/librte_eal/linuxapp/kni/kni_fifo.h

   1 /*-
   2  * GPL LICENSE SUMMARY
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of version 2 of the GNU General Public License as
   8  *   published by the Free Software Foundation.
   9  *
  10  *   This program is distributed in the hope that it will be useful, but
  11  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *   General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program; if not, write to the Free Software
  17  *   Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  *   The full GNU General Public License is included in this distribution
  19  *   in the file called LICENSE.GPL.
  20  *
  21  *   Contact Information:
  22  *   Intel Corporation
  23  */
  24
  25 #ifndef _KNI_FIFO_H_
  26 #define _KNI_FIFO_H_
  27
  28 #include <exec-env/rte_kni_common.h>
  29
  30 /**
  31  * Adds num elements into the fifo. Return the number actually written
  32  */
  33 static inline uint32_t
  34 kni_fifo_put(struct rte_kni_fifo *fifo, void **data, uint32_t num)
  35 {
  36         uint32_t i = 0;
  37         uint32_t fifo_write = fifo->write;
  38         uint32_t fifo_read = fifo->read;
  39         uint32_t new_write = fifo_write;
  40
  41         for (i = 0; i < num; i++) {
  42                 new_write = (new_write + 1) & (fifo->len - 1);
  43
  44                 if (new_write == fifo_read)
  45                         break;
  46                 fifo->buffer[fifo_write] = data[i];
  47                 fifo_write = new_write;
  48         }
  49         fifo->write = fifo_write;
  50
  51         return i;
  52 }
  53
  54 /**
  55  * Get up to num elements from the fifo. Return the number actully read
  56  */
  57 static inline uint32_t
  58 kni_fifo_get(struct rte_kni_fifo *fifo, void **data, uint32_t num)
  59 {
  60         uint32_t i = 0;
  61         uint32_t new_read = fifo->read;
  62         uint32_t fifo_write = fifo->write;
  63
  64         for (i = 0; i < num; i++) {
  65                 if (new_read == fifo_write)
  66                         break;
  67
  68                 data[i] = fifo->buffer[new_read];
  69                 new_read = (new_read + 1) & (fifo->len - 1);
  70         }
  71         fifo->read = new_read;
  72
  73         return i;
  74 }
  75
  76 /**
  77  * Get the num of elements in the fifo
  78  */
  79 static inline uint32_t
  80 kni_fifo_count(struct rte_kni_fifo *fifo)
  81 {
  82         return (fifo->len + fifo->write - fifo->read) & (fifo->len - 1);
  83 }
  84
  85 /**
  86  * Get the num of available elements in the fifo
  87  */
  88 static inline uint32_t
  89 kni_fifo_free_count(struct rte_kni_fifo *fifo)
  90 {
  91         return (fifo->read - fifo->write - 1) & (fifo->len - 1);
  92 }
  93
  94 #ifdef RTE_KNI_VHOST
  95 /**
  96  * Initializes the kni fifo structure
  97  */
  98 static inline void
  99 kni_fifo_init(struct rte_kni_fifo *fifo, uint32_t size)
 100 {
 101         fifo->write = 0;
 102         fifo->read = 0;
 103         fifo->len = size;
 104         fifo->elem_size = sizeof(void *);
 105 }
 106 #endif
 107
 108 #endif /* _KNI_FIFO_H_ */