X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fsvm%2Fsvm_fifo.c;h=918ad77956e535b5a5aac9d0726173833fd00ac6;hb=402377e80c19b103792a0f340d9376e0138abbfe;hp=11f901931be18facfa6c0f02b9ab41c3de05cafb;hpb=68b0fb0c620c7451ef1a6380c43c39de6614db51;p=vpp.git diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c index 11f901931be..918ad77956e 100644 --- a/src/svm/svm_fifo.c +++ b/src/svm/svm_fifo.c @@ -1,5 +1,9 @@ /* - * Copyright (c) 2016 Cisco and/or its affiliates. + * Copyright (c) 2016-2019 Cisco and/or its affiliates. + * Copyright (c) 2019 Arm Limited + * Copyright (c) 2010-2017 Intel Corporation and/or its affiliates. + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org + * Inspired from DPDK rte_ring.h (SPSC only) (derived from freebsd bufring.h). * 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: @@ -13,47 +17,233 @@ * limitations under the License. */ -#include "svm_fifo.h" +#include +#include + +static inline u8 +position_lt (svm_fifo_t * f, u32 a, u32 b, u32 tail) +{ + return (ooo_segment_distance_from_tail (f, a, tail) + < ooo_segment_distance_from_tail (f, b, tail)); +} + +static inline u8 +position_leq (svm_fifo_t * f, u32 a, u32 b, u32 tail) +{ + return (ooo_segment_distance_from_tail (f, a, tail) + <= ooo_segment_distance_from_tail (f, b, tail)); +} + +static inline u8 +position_gt (svm_fifo_t * f, u32 a, u32 b, u32 tail) +{ + return (ooo_segment_distance_from_tail (f, a, tail) + > ooo_segment_distance_from_tail (f, b, tail)); +} + +static inline u32 +position_diff (svm_fifo_t * f, u32 posa, u32 posb, u32 tail) +{ + return ooo_segment_distance_from_tail (f, posa, tail) + - ooo_segment_distance_from_tail (f, posb, tail); +} + +static inline u32 +ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s) +{ + return s->start + s->length; +} + +#ifndef CLIB_MARCH_VARIANT + +u8 * +format_ooo_segment (u8 * s, va_list * args) +{ + svm_fifo_t *f = va_arg (*args, svm_fifo_t *); + ooo_segment_t *seg = va_arg (*args, ooo_segment_t *); + u32 normalized_start = (seg->start + f->nitems - f->tail) % f->size; + s = format (s, "[%u, %u], len %u, next %d, prev %d", normalized_start, + (normalized_start + seg->length) % f->size, seg->length, + seg->next, seg->prev); + return s; +} + +u8 * +svm_fifo_dump_trace (u8 * s, svm_fifo_t * f) +{ +#if SVM_FIFO_TRACE + svm_fifo_trace_elem_t *seg = 0; + int i = 0; + + if (f->trace) + { + vec_foreach (seg, f->trace) + { + s = format (s, "{%u, %u, %u}, ", seg->offset, seg->len, seg->action); + i++; + if (i % 5 == 0) + s = format (s, "\n"); + } + s = format (s, "\n"); + } + return s; +#else + return 0; +#endif +} + +u8 * +svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose) +{ + int i, trace_len; + u8 *data = 0; + svm_fifo_trace_elem_t *trace; + u32 offset; + svm_fifo_t *dummy_fifo; + + if (!f) + return s; + +#if SVM_FIFO_TRACE + trace = f->trace; + trace_len = vec_len (trace); +#else + trace = 0; + trace_len = 0; +#endif + + dummy_fifo = svm_fifo_create (f->size); + clib_memset (f->data, 0xFF, f->nitems); + + vec_validate (data, f->nitems); + for (i = 0; i < vec_len (data); i++) + data[i] = i; + + for (i = 0; i < trace_len; i++) + { + offset = trace[i].offset; + if (trace[i].action == 1) + { + if (verbose) + s = format (s, "adding [%u, %u]:", trace[i].offset, + (trace[i].offset + trace[i].len) % dummy_fifo->size); + svm_fifo_enqueue_with_offset (dummy_fifo, trace[i].offset, + trace[i].len, &data[offset]); + } + else if (trace[i].action == 2) + { + if (verbose) + s = format (s, "adding [%u, %u]:", 0, trace[i].len); + svm_fifo_enqueue_nowait (dummy_fifo, trace[i].len, &data[offset]); + } + else if (!no_read) + { + if (verbose) + s = format (s, "read: %u", trace[i].len); + svm_fifo_dequeue_drop (dummy_fifo, trace[i].len); + } + if (verbose) + s = format (s, "%U", format_svm_fifo, dummy_fifo, 1); + } + + s = format (s, "result: %U", format_svm_fifo, dummy_fifo, 1); + + return s; +} + +u8 * +format_ooo_list (u8 * s, va_list * args) +{ + svm_fifo_t *f = va_arg (*args, svm_fifo_t *); + u32 indent = va_arg (*args, u32); + u32 ooo_segment_index = f->ooos_list_head; + ooo_segment_t *seg; + + while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX) + { + seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index); + s = format (s, "%U%U\n", format_white_space, indent, format_ooo_segment, + f, seg); + ooo_segment_index = seg->next; + } + + return s; +} + +u8 * +format_svm_fifo (u8 * s, va_list * args) +{ + svm_fifo_t *f = va_arg (*args, svm_fifo_t *); + int verbose = va_arg (*args, int); + u32 indent; + + if (!s) + return s; + + indent = format_get_indent (s); + s = format (s, "cursize %u nitems %u has_event %d\n", + svm_fifo_max_dequeue (f), f->nitems, f->has_event); + s = format (s, "%Uhead %u tail %u segment manager %u\n", format_white_space, + indent, (f->head % f->size), (f->tail % f->size), + f->segment_manager); + + if (verbose > 1) + s = format (s, "%Uvpp session %d thread %d app session %d thread %d\n", + format_white_space, indent, f->master_session_index, + f->master_thread_index, f->client_session_index, + f->client_thread_index); + + if (verbose) + { + s = format (s, "%Uooo pool %d active elts newest %u\n", + format_white_space, indent, pool_elts (f->ooo_segments), + f->ooos_newest); + if (svm_fifo_has_ooo_data (f)) + s = format (s, " %U", format_ooo_list, f, indent, verbose); + } + return s; +} /** create an svm fifo, in the current heap. Fails vs blow up the process */ svm_fifo_t * svm_fifo_create (u32 data_size_in_bytes) { svm_fifo_t *f; - pthread_mutexattr_t attr; - pthread_condattr_t cattr; + u32 rounded_data_size; - f = clib_mem_alloc_aligned_or_null (sizeof (*f) + data_size_in_bytes, + /* always round fifo data size to the next highest power-of-two */ + rounded_data_size = (1 << (max_log2 (data_size_in_bytes))); + f = clib_mem_alloc_aligned_or_null (sizeof (*f) + rounded_data_size, CLIB_CACHE_LINE_BYTES); if (f == 0) return 0; - memset (f, 0, sizeof (*f) + data_size_in_bytes); - f->nitems = data_size_in_bytes; + clib_memset (f, 0, sizeof (*f)); + f->size = rounded_data_size; + /* + * usable size of the fifo set to rounded_data_size - 1 + * to differentiate between free fifo and empty fifo. + */ + f->nitems = f->size - 1; f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX; + f->ct_session_index = SVM_FIFO_INVALID_SESSION_INDEX; + f->segment_index = SVM_FIFO_INVALID_INDEX; + f->refcnt = 1; + return (f); +} - memset (&attr, 0, sizeof (attr)); - memset (&cattr, 0, sizeof (cattr)); - - if (pthread_mutexattr_init (&attr)) - clib_unix_warning ("mutexattr_init"); - if (pthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED)) - clib_unix_warning ("pthread_mutexattr_setpshared"); - if (pthread_mutex_init (&f->mutex, &attr)) - clib_unix_warning ("mutex_init"); - if (pthread_mutexattr_destroy (&attr)) - clib_unix_warning ("mutexattr_destroy"); - if (pthread_condattr_init (&cattr)) - clib_unix_warning ("condattr_init"); - if (pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED)) - clib_unix_warning ("condattr_setpshared"); - if (pthread_cond_init (&f->condvar, &cattr)) - clib_unix_warning ("cond_init1"); - if (pthread_condattr_destroy (&cattr)) - clib_unix_warning ("cond_init2"); +void +svm_fifo_free (svm_fifo_t * f) +{ + ASSERT (f->refcnt > 0); - return (f); + if (--f->refcnt == 0) + { + pool_free (f->ooo_segments); + clib_mem_free (f); + } } +#endif always_inline ooo_segment_t * ooo_segment_new (svm_fifo_t * f, u32 start, u32 length) @@ -62,7 +252,7 @@ ooo_segment_new (svm_fifo_t * f, u32 start, u32 length) pool_get (f->ooo_segments, s); - s->fifo_position = start; + s->start = start; s->length = length; s->prev = s->next = OOO_SEGMENT_INVALID_INDEX; @@ -100,17 +290,21 @@ ooo_segment_del (svm_fifo_t * f, u32 index) * adjacent segments and removing overlapping ones. */ static void -ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) +ooo_segment_add (svm_fifo_t * f, u32 offset, u32 head, u32 tail, u32 length) { ooo_segment_t *s, *new_s, *prev, *next, *it; - u32 new_index, position, end_offset, s_sof, s_eof, s_index; + u32 new_index, s_end_pos, s_index; + u32 offset_pos, offset_end_pos; - position = (f->tail + offset) % f->nitems; - end_offset = offset + length; + ASSERT (offset + length <= ooo_segment_distance_from_tail (f, head, tail)); + offset_pos = tail + offset; + offset_end_pos = tail + offset + length; + + f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX) { - s = ooo_segment_new (f, position, length); + s = ooo_segment_new (f, offset_pos, length); f->ooos_list_head = s - f->ooo_segments; f->ooos_newest = f->ooos_list_head; return; @@ -119,26 +313,37 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) /* Find first segment that starts after new segment */ s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head); while (s->next != OOO_SEGMENT_INVALID_INDEX - && ooo_segment_offset (f, s) <= offset) + && position_lt (f, s->start, offset_pos, tail)) s = pool_elt_at_index (f->ooo_segments, s->next); + /* If we have a previous and we overlap it, use it as starting point */ + prev = ooo_segment_get_prev (f, s); + if (prev + && position_leq (f, offset_pos, ooo_segment_end_pos (f, prev), tail)) + { + s = prev; + s_end_pos = ooo_segment_end_pos (f, s); + + /* Since we have previous, offset start position cannot be smaller + * than prev->start. Check tail */ + ASSERT (position_lt (f, s->start, offset_pos, tail)); + goto check_tail; + } + s_index = s - f->ooo_segments; - s_sof = ooo_segment_offset (f, s); - s_eof = ooo_segment_end_offset (f, s); + s_end_pos = ooo_segment_end_pos (f, s); /* No overlap, add before current segment */ - if (end_offset < s_sof) + if (position_lt (f, offset_end_pos, s->start, tail)) { - new_s = ooo_segment_new (f, position, length); + new_s = ooo_segment_new (f, offset_pos, length); new_index = new_s - f->ooo_segments; /* Pool might've moved, get segment again */ s = pool_elt_at_index (f->ooo_segments, s_index); - if (s->prev != OOO_SEGMENT_INVALID_INDEX) { new_s->prev = s->prev; - prev = pool_elt_at_index (f->ooo_segments, new_s->prev); prev->next = new_index; } @@ -148,29 +353,24 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) f->ooos_list_head = new_index; } - new_s->next = s - f->ooo_segments; + new_s->next = s_index; s->prev = new_index; f->ooos_newest = new_index; return; } /* No overlap, add after current segment */ - else if (s_eof < offset) + else if (position_gt (f, offset_pos, s_end_pos, tail)) { - new_s = ooo_segment_new (f, position, length); + new_s = ooo_segment_new (f, offset_pos, length); new_index = new_s - f->ooo_segments; /* Pool might've moved, get segment again */ s = pool_elt_at_index (f->ooo_segments, s_index); - if (s->next != OOO_SEGMENT_INVALID_INDEX) - { - new_s->next = s->next; + /* Needs to be last */ + ASSERT (s->next == OOO_SEGMENT_INVALID_INDEX); - next = pool_elt_at_index (f->ooo_segments, new_s->next); - next->prev = new_index; - } - - new_s->prev = s - f->ooo_segments; + new_s->prev = s_index; s->next = new_index; f->ooos_newest = new_index; @@ -182,67 +382,39 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) */ /* Merge at head */ - if (offset <= s_sof) + if (position_lt (f, offset_pos, s->start, tail)) { - /* If we have a previous, check if we overlap */ - if (s->prev != OOO_SEGMENT_INVALID_INDEX) - { - prev = pool_elt_at_index (f->ooo_segments, s->prev); - - /* New segment merges prev and current. Remove previous and - * update position of current. */ - if (ooo_segment_end_offset (f, prev) >= offset) - { - s->fifo_position = prev->fifo_position; - s->length = s_eof - ooo_segment_offset (f, prev); - ooo_segment_del (f, s->prev); - } - } - else + s->start = offset_pos; + s->length = position_diff (f, s_end_pos, s->start, tail); + f->ooos_newest = s - f->ooo_segments; + } + +check_tail: + + /* Overlapping tail */ + if (position_gt (f, offset_end_pos, s_end_pos, tail)) + { + s->length = position_diff (f, offset_end_pos, s->start, tail); + + /* Remove the completely overlapped segments in the tail */ + it = ooo_segment_next (f, s); + while (it && position_leq (f, ooo_segment_end_pos (f, it), + offset_end_pos, tail)) { - s->fifo_position = position; - s->length = s_eof - ooo_segment_offset (f, s); + next = ooo_segment_next (f, it); + ooo_segment_del (f, it - f->ooo_segments); + it = next; } - /* The new segment's tail may cover multiple smaller ones */ - if (s_eof < end_offset) + /* If partial overlap with last, merge */ + if (it && position_leq (f, it->start, offset_end_pos, tail)) { - /* Remove segments completely covered */ - it = (s->next != OOO_SEGMENT_INVALID_INDEX) ? - pool_elt_at_index (f->ooo_segments, s->next) : 0; - while (it && ooo_segment_end_offset (f, it) < end_offset) - { - next = (it->next != OOO_SEGMENT_INVALID_INDEX) ? - pool_elt_at_index (f->ooo_segments, it->next) : 0; - ooo_segment_del (f, it - f->ooo_segments); - it = next; - } - - /* Update length. Segment's start might have changed. */ - s->length = end_offset - ooo_segment_offset (f, s); - - /* If partial overlap with last, merge */ - if (it && ooo_segment_offset (f, it) < end_offset) - { - s->length += - it->length - (ooo_segment_offset (f, it) - end_offset); - ooo_segment_del (f, it - f->ooo_segments); - } + s->length = position_diff (f, ooo_segment_end_pos (f, it), + s->start, tail); + ooo_segment_del (f, it - f->ooo_segments); } + f->ooos_newest = s - f->ooo_segments; } - /* Last but overlapping previous */ - else if (s_eof <= end_offset) - { - s->length = end_offset - ooo_segment_offset (f, s); - } - /* New segment completely covered by current one */ - else - { - /* Do Nothing */ - } - - /* Most recently updated segment */ - f->ooos_newest = s - f->ooo_segments; } /** @@ -250,315 +422,476 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) * advanced. Returns the number of bytes added to tail. */ static int -ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued) +ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued, u32 * tail) { ooo_segment_t *s; - u32 index, bytes = 0, diff; + u32 index, bytes = 0; + i32 diff; s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head); + diff = ooo_segment_distance_to_tail (f, s->start, *tail); + + ASSERT (diff != n_bytes_enqueued); + + if (diff > n_bytes_enqueued) + return 0; /* If last tail update overlaps one/multiple ooo segments, remove them */ - diff = (f->nitems + f->tail - s->fifo_position) % f->nitems; - while (0 < diff && diff < n_bytes_enqueued) + while (0 <= diff && diff < n_bytes_enqueued) { - /* Segment end is beyond the tail. Advance tail and be done */ - if (diff < s->length) + index = s - f->ooo_segments; + + /* Segment end is beyond the tail. Advance tail and remove segment */ + if (s->length > diff) { - f->tail += s->length - diff; - f->tail %= f->nitems; + bytes = s->length - diff; + *tail = *tail + bytes; + ooo_segment_del (f, index); break; } + /* If we have next go on */ - else if (s->next != OOO_SEGMENT_INVALID_INDEX) + if (s->next != OOO_SEGMENT_INVALID_INDEX) { - index = s - f->ooo_segments; s = pool_elt_at_index (f->ooo_segments, s->next); - diff = (f->nitems + f->tail - s->fifo_position) % f->nitems; + diff = ooo_segment_distance_to_tail (f, s->start, *tail); ooo_segment_del (f, index); } /* End of search */ else { + ooo_segment_del (f, index); break; } } - /* If tail is adjacent to an ooo segment, 'consume' it */ - if (diff == 0) - { - bytes = ((f->nitems - f->cursize) >= s->length) ? s->length : - f->nitems - f->cursize; - - f->tail += bytes; - f->tail %= f->nitems; - - ooo_segment_del (f, s - f->ooo_segments); - } - + ASSERT (bytes <= f->nitems); return bytes; } -static int -svm_fifo_enqueue_internal (svm_fifo_t * f, - int pid, u32 max_bytes, u8 * copy_from_here) +CLIB_MARCH_FN (svm_fifo_enqueue_nowait, int, svm_fifo_t * f, u32 max_bytes, + const u8 * copy_from_here) { u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems; + u32 tail, head, free_count, tail_idx; - if (PREDICT_FALSE (f->cursize == f->nitems)) - return -2; /* fifo stuffed */ + f_load_head_tail_prod (f, &head, &tail); - /* read cursize, which can only decrease while we're working */ - cursize = f->cursize; - nitems = f->nitems; + /* free space in fifo can only increase during enqueue: SPSC */ + free_count = f_free_count (f, head, tail); - /* Number of bytes we're going to copy */ - total_copy_bytes = (nitems - cursize) < max_bytes ? - (nitems - cursize) : max_bytes; + f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; - if (PREDICT_TRUE (copy_from_here != 0)) - { - /* Number of bytes in first copy segment */ - first_copy_bytes = ((nitems - f->tail) < total_copy_bytes) - ? (nitems - f->tail) : total_copy_bytes; + if (PREDICT_FALSE (free_count == 0)) + return SVM_FIFO_FULL; - clib_memcpy (&f->data[f->tail], copy_from_here, first_copy_bytes); - f->tail += first_copy_bytes; - f->tail = (f->tail == nitems) ? 0 : f->tail; + /* number of bytes we're going to copy */ + total_copy_bytes = free_count < max_bytes ? free_count : max_bytes; - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) + tail_idx = tail % f->size; + + if (PREDICT_TRUE (copy_from_here != 0)) + { + first_copy_bytes = f->size - tail_idx; + if (first_copy_bytes < total_copy_bytes) + { + clib_memcpy_fast (&f->data[tail_idx], copy_from_here, + first_copy_bytes); + /* number of bytes in second copy segment */ + second_copy_bytes = total_copy_bytes - first_copy_bytes; + /* wrap around */ + clib_memcpy_fast (&f->data[0], + copy_from_here + first_copy_bytes, + second_copy_bytes); + } + else { - clib_memcpy (&f->data[f->tail], copy_from_here + first_copy_bytes, - second_copy_bytes); - f->tail += second_copy_bytes; - f->tail = (f->tail == nitems) ? 0 : f->tail; + clib_memcpy_fast (&f->data[tail_idx], copy_from_here, + total_copy_bytes); } + tail += total_copy_bytes; } else { + ASSERT (0); /* Account for a zero-copy enqueue done elsewhere */ - ASSERT (max_bytes <= (nitems - cursize)); - f->tail += max_bytes; - f->tail = f->tail % nitems; - total_copy_bytes = max_bytes; + tail += max_bytes; } - /* Any out-of-order segments to collect? */ + svm_fifo_trace_add (f, head, total_copy_bytes, 2); + + /* collect out-of-order segments */ if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX)) - total_copy_bytes += ooo_segment_try_collect (f, total_copy_bytes); + total_copy_bytes += ooo_segment_try_collect (f, total_copy_bytes, &tail); + + ASSERT (total_copy_bytes <= free_count); - /* Atomically increase the queue length */ - __sync_fetch_and_add (&f->cursize, total_copy_bytes); + /* store-rel: producer owned index (paired with load-acq in consumer) */ + clib_atomic_store_rel_n (&f->tail, tail); - return (total_copy_bytes); + return total_copy_bytes; } +#ifndef CLIB_MARCH_VARIANT int -svm_fifo_enqueue_nowait (svm_fifo_t * f, - int pid, u32 max_bytes, u8 * copy_from_here) +svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, + const u8 * copy_from_here) { - return svm_fifo_enqueue_internal (f, pid, max_bytes, copy_from_here); + return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_nowait) (f, max_bytes, + copy_from_here); } +#endif -/** Enqueue a future segment. +/** + * Enqueue a future segment. + * * Two choices: either copies the entire segment, or copies nothing * Returns 0 of the entire segment was copied * Returns -1 if none of the segment was copied due to lack of space */ - -static int -svm_fifo_enqueue_with_offset_internal2 (svm_fifo_t * f, - int pid, - u32 offset, - u32 required_bytes, - u8 * copy_from_here) +CLIB_MARCH_FN (svm_fifo_enqueue_with_offset, int, svm_fifo_t * f, + u32 offset, u32 required_bytes, u8 * copy_from_here) { u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems; - u32 tail_plus_offset; + u32 tail_offset; + u32 tail, head, free_count, tail_offset_idx; - ASSERT (offset > 0); + f_load_head_tail_prod (f, &head, &tail); - /* read cursize, which can only decrease while we're working */ - cursize = f->cursize; - nitems = f->nitems; + /* free space in fifo can only increase during enqueue: SPSC */ + free_count = f_free_count (f, head, tail); - /* Will this request fit? */ - if ((required_bytes + offset) > (nitems - cursize)) + /* will this request fit? */ + if ((required_bytes + offset) > free_count) return -1; - ooo_segment_add (f, offset, required_bytes); + f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; - /* Number of bytes we're going to copy */ - total_copy_bytes = required_bytes; - tail_plus_offset = (f->tail + offset) % nitems; + ASSERT (required_bytes < f->nitems); - /* Number of bytes in first copy segment */ - first_copy_bytes = ((nitems - tail_plus_offset) < total_copy_bytes) - ? (nitems - tail_plus_offset) : total_copy_bytes; + tail_offset = tail + offset; + tail_offset_idx = tail_offset % f->size; - clib_memcpy (&f->data[tail_plus_offset], copy_from_here, first_copy_bytes); + svm_fifo_trace_add (f, offset, required_bytes, 1); - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) - { - tail_plus_offset += first_copy_bytes; - tail_plus_offset %= nitems; + ooo_segment_add (f, offset, head, tail, required_bytes); - ASSERT (tail_plus_offset == 0); + /* number of bytes we're going to copy */ + total_copy_bytes = required_bytes; + + /* number of bytes in first copy segment */ + first_copy_bytes = f->size - tail_offset_idx; + + if (first_copy_bytes < total_copy_bytes) + { + clib_memcpy_fast (&f->data[tail_offset_idx], copy_from_here, + first_copy_bytes); - clib_memcpy (&f->data[tail_plus_offset], - copy_from_here + first_copy_bytes, second_copy_bytes); + /* number of bytes in second copy segment */ + second_copy_bytes = total_copy_bytes - first_copy_bytes; + /* wrap around */ + clib_memcpy_fast (&f->data[0], + copy_from_here + first_copy_bytes, second_copy_bytes); + } + else + { + clib_memcpy_fast (&f->data[tail_offset_idx], copy_from_here, + total_copy_bytes); } - return (0); + return 0; } +#ifndef CLIB_MARCH_VARIANT int -svm_fifo_enqueue_with_offset (svm_fifo_t * f, - int pid, - u32 offset, - u32 required_bytes, u8 * copy_from_here) +svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 required_bytes, + u8 * copy_from_here) { - return svm_fifo_enqueue_with_offset_internal2 - (f, pid, offset, required_bytes, copy_from_here); + return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_with_offset) (f, offset, + required_bytes, + copy_from_here); } +void +svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len) +{ + u32 first_chunk; + u32 head, tail, head_idx; + + f_load_head_tail_cons (f, &head, &tail); + head_idx = head % f->size; + first_chunk = f->size - (head_idx); + ASSERT (len <= f->nitems); + if (len <= first_chunk) + clib_memcpy_fast (&f->data[head_idx], data, len); + else + { + clib_memcpy_fast (&f->data[head_idx], data, first_chunk); + clib_memcpy_fast (&f->data[0], data + first_chunk, len - first_chunk); + } +} +#endif -static int -svm_fifo_dequeue_internal2 (svm_fifo_t * f, - int pid, u32 max_bytes, u8 * copy_here) +CLIB_MARCH_FN (svm_fifo_dequeue_nowait, int, svm_fifo_t * f, u32 max_bytes, + u8 * copy_here) { u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems; + u32 tail, head, cursize, head_idx; - if (PREDICT_FALSE (f->cursize == 0)) - return -2; /* nothing in the fifo */ + f_load_head_tail_cons (f, &head, &tail); - /* read cursize, which can only increase while we're working */ - cursize = f->cursize; - nitems = f->nitems; + /* current size of fifo can only increase during dequeue: SPSC */ + cursize = f_cursize (f, head, tail); - /* Number of bytes we're going to copy */ + if (PREDICT_FALSE (cursize == 0)) + return -2; /* nothing in the fifo */ + + /* number of bytes we're going to copy */ total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes; + head_idx = head % f->size; + if (PREDICT_TRUE (copy_here != 0)) { - /* Number of bytes in first copy segment */ - first_copy_bytes = ((nitems - f->head) < total_copy_bytes) - ? (nitems - f->head) : total_copy_bytes; - clib_memcpy (copy_here, &f->data[f->head], first_copy_bytes); - f->head += first_copy_bytes; - f->head = (f->head == nitems) ? 0 : f->head; - - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) + /* number of bytes in first copy segment */ + first_copy_bytes = f->size - head_idx; + if (first_copy_bytes < total_copy_bytes) + { + clib_memcpy_fast (copy_here, &f->data[head_idx], first_copy_bytes); + /* number of bytes in second copy segment */ + second_copy_bytes = total_copy_bytes - first_copy_bytes; + /* wrap around */ + clib_memcpy_fast (copy_here + first_copy_bytes, + &f->data[0], second_copy_bytes); + } + else { - clib_memcpy (copy_here + first_copy_bytes, - &f->data[f->head], second_copy_bytes); - f->head += second_copy_bytes; - f->head = (f->head == nitems) ? 0 : f->head; + clib_memcpy_fast (copy_here, &f->data[head_idx], total_copy_bytes); } + head += total_copy_bytes; } else { + ASSERT (0); /* Account for a zero-copy dequeue done elsewhere */ - ASSERT (max_bytes <= cursize); - f->head += max_bytes; - f->head = f->head % nitems; - cursize -= max_bytes; - total_copy_bytes = max_bytes; + head += max_bytes; } - __sync_fetch_and_sub (&f->cursize, total_copy_bytes); + ASSERT (cursize >= total_copy_bytes); + /* store-rel: consumer owned index (paired with load-acq in producer) */ + clib_atomic_store_rel_n (&f->head, head); - return (total_copy_bytes); + return total_copy_bytes; } +#ifndef CLIB_MARCH_VARIANT + int -svm_fifo_dequeue_nowait (svm_fifo_t * f, - int pid, u32 max_bytes, u8 * copy_here) +svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here) { - return svm_fifo_dequeue_internal2 (f, pid, max_bytes, copy_here); + return CLIB_MARCH_FN_SELECT (svm_fifo_dequeue_nowait) (f, max_bytes, + copy_here); } +#endif -int -svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes, - u8 * copy_here) +CLIB_MARCH_FN (svm_fifo_peek, int, svm_fifo_t * f, u32 relative_offset, + u32 max_bytes, u8 * copy_here) { u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems; + u32 tail, head, cursize; + u32 relative_head_idx; - if (PREDICT_FALSE (f->cursize == 0)) + f_load_head_tail_cons (f, &head, &tail); + + /* current size of fifo can only increase during peek: SPSC */ + cursize = f_cursize (f, head, tail); + + if (PREDICT_FALSE (cursize < relative_offset)) return -2; /* nothing in the fifo */ - /* read cursize, which can only increase while we're working */ - cursize = f->cursize; - nitems = f->nitems; + relative_head_idx = (head + relative_offset) % f->size; - /* Number of bytes we're going to copy */ - total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes; + /* number of bytes we're going to copy */ + total_copy_bytes = ((cursize - relative_offset) < max_bytes) ? + cursize - relative_offset : max_bytes; if (PREDICT_TRUE (copy_here != 0)) { - /* Number of bytes in first copy segment */ - first_copy_bytes = - ((nitems - f->head) < total_copy_bytes) ? - (nitems - f->head) : total_copy_bytes; - clib_memcpy (copy_here, &f->data[f->head], first_copy_bytes); + /* number of bytes in first copy segment */ + first_copy_bytes = f->size - relative_head_idx; + if (first_copy_bytes < total_copy_bytes) + { + clib_memcpy_fast (copy_here, &f->data[relative_head_idx], + first_copy_bytes); - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) + /* number of bytes in second copy segment */ + second_copy_bytes = total_copy_bytes - first_copy_bytes; + clib_memcpy_fast (copy_here + first_copy_bytes, &f->data[0], + second_copy_bytes); + } + else { - clib_memcpy (copy_here + first_copy_bytes, &f->data[0], - second_copy_bytes); + clib_memcpy_fast (copy_here, &f->data[relative_head_idx], + total_copy_bytes); } } return total_copy_bytes; } +#ifndef CLIB_MARCH_VARIANT + +int +svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes, + u8 * copy_here) +{ + return CLIB_MARCH_FN_SELECT (svm_fifo_peek) (f, relative_offset, max_bytes, + copy_here); +} + int -svm_fifo_dequeue_drop (svm_fifo_t * f, int pid, u32 max_bytes) +svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes) { - u32 total_drop_bytes, first_drop_bytes, second_drop_bytes; - u32 cursize, nitems; + u32 total_drop_bytes; + u32 tail, head, cursize; - if (PREDICT_FALSE (f->cursize == 0)) + f_load_head_tail_cons (f, &head, &tail); + + /* number of bytes we're going to drop */ + cursize = f_cursize (f, head, tail); + + if (PREDICT_FALSE (cursize == 0)) return -2; /* nothing in the fifo */ - /* read cursize, which can only increase while we're working */ - cursize = f->cursize; - nitems = f->nitems; + svm_fifo_trace_add (f, tail, total_drop_bytes, 3); - /* Number of bytes we're going to drop */ + /* number of bytes we're going to drop */ total_drop_bytes = (cursize < max_bytes) ? cursize : max_bytes; - /* Number of bytes in first copy segment */ - first_drop_bytes = - ((nitems - f->head) < total_drop_bytes) ? - (nitems - f->head) : total_drop_bytes; - f->head += first_drop_bytes; - f->head = (f->head == nitems) ? 0 : f->head; + /* move head */ + head += total_drop_bytes; + + ASSERT (cursize >= total_drop_bytes); + /* store-rel: consumer owned index (paired with load-acq in producer) */ + clib_atomic_store_rel_n (&f->head, head); + + return total_drop_bytes; +} + +void +svm_fifo_dequeue_drop_all (svm_fifo_t * f) +{ + /* consumer foreign index */ + u32 tail = clib_atomic_load_acq_n (&f->tail); + /* store-rel: consumer owned index (paired with load-acq in producer) */ + clib_atomic_store_rel_n (&f->head, tail); +} + +int +svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs) +{ + u32 cursize, head, tail, head_idx; + + f_load_head_tail_cons (f, &head, &tail); + + /* consumer function, cursize can only increase while we're working */ + cursize = f_cursize (f, head, tail); + + if (PREDICT_FALSE (cursize == 0)) + return -2; /* nothing in the fifo */ - /* Number of bytes in second drop segment, if any */ - second_drop_bytes = total_drop_bytes - first_drop_bytes; - if (second_drop_bytes) + head_idx = head % f->size; + + if (tail < head) + { + fs[0].len = f->size - head_idx; + fs[0].data = f->data + head_idx; + fs[1].len = cursize - fs[0].len; + fs[1].data = f->data; + } + else { - f->head += second_drop_bytes; - f->head = (f->head == nitems) ? 0 : f->head; + fs[0].len = cursize; + fs[0].data = f->data + head_idx; + fs[1].len = 0; + fs[1].data = 0; } + return cursize; +} + +void +svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs) +{ + u32 head, head_idx; - __sync_fetch_and_sub (&f->cursize, total_drop_bytes); + /* consumer owned index */ + head = f->head; + head_idx = head % f->size; - return total_drop_bytes; + ASSERT (fs[0].data == f->data + head_idx); + head += fs[0].len + fs[1].len; + /* store-rel: consumer owned index (paired with load-acq in producer) */ + clib_atomic_store_rel_n (&f->head, head); +} + +/* Assumption: no prod and cons are accessing either dest or src fifo */ +void +svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf) +{ + u32 head, tail; + clib_memcpy_fast (df->data, sf->data, sf->size); + + f_load_head_tail_all_acq (sf, &head, &tail); + clib_atomic_store_rel_n (&df->head, head); + clib_atomic_store_rel_n (&df->tail, tail); +} + +u32 +svm_fifo_number_ooo_segments (svm_fifo_t * f) +{ + return pool_elts (f->ooo_segments); +} + +ooo_segment_t * +svm_fifo_first_ooo_segment (svm_fifo_t * f) +{ + return pool_elt_at_index (f->ooo_segments, f->ooos_list_head); +} + +/** + * Set fifo pointers to requested offset + */ +void +svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer) +{ + clib_atomic_store_rel_n (&f->head, pointer); + clib_atomic_store_rel_n (&f->tail, pointer); +} + +void +svm_fifo_add_subscriber (svm_fifo_t * f, u8 subscriber) +{ + if (f->n_subscribers >= SVM_FIFO_MAX_EVT_SUBSCRIBERS) + return; + f->subscribers[f->n_subscribers++] = subscriber; +} + +void +svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber) +{ + int i; + + for (i = 0; i < f->n_subscribers; i++) + { + if (f->subscribers[i] != subscriber) + continue; + f->subscribers[i] = f->subscribers[f->n_subscribers - 1]; + f->n_subscribers--; + break; + } } +#endif /* * fd.io coding-style-patch-verification: ON *