DPDK  17.05.2
rte_kni_fifo.h
1 /*-
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33 
34 
35 
39 static void
40 kni_fifo_init(struct rte_kni_fifo *fifo, unsigned size)
41 {
42  /* Ensure size is power of 2 */
43  if (size & (size - 1))
44  rte_panic("KNI fifo size must be power of 2\n");
45 
46  fifo->write = 0;
47  fifo->read = 0;
48  fifo->len = size;
49  fifo->elem_size = sizeof(void *);
50 }
51 
55 static inline unsigned
56 kni_fifo_put(struct rte_kni_fifo *fifo, void **data, unsigned num)
57 {
58  unsigned i = 0;
59  unsigned fifo_write = fifo->write;
60  unsigned fifo_read = fifo->read;
61  unsigned new_write = fifo_write;
62 
63  for (i = 0; i < num; i++) {
64  new_write = (new_write + 1) & (fifo->len - 1);
65 
66  if (new_write == fifo_read)
67  break;
68  fifo->buffer[fifo_write] = data[i];
69  fifo_write = new_write;
70  }
71  fifo->write = fifo_write;
72  return i;
73 }
74 
78 static inline unsigned
79 kni_fifo_get(struct rte_kni_fifo *fifo, void **data, unsigned num)
80 {
81  unsigned i = 0;
82  unsigned new_read = fifo->read;
83  unsigned fifo_write = fifo->write;
84  for (i = 0; i < num; i++) {
85  if (new_read == fifo_write)
86  break;
87 
88  data[i] = fifo->buffer[new_read];
89  new_read = (new_read + 1) & (fifo->len - 1);
90  }
91  fifo->read = new_read;
92  return i;
93 }
94 
98 static inline uint32_t
99 kni_fifo_count(struct rte_kni_fifo *fifo)
100 {
101  return (fifo->len + fifo->write - fifo->read) & (fifo->len - 1);
102 }