2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
15 #ifndef __included_ssvm_fifo_h__
16 #define __included_ssvm_fifo_h__
18 #include <vppinfra/clib.h>
19 #include <vppinfra/vec.h>
20 #include <vppinfra/mheap.h>
21 #include <vppinfra/heap.h>
22 #include <vppinfra/pool.h>
23 #include <vppinfra/format.h>
26 /** Out-of-order segment */
29 u32 next; /**< Next linked-list element pool index */
30 u32 prev; /**< Previous linked-list element pool index */
32 u32 start; /**< Start of segment, normalized*/
33 u32 length; /**< Length of segment */
36 format_function_t format_ooo_segment;
37 format_function_t format_ooo_list;
39 #define SVM_FIFO_TRACE (0)
40 #define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
47 } svm_fifo_trace_elem_t;
49 typedef struct _svm_fifo
51 volatile u32 cursize; /**< current fifo size */
53 CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
55 volatile u32 has_event; /**< non-zero if deq event exists */
58 u32 master_session_index;
59 u32 client_session_index;
60 u8 master_thread_index;
61 u8 client_thread_index;
63 CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
65 CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
70 ooo_segment_t *ooo_segments; /**< Pool of ooo segments */
71 u32 ooos_list_head; /**< Head of out-of-order linked-list */
72 u32 ooos_newest; /**< Last segment to have been updated */
73 struct _svm_fifo *next; /**< next in freelist/active chain */
74 struct _svm_fifo *prev; /**< prev in active chain */
76 svm_fifo_trace_elem_t *trace;
78 u32 freelist_index; /**< aka log2(allocated_size) - const. */
79 i8 refcnt; /**< reference count */
80 CLIB_CACHE_LINE_ALIGN_MARK (data);
84 #define svm_fifo_trace_add(_f, _s, _l, _t) \
86 svm_fifo_trace_elem_t *trace_elt; \
87 vec_add2(_f->trace, trace_elt, 1); \
88 trace_elt->offset = _s; \
89 trace_elt->len = _l; \
90 trace_elt->action = _t; \
93 #define svm_fifo_trace_add(_f, _s, _l, _t)
96 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
97 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
100 svm_fifo_max_dequeue (svm_fifo_t * f)
106 svm_fifo_max_enqueue (svm_fifo_t * f)
108 return f->nitems - svm_fifo_max_dequeue (f);
112 svm_fifo_has_ooo_data (svm_fifo_t * f)
114 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
118 * Sets fifo event flag.
120 * @return 1 if flag was not set.
123 svm_fifo_set_event (svm_fifo_t * f)
125 /* Probably doesn't need to be atomic. Still, better avoid surprises */
126 return __sync_lock_test_and_set (&f->has_event, 1) == 0;
130 * Unsets fifo event flag.
133 svm_fifo_unset_event (svm_fifo_t * f)
135 /* Probably doesn't need to be atomic. Still, better avoid surprises */
136 __sync_lock_release (&f->has_event);
139 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
140 void svm_fifo_free (svm_fifo_t * f);
142 int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
143 const u8 * copy_from_here);
144 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset,
145 u32 required_bytes, u8 * copy_from_here);
146 int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
148 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
149 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
150 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
151 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
152 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
154 format_function_t format_svm_fifo;
156 always_inline ooo_segment_t *
157 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
159 if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
161 return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
165 svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
167 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
171 * Max contiguous chunk of data that can be read
174 svm_fifo_max_read_chunk (svm_fifo_t * f)
176 return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head));
180 * Max contiguous chunk of data that can be written
183 svm_fifo_max_write_chunk (svm_fifo_t * f)
185 return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail));
189 * Advance tail pointer
191 * Useful for moving tail pointer after external enqueue.
194 svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes)
196 ASSERT (bytes <= svm_fifo_max_enqueue (f));
197 f->tail = (f->tail + bytes) % f->nitems;
202 svm_fifo_head (svm_fifo_t * f)
204 return (f->data + f->head);
208 svm_fifo_tail (svm_fifo_t * f)
210 return (f->data + f->tail);
214 ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos)
216 /* Ambiguous. Assumption is that ooo segments don't touch tail */
217 if (PREDICT_FALSE (pos == f->tail && f->tail == f->head))
220 return (((f->nitems + pos) - f->tail) % f->nitems);
224 ooo_segment_distance_to_tail (svm_fifo_t * f, u32 pos)
226 return (((f->nitems + f->tail) - pos) % f->nitems);
230 ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
232 return ooo_segment_distance_from_tail (f, s->start);
236 ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
238 return ooo_segment_distance_from_tail (f, s->start) + s->length;
242 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
247 always_inline ooo_segment_t *
248 ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s)
250 if (s->prev == OOO_SEGMENT_INVALID_INDEX)
252 return pool_elt_at_index (f->ooo_segments, s->prev);
255 always_inline ooo_segment_t *
256 ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s)
258 if (s->next == OOO_SEGMENT_INVALID_INDEX)
260 return pool_elt_at_index (f->ooo_segments, s->next);
263 #endif /* __included_ssvm_fifo_h__ */
266 * fd.io coding-style-patch-verification: ON
269 * eval: (c-set-style "gnu")