/* * Copyright (c) 2016 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <svm/svm_fifo.h> #include <vppinfra/cpu.h> static inline u8 position_lt (svm_fifo_t * f, u32 a, u32 b) { return (ooo_segment_distance_from_tail (f, a) < ooo_segment_distance_from_tail (f, b)); } static inline u8 position_leq (svm_fifo_t * f, u32 a, u32 b) { return (ooo_segment_distance_from_tail (f, a) <= ooo_segment_distance_from_tail (f, b)); } static inline u8 position_gt (svm_fifo_t * f, u32 a, u32 b) { return (ooo_segment_distance_from_tail (f, a) > ooo_segment_distance_from_tail (f, b)); } static inline u32 position_diff (svm_fifo_t * f, u32 posa, u32 posb) { return ooo_segment_distance_from_tail (f, posa) - ooo_segment_distance_from_tail (f, posb); } static inline u32 ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s) { return (s->start + s->length) % f->nitems; } u8 * format_ooo_segment (u8 * s, va_list * args) { 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); return s; } u8 * format_ooo_list (u8 * s, va_list * args) { 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, 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); 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\n", pool_elts (f->ooo_segments)); if (svm_fifo_has_ooo_data (f)) s = format (s, " %U", format_ooo_list, f); } 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; f = clib_mem_alloc_aligned_or_null (sizeof (*f) + data_size_in_bytes, CLIB_CACHE_LINE_BYTES); if (f == 0) return 0; memset (f, 0, sizeof (*f)); f->nitems = data_size_in_bytes; f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX; return (f); } void svm_fifo_free (svm_fifo_t * f) { pool_free (f->ooo_segments); clib_mem_free (f); } always_inline ooo_segment_t * ooo_segment_new (svm_fifo_t * f, u32 start, u32 length) { ooo_segment_t *s; pool_get (f->ooo_segments, s); 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) { ooo_segment_t *cur, *prev = 0, *next = 0; cur = pool_elt_at_index (f->ooo_segments, index); if (cur->next != OOO_SEGMENT_INVALID_INDEX) { next = pool_elt_at_index (f->ooo_segments, cur->next); next->prev = cur->prev; } if (cur->prev != OOO_SEGMENT_INVALID_INDEX) { prev = pool_elt_at_index (f->ooo_segments, cur->prev); prev->next = cur->next; } else { f->ooos_list_head = cur->next; } pool_put (f->ooo_segments, cur); } /** * Add segment to fifo's out-of-order segment list. Takes care of merging * adjacent segments and removing overlapping ones. */ static void ooo_segment_add (svm_fifo_t * f, u32 offset, 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; normalized_position = (f->tail + offset) % f->nitems; normalized_end_position = (f->tail + offset + length) % f->nitems; f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX) { s = ooo_segment_new (f, normalized_position, 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)) 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))) { s = prev; s_end_pos = ooo_segment_end_pos (f, s); /* Check head and tail now since segment may be wider at both ends so * merge tests lower won't work */ if (position_lt (f, normalized_position, s->start)) { s->start = normalized_position; s->length = position_diff (f, s_end_pos, s->start); } if (position_gt (f, normalized_end_position, s_end_pos)) { s->length = position_diff (f, normalized_end_position, s->start); } goto check_tail; } s_index = s - f->ooo_segments; s_end_pos = ooo_segment_end_pos (f, s); /* No overlap, add before current segment */ if (position_lt (f, normalized_end_position, s->start)) { new_s = ooo_segment_new (f, normalized_position, 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; } else { /* New head */ f->ooos_list_head = new_index; } new_s->next = s_index; s->prev = new_index; f->ooos_newest = new_index; return; } /* No overlap, add after current segment */ else if (position_gt (f, normalized_position, s_end_pos)) { new_s = ooo_segment_new (f, normalized_position, 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); ASSERT (s->next == OOO_SEGMENT_INVALID_INDEX); new_s->prev = s_index; s->next = new_index; f->ooos_newest = new_index; return; } /* * Merge needed */ /* Merge at head */ if (position_lt (f, normalized_position, s->start)) { s->start = normalized_position; s->length = position_diff (f, s_end_pos, s->start); } /* Overlapping tail */ else if (position_gt (f, normalized_end_position, s_end_pos)) { s->length = position_diff (f, normalized_end_position, s->start); } /* New segment completely covered by current one */ else { /* Do Nothing */ s = 0; goto done; } check_tail: /* The new segment's tail may cover multiple smaller ones */ if (position_gt (f, normalized_end_position, s_end_pos)) { /* Remove the completely overlapped segments */ it = (s->next != OOO_SEGMENT_INVALID_INDEX) ? pool_elt_at_index (f->ooo_segments, s->next) : 0; while (it && position_leq (f, ooo_segment_end_pos (f, it), normalized_end_position)) { 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; } /* If partial overlap with last, merge */ if (it && position_leq (f, it->start, normalized_end_position)) { s->length = position_diff (f, ooo_segment_end_pos (f, it), s->start); ooo_segment_del (f, it - f->ooo_segments); } } done: /* Most recently updated segment */ if (s) f->ooos_newest = s - f->ooo_segments; } /** * Removes segments that can now be enqueued because the fifo's tail has * 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_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); ASSERT (diff != n_bytes_enqueued); if (diff > n_bytes_enqueued) return 0; /* If last tail update overlaps one/multiple ooo segments, remove them */ while (0 <= diff && diff < n_bytes_enqueued) { 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); break; } /* If we have next go on */ 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); } /* End of search */ else { ooo_segment_del (f, index); break; } } ASSERT (bytes >= 0 && bytes <= f->nitems); return bytes; } static int svm_fifo_enqueue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here) { u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; u32 cursize, nitems; /* 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 */ nitems = f->nitems; /* Number of bytes we're going to copy */ total_copy_bytes = (nitems - cursize) < max_bytes ? (nitems - cursize) : max_bytes; 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) { 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 { 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; } /* 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, u8 * copy_from_here) { return svm_fifo_enqueue_internal (f, max_bytes, copy_from_here); } foreach_march_variant (SVM_ENQUEUE_CLONE_TEMPLATE, svm_fifo_enqueue_nowait_ma); CLIB_MULTIARCH_SELECT_FN (svm_fifo_enqueue_nowait_ma); int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, 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 } /** * 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_internal (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; f->ooos_newest = OOO_SEGMENT_INVALID_INDEX; /* read cursize, which can only increase while we're working */ cursize = svm_fifo_max_dequeue (f); nitems = f->nitems; ASSERT (required_bytes < nitems); normalized_offset = (f->tail + offset) % nitems; /* Will this request fit? */ offset_from_tail = (nitems + normalized_offset - f->tail) % nitems; if ((required_bytes + offset_from_tail) > (nitems - cursize)) return -1; ooo_segment_add (f, offset, required_bytes); /* 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 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; ASSERT (normalized_offset == 0); clib_memcpy (&f->data[normalized_offset], copy_from_here + first_copy_bytes, second_copy_bytes); } return (0); } int 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); } static int svm_fifo_dequeue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_here) { u32 total_copy_bytes, first_copy_bytes, second_copy_bytes; u32 cursize, nitems; /* 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 */ total_copy_bytes = (cursize < max_bytes) ? cursize : 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); 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) { 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; } } 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; } ASSERT (f->head <= nitems); ASSERT (cursize >= total_copy_bytes); __sync_fetch_and_sub (&f->cursize, total_copy_bytes); return (total_copy_bytes); } 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); } #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); 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 } static int svm_fifo_peek_ma (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; /* 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; /* 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 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); } } 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); 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 } 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; /* 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 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; /* Number of bytes in second drop segment, if any */ second_drop_bytes = total_drop_bytes - first_drop_bytes; if (second_drop_bytes) { f->head += second_drop_bytes; f->head = (f->head == nitems) ? 0 : f->head; } ASSERT (f->head <= nitems); ASSERT (cursize >= total_drop_bytes); __sync_fetch_and_sub (&f->cursize, total_drop_bytes); return total_drop_bytes; } 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) { f->head = f->tail = pointer % f->nitems; } /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */