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1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
8 * @internal when c11 memory model enabled use c11 atomic memory barrier.
9 * when under non c11 memory model use rte_smp_* memory barrier.
12 * Pointer to the source data.
14 * Pointer to the destination data.
18 #ifdef RTE_USE_C11_MEM_MODEL
19 #define __KNI_LOAD_ACQUIRE(src) ({ \
20 __atomic_load_n((src), __ATOMIC_ACQUIRE); \
22 #define __KNI_STORE_RELEASE(dst, value) do { \
23 __atomic_store_n((dst), value, __ATOMIC_RELEASE); \
26 #define __KNI_LOAD_ACQUIRE(src) ({ \
27 typeof (*(src)) val = *(src); \
31 #define __KNI_STORE_RELEASE(dst, value) do { \
38 * Initializes the kni fifo structure
41 kni_fifo_init(struct rte_kni_fifo
*fifo
, unsigned size
)
43 /* Ensure size is power of 2 */
44 if (size
& (size
- 1))
45 rte_panic("KNI fifo size must be power of 2\n");
50 fifo
->elem_size
= sizeof(void *);
54 * Adds num elements into the fifo. Return the number actually written
56 static inline unsigned
57 kni_fifo_put(struct rte_kni_fifo
*fifo
, void **data
, unsigned num
)
60 unsigned fifo_write
= fifo
->write
;
61 unsigned new_write
= fifo_write
;
62 unsigned fifo_read
= __KNI_LOAD_ACQUIRE(&fifo
->read
);
64 for (i
= 0; i
< num
; i
++) {
65 new_write
= (new_write
+ 1) & (fifo
->len
- 1);
67 if (new_write
== fifo_read
)
69 fifo
->buffer
[fifo_write
] = data
[i
];
70 fifo_write
= new_write
;
72 __KNI_STORE_RELEASE(&fifo
->write
, fifo_write
);
77 * Get up to num elements from the fifo. Return the number actually read
79 static inline unsigned
80 kni_fifo_get(struct rte_kni_fifo
*fifo
, void **data
, unsigned num
)
83 unsigned new_read
= fifo
->read
;
84 unsigned fifo_write
= __KNI_LOAD_ACQUIRE(&fifo
->write
);
86 for (i
= 0; i
< num
; i
++) {
87 if (new_read
== fifo_write
)
90 data
[i
] = fifo
->buffer
[new_read
];
91 new_read
= (new_read
+ 1) & (fifo
->len
- 1);
93 __KNI_STORE_RELEASE(&fifo
->read
, new_read
);
98 * Get the num of elements in the fifo
100 static inline uint32_t
101 kni_fifo_count(struct rte_kni_fifo
*fifo
)
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);