X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fsvm%2Fsvm_fifo.c;h=3df67135cfd90e2e71e9550ef5be18d8d647c01a;hb=b020806806c0e6c54886cdb4347a5fd1f19504b0;hp=3552192a768f1a25ef0a04b60533b055acaaf151;hpb=7fb0fe1f6972a7a35146fa9115b866ba29a6fbb7;p=vpp.git diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c index 3552192a768..3df67135cfd 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: @@ -16,217 +20,138 @@ #include #include -static inline u8 -position_lt (svm_fifo_t * f, u32 a, u32 b) +CLIB_MARCH_FN (svm_fifo_copy_to_chunk, void, svm_fifo_t * f, + svm_fifo_chunk_t * c, u32 tail_idx, const u8 * src, u32 len, + svm_fifo_chunk_t ** last) { - return (ooo_segment_distance_from_tail (f, a) - < ooo_segment_distance_from_tail (f, b)); + u32 n_chunk; + + ASSERT (tail_idx >= c->start_byte && tail_idx < c->start_byte + c->length); + + tail_idx -= c->start_byte; + n_chunk = c->length - tail_idx; + if (n_chunk <= len) + { + u32 to_copy = len; + clib_memcpy_fast (&c->data[tail_idx], src, n_chunk); + c = c->next; + while ((to_copy -= n_chunk)) + { + n_chunk = clib_min (c->length, to_copy); + clib_memcpy_fast (&c->data[0], src + (len - to_copy), n_chunk); + c = c->length <= to_copy ? c->next : c; + } + if (*last) + *last = c; + } + else + { + clib_memcpy_fast (&c->data[tail_idx], src, len); + } } -static inline u8 -position_leq (svm_fifo_t * f, u32 a, u32 b) +CLIB_MARCH_FN (svm_fifo_copy_from_chunk, void, svm_fifo_t * f, + svm_fifo_chunk_t * c, u32 head_idx, u8 * dst, u32 len, + svm_fifo_chunk_t ** last) { - return (ooo_segment_distance_from_tail (f, a) - <= ooo_segment_distance_from_tail (f, b)); + u32 n_chunk; + + ASSERT (head_idx >= c->start_byte && head_idx < c->start_byte + c->length); + + head_idx -= c->start_byte; + n_chunk = c->length - head_idx; + if (n_chunk <= len) + { + u32 to_copy = len; + clib_memcpy_fast (dst, &c->data[head_idx], n_chunk); + c = c->next; + while ((to_copy -= n_chunk)) + { + n_chunk = clib_min (c->length, to_copy); + clib_memcpy_fast (dst + (len - to_copy), &c->data[0], n_chunk); + c = c->length <= to_copy ? c->next : c; + } + if (*last) + *last = c; + } + else + { + clib_memcpy_fast (dst, &c->data[head_idx], len); + } } -static inline u8 -position_gt (svm_fifo_t * f, u32 a, u32 b) +#ifndef CLIB_MARCH_VARIANT + +static inline void +svm_fifo_copy_to_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c, u32 tail_idx, + const u8 * src, u32 len, svm_fifo_chunk_t ** last) { - return (ooo_segment_distance_from_tail (f, a) - > ooo_segment_distance_from_tail (f, b)); + CLIB_MARCH_FN_SELECT (svm_fifo_copy_to_chunk) (f, c, tail_idx, src, len, + last); } -static inline u32 -position_diff (svm_fifo_t * f, u32 posa, u32 posb) +static inline void +svm_fifo_copy_from_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c, u32 head_idx, + u8 * dst, u32 len, svm_fifo_chunk_t ** last) { - return ooo_segment_distance_from_tail (f, posa) - - ooo_segment_distance_from_tail (f, posb); + CLIB_MARCH_FN_SELECT (svm_fifo_copy_from_chunk) (f, c, head_idx, dst, len, + last); } -static inline u32 -ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s) +static inline u8 +position_lt (svm_fifo_t * f, u32 a, u32 b, u32 tail) { - return (s->start + s->length) % f->nitems; + return (f_distance_to (f, a, tail) < f_distance_to (f, b, tail)); } -u8 * -format_ooo_segment (u8 * s, va_list * args) +static inline u8 +position_leq (svm_fifo_t * f, u32 a, u32 b, u32 tail) { - 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->nitems; - s = format (s, "[%u, %u], len %u, next %d, prev %d", normalized_start, - (normalized_start + seg->length) % f->nitems, seg->length, - seg->next, seg->prev); - return s; + return (f_distance_to (f, a, tail) <= f_distance_to (f, b, tail)); } -u8 * -svm_fifo_dump_trace (u8 * s, svm_fifo_t * f) +static inline u8 +position_gt (svm_fifo_t * f, u32 a, u32 b, u32 tail) { -#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 + return (f_distance_to (f, a, tail) > f_distance_to (f, b, tail)); } -u8 * -svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose) +static inline u32 +position_diff (svm_fifo_t * f, u32 a, u32 b, u32 tail) { - 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->nitems); - 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->nitems); - 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; + return f_distance_to (f, a, tail) - f_distance_to (f, b, tail); } -u8 * -format_ooo_list (u8 * s, va_list * args) +static inline u32 +ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s) { - svm_fifo_t *f = va_arg (*args, svm_fifo_t *); - 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\n", format_ooo_segment, f, seg); - ooo_segment_index = seg->next; - } - - return s; + return (s->start + s->length) % f->size; } -u8 * -format_svm_fifo (u8 * s, va_list * args) +void +svm_fifo_free_ooo_data (svm_fifo_t * f) { - svm_fifo_t *f = va_arg (*args, svm_fifo_t *); - int verbose = va_arg (*args, int); - - if (!s) - return s; - - s = format (s, "cursize %u nitems %u has_event %d\n", - f->cursize, f->nitems, f->has_event); - s = format (s, " head %d tail %d\n", f->head, f->tail); - - if (verbose > 1) - s = format - (s, " server session %d thread %d client session %d thread %d\n", - f->master_session_index, f->master_thread_index, - f->client_session_index, f->client_thread_index); - - if (verbose) - { - s = format (s, " ooo pool %d active elts newest %u\n", - pool_elts (f->ooo_segments), f->ooos_newest); - if (svm_fifo_has_ooo_data (f)) - s = format (s, " %U", format_ooo_list, f, verbose); - } - return s; + pool_free (f->ooo_segments); } -/** 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) +static inline ooo_segment_t * +ooo_segment_prev (svm_fifo_t * f, ooo_segment_t * s) { - svm_fifo_t *f; - u32 rounded_data_size; - - /* 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) + if (s->prev == OOO_SEGMENT_INVALID_INDEX) return 0; - - memset (f, 0, sizeof (*f)); - f->nitems = data_size_in_bytes; - f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX; - f->refcnt = 1; - return (f); + return pool_elt_at_index (f->ooo_segments, s->prev); } -void -svm_fifo_free (svm_fifo_t * f) +static inline ooo_segment_t * +ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s) { - ASSERT (f->refcnt > 0); - - if (--f->refcnt == 0) - { - pool_free (f->ooo_segments); - clib_mem_free (f); - } + if (s->next == OOO_SEGMENT_INVALID_INDEX) + return 0; + return pool_elt_at_index (f->ooo_segments, s->next); } -always_inline ooo_segment_t * -ooo_segment_new (svm_fifo_t * f, u32 start, u32 length) +static inline ooo_segment_t * +ooo_segment_alloc (svm_fifo_t * f, u32 start, u32 length) { ooo_segment_t *s; @@ -234,14 +159,13 @@ ooo_segment_new (svm_fifo_t * f, u32 start, u32 length) s->start = start; s->length = length; - s->prev = s->next = OOO_SEGMENT_INVALID_INDEX; return s; } -always_inline void -ooo_segment_del (svm_fifo_t * f, u32 index) +static inline void +ooo_segment_free (svm_fifo_t * f, u32 index) { ooo_segment_t *cur, *prev = 0, *next = 0; cur = pool_elt_at_index (f->ooo_segments, index); @@ -270,21 +194,22 @@ 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, s_end_pos, s_index; - u32 normalized_position, normalized_end_position; + u32 offset_pos, offset_end_pos; - ASSERT (offset + length <= ooo_segment_distance_from_tail (f, f->head)); - normalized_position = (f->tail + offset) % f->nitems; - normalized_end_position = (f->tail + offset + length) % f->nitems; + ASSERT (offset + length <= f_distance_to (f, head, tail) || head == tail); + + offset_pos = (tail + offset) % f->size; + offset_end_pos = (tail + offset + length) % f->size; f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX) { - s = ooo_segment_new (f, normalized_position, length); + s = ooo_segment_alloc (f, offset_pos, length); f->ooos_list_head = s - f->ooo_segments; f->ooos_newest = f->ooos_list_head; return; @@ -293,20 +218,20 @@ 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 - && position_lt (f, s->start, normalized_position)) + && 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); + prev = ooo_segment_prev (f, s); if (prev - && position_leq (f, normalized_position, ooo_segment_end_pos (f, 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, normalized start position cannot be smaller + /* Since we have previous, offset start position cannot be smaller * than prev->start. Check tail */ - ASSERT (position_lt (f, s->start, normalized_position)); + ASSERT (position_lt (f, s->start, offset_pos, tail)); goto check_tail; } @@ -314,9 +239,9 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) s_end_pos = ooo_segment_end_pos (f, s); /* No overlap, add before current segment */ - if (position_lt (f, normalized_end_position, s->start)) + if (position_lt (f, offset_end_pos, s->start, tail)) { - new_s = ooo_segment_new (f, normalized_position, length); + new_s = ooo_segment_alloc (f, offset_pos, length); new_index = new_s - f->ooo_segments; /* Pool might've moved, get segment again */ @@ -339,9 +264,9 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) return; } /* No overlap, add after current segment */ - else if (position_gt (f, normalized_position, s_end_pos)) + else if (position_gt (f, offset_pos, s_end_pos, tail)) { - new_s = ooo_segment_new (f, normalized_position, length); + new_s = ooo_segment_alloc (f, offset_pos, length); new_index = new_s - f->ooo_segments; /* Pool might've moved, get segment again */ @@ -362,36 +287,36 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length) */ /* Merge at head */ - if (position_lt (f, normalized_position, s->start)) + if (position_lt (f, offset_pos, s->start, tail)) { - s->start = normalized_position; - s->length = position_diff (f, s_end_pos, s->start); + 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, normalized_end_position, s_end_pos)) + if (position_gt (f, offset_end_pos, s_end_pos, tail)) { - s->length = position_diff (f, normalized_end_position, s->start); + 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), - normalized_end_position)) + offset_end_pos, tail)) { next = ooo_segment_next (f, it); - ooo_segment_del (f, it - f->ooo_segments); + ooo_segment_free (f, it - f->ooo_segments); it = next; } /* If partial overlap with last, merge */ - if (it && position_leq (f, it->start, normalized_end_position)) + if (it && position_leq (f, it->start, offset_end_pos, tail)) { s->length = position_diff (f, ooo_segment_end_pos (f, it), - s->start); - ooo_segment_del (f, it - f->ooo_segments); + s->start, tail); + ooo_segment_free (f, it - f->ooo_segments); } f->ooos_newest = s - f->ooo_segments; } @@ -402,14 +327,14 @@ check_tail: * 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) { + u32 s_index, bytes = 0; ooo_segment_t *s; - 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); + diff = f_distance_from (f, s->start, *tail); ASSERT (diff != n_bytes_enqueued); @@ -419,15 +344,14 @@ ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued) /* If last tail update overlaps one/multiple ooo segments, remove them */ while (0 <= diff && diff < n_bytes_enqueued) { - index = s - f->ooo_segments; + s_index = s - f->ooo_segments; /* Segment end is beyond the tail. Advance tail and remove segment */ if (s->length > diff) { bytes = s->length - diff; - f->tail += bytes; - f->tail %= f->nitems; - ooo_segment_del (f, index); + *tail = (*tail + bytes) % f->size; + ooo_segment_free (f, s_index); break; } @@ -435,13 +359,13 @@ ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued) if (s->next != OOO_SEGMENT_INVALID_INDEX) { s = pool_elt_at_index (f->ooo_segments, s->next); - diff = ooo_segment_distance_to_tail (f, s->start); - ooo_segment_del (f, index); + diff = f_distance_from (f, s->start, *tail); + ooo_segment_free (f, s_index); } /* End of search */ else { - ooo_segment_del (f, index); + ooo_segment_free (f, s_index); break; } } @@ -450,385 +374,966 @@ ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued) return bytes; } -static int -svm_fifo_enqueue_internal (svm_fifo_t * f, u32 max_bytes, - const u8 * copy_from_here) +static ooo_segment_t * +ooo_segment_last (svm_fifo_t * f) { - u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems; + ooo_segment_t *s; - /* read cursize, which can only increase while we're working */ - cursize = svm_fifo_max_dequeue (f); - f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; + if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX) + return 0; + + s = svm_fifo_first_ooo_segment (f); + while (s->next != OOO_SEGMENT_INVALID_INDEX) + s = pool_elt_at_index (f->ooo_segments, s->next); + return s; +} - if (PREDICT_FALSE (cursize == f->nitems)) - return SVM_FIFO_FULL; +void +svm_fifo_init (svm_fifo_t * f, u32 size) +{ + f->size = 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->segment_index = SVM_FIFO_INVALID_INDEX; + f->refcnt = 1; + f->head = f->tail = f->flags = 0; + f->head_chunk = f->tail_chunk = f->ooo_enq = f->ooo_deq = f->start_chunk; +} - nitems = f->nitems; +void +svm_fifo_init_chunks (svm_fifo_t * f) +{ + svm_fifo_chunk_t *c, *prev; - /* Number of bytes we're going to copy */ - total_copy_bytes = (nitems - cursize) < max_bytes ? - (nitems - cursize) : max_bytes; + if (f->start_chunk->next == f->start_chunk) + return; - 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; + f->flags |= SVM_FIFO_F_MULTI_CHUNK; + rb_tree_init (&f->ooo_enq_lookup); + rb_tree_init (&f->ooo_deq_lookup); - 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; + f->start_chunk->start_byte = 0; + prev = f->start_chunk; + c = prev->next; - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) - { - 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; - } - } - else + while (c != f->start_chunk) { - 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; + c->start_byte = prev->start_byte + prev->length; + prev = c; + c = c->next; } - - svm_fifo_trace_add (f, f->head, total_copy_bytes, 2); - - /* Any out-of-order segments to collect? */ - if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX)) - total_copy_bytes += ooo_segment_try_collect (f, total_copy_bytes); - - /* Atomically increase the queue length */ - ASSERT (cursize + total_copy_bytes <= nitems); - __sync_fetch_and_add (&f->cursize, total_copy_bytes); - - return (total_copy_bytes); } -#define SVM_ENQUEUE_CLONE_TEMPLATE(arch, fn, tgt) \ - uword \ - __attribute__ ((flatten)) \ - __attribute__ ((target (tgt))) \ - CLIB_CPU_OPTIMIZED \ - fn ## _ ## arch ( svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here) \ - { return fn (f, max_bytes, copy_from_here);} - -static int -svm_fifo_enqueue_nowait_ma (svm_fifo_t * f, u32 max_bytes, - const u8 * copy_from_here) +/** + * Creates a fifo in the current heap. Fails vs blow up the process + */ +svm_fifo_t * +svm_fifo_create (u32 data_size_in_bytes) { - return svm_fifo_enqueue_internal (f, max_bytes, copy_from_here); -} + u32 rounded_data_size; + svm_fifo_chunk_t *c; + svm_fifo_t *f; -foreach_march_variant (SVM_ENQUEUE_CLONE_TEMPLATE, - svm_fifo_enqueue_nowait_ma); -CLIB_MULTIARCH_SELECT_FN (svm_fifo_enqueue_nowait_ma); + f = clib_mem_alloc_aligned_or_null (sizeof (*f), CLIB_CACHE_LINE_BYTES); + if (f == 0) + return 0; -int -svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, - const u8 * copy_from_here) -{ -#if CLIB_DEBUG > 0 - return svm_fifo_enqueue_nowait_ma (f, max_bytes, copy_from_here); -#else - static int (*fp) (svm_fifo_t *, u32, const u8 *); + clib_memset (f, 0, sizeof (*f)); - if (PREDICT_FALSE (fp == 0)) - fp = (void *) svm_fifo_enqueue_nowait_ma_multiarch_select (); + /* always round fifo data size to the next highest power-of-two */ + rounded_data_size = (1 << (max_log2 (data_size_in_bytes))); + c = clib_mem_alloc_aligned_or_null (sizeof (*c) + rounded_data_size, + CLIB_CACHE_LINE_BYTES); + if (!c) + { + clib_mem_free (f); + return 0; + } - return (*fp) (f, max_bytes, copy_from_here); -#endif + c->next = c; + c->start_byte = 0; + c->length = data_size_in_bytes; + c->rb_index = RBTREE_TNIL_INDEX; + f->start_chunk = f->end_chunk = c; + + svm_fifo_init (f, data_size_in_bytes); + return f; } /** - * 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 + * Creates a fifo chunk in the current heap */ -static int -svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f, - u32 offset, - u32 required_bytes, - u8 * copy_from_here) +svm_fifo_chunk_t * +svm_fifo_chunk_alloc (u32 size) { - u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems, normalized_offset; + svm_fifo_chunk_t *c; + u32 rounded_size; - f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; + /* round chunk size to the next highest power-of-two */ + rounded_size = (1 << (max_log2 (size))); + c = clib_mem_alloc_aligned_or_null (sizeof (*c) + rounded_size, + CLIB_CACHE_LINE_BYTES); + if (c == 0) + return 0; - /* read cursize, which can only increase while we're working */ - cursize = svm_fifo_max_dequeue (f); - nitems = f->nitems; + clib_memset (c, 0, sizeof (*c)); + c->length = rounded_size; + return c; +} - ASSERT (required_bytes < nitems); +static inline u8 +svm_fifo_chunk_includes_pos (svm_fifo_chunk_t * c, u32 pos) +{ + return (pos >= c->start_byte && pos < c->start_byte + c->length); +} - normalized_offset = (f->tail + offset) % nitems; +static rb_node_t * +svm_fifo_find_node_rbtree (rb_tree_t * rt, u32 pos) +{ + rb_node_t *cur, *prev; - /* Will this request fit? */ - if ((required_bytes + offset) > (nitems - cursize)) - return -1; + cur = rb_node (rt, rt->root); + if (PREDICT_FALSE (rb_node_is_tnil (rt, cur))) + return 0; - svm_fifo_trace_add (f, offset, required_bytes, 1); + while (pos != cur->key) + { + prev = cur; + if (pos < cur->key) + { + cur = rb_node_left (rt, cur); + if (rb_node_is_tnil (rt, cur)) + { + cur = rb_tree_predecessor (rt, prev); + break; + } + } + else + { + cur = rb_node_right (rt, cur); + if (rb_node_is_tnil (rt, cur)) + { + cur = prev; + break; + } + } + } - ooo_segment_add (f, offset, required_bytes); + if (rb_node_is_tnil (rt, cur)) + return 0; - /* Number of bytes we're going to copy */ - total_copy_bytes = required_bytes; + return cur; +} - /* Number of bytes in first copy segment */ - first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes) - ? (nitems - normalized_offset) : total_copy_bytes; +static svm_fifo_chunk_t * +svm_fifo_find_chunk_rbtree (rb_tree_t * rt, u32 pos) +{ + svm_fifo_chunk_t *c; + rb_node_t *n; - clib_memcpy (&f->data[normalized_offset], copy_from_here, first_copy_bytes); + n = svm_fifo_find_node_rbtree (rt, pos); + if (!n) + return 0; + c = uword_to_pointer (n->opaque, svm_fifo_chunk_t *); + if (svm_fifo_chunk_includes_pos (c, pos)) + return c; - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) - { - normalized_offset += first_copy_bytes; - normalized_offset %= nitems; + return 0; +} - ASSERT (normalized_offset == 0); +/** + * Find chunk for given byte position + * + * @param f fifo + * @param pos normalized position in fifo + * + * @return chunk that includes given position or 0 + */ +static svm_fifo_chunk_t * +svm_fifo_find_chunk (svm_fifo_t * f, u32 pos) +{ + svm_fifo_chunk_t *c; - clib_memcpy (&f->data[normalized_offset], - copy_from_here + first_copy_bytes, second_copy_bytes); + c = f->start_chunk; + do + { + if (svm_fifo_chunk_includes_pos (c, pos)) + return c; + c = c->next; } + while (c != f->start_chunk); - return (0); + return 0; } - -int -svm_fifo_enqueue_with_offset (svm_fifo_t * f, - u32 offset, - u32 required_bytes, u8 * copy_from_here) +static void +svm_fifo_update_ooo_enq (svm_fifo_t * f, u32 ref_pos, u32 start_pos, + u32 end_pos) { - return svm_fifo_enqueue_with_offset_internal (f, offset, required_bytes, - copy_from_here); -} + rb_tree_t *rt = &f->ooo_enq_lookup; + svm_fifo_chunk_t *c; + rb_node_t *cur; -void -svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len) + if (svm_fifo_chunk_includes_pos (f->ooo_enq, start_pos) + && svm_fifo_chunk_includes_pos (f->ooo_enq, end_pos) + && ref_pos < start_pos) + return; + + if (rt->root == RBTREE_TNIL_INDEX) + { + c = f->tail_chunk; + c->rb_index = rb_tree_add2 (rt, c->start_byte, pointer_to_uword (c)); + } + else + { + cur = svm_fifo_find_node_rbtree (rt, start_pos); + c = uword_to_pointer (cur->opaque, svm_fifo_chunk_t *); + if (ref_pos > start_pos && c->start_byte > start_pos) + { + c = f->end_chunk; + ASSERT (c->rb_index != RBTREE_TNIL_INDEX); + } + } + + if (svm_fifo_chunk_includes_pos (c, start_pos)) + f->ooo_enq = c; + + if (svm_fifo_chunk_includes_pos (c, end_pos) && ref_pos < end_pos) + return; + + do + { + c = c->next; + if (c->rb_index != RBTREE_TNIL_INDEX) + break; + + c->rb_index = rb_tree_add2 (rt, c->start_byte, pointer_to_uword (c)); + + if (svm_fifo_chunk_includes_pos (c, start_pos)) + f->ooo_enq = c; + + } + while (!svm_fifo_chunk_includes_pos (c, end_pos)); +} + +static void +svm_fifo_update_ooo_deq (svm_fifo_t * f, u32 ref_pos, u32 start_pos, + u32 end_pos) { - u32 first_chunk; - ASSERT (len <= f->nitems); - if (len < f->nitems - f->head) - clib_memcpy (&f->data[f->head], data, len); + rb_tree_t *rt = &f->ooo_deq_lookup; + rb_node_t *cur; + svm_fifo_chunk_t *c; + + if (svm_fifo_chunk_includes_pos (f->ooo_deq, start_pos) + && svm_fifo_chunk_includes_pos (f->ooo_deq, end_pos) + && ref_pos < start_pos) + return; + + if (rt->root == RBTREE_TNIL_INDEX) + { + c = f->head_chunk; + c->rb_index = rb_tree_add2 (rt, c->start_byte, pointer_to_uword (c)); + } else { - first_chunk = len - (f->nitems - f->head); - clib_memcpy (&f->data[f->head], data, first_chunk); - clib_memcpy (f->data, data + first_chunk, len - first_chunk); + cur = svm_fifo_find_node_rbtree (rt, start_pos); + c = uword_to_pointer (cur->opaque, svm_fifo_chunk_t *); + if (ref_pos > start_pos && c->start_byte > start_pos) + { + c = f->end_chunk; + ASSERT (c->rb_index != RBTREE_TNIL_INDEX); + } + } + + if (svm_fifo_chunk_includes_pos (c, start_pos)) + f->ooo_deq = c; + + if (svm_fifo_chunk_includes_pos (c, end_pos) && ref_pos < end_pos) + return; + + do + { + c = c->next; + if (c->rb_index != RBTREE_TNIL_INDEX) + break; + + c->rb_index = rb_tree_add2 (rt, c->start_byte, pointer_to_uword (c)); + + if (svm_fifo_chunk_includes_pos (c, start_pos)) + f->ooo_deq = c; + } + while (!svm_fifo_chunk_includes_pos (c, end_pos)); } -static int -svm_fifo_dequeue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_here) +void +svm_fifo_ooo_deq_track (svm_fifo_t * f, u32 start_pos, u32 end_pos) { - u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems; + rb_tree_t *rt = &f->ooo_deq_lookup; + svm_fifo_chunk_t *c; - /* read cursize, which can only increase while we're working */ - cursize = svm_fifo_max_dequeue (f); - if (PREDICT_FALSE (cursize == 0)) - return -2; /* nothing in the fifo */ + if (svm_fifo_chunk_includes_pos (f->ooo_deq, end_pos) + && start_pos < end_pos) + return; + + c = f->ooo_deq->next; + do + { + ASSERT (c->rb_index == RBTREE_TNIL_INDEX); + rb_tree_add2 (rt, c->start_byte, pointer_to_uword (c)); + + c = c->next; + } + while (!svm_fifo_chunk_includes_pos (c, end_pos)); +} + +static svm_fifo_chunk_t * +svm_fifo_lookup_clear_chunks (svm_fifo_t * f, rb_tree_t * rt, + svm_fifo_chunk_t * start, u32 start_pos, + u32 end_pos) +{ + svm_fifo_chunk_t *c; + rb_node_t *n; + + /* Nothing to do if still in the same chunk and not wrapped */ + if (svm_fifo_chunk_includes_pos (start, end_pos) && start_pos < end_pos) + return start; + + c = start; + do + { + if (c->rb_index == RBTREE_TNIL_INDEX) + { + c = c->next; + continue; + } + + n = rb_node (rt, c->rb_index); + rb_tree_del_node (rt, n); + c->rb_index = RBTREE_TNIL_INDEX; + c = c->next; + } + while (!svm_fifo_chunk_includes_pos (c, end_pos)); - nitems = f->nitems; + return c; +} + +static inline void +svm_fifo_grow (svm_fifo_t * f, svm_fifo_chunk_t * c) +{ + svm_fifo_chunk_t *prev; + u32 add_bytes = 0; + + if (!c) + return; + + f->end_chunk->next = c; + while (c) + { + add_bytes += c->length; + prev = c; + c = c->next; + } + f->end_chunk = prev; + prev->next = f->start_chunk; + f->size += add_bytes; + f->nitems = f->size - 1; + f->new_chunks = 0; +} + +static void +svm_fifo_try_grow (svm_fifo_t * f, u32 new_head) +{ + if (new_head > f->tail) + return; + + svm_fifo_grow (f, f->new_chunks); + f->flags &= ~SVM_FIFO_F_GROW; +} - /* Number of bytes we're going to copy */ - total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes; +void +svm_fifo_add_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c) +{ + svm_fifo_chunk_t *cur, *prev; - if (PREDICT_TRUE (copy_here != 0)) + /* Initialize rbtree if needed and add default chunk to it. Expectation is + * that this is called with the heap where the rbtree's pool is pushed. */ + if (!(f->flags & SVM_FIFO_F_MULTI_CHUNK)) { - /* 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; + ASSERT (f->start_chunk->next == f->start_chunk); + rb_tree_init (&f->ooo_enq_lookup); + rb_tree_init (&f->ooo_deq_lookup); + f->flags |= SVM_FIFO_F_MULTI_CHUNK; + } - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) + /* If fifo is not wrapped, update the size now */ + if (!svm_fifo_is_wrapped (f)) + { + /* Initialize chunks and add to lookup rbtree */ + cur = c; + if (f->new_chunks) { - 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; + prev = f->new_chunks; + while (prev->next) + prev = prev->next; + prev->next = c; } + else + prev = f->end_chunk; + + while (cur) + { + cur->start_byte = prev->start_byte + prev->length; + cur->rb_index = RBTREE_TNIL_INDEX; + prev = cur; + cur = cur->next; + } + + ASSERT (!f->new_chunks); + svm_fifo_grow (f, c); + return; } - else + + /* Wrapped */ + if (f->flags & SVM_FIFO_F_SINGLE_THREAD_OWNED) + { + ASSERT (f->master_thread_index == os_get_thread_index ()); + + if (!f->new_chunks && f->head_chunk != f->tail_chunk) + { + u32 head = 0, tail = 0; + f_load_head_tail_cons (f, &head, &tail); + + svm_fifo_chunk_t *tmp = f->tail_chunk->next; + + prev = f->tail_chunk; + u32 add_bytes = 0; + cur = prev->next; + while (cur != f->start_chunk) + { + /* remove any existing rb_tree entry */ + if (cur->rb_index != RBTREE_TNIL_INDEX) + { + rb_tree_del (&f->ooo_enq_lookup, cur->start_byte); + rb_tree_del (&f->ooo_deq_lookup, cur->start_byte); + } + cur->rb_index = RBTREE_TNIL_INDEX; + cur = cur->next; + } + + /* insert new chunk after the tail_chunk */ + f->tail_chunk->next = c; + while (c) + { + add_bytes += c->length; + c->start_byte = prev->start_byte + prev->length; + cur->rb_index = RBTREE_TNIL_INDEX; + + prev = c; + c = c->next; + } + prev->next = tmp; + + /* shift existing chunks along */ + cur = tmp; + while (cur != f->start_chunk) + { + cur->start_byte = prev->start_byte + prev->length; + prev = cur; + cur = cur->next; + } + + f->size += add_bytes; + f->nitems = f->size - 1; + f->new_chunks = 0; + head += add_bytes; + + clib_atomic_store_rel_n (&f->head, head); + ASSERT (svm_fifo_is_sane (f)); + + return; + } + } + + /* Wrapped, and optimization of single-thread-owned fifo cannot be applied */ + /* Initialize chunks and add to lookup rbtree */ + cur = c; + if (f->new_chunks) { - 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; + prev = f->new_chunks; + while (prev->next) + prev = prev->next; + prev->next = c; } + else + prev = f->end_chunk; - ASSERT (f->head <= nitems); - ASSERT (cursize >= total_copy_bytes); - __sync_fetch_and_sub (&f->cursize, total_copy_bytes); + while (cur) + { + cur->start_byte = prev->start_byte + prev->length; + cur->rb_index = RBTREE_TNIL_INDEX; + prev = cur; + cur = cur->next; + } - return (total_copy_bytes); + /* Postpone size update */ + if (!f->new_chunks) + { + f->new_chunks = c; + f->flags |= SVM_FIFO_F_GROW; + } } -static int -svm_fifo_dequeue_nowait_ma (svm_fifo_t * f, u32 max_bytes, u8 * copy_here) +/** + * Removes chunks that are after fifo end byte + */ +svm_fifo_chunk_t * +svm_fifo_collect_chunks (svm_fifo_t * f) { - return svm_fifo_dequeue_internal (f, max_bytes, copy_here); + svm_fifo_chunk_t *list, *cur; + + f->flags &= ~SVM_FIFO_F_COLLECT_CHUNKS; + + list = f->new_chunks; + f->new_chunks = 0; + cur = list; + while (cur) + { + if (cur->rb_index != RBTREE_TNIL_INDEX) + { + rb_tree_del (&f->ooo_enq_lookup, cur->start_byte); + rb_tree_del (&f->ooo_deq_lookup, cur->start_byte); + } + cur = cur->next; + } + + return list; } -#define SVM_FIFO_DEQUEUE_CLONE_TEMPLATE(arch, fn, tgt) \ - uword \ - __attribute__ ((flatten)) \ - __attribute__ ((target (tgt))) \ - CLIB_CPU_OPTIMIZED \ - fn ## _ ## arch ( svm_fifo_t * f, u32 max_bytes, \ - u8 * copy_here) \ - { return fn (f, max_bytes, copy_here);} +void +svm_fifo_try_shrink (svm_fifo_t * f, u32 head, u32 tail) +{ + u32 len_to_shrink = 0, tail_pos, len, last_pos; + svm_fifo_chunk_t *cur, *prev, *next, *start; + + tail_pos = tail; + if (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX) + { + ooo_segment_t *last = ooo_segment_last (f); + tail_pos = ooo_segment_end_pos (f, last); + } + + if (f->size_decrement) + { + /* Figure out available free space considering that there may be + * ooo segments */ + len = clib_min (f->size_decrement, f_free_count (f, head, tail_pos)); + f->nitems -= len; + f->size_decrement -= len; + } -foreach_march_variant (SVM_FIFO_DEQUEUE_CLONE_TEMPLATE, - svm_fifo_dequeue_nowait_ma); -CLIB_MULTIARCH_SELECT_FN (svm_fifo_dequeue_nowait_ma); + /* Remove tail chunks if the following hold: + * - not wrapped + * - last used byte less than start of last chunk + */ + if (tail_pos >= head && tail_pos < f->end_chunk->start_byte) + { + /* Lookup the last position not to be removed. Since size still needs + * to be nitems + 1, nitems must fall within the usable space. Also, + * first segment is not removable, so tail_pos can be 0. */ + last_pos = tail_pos > 0 ? tail_pos - 1 : tail_pos; + prev = svm_fifo_find_chunk (f, clib_max (f->nitems, last_pos)); + next = prev->next; + /* If tail_pos is first position in next, skip the chunk, otherwise, + * we must update the tail and, if fifo size is 0, even the head. + * We should not invalidate the tail for the caller and must not change + * consumer owned variables from code that's typically called by the + * producer */ + if (next->start_byte == tail_pos) + { + prev = next; + next = next->next; + } + while (next != f->start_chunk) + { + cur = next; + next = cur->next; + len_to_shrink += cur->length; + } + if (len_to_shrink) + { + f->size -= len_to_shrink; + start = prev->next; + prev->next = f->start_chunk; + f->end_chunk = prev; + cur->next = f->new_chunks; + f->new_chunks = start; + } + } + + if (!f->size_decrement && f->size == f->nitems + 1) + { + f->flags &= ~SVM_FIFO_F_SHRINK; + f->flags |= SVM_FIFO_F_COLLECT_CHUNKS; + if (f->start_chunk == f->start_chunk->next) + f->flags &= ~SVM_FIFO_F_MULTI_CHUNK; + } +} +/** + * Request to reduce fifo size by amount of bytes + */ int -svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here) +svm_fifo_reduce_size (svm_fifo_t * f, u32 len, u8 try_shrink) { -#if CLIB_DEBUG > 0 - return svm_fifo_dequeue_nowait_ma (f, max_bytes, copy_here); -#else - static int (*fp) (svm_fifo_t *, u32, u8 *); + svm_fifo_chunk_t *cur; + u32 actual_len = 0; - if (PREDICT_FALSE (fp == 0)) - fp = (void *) svm_fifo_dequeue_nowait_ma_multiarch_select (); + /* Abort if trying to reduce by more than fifo size or if + * fifo is undergoing resizing already */ + if (len >= f->size || f->size > f->nitems + 1 + || (f->flags & SVM_FIFO_F_SHRINK) || (f->flags & SVM_FIFO_F_GROW)) + return 0; - return (*fp) (f, max_bytes, copy_here); -#endif + /* last chunk that will not be removed */ + cur = svm_fifo_find_chunk (f, f->nitems - len); + + /* sum length of chunks that will be removed */ + cur = cur->next; + while (cur != f->start_chunk) + { + actual_len += cur->length; + cur = cur->next; + } + + ASSERT (actual_len <= len); + if (!actual_len) + return 0; + + f->size_decrement = actual_len; + f->flags |= SVM_FIFO_F_SHRINK; + + if (try_shrink) + { + u32 head, tail; + f_load_head_tail_prod (f, &head, &tail); + svm_fifo_try_shrink (f, head, tail); + } + + return actual_len; } -static int -svm_fifo_peek_ma (svm_fifo_t * f, u32 relative_offset, u32 max_bytes, - u8 * copy_here) +void +svm_fifo_free_chunk_lookup (svm_fifo_t * f) { - u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; - u32 cursize, nitems, real_head; + rb_tree_free_nodes (&f->ooo_enq_lookup); + rb_tree_free_nodes (&f->ooo_deq_lookup); +} - /* read cursize, which can only increase while we're working */ - cursize = svm_fifo_max_dequeue (f); - if (PREDICT_FALSE (cursize < relative_offset)) - return -2; /* nothing in the fifo */ +void +svm_fifo_free (svm_fifo_t * f) +{ + ASSERT (f->refcnt > 0); + + if (--f->refcnt == 0) + { + /* ooo data is not allocated on segment heap */ + svm_fifo_free_chunk_lookup (f); + clib_mem_free (f); + } +} - nitems = f->nitems; - real_head = f->head + relative_offset; - real_head = real_head >= nitems ? real_head - nitems : real_head; +void +svm_fifo_overwrite_head (svm_fifo_t * f, u8 * src, u32 len) +{ + u32 n_chunk; + u32 head, tail, head_idx; + svm_fifo_chunk_t *c; - /* Number of bytes we're going to copy */ - total_copy_bytes = (cursize - relative_offset < max_bytes) ? - cursize - relative_offset : max_bytes; + ASSERT (len <= f->nitems); - if (PREDICT_TRUE (copy_here != 0)) + f_load_head_tail_cons (f, &head, &tail); + c = f->head_chunk; + head_idx = head - c->start_byte; + n_chunk = c->length - head_idx; + if (len <= n_chunk) + clib_memcpy_fast (&c->data[head_idx], src, len); + else { - /* Number of bytes in first copy segment */ - first_copy_bytes = - ((nitems - real_head) < total_copy_bytes) ? - (nitems - real_head) : total_copy_bytes; - clib_memcpy (copy_here, &f->data[real_head], first_copy_bytes); + clib_memcpy_fast (&c->data[head_idx], src, n_chunk); + clib_memcpy_fast (&c->next->data[0], src + n_chunk, len - n_chunk); + } +} - /* Number of bytes in second copy segment, if any */ - second_copy_bytes = total_copy_bytes - first_copy_bytes; - if (second_copy_bytes) - { - clib_memcpy (copy_here + first_copy_bytes, &f->data[0], - second_copy_bytes); - } +int +svm_fifo_enqueue (svm_fifo_t * f, u32 len, const u8 * src) +{ + u32 tail, head, free_count; + + f_load_head_tail_prod (f, &head, &tail); + + /* free space in fifo can only increase during enqueue: SPSC */ + free_count = f_free_count (f, head, tail); + + f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; + + if (PREDICT_FALSE (free_count == 0)) + return SVM_FIFO_EFULL; + + /* number of bytes we're going to copy */ + len = clib_min (free_count, len); + svm_fifo_copy_to_chunk (f, f->tail_chunk, tail, src, len, &f->tail_chunk); + tail = (tail + len) % f->size; + + svm_fifo_trace_add (f, head, len, 2); + + /* collect out-of-order segments */ + if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX)) + { + len += ooo_segment_try_collect (f, len, &tail); + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + f->tail_chunk = svm_fifo_lookup_clear_chunks (f, &f->ooo_enq_lookup, + f->tail_chunk, f->tail, + tail); } - return total_copy_bytes; + + /* store-rel: producer owned index (paired with load-acq in consumer) */ + clib_atomic_store_rel_n (&f->tail, tail); + + return len; +} + +/** + * 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 + */ +int +svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 len, u8 * src) +{ + u32 tail, head, free_count, tail_idx; + + f_load_head_tail_prod (f, &head, &tail); + + if (PREDICT_FALSE (f->flags & SVM_FIFO_F_SHRINK)) + svm_fifo_try_shrink (f, head, tail); + + /* free space in fifo can only increase during enqueue: SPSC */ + free_count = f_free_count (f, head, tail); + + /* will this request fit? */ + if ((len + offset) > free_count) + return SVM_FIFO_EFULL; + + f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; + svm_fifo_trace_add (f, offset, len, 1); + ooo_segment_add (f, offset, head, tail, len); + tail_idx = (tail + offset) % f->size; + + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + svm_fifo_update_ooo_enq (f, f->tail, tail_idx, + (tail_idx + len) % f->size); + + svm_fifo_copy_to_chunk (f, f->ooo_enq, tail_idx, src, len, &f->ooo_enq); + + return 0; } -#define SVM_FIFO_PEEK_CLONE_TEMPLATE(arch, fn, tgt) \ - uword \ - __attribute__ ((flatten)) \ - __attribute__ ((target (tgt))) \ - CLIB_CPU_OPTIMIZED \ - fn ## _ ## arch ( svm_fifo_t * f, u32 relative_offset, u32 max_bytes, \ - u8 * copy_here) \ - { return fn (f, relative_offset, max_bytes, copy_here);} +/** + * Advance tail + */ +void +svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 len) +{ + u32 tail; + + ASSERT (len <= svm_fifo_max_enqueue_prod (f)); + /* load-relaxed: producer owned index */ + tail = f->tail; + tail = (tail + len) % f->size; -foreach_march_variant (SVM_FIFO_PEEK_CLONE_TEMPLATE, svm_fifo_peek_ma); -CLIB_MULTIARCH_SELECT_FN (svm_fifo_peek_ma); + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + f->tail_chunk = svm_fifo_lookup_clear_chunks (f, &f->ooo_enq_lookup, + f->tail_chunk, f->tail, + tail); + + /* store-rel: producer owned index (paired with load-acq in consumer) */ + clib_atomic_store_rel_n (&f->tail, tail); +} int -svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes, - u8 * copy_here) +svm_fifo_dequeue (svm_fifo_t * f, u32 len, u8 * dst) { -#if CLIB_DEBUG > 0 - return svm_fifo_peek_ma (f, relative_offset, max_bytes, copy_here); -#else - static int (*fp) (svm_fifo_t *, u32, u32, u8 *); + u32 tail, head, cursize; - if (PREDICT_FALSE (fp == 0)) - fp = (void *) svm_fifo_peek_ma_multiarch_select (); + f_load_head_tail_cons (f, &head, &tail); - return (*fp) (f, relative_offset, max_bytes, copy_here); -#endif + /* current size of fifo can only increase during dequeue: SPSC */ + cursize = f_cursize (f, head, tail); + + if (PREDICT_FALSE (cursize == 0)) + return SVM_FIFO_EEMPTY; + + len = clib_min (cursize, len); + svm_fifo_copy_from_chunk (f, f->head_chunk, head, dst, len, &f->head_chunk); + head = (head + len) % f->size; + + if (PREDICT_FALSE (f->flags & SVM_FIFO_F_GROW)) + svm_fifo_try_grow (f, head); + + /* store-rel: consumer owned index (paired with load-acq in producer) */ + clib_atomic_store_rel_n (&f->head, head); + + return len; } int -svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes) +svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 len, u8 * dst) { - u32 total_drop_bytes, first_drop_bytes, second_drop_bytes; - u32 cursize, nitems; + u32 tail, head, cursize, head_idx; + + 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 < offset)) + return SVM_FIFO_EEMPTY; - /* read cursize, which can only increase while we're working */ - cursize = svm_fifo_max_dequeue (f); + len = clib_min (cursize - offset, len); + head_idx = (head + offset) % f->size; + + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + svm_fifo_update_ooo_deq (f, head, head_idx, (head_idx + len) % f->size); + + svm_fifo_copy_from_chunk (f, f->ooo_deq, head_idx, dst, len, &f->ooo_deq); + return len; +} + +int +svm_fifo_dequeue_drop (svm_fifo_t * f, u32 len) +{ + u32 total_drop_bytes, tail, head, cursize; + + f_load_head_tail_cons (f, &head, &tail); + + /* number of bytes available */ + cursize = f_cursize (f, head, tail); if (PREDICT_FALSE (cursize == 0)) - return -2; /* nothing in the fifo */ + return SVM_FIFO_EEMPTY; + + /* number of bytes we're going to drop */ + total_drop_bytes = clib_min (cursize, len); + + svm_fifo_trace_add (f, tail, total_drop_bytes, 3); + + /* move head */ + head = (head + total_drop_bytes) % f->size; + + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + f->head_chunk = svm_fifo_lookup_clear_chunks (f, &f->ooo_deq_lookup, + f->head_chunk, f->head, + head); + + if (PREDICT_FALSE (f->flags & SVM_FIFO_F_GROW)) + svm_fifo_try_grow (f, head); + + /* 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); + + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + f->head_chunk = svm_fifo_lookup_clear_chunks (f, &f->ooo_deq_lookup, + f->head_chunk, tail, + tail - 1); + + if (PREDICT_FALSE (f->flags & SVM_FIFO_F_GROW)) + svm_fifo_try_grow (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_seg_t * fs) +{ + u32 cursize, head, tail, head_idx; - nitems = f->nitems; + f_load_head_tail_cons (f, &head, &tail); - /* Number of bytes we're going to drop */ - total_drop_bytes = (cursize < max_bytes) ? cursize : max_bytes; + /* consumer function, cursize can only increase while we're working */ + cursize = f_cursize (f, head, tail); - svm_fifo_trace_add (f, f->tail, total_drop_bytes, 3); + if (PREDICT_FALSE (cursize == 0)) + return SVM_FIFO_EEMPTY; - /* 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; + head_idx = head; - /* Number of bytes in second drop segment, if any */ - second_drop_bytes = total_drop_bytes - first_drop_bytes; - if (second_drop_bytes) + if (tail < head) { - f->head += second_drop_bytes; - f->head = (f->head == nitems) ? 0 : f->head; + fs[0].len = f->size - head_idx; + fs[0].data = f->head_chunk->data + head_idx; + fs[1].len = cursize - fs[0].len; + fs[1].data = f->head_chunk->data; } + else + { + fs[0].len = cursize; + fs[0].data = f->head_chunk->data + head_idx; + fs[1].len = 0; + fs[1].data = 0; + } + return cursize; +} - ASSERT (f->head <= nitems); - ASSERT (cursize >= total_drop_bytes); - __sync_fetch_and_sub (&f->cursize, total_drop_bytes); +void +svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_seg_t * fs) +{ + u32 head; - return total_drop_bytes; + /* consumer owned index */ + head = f->head; + + ASSERT (fs[0].data == f->head_chunk->data + head); + head = (head + fs[0].len + fs[1].len) % f->size; + /* store-rel: consumer owned index (paired with load-acq in producer) */ + clib_atomic_store_rel_n (&f->head, head); +} + +/** + * Clones fifo + * + * Assumptions: + * - no prod and cons are accessing either dest or src fifo + * - fifo is not multi chunk + */ +void +svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf) +{ + u32 head, tail; + clib_memcpy_fast (df->head_chunk->data, sf->head_chunk->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) +svm_fifo_n_ooo_segments (svm_fifo_t * f) { return pool_elts (f->ooo_segments); } @@ -843,11 +1348,282 @@ svm_fifo_first_ooo_segment (svm_fifo_t * f) * Set fifo pointers to requested offset */ void -svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer) +svm_fifo_init_pointers (svm_fifo_t * f, u32 head, u32 tail) +{ + head = head % f->size; + tail = tail % f->size; + clib_atomic_store_rel_n (&f->head, head); + clib_atomic_store_rel_n (&f->tail, tail); + if (f->flags & SVM_FIFO_F_MULTI_CHUNK) + { + svm_fifo_chunk_t *c; + c = svm_fifo_find_chunk (f, head); + ASSERT (c != 0); + f->head_chunk = f->ooo_deq = c; + c = svm_fifo_find_chunk (f, tail); + ASSERT (c != 0); + f->tail_chunk = f->ooo_enq = c; + } +} + +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; + } +} + +u8 +svm_fifo_is_sane (svm_fifo_t * f) +{ + if (f->size - 1 != f->nitems && !(f->flags & SVM_FIFO_F_SHRINK)) + return 0; + if (!svm_fifo_chunk_includes_pos (f->head_chunk, f->head)) + return 0; + if (!svm_fifo_chunk_includes_pos (f->tail_chunk, f->tail)) + return 0; + + if (f->start_chunk->next != f->start_chunk) + { + svm_fifo_chunk_t *c, *prev = 0, *tmp; + u32 size = 0; + + if (!(f->flags & SVM_FIFO_F_MULTI_CHUNK)) + return 0; + + c = f->start_chunk; + do + { + tmp = svm_fifo_find_chunk (f, c->start_byte); + if (tmp != c) + return 0; + if (prev && (prev->start_byte + prev->length != c->start_byte)) + return 0; + + if (c->rb_index != RBTREE_TNIL_INDEX) + { + u8 found = 0; + + tmp = svm_fifo_find_chunk_rbtree (&f->ooo_enq_lookup, + c->start_byte); + if (tmp) + { + found = 1; + if (tmp != c) + return 0; + } + + tmp = svm_fifo_find_chunk_rbtree (&f->ooo_deq_lookup, + c->start_byte); + if (tmp) + { + if (found) + return 0; + + found = 1; + if (tmp != c) + return 0; + } + if (!found) + return 0; + } + + size += c->length; + prev = c; + c = c->next; + } + while (c != f->start_chunk); + + if (size != f->size) + return 0; + } + + return 1; +} + +u8 +svm_fifo_set_single_thread_owned (svm_fifo_t * f) +{ + if (f->flags & SVM_FIFO_F_SINGLE_THREAD_OWNED) + { + if (f->master_thread_index == os_get_thread_index ()) + { + /* just a duplicate call */ + return 0; + } + + /* already owned by another thread */ + return 1; + } + + f->flags |= SVM_FIFO_F_SINGLE_THREAD_OWNED; + return 0; +} + +u8 * +format_ooo_segment (u8 * s, va_list * args) { - f->head = f->tail = pointer % f->nitems; + 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->head_chunk->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 (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; +} + +#endif /* * fd.io coding-style-patch-verification: ON *