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)
46 SVM_FIFO_NO_TX_NOTIF = 0,
47 SVM_FIFO_WANT_TX_NOTIF = 1,
48 SVM_FIFO_WANT_TX_NOTIF_IF_FULL = 2,
56 } svm_fifo_trace_elem_t;
58 typedef struct _svm_fifo
60 volatile u32 cursize; /**< current fifo size */
62 CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
64 volatile u32 has_event; /**< non-zero if deq event exists */
67 u32 master_session_index;
68 u32 client_session_index;
69 u8 master_thread_index;
70 u8 client_thread_index;
73 u32 ct_session_index; /**< Local session index for vpp */
74 CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
76 volatile u32 want_tx_ntf; /**< producer wants nudge */
77 volatile u32 has_tx_ntf;
78 CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
83 ooo_segment_t *ooo_segments; /**< Pool of ooo segments */
84 u32 ooos_list_head; /**< Head of out-of-order linked-list */
85 u32 ooos_newest; /**< Last segment to have been updated */
86 struct _svm_fifo *next; /**< next in freelist/active chain */
87 struct _svm_fifo *prev; /**< prev in active chain */
89 svm_fifo_trace_elem_t *trace;
91 u32 freelist_index; /**< aka log2(allocated_size) - const. */
92 i8 refcnt; /**< reference count */
93 CLIB_CACHE_LINE_ALIGN_MARK (data);
101 typedef struct svm_fifo_segment_
105 } svm_fifo_segment_t;
108 #define svm_fifo_trace_add(_f, _s, _l, _t) \
110 svm_fifo_trace_elem_t *trace_elt; \
111 vec_add2(_f->trace, trace_elt, 1); \
112 trace_elt->offset = _s; \
113 trace_elt->len = _l; \
114 trace_elt->action = _t; \
117 #define svm_fifo_trace_add(_f, _s, _l, _t)
120 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
121 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
124 svm_fifo_max_dequeue (svm_fifo_t * f)
126 return clib_atomic_load_acq_n (&f->cursize);
130 svm_fifo_is_full (svm_fifo_t * f)
132 return (clib_atomic_load_acq_n (&f->cursize) == f->nitems);
136 svm_fifo_is_empty (svm_fifo_t * f)
138 return (clib_atomic_load_acq_n (&f->cursize) == 0);
142 svm_fifo_max_enqueue (svm_fifo_t * f)
144 return f->nitems - svm_fifo_max_dequeue (f);
148 svm_fifo_has_event (svm_fifo_t * f)
154 svm_fifo_has_ooo_data (svm_fifo_t * f)
156 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
160 * Sets fifo event flag.
162 * Also acts as a release barrier.
164 * @return 1 if flag was not set.
167 svm_fifo_set_event (svm_fifo_t * f)
169 /* return __sync_lock_test_and_set (&f->has_event, 1) == 0;
170 return __sync_bool_compare_and_swap (&f->has_event, 0, 1); */
171 return !__atomic_exchange_n (&f->has_event, 1, __ATOMIC_RELEASE);
175 * Unsets fifo event flag.
177 * Also acts as a release barrier.
180 svm_fifo_unset_event (svm_fifo_t * f)
182 clib_atomic_release (&f->has_event);
185 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
186 void svm_fifo_free (svm_fifo_t * f);
188 int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
189 const u8 * copy_from_here);
190 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset,
191 u32 required_bytes, u8 * copy_from_here);
192 int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
194 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
195 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
196 void svm_fifo_dequeue_drop_all (svm_fifo_t * f);
197 int svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs);
198 void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs);
199 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
200 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
201 format_function_t format_svm_fifo;
204 * Max contiguous chunk of data that can be read
207 svm_fifo_max_read_chunk (svm_fifo_t * f)
209 return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head));
213 * Max contiguous chunk of data that can be written
216 svm_fifo_max_write_chunk (svm_fifo_t * f)
218 return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail));
222 * Advance tail pointer
224 * Useful for moving tail pointer after external enqueue.
227 svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes)
229 ASSERT (bytes <= svm_fifo_max_enqueue (f));
230 f->tail = (f->tail + bytes) % f->nitems;
235 svm_fifo_head (svm_fifo_t * f)
237 return (f->data + f->head);
241 svm_fifo_tail (svm_fifo_t * f)
243 return (f->data + f->tail);
247 svm_fifo_nitems (svm_fifo_t * f)
253 svm_fifo_add_want_tx_ntf (svm_fifo_t * f, u8 ntf_type)
255 f->want_tx_ntf |= ntf_type;
259 svm_fifo_del_want_tx_ntf (svm_fifo_t * f, u8 ntf_type)
261 f->want_tx_ntf &= ~ntf_type;
265 svm_fifo_clear_tx_ntf (svm_fifo_t * f)
267 /* Set the flag if want_tx_notif_if_full was the only ntf requested */
268 f->has_tx_ntf = f->want_tx_ntf == SVM_FIFO_WANT_TX_NOTIF_IF_FULL;
269 svm_fifo_del_want_tx_ntf (f, SVM_FIFO_WANT_TX_NOTIF);
273 svm_fifo_reset_tx_ntf (svm_fifo_t * f)
279 svm_fifo_needs_tx_ntf (svm_fifo_t * f, u32 n_last_deq)
281 u8 want_ntf = f->want_tx_ntf;
283 if (PREDICT_TRUE (want_ntf == SVM_FIFO_NO_TX_NOTIF))
285 else if (want_ntf & SVM_FIFO_WANT_TX_NOTIF)
287 else if (want_ntf & SVM_FIFO_WANT_TX_NOTIF_IF_FULL)
289 u32 max_deq = svm_fifo_max_dequeue (f);
290 u32 nitems = svm_fifo_nitems (f);
291 if (!f->has_tx_ntf && max_deq < nitems
292 && max_deq + n_last_deq >= nitems)
300 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
301 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
303 always_inline ooo_segment_t *
304 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
306 if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
308 return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
312 svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
314 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
318 ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos)
320 /* Ambiguous. Assumption is that ooo segments don't touch tail */
321 if (PREDICT_FALSE (pos == f->tail && f->tail == f->head))
324 return (((f->nitems + pos) - f->tail) % f->nitems);
328 ooo_segment_distance_to_tail (svm_fifo_t * f, u32 pos)
330 return (((f->nitems + f->tail) - pos) % f->nitems);
334 ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
336 return ooo_segment_distance_from_tail (f, s->start);
340 ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
342 return ooo_segment_distance_from_tail (f, s->start) + s->length;
346 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
351 always_inline ooo_segment_t *
352 ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s)
354 if (s->prev == OOO_SEGMENT_INVALID_INDEX)
356 return pool_elt_at_index (f->ooo_segments, s->prev);
359 always_inline ooo_segment_t *
360 ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s)
362 if (s->next == OOO_SEGMENT_INVALID_INDEX)
364 return pool_elt_at_index (f->ooo_segments, s->next);
367 #endif /* __included_ssvm_fifo_h__ */
370 * fd.io coding-style-patch-verification: ON
373 * eval: (c-set-style "gnu")