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);
89 #define svm_fifo_trace_add(_f, _s, _l, _t) \
91 svm_fifo_trace_elem_t *trace_elt; \
92 vec_add2(_f->trace, trace_elt, 1); \
93 trace_elt->offset = _s; \
94 trace_elt->len = _l; \
95 trace_elt->action = _t; \
98 #define svm_fifo_trace_add(_f, _s, _l, _t)
101 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
102 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
105 svm_fifo_max_dequeue (svm_fifo_t * f)
111 svm_fifo_max_enqueue (svm_fifo_t * f)
113 return f->nitems - svm_fifo_max_dequeue (f);
117 svm_fifo_has_ooo_data (svm_fifo_t * f)
119 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
123 * Sets fifo event flag.
125 * @return 1 if flag was not set.
128 svm_fifo_set_event (svm_fifo_t * f)
130 /* Probably doesn't need to be atomic. Still, better avoid surprises */
131 return __sync_lock_test_and_set (&f->has_event, 1) == 0;
135 * Unsets fifo event flag.
138 svm_fifo_unset_event (svm_fifo_t * f)
140 /* Probably doesn't need to be atomic. Still, better avoid surprises */
141 __sync_lock_release (&f->has_event);
144 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
145 void svm_fifo_free (svm_fifo_t * f);
147 int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
148 const u8 * copy_from_here);
149 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset,
150 u32 required_bytes, u8 * copy_from_here);
151 int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
153 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
154 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
155 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
156 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
157 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
158 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
160 format_function_t format_svm_fifo;
162 always_inline ooo_segment_t *
163 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
165 if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
167 return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
171 svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
173 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
177 * Max contiguous chunk of data that can be read
180 svm_fifo_max_read_chunk (svm_fifo_t * f)
182 return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head));
186 * Max contiguous chunk of data that can be written
189 svm_fifo_max_write_chunk (svm_fifo_t * f)
191 return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail));
195 * Advance tail pointer
197 * Useful for moving tail pointer after external enqueue.
200 svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes)
202 ASSERT (bytes <= svm_fifo_max_enqueue (f));
203 f->tail = (f->tail + bytes) % f->nitems;
208 svm_fifo_head (svm_fifo_t * f)
210 return (f->data + f->head);
214 svm_fifo_tail (svm_fifo_t * f)
216 return (f->data + f->tail);
220 ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos)
222 /* Ambiguous. Assumption is that ooo segments don't touch tail */
223 if (PREDICT_FALSE (pos == f->tail && f->tail == f->head))
226 return (((f->nitems + pos) - f->tail) % f->nitems);
230 ooo_segment_distance_to_tail (svm_fifo_t * f, u32 pos)
232 return (((f->nitems + f->tail) - pos) % f->nitems);
236 ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
238 return ooo_segment_distance_from_tail (f, s->start);
242 ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
244 return ooo_segment_distance_from_tail (f, s->start) + s->length;
248 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
253 always_inline ooo_segment_t *
254 ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s)
256 if (s->prev == OOO_SEGMENT_INVALID_INDEX)
258 return pool_elt_at_index (f->ooo_segments, s->prev);
261 always_inline ooo_segment_t *
262 ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s)
264 if (s->next == OOO_SEGMENT_INVALID_INDEX)
266 return pool_elt_at_index (f->ooo_segments, s->next);
269 #endif /* __included_ssvm_fifo_h__ */
272 * fd.io coding-style-patch-verification: ON
275 * eval: (c-set-style "gnu")