net/bnxt: add initial TruFlow core session close
[dpdk.git] / lib / librte_kni / rte_kni_fifo.h
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4
5
6
7 /**
8  * @internal when c11 memory model enabled use c11 atomic memory barrier.
9  * when under non c11 memory model use rte_smp_* memory barrier.
10  *
11  * @param src
12  *   Pointer to the source data.
13  * @param dst
14  *   Pointer to the destination data.
15  * @param value
16  *   Data value.
17  */
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
37 /**
38  * Initializes the kni fifo structure
39  */
40 static void
41 kni_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
53 /**
54  * Adds num elements into the fifo. Return the number actually written
55  */
56 static inline unsigned
57 kni_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
76 /**
77  * Get up to num elements from the fifo. Return the number actually read
78  */
79 static inline unsigned
80 kni_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
97 /**
98  * Get the num of elements in the fifo
99  */
100 static inline uint32_t
101 kni_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
108 /**
109  * Get the num of available elements in the fifo
110  */
111 static inline uint32_t
112 kni_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 }