DPDK  22.11.0
rte_ring_peek_elem_pvt.h
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1 /* SPDX-License-Identifier: BSD-3-Clause
2  *
3  * Copyright (c) 2010-2020 Intel Corporation
4  * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
5  * All rights reserved.
6  * Derived from FreeBSD's bufring.h
7  * Used as BSD-3 Licensed with permission from Kip Macy.
8  */
9 
10 #ifndef _RTE_RING_PEEK_ELEM_PVT_H_
11 #define _RTE_RING_PEEK_ELEM_PVT_H_
12 
30 static __rte_always_inline uint32_t
31 __rte_ring_st_get_tail(struct rte_ring_headtail *ht, uint32_t *tail,
32  uint32_t num)
33 {
34  uint32_t h, n, t;
35 
36  h = ht->head;
37  t = ht->tail;
38  n = h - t;
39 
40  RTE_ASSERT(n >= num);
41  num = (n >= num) ? num : 0;
42 
43  *tail = t;
44  return num;
45 }
46 
52 static __rte_always_inline void
53 __rte_ring_st_set_head_tail(struct rte_ring_headtail *ht, uint32_t tail,
54  uint32_t num, uint32_t enqueue)
55 {
56  uint32_t pos;
57 
58  RTE_SET_USED(enqueue);
59 
60  pos = tail + num;
61  ht->head = pos;
62  __atomic_store_n(&ht->tail, pos, __ATOMIC_RELEASE);
63 }
64 
74 static __rte_always_inline uint32_t
75 __rte_ring_hts_get_tail(struct rte_ring_hts_headtail *ht, uint32_t *tail,
76  uint32_t num)
77 {
78  uint32_t n;
79  union __rte_ring_hts_pos p;
80 
81  p.raw = __atomic_load_n(&ht->ht.raw, __ATOMIC_RELAXED);
82  n = p.pos.head - p.pos.tail;
83 
84  RTE_ASSERT(n >= num);
85  num = (n >= num) ? num : 0;
86 
87  *tail = p.pos.tail;
88  return num;
89 }
90 
96 static __rte_always_inline void
97 __rte_ring_hts_set_head_tail(struct rte_ring_hts_headtail *ht, uint32_t tail,
98  uint32_t num, uint32_t enqueue)
99 {
100  union __rte_ring_hts_pos p;
101 
102  RTE_SET_USED(enqueue);
103 
104  p.pos.head = tail + num;
105  p.pos.tail = p.pos.head;
106 
107  __atomic_store_n(&ht->ht.raw, p.raw, __ATOMIC_RELEASE);
108 }
109 
113 static __rte_always_inline unsigned int
114 __rte_ring_do_enqueue_start(struct rte_ring *r, uint32_t n,
115  enum rte_ring_queue_behavior behavior, uint32_t *free_space)
116 {
117  uint32_t free, head, next;
118 
119  switch (r->prod.sync_type) {
120  case RTE_RING_SYNC_ST:
121  n = __rte_ring_move_prod_head(r, RTE_RING_SYNC_ST, n,
122  behavior, &head, &next, &free);
123  break;
125  n = __rte_ring_hts_move_prod_head(r, n, behavior,
126  &head, &free);
127  break;
128  case RTE_RING_SYNC_MT:
130  default:
131  /* unsupported mode, shouldn't be here */
132  RTE_ASSERT(0);
133  n = 0;
134  free = 0;
135  }
136 
137  if (free_space != NULL)
138  *free_space = free - n;
139  return n;
140 }
141 
146 static __rte_always_inline unsigned int
147 __rte_ring_do_dequeue_start(struct rte_ring *r, void *obj_table,
148  uint32_t esize, uint32_t n, enum rte_ring_queue_behavior behavior,
149  uint32_t *available)
150 {
151  uint32_t avail, head, next;
152 
153  switch (r->cons.sync_type) {
154  case RTE_RING_SYNC_ST:
155  n = __rte_ring_move_cons_head(r, RTE_RING_SYNC_ST, n,
156  behavior, &head, &next, &avail);
157  break;
159  n = __rte_ring_hts_move_cons_head(r, n, behavior,
160  &head, &avail);
161  break;
162  case RTE_RING_SYNC_MT:
164  default:
165  /* unsupported mode, shouldn't be here */
166  RTE_ASSERT(0);
167  n = 0;
168  avail = 0;
169  }
170 
171  if (n != 0)
172  __rte_ring_dequeue_elems(r, head, obj_table, esize, n);
173 
174  if (available != NULL)
175  *available = avail - n;
176  return n;
177 }
178 
179 #endif /* _RTE_RING_PEEK_ELEM_PVT_H_ */
volatile uint32_t head
Definition: rte_ring_core.h:69
#define __rte_always_inline
Definition: rte_common.h:255
rte_ring_queue_behavior
Definition: rte_ring_core.h:43
enum rte_ring_sync_type sync_type
Definition: rte_ring_core.h:74
#define RTE_SET_USED(x)
Definition: rte_common.h:135
volatile uint32_t tail
Definition: rte_ring_core.h:70