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)
41 #define SVM_FIFO_INVALID_SESSION_INDEX ((u32)~0)
42 #define SVM_FIFO_INVALID_INDEX ((u32)~0)
49 } svm_fifo_trace_elem_t;
51 typedef struct _svm_fifo
53 volatile u32 cursize; /**< current fifo size */
55 CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
57 volatile u32 has_event; /**< non-zero if deq event exists */
60 u32 master_session_index;
61 u32 client_session_index;
62 u8 master_thread_index;
63 u8 client_thread_index;
66 u32 ct_session_index; /**< Local session index for vpp */
67 CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
69 volatile u32 want_tx_evt; /**< producer wants nudge */
70 CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
75 ooo_segment_t *ooo_segments; /**< Pool of ooo segments */
76 u32 ooos_list_head; /**< Head of out-of-order linked-list */
77 u32 ooos_newest; /**< Last segment to have been updated */
78 struct _svm_fifo *next; /**< next in freelist/active chain */
79 struct _svm_fifo *prev; /**< prev in active chain */
81 svm_fifo_trace_elem_t *trace;
83 u32 freelist_index; /**< aka log2(allocated_size) - const. */
84 i8 refcnt; /**< reference count */
85 CLIB_CACHE_LINE_ALIGN_MARK (data);
93 typedef struct svm_fifo_segment_
100 #define svm_fifo_trace_add(_f, _s, _l, _t) \
102 svm_fifo_trace_elem_t *trace_elt; \
103 vec_add2(_f->trace, trace_elt, 1); \
104 trace_elt->offset = _s; \
105 trace_elt->len = _l; \
106 trace_elt->action = _t; \
109 #define svm_fifo_trace_add(_f, _s, _l, _t)
112 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
113 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
116 svm_fifo_max_dequeue (svm_fifo_t * f)
118 return clib_atomic_load_acq_n (&f->cursize);
122 svm_fifo_is_full (svm_fifo_t * f)
124 return (clib_atomic_load_acq_n (&f->cursize) == f->nitems);
128 svm_fifo_is_empty (svm_fifo_t * f)
130 return (clib_atomic_load_acq_n (&f->cursize) == 0);
134 svm_fifo_max_enqueue (svm_fifo_t * f)
136 return f->nitems - svm_fifo_max_dequeue (f);
140 svm_fifo_has_event (svm_fifo_t * f)
146 svm_fifo_has_ooo_data (svm_fifo_t * f)
148 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
152 * Sets fifo event flag.
154 * Also acts as a release barrier.
156 * @return 1 if flag was not set.
159 svm_fifo_set_event (svm_fifo_t * f)
161 /* return __sync_lock_test_and_set (&f->has_event, 1) == 0;
162 return __sync_bool_compare_and_swap (&f->has_event, 0, 1); */
163 return !__atomic_exchange_n (&f->has_event, 1, __ATOMIC_RELEASE);
167 * Unsets fifo event flag.
169 * Also acts as a release barrier.
172 svm_fifo_unset_event (svm_fifo_t * f)
174 clib_atomic_release (&f->has_event);
178 svm_fifo_set_want_tx_evt (svm_fifo_t * f, u8 want_evt)
180 f->want_tx_evt = want_evt;
184 svm_fifo_want_tx_evt (svm_fifo_t * f)
186 return f->want_tx_evt;
189 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
190 void svm_fifo_free (svm_fifo_t * f);
192 int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
193 const u8 * copy_from_here);
194 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset,
195 u32 required_bytes, u8 * copy_from_here);
196 int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
198 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
199 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
200 void svm_fifo_dequeue_drop_all (svm_fifo_t * f);
201 int svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs);
202 void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs);
203 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
204 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
205 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
206 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
208 format_function_t format_svm_fifo;
210 always_inline ooo_segment_t *
211 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
213 if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
215 return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
219 svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
221 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
225 * Max contiguous chunk of data that can be read
228 svm_fifo_max_read_chunk (svm_fifo_t * f)
230 return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head));
234 * Max contiguous chunk of data that can be written
237 svm_fifo_max_write_chunk (svm_fifo_t * f)
239 return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail));
243 * Advance tail pointer
245 * Useful for moving tail pointer after external enqueue.
248 svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes)
250 ASSERT (bytes <= svm_fifo_max_enqueue (f));
251 f->tail = (f->tail + bytes) % f->nitems;
256 svm_fifo_head (svm_fifo_t * f)
258 return (f->data + f->head);
262 svm_fifo_tail (svm_fifo_t * f)
264 return (f->data + f->tail);
268 ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos)
270 /* Ambiguous. Assumption is that ooo segments don't touch tail */
271 if (PREDICT_FALSE (pos == f->tail && f->tail == f->head))
274 return (((f->nitems + pos) - f->tail) % f->nitems);
278 ooo_segment_distance_to_tail (svm_fifo_t * f, u32 pos)
280 return (((f->nitems + f->tail) - pos) % f->nitems);
284 ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
286 return ooo_segment_distance_from_tail (f, s->start);
290 ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
292 return ooo_segment_distance_from_tail (f, s->start) + s->length;
296 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
301 always_inline ooo_segment_t *
302 ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s)
304 if (s->prev == OOO_SEGMENT_INVALID_INDEX)
306 return pool_elt_at_index (f->ooo_segments, s->prev);
309 always_inline ooo_segment_t *
310 ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s)
312 if (s->next == OOO_SEGMENT_INVALID_INDEX)
314 return pool_elt_at_index (f->ooo_segments, s->next);
317 #endif /* __included_ssvm_fifo_h__ */
320 * fd.io coding-style-patch-verification: ON
323 * eval: (c-set-style "gnu")