DPDK 22.11.6
rte_kni_fifo.h
1/* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
3 */
4
5
6
18#ifdef RTE_USE_C11_MEM_MODEL
19#define __KNI_LOAD_ACQUIRE(src) ({ \
20 __atomic_load_n((src), __ATOMIC_ACQUIRE); \
21 })
22#define __KNI_STORE_RELEASE(dst, value) do { \
23 __atomic_store_n((dst), value, __ATOMIC_RELEASE); \
24 } while(0)
25#else
26#define __KNI_LOAD_ACQUIRE(src) ({ \
27 typeof (*(src)) val = *(src); \
28 rte_smp_rmb(); \
29 val; \
30 })
31#define __KNI_STORE_RELEASE(dst, value) do { \
32 *(dst) = value; \
33 rte_smp_wmb(); \
34 } while(0)
35#endif
36
40static void
41kni_fifo_init(struct rte_kni_fifo *fifo, unsigned size)
42{
43 /* Ensure size is power of 2 */
44 if (size & (size - 1))
45 rte_panic("KNI fifo size must be power of 2\n");
46
47 fifo->write = 0;
48 fifo->read = 0;
49 fifo->len = size;
50 fifo->elem_size = sizeof(void *);
51}
52
56static inline unsigned
57kni_fifo_put(struct rte_kni_fifo *fifo, void **data, unsigned num)
58{
59 unsigned i = 0;
60 unsigned fifo_write = fifo->write;
61 unsigned new_write = fifo_write;
62 unsigned fifo_read = __KNI_LOAD_ACQUIRE(&fifo->read);
63
64 for (i = 0; i < num; i++) {
65 new_write = (new_write + 1) & (fifo->len - 1);
66
67 if (new_write == fifo_read)
68 break;
69 fifo->buffer[fifo_write] = data[i];
70 fifo_write = new_write;
71 }
72 __KNI_STORE_RELEASE(&fifo->write, fifo_write);
73 return i;
74}
75
79static inline unsigned
80kni_fifo_get(struct rte_kni_fifo *fifo, void **data, unsigned num)
81{
82 unsigned i = 0;
83 unsigned new_read = fifo->read;
84 unsigned fifo_write = __KNI_LOAD_ACQUIRE(&fifo->write);
85
86 for (i = 0; i < num; i++) {
87 if (new_read == fifo_write)
88 break;
89
90 data[i] = fifo->buffer[new_read];
91 new_read = (new_read + 1) & (fifo->len - 1);
92 }
93 __KNI_STORE_RELEASE(&fifo->read, new_read);
94 return i;
95}
96
100static inline uint32_t
101kni_fifo_count(struct rte_kni_fifo *fifo)
102{
103 unsigned fifo_write = __KNI_LOAD_ACQUIRE(&fifo->write);
104 unsigned fifo_read = __KNI_LOAD_ACQUIRE(&fifo->read);
105 return (fifo->len + fifo_write - fifo_read) & (fifo->len - 1);
106}
107
111static inline uint32_t
112kni_fifo_free_count(struct rte_kni_fifo *fifo)
113{
114 uint32_t fifo_write = __KNI_LOAD_ACQUIRE(&fifo->write);
115 uint32_t fifo_read = __KNI_LOAD_ACQUIRE(&fifo->read);
116 return (fifo_read - fifo_write - 1) & (fifo->len - 1);
117}
#define rte_panic(...)
Definition: rte_debug.h:43