/* * Copyright (c) 2016 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __included_ssvm_fifo_h__ #define __included_ssvm_fifo_h__ #include <vppinfra/clib.h> #include <vppinfra/vec.h> #include <vppinfra/mheap.h> #include <vppinfra/heap.h> #include <vppinfra/pool.h> #include <vppinfra/format.h> #include <pthread.h> /** Out-of-order segment */ typedef struct { u32 next; /**< Next linked-list element pool index */ u32 prev; /**< Previous linked-list element pool index */ u32 start; /**< Start of segment, normalized*/ u32 length; /**< Length of segment */ } ooo_segment_t; format_function_t format_ooo_segment; format_function_t format_ooo_list; #define SVM_FIFO_TRACE (0) #define OOO_SEGMENT_INVALID_INDEX ((u32)~0) #define SVM_FIFO_INVALID_SESSION_INDEX ((u32)~0) #define SVM_FIFO_INVALID_INDEX ((u32)~0) #define SVM_FIFO_MAX_EVT_SUBSCRIBERS 8 enum { SVM_FIFO_NO_TX_NOTIF = 0, SVM_FIFO_WANT_TX_NOTIF = 1, SVM_FIFO_WANT_TX_NOTIF_IF_FULL = 2, }; typedef struct { u32 offset; u32 len; u32 action; } svm_fifo_trace_elem_t; typedef struct _svm_fifo { CLIB_CACHE_LINE_ALIGN_MARK (shared_first); volatile u32 cursize; /**< current fifo size */ u32 nitems; CLIB_CACHE_LINE_ALIGN_MARK (shared_second); volatile u32 has_event; /**< non-zero if deq event exists */ u32 master_session_index; u32 client_session_index; u8 master_thread_index; u8 client_thread_index; u32 segment_manager; u32 segment_index; u32 ct_session_index; /**< Local session index for vpp */ u32 freelist_index; /**< aka log2(allocated_size) - const. */ i8 refcnt; /**< reference count */ CLIB_CACHE_LINE_ALIGN_MARK (consumer); u32 head; volatile u32 want_tx_ntf; /**< producer wants nudge */ volatile u32 has_tx_ntf; CLIB_CACHE_LINE_ALIGN_MARK (producer); u32 tail; ooo_segment_t *ooo_segments; /**< Pool of ooo segments */ u32 ooos_list_head; /**< Head of out-of-order linked-list */ u32 ooos_newest; /**< Last segment to have been updated */ struct _svm_fifo *next; /**< next in freelist/active chain */ struct _svm_fifo *prev; /**< prev in active chain */ volatile u8 n_subscribers; u8 subscribers[SVM_FIFO_MAX_EVT_SUBSCRIBERS]; #if SVM_FIFO_TRACE svm_fifo_trace_elem_t *trace; #endif CLIB_CACHE_LINE_ALIGN_MARK (data); } svm_fifo_t; typedef enum { SVM_FIFO_FULL = -2, } svm_fifo_err_t; typedef struct svm_fifo_segment_ { u8 *data; u32 len; } svm_fifo_segment_t; #if SVM_FIFO_TRACE #define svm_fifo_trace_add(_f, _s, _l, _t) \ { \ svm_fifo_trace_elem_t *trace_elt; \ vec_add2(_f->trace, trace_elt, 1); \ trace_elt->offset = _s; \ trace_elt->len = _l; \ trace_elt->action = _t; \ } #else #define svm_fifo_trace_add(_f, _s, _l, _t) #endif u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f); u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose); static inline u32 svm_fifo_max_dequeue (svm_fifo_t * f) { return clib_atomic_load_acq_n (&f->cursize); } static inline int svm_fifo_is_full (svm_fifo_t * f) { return (clib_atomic_load_acq_n (&f->cursize) == f->nitems); } static inline int svm_fifo_is_empty (svm_fifo_t * f) { return (clib_atomic_load_acq_n (&f->cursize) == 0); } static inline u32 svm_fifo_max_enqueue (svm_fifo_t * f) { return f->nitems - svm_fifo_max_dequeue (f); } static inline int svm_fifo_has_event (svm_fifo_t * f) { return f->has_event; } static inline u8 svm_fifo_has_ooo_data (svm_fifo_t * f) { return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX; } /** * Sets fifo event flag. * * Also acts as a release barrier. * * @return 1 if flag was not set. */ always_inline u8 svm_fifo_set_event (svm_fifo_t * f) { /* return __sync_lock_test_and_set (&f->has_event, 1) == 0; return __sync_bool_compare_and_swap (&f->has_event, 0, 1); */ return !__atomic_exchange_n (&f->has_event, 1, __ATOMIC_RELEASE); } /** * Unsets fifo event flag. * * Also acts as a release barrier. */ always_inline void svm_fifo_unset_event (svm_fifo_t * f) { clib_atomic_release (&f->has_event); } svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes); void svm_fifo_free (svm_fifo_t * f); int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, const u8 * copy_from_here); int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 required_bytes, u8 * copy_from_here); int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here); int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here); int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes); void svm_fifo_dequeue_drop_all (svm_fifo_t * f); int svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs); void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs); void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer); void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len); void svm_fifo_add_subscriber (svm_fifo_t * f, u8 subscriber); void svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber); format_function_t format_svm_fifo; /** * Max contiguous chunk of data that can be read */ always_inline u32 svm_fifo_max_read_chunk (svm_fifo_t * f) { return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head)); } /** * Max contiguous chunk of data that can be written */ always_inline u32 svm_fifo_max_write_chunk (svm_fifo_t * f) { return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail)); } /** * Advance tail pointer * * Useful for moving tail pointer after external enqueue. */ always_inline void svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes) { ASSERT (bytes <= svm_fifo_max_enqueue (f)); f->tail = (f->tail + bytes) % f->nitems; clib_atomic_fetch_add_rel (&f->cursize, bytes); } always_inline u8 * svm_fifo_head (svm_fifo_t * f) { return (f->data + f->head); } always_inline u8 * svm_fifo_tail (svm_fifo_t * f) { return (f->data + f->tail); } always_inline u32 svm_fifo_nitems (svm_fifo_t * f) { return f->nitems; } static inline void svm_fifo_add_want_tx_ntf (svm_fifo_t * f, u8 ntf_type) { f->want_tx_ntf |= ntf_type; } static inline void svm_fifo_del_want_tx_ntf (svm_fifo_t * f, u8 ntf_type) { f->want_tx_ntf &= ~ntf_type; } static inline void svm_fifo_clear_tx_ntf (svm_fifo_t * f) { /* Set the flag if want_tx_notif_if_full was the only ntf requested */ f->has_tx_ntf = f->want_tx_ntf == SVM_FIFO_WANT_TX_NOTIF_IF_FULL; svm_fifo_del_want_tx_ntf (f, SVM_FIFO_WANT_TX_NOTIF); } static inline void svm_fifo_reset_tx_ntf (svm_fifo_t * f) { f->has_tx_ntf = 0; } static inline u8 svm_fifo_needs_tx_ntf (svm_fifo_t * f, u32 n_last_deq) { u8 want_ntf = f->want_tx_ntf; if (PREDICT_TRUE (want_ntf == SVM_FIFO_NO_TX_NOTIF)) return 0; else if (want_ntf & SVM_FIFO_WANT_TX_NOTIF) return 1; else if (want_ntf & SVM_FIFO_WANT_TX_NOTIF_IF_FULL) { u32 max_deq = svm_fifo_max_dequeue (f); u32 nitems = svm_fifo_nitems (f); if (!f->has_tx_ntf && max_deq < nitems && max_deq + n_last_deq >= nitems) return 1; return 0; } return 0; } always_inline u8 svm_fifo_n_subscribers (svm_fifo_t * f) { return f->n_subscribers; } u32 svm_fifo_number_ooo_segments (svm_fifo_t * f); ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f); always_inline ooo_segment_t * svm_fifo_newest_ooo_segment (svm_fifo_t * f) { if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX) return 0; return pool_elt_at_index (f->ooo_segments, f->ooos_newest); } always_inline void svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f) { f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; } always_inline u32 ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos) { /* Ambiguous. Assumption is that ooo segments don't touch tail */ if (PREDICT_FALSE (pos == f->tail && f->tail == f->head)) return f->nitems; return (((f->nitems + pos) - f->tail) % f->nitems); } always_inline u32 ooo_segment_distance_to_tail (svm_fifo_t * f, u32 pos) { return (((f->nitems + f->tail) - pos) % f->nitems); } always_inline u32 ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s) { return ooo_segment_distance_from_tail (f, s->start); } always_inline u32 ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s) { return ooo_segment_distance_from_tail (f, s->start) + s->length; } always_inline u32 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s) { return s->length; } always_inline ooo_segment_t * ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s) { if (s->prev == OOO_SEGMENT_INVALID_INDEX) return 0; return pool_elt_at_index (f->ooo_segments, s->prev); } always_inline ooo_segment_t * ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s) { if (s->next == OOO_SEGMENT_INVALID_INDEX) return 0; return pool_elt_at_index (f->ooo_segments, s->next); } #endif /* __included_ssvm_fifo_h__ */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */