/*
- * 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:
#include <vppinfra/cpu.h>
static inline u8
-position_lt (svm_fifo_t * f, u32 a, u32 b)
+position_lt (svm_fifo_t * f, u32 a, u32 b, u32 tail)
{
- return (ooo_segment_distance_from_tail (f, a)
- < ooo_segment_distance_from_tail (f, b));
+ 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)
+position_leq (svm_fifo_t * f, u32 a, u32 b, u32 tail)
{
- return (ooo_segment_distance_from_tail (f, a)
- <= ooo_segment_distance_from_tail (f, b));
+ 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)
+position_gt (svm_fifo_t * f, u32 a, u32 b, u32 tail)
{
- return (ooo_segment_distance_from_tail (f, a)
- > ooo_segment_distance_from_tail (f, b));
+ 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)
+position_diff (svm_fifo_t * f, u32 posa, u32 posb, u32 tail)
{
- return ooo_segment_distance_from_tail (f, posa)
- - ooo_segment_distance_from_tail (f, posb);
+ 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) % f->nitems;
+ 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 *);
-
- s = format (s, "pos %u, len %u, next %d, prev %d",
- seg->start, seg->length, seg->next, seg->prev);
+ 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;
}
trace_len = 0;
#endif
- dummy_fifo = svm_fifo_create (f->nitems);
- memset (f->data, 0xFF, f->nitems);
+ 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++)
{
if (verbose)
s = format (s, "adding [%u, %u]:", trace[i].offset,
- (trace[i].offset +
- trace[i].len) % dummy_fifo->nitems);
+ (trace[i].offset + trace[i].len) % dummy_fifo->size);
svm_fifo_enqueue_with_offset (dummy_fifo, trace[i].offset,
trace[i].len, &data[offset]);
}
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\n", format_ooo_segment, seg);
+ s = format (s, "%U%U\n", format_white_space, indent, format_ooo_segment,
+ f, seg);
ooo_segment_index = seg->next;
}
{
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",
- f->cursize, f->nitems, f->has_event);
- s = format (s, " head %d tail %d\n", f->head, f->tail);
+ 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, " 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);
+ 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, " ooo pool %d active elts newest %u\n",
- pool_elts (f->ooo_segments), f->ooos_newest);
+ 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, verbose);
+ s = format (s, " %U", format_ooo_list, f, indent, verbose);
}
return s;
}
svm_fifo_create (u32 data_size_in_bytes)
{
svm_fifo_t *f;
+ 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));
- 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);
}
clib_mem_free (f);
}
}
+#endif
always_inline ooo_segment_t *
ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
* 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 <= 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, normalized_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;
/* 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);
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;
}
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_new (f, offset_pos, length);
new_index = new_s - f->ooo_segments;
/* Pool might've moved, get segment again */
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_new (f, offset_pos, length);
new_index = new_s - f->ooo_segments;
/* Pool might've moved, get segment again */
*/
/* 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);
}
/* 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);
+ s->start, tail);
ooo_segment_del (f, it - f->ooo_segments);
}
f->ooos_newest = s - f->ooo_segments;
* 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;
i32 diff;
s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
- diff = ooo_segment_distance_to_tail (f, s->start);
+ diff = ooo_segment_distance_to_tail (f, s->start, *tail);
ASSERT (diff != n_bytes_enqueued);
if (s->length > diff)
{
bytes = s->length - diff;
- f->tail += bytes;
- f->tail %= f->nitems;
+ *tail = *tail + bytes;
ooo_segment_del (f, index);
break;
}
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);
+ diff = ooo_segment_distance_to_tail (f, s->start, *tail);
ooo_segment_del (f, index);
}
/* End of search */
}
}
- ASSERT (bytes >= 0 && bytes <= f->nitems);
+ ASSERT (bytes <= f->nitems);
return bytes;
}
-static int
-svm_fifo_enqueue_internal (svm_fifo_t * f, 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;
+
+ 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);
- /* read cursize, which can only increase while we're working */
- cursize = svm_fifo_max_dequeue (f);
f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
- if (PREDICT_FALSE (cursize == f->nitems))
- return -2; /* fifo stuffed */
+ if (PREDICT_FALSE (free_count == 0))
+ return SVM_FIFO_FULL;
- nitems = f->nitems;
+ /* number of bytes we're going to copy */
+ total_copy_bytes = free_count < max_bytes ? free_count : max_bytes;
- /* Number of bytes we're going to copy */
- total_copy_bytes = (nitems - cursize) < max_bytes ?
- (nitems - cursize) : max_bytes;
+ tail_idx = tail % f->size;
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;
-
- 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 in second copy segment, if any */
- second_copy_bytes = total_copy_bytes - first_copy_bytes;
- if (second_copy_bytes)
+ 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;
}
- svm_fifo_trace_add (f, f->head, total_copy_bytes, 2);
+ svm_fifo_trace_add (f, head, total_copy_bytes, 2);
- /* Any out-of-order segments to collect? */
+ /* 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);
- /* Atomically increase the queue length */
- ASSERT (cursize + total_copy_bytes <= nitems);
- __sync_fetch_and_add (&f->cursize, total_copy_bytes);
-
- return (total_copy_bytes);
-}
+ ASSERT (total_copy_bytes <= free_count);
-#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);}
+ /* store-rel: producer owned index (paired with load-acq in consumer) */
+ clib_atomic_store_rel_n (&f->tail, tail);
-static int
-svm_fifo_enqueue_nowait_ma (svm_fifo_t * f, u32 max_bytes,
- u8 * copy_from_here)
-{
- return svm_fifo_enqueue_internal (f, max_bytes, copy_from_here);
+ return total_copy_bytes;
}
-foreach_march_variant (SVM_ENQUEUE_CLONE_TEMPLATE,
- svm_fifo_enqueue_nowait_ma);
-CLIB_MULTIARCH_SELECT_FN (svm_fifo_enqueue_nowait_ma);
-
+#ifndef CLIB_MARCH_VARIANT
int
-svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here)
+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, u8 *);
-
- if (PREDICT_FALSE (fp == 0))
- fp = (void *) svm_fifo_enqueue_nowait_ma_multiarch_select ();
-
- return (*fp) (f, max_bytes, copy_from_here);
-#endif
+ return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_nowait) (f, max_bytes,
+ copy_from_here);
}
+#endif
/**
* Enqueue a future segment.
* 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_internal (svm_fifo_t * f,
- 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, normalized_offset;
- u32 offset_from_tail;
+ u32 tail_offset;
+ u32 tail, head, free_count, tail_offset_idx;
- f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
+ 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);
- /* read cursize, which can only increase while we're working */
- cursize = svm_fifo_max_dequeue (f);
- nitems = f->nitems;
+ /* will this request fit? */
+ if ((required_bytes + offset) > free_count)
+ return -1;
- ASSERT (required_bytes < nitems);
+ f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
- normalized_offset = (f->tail + offset) % nitems;
+ ASSERT (required_bytes < f->nitems);
- /* Will this request fit? */
- offset_from_tail = (nitems + normalized_offset - f->tail) % nitems;
- if ((required_bytes + offset_from_tail) > (nitems - cursize))
- return -1;
+ tail_offset = tail + offset;
+ tail_offset_idx = tail_offset % f->size;
svm_fifo_trace_add (f, offset, required_bytes, 1);
- ooo_segment_add (f, offset, required_bytes);
+ ooo_segment_add (f, offset, head, tail, required_bytes);
- /* Number of bytes we're going to copy */
+ /* number of bytes we're going to copy */
total_copy_bytes = required_bytes;
- /* Number of bytes in first copy segment */
- first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
- ? (nitems - normalized_offset) : total_copy_bytes;
-
- clib_memcpy (&f->data[normalized_offset], copy_from_here, first_copy_bytes);
+ /* number of bytes in first copy segment */
+ first_copy_bytes = f->size - tail_offset_idx;
- /* Number of bytes in second copy segment, if any */
- second_copy_bytes = total_copy_bytes - first_copy_bytes;
- if (second_copy_bytes)
+ if (first_copy_bytes < total_copy_bytes)
{
- normalized_offset += first_copy_bytes;
- normalized_offset %= nitems;
+ clib_memcpy_fast (&f->data[tail_offset_idx], copy_from_here,
+ first_copy_bytes);
- ASSERT (normalized_offset == 0);
-
- clib_memcpy (&f->data[normalized_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,
- 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_internal (f, 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_internal (svm_fifo_t * f, 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;
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ /* current size of fifo can only increase during dequeue: SPSC */
+ cursize = f_cursize (f, head, tail);
- /* 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 */
- nitems = f->nitems;
-
- /* Number of bytes we're going to copy */
+ /* 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 (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], 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_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;
}
- ASSERT (f->head <= nitems);
ASSERT (cursize >= total_copy_bytes);
- __sync_fetch_and_sub (&f->cursize, total_copy_bytes);
-
- return (total_copy_bytes);
-}
+ /* store-rel: consumer owned index (paired with load-acq in producer) */
+ clib_atomic_store_rel_n (&f->head, head);
-static int
-svm_fifo_dequeue_nowait_ma (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
-{
- return svm_fifo_dequeue_internal (f, max_bytes, copy_here);
+ return total_copy_bytes;
}
-#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);}
-
-foreach_march_variant (SVM_FIFO_DEQUEUE_CLONE_TEMPLATE,
- svm_fifo_dequeue_nowait_ma);
-CLIB_MULTIARCH_SELECT_FN (svm_fifo_dequeue_nowait_ma);
+#ifndef CLIB_MARCH_VARIANT
int
svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
{
-#if CLIB_DEBUG > 0
- return svm_fifo_dequeue_nowait_ma (f, max_bytes, copy_here);
-#else
- static int (*fp) (svm_fifo_t *, u32, u8 *);
-
- if (PREDICT_FALSE (fp == 0))
- fp = (void *) svm_fifo_dequeue_nowait_ma_multiarch_select ();
-
- return (*fp) (f, max_bytes, copy_here);
-#endif
+ return CLIB_MARCH_FN_SELECT (svm_fifo_dequeue_nowait) (f, max_bytes,
+ copy_here);
}
+#endif
-static int
-svm_fifo_peek_ma (svm_fifo_t * f, u32 relative_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, real_head;
+ u32 tail, head, cursize;
+ u32 relative_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);
- /* 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 */
- nitems = f->nitems;
- real_head = f->head + relative_offset;
- real_head = real_head >= nitems ? real_head - nitems : real_head;
+ relative_head_idx = (head + relative_offset) % f->size;
- /* Number of bytes we're going to copy */
- total_copy_bytes = (cursize - relative_offset < 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 - real_head) < total_copy_bytes) ?
- (nitems - real_head) : total_copy_bytes;
- clib_memcpy (copy_here, &f->data[real_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;
}
-#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);}
-
-foreach_march_variant (SVM_FIFO_PEEK_CLONE_TEMPLATE, svm_fifo_peek_ma);
-CLIB_MULTIARCH_SELECT_FN (svm_fifo_peek_ma);
+#ifndef CLIB_MARCH_VARIANT
int
svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
u8 * copy_here)
{
-#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 *);
-
- if (PREDICT_FALSE (fp == 0))
- fp = (void *) svm_fifo_peek_ma_multiarch_select ();
-
- return (*fp) (f, relative_offset, max_bytes, copy_here);
-#endif
+ return CLIB_MARCH_FN_SELECT (svm_fifo_peek) (f, relative_offset, max_bytes,
+ copy_here);
}
int
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;
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ /* number of bytes we're going to drop */
+ cursize = f_cursize (f, head, tail);
- /* 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 */
- 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;
- svm_fifo_trace_add (f, f->tail, total_drop_bytes, 3);
+ /* 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;
- /* 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;
+ f_load_head_tail_cons (f, &head, &tail);
- /* Number of bytes in second drop segment, if any */
- second_drop_bytes = total_drop_bytes - first_drop_bytes;
- if (second_drop_bytes)
+ /* 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 */
+
+ 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;
+}
- 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_segment_t * fs)
+{
+ u32 head, head_idx;
- return total_drop_bytes;
+ /* consumer owned index */
+ head = f->head;
+ head_idx = head % f->size;
+
+ 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
void
svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
{
- f->head = f->tail = pointer % f->nitems;
+ 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
*
Code Review / vpp.git / blobdiff