--- /dev/null
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <sys/queue.h>
+#include <string.h>
+#include <rte_mbuf.h>
+#include <rte_memory.h>
+#include <rte_memzone.h>
+#include <rte_errno.h>
+#include <rte_compat.h>
+#include <rte_string_fns.h>
+#include <rte_eal_memconfig.h>
+#include "rte_distributor_v20.h"
+#include "rte_distributor_private.h"
+
+TAILQ_HEAD(rte_distributor_list, rte_distributor_v20);
+
+static struct rte_tailq_elem rte_distributor_tailq = {
+ .name = "RTE_DISTRIBUTOR",
+};
+EAL_REGISTER_TAILQ(rte_distributor_tailq)
+
+/**** APIs called by workers ****/
+
+void
+rte_distributor_request_pkt_v20(struct rte_distributor_v20 *d,
+ unsigned worker_id, struct rte_mbuf *oldpkt)
+{
+ union rte_distributor_buffer_v20 *buf = &d->bufs[worker_id];
+ int64_t req = (((int64_t)(uintptr_t)oldpkt) << RTE_DISTRIB_FLAG_BITS)
+ | RTE_DISTRIB_GET_BUF;
+ while (unlikely(buf->bufptr64 & RTE_DISTRIB_FLAGS_MASK))
+ rte_pause();
+ buf->bufptr64 = req;
+}
+VERSION_SYMBOL(rte_distributor_request_pkt, _v20, 2.0);
+
+struct rte_mbuf *
+rte_distributor_poll_pkt_v20(struct rte_distributor_v20 *d,
+ unsigned worker_id)
+{
+ union rte_distributor_buffer_v20 *buf = &d->bufs[worker_id];
+ if (buf->bufptr64 & RTE_DISTRIB_GET_BUF)
+ return NULL;
+
+ /* since bufptr64 is signed, this should be an arithmetic shift */
+ int64_t ret = buf->bufptr64 >> RTE_DISTRIB_FLAG_BITS;
+ return (struct rte_mbuf *)((uintptr_t)ret);
+}
+VERSION_SYMBOL(rte_distributor_poll_pkt, _v20, 2.0);
+
+struct rte_mbuf *
+rte_distributor_get_pkt_v20(struct rte_distributor_v20 *d,
+ unsigned worker_id, struct rte_mbuf *oldpkt)
+{
+ struct rte_mbuf *ret;
+ rte_distributor_request_pkt_v20(d, worker_id, oldpkt);
+ while ((ret = rte_distributor_poll_pkt_v20(d, worker_id)) == NULL)
+ rte_pause();
+ return ret;
+}
+VERSION_SYMBOL(rte_distributor_get_pkt, _v20, 2.0);
+
+int
+rte_distributor_return_pkt_v20(struct rte_distributor_v20 *d,
+ unsigned worker_id, struct rte_mbuf *oldpkt)
+{
+ union rte_distributor_buffer_v20 *buf = &d->bufs[worker_id];
+ uint64_t req = (((int64_t)(uintptr_t)oldpkt) << RTE_DISTRIB_FLAG_BITS)
+ | RTE_DISTRIB_RETURN_BUF;
+ buf->bufptr64 = req;
+ return 0;
+}
+VERSION_SYMBOL(rte_distributor_return_pkt, _v20, 2.0);
+
+/**** APIs called on distributor core ***/
+
+/* as name suggests, adds a packet to the backlog for a particular worker */
+static int
+add_to_backlog(struct rte_distributor_backlog *bl, int64_t item)
+{
+ if (bl->count == RTE_DISTRIB_BACKLOG_SIZE)
+ return -1;
+
+ bl->pkts[(bl->start + bl->count++) & (RTE_DISTRIB_BACKLOG_MASK)]
+ = item;
+ return 0;
+}
+
+/* takes the next packet for a worker off the backlog */
+static int64_t
+backlog_pop(struct rte_distributor_backlog *bl)
+{
+ bl->count--;
+ return bl->pkts[bl->start++ & RTE_DISTRIB_BACKLOG_MASK];
+}
+
+/* stores a packet returned from a worker inside the returns array */
+static inline void
+store_return(uintptr_t oldbuf, struct rte_distributor_v20 *d,
+ unsigned *ret_start, unsigned *ret_count)
+{
+ /* store returns in a circular buffer - code is branch-free */
+ d->returns.mbufs[(*ret_start + *ret_count) & RTE_DISTRIB_RETURNS_MASK]
+ = (void *)oldbuf;
+ *ret_start += (*ret_count == RTE_DISTRIB_RETURNS_MASK) & !!(oldbuf);
+ *ret_count += (*ret_count != RTE_DISTRIB_RETURNS_MASK) & !!(oldbuf);
+}
+
+static inline void
+handle_worker_shutdown(struct rte_distributor_v20 *d, unsigned int wkr)
+{
+ d->in_flight_tags[wkr] = 0;
+ d->in_flight_bitmask &= ~(1UL << wkr);
+ d->bufs[wkr].bufptr64 = 0;
+ if (unlikely(d->backlog[wkr].count != 0)) {
+ /* On return of a packet, we need to move the
+ * queued packets for this core elsewhere.
+ * Easiest solution is to set things up for
+ * a recursive call. That will cause those
+ * packets to be queued up for the next free
+ * core, i.e. it will return as soon as a
+ * core becomes free to accept the first
+ * packet, as subsequent ones will be added to
+ * the backlog for that core.
+ */
+ struct rte_mbuf *pkts[RTE_DISTRIB_BACKLOG_SIZE];
+ unsigned i;
+ struct rte_distributor_backlog *bl = &d->backlog[wkr];
+
+ for (i = 0; i < bl->count; i++) {
+ unsigned idx = (bl->start + i) &
+ RTE_DISTRIB_BACKLOG_MASK;
+ pkts[i] = (void *)((uintptr_t)(bl->pkts[idx] >>
+ RTE_DISTRIB_FLAG_BITS));
+ }
+ /* recursive call.
+ * Note that the tags were set before first level call
+ * to rte_distributor_process.
+ */
+ rte_distributor_process_v20(d, pkts, i);
+ bl->count = bl->start = 0;
+ }
+}
+
+/* this function is called when process() fn is called without any new
+ * packets. It goes through all the workers and clears any returned packets
+ * to do a partial flush.
+ */
+static int
+process_returns(struct rte_distributor_v20 *d)
+{
+ unsigned wkr;
+ unsigned flushed = 0;
+ unsigned ret_start = d->returns.start,
+ ret_count = d->returns.count;
+
+ for (wkr = 0; wkr < d->num_workers; wkr++) {
+
+ const int64_t data = d->bufs[wkr].bufptr64;
+ uintptr_t oldbuf = 0;
+
+ if (data & RTE_DISTRIB_GET_BUF) {
+ flushed++;
+ if (d->backlog[wkr].count)
+ d->bufs[wkr].bufptr64 =
+ backlog_pop(&d->backlog[wkr]);
+ else {
+ d->bufs[wkr].bufptr64 = RTE_DISTRIB_GET_BUF;
+ d->in_flight_tags[wkr] = 0;
+ d->in_flight_bitmask &= ~(1UL << wkr);
+ }
+ oldbuf = data >> RTE_DISTRIB_FLAG_BITS;
+ } else if (data & RTE_DISTRIB_RETURN_BUF) {
+ handle_worker_shutdown(d, wkr);
+ oldbuf = data >> RTE_DISTRIB_FLAG_BITS;
+ }
+
+ store_return(oldbuf, d, &ret_start, &ret_count);
+ }
+
+ d->returns.start = ret_start;
+ d->returns.count = ret_count;
+
+ return flushed;
+}
+
+/* process a set of packets to distribute them to workers */
+int
+rte_distributor_process_v20(struct rte_distributor_v20 *d,
+ struct rte_mbuf **mbufs, unsigned num_mbufs)
+{
+ unsigned next_idx = 0;
+ unsigned wkr = 0;
+ struct rte_mbuf *next_mb = NULL;
+ int64_t next_value = 0;
+ uint32_t new_tag = 0;
+ unsigned ret_start = d->returns.start,
+ ret_count = d->returns.count;
+
+ if (unlikely(num_mbufs == 0))
+ return process_returns(d);
+
+ while (next_idx < num_mbufs || next_mb != NULL) {
+
+ int64_t data = d->bufs[wkr].bufptr64;
+ uintptr_t oldbuf = 0;
+
+ if (!next_mb) {
+ next_mb = mbufs[next_idx++];
+ next_value = (((int64_t)(uintptr_t)next_mb)
+ << RTE_DISTRIB_FLAG_BITS);
+ /*
+ * User is advocated to set tag vaue for each
+ * mbuf before calling rte_distributor_process.
+ * User defined tags are used to identify flows,
+ * or sessions.
+ */
+ new_tag = next_mb->hash.usr;
+
+ /*
+ * Note that if RTE_DISTRIB_MAX_WORKERS is larger than 64
+ * then the size of match has to be expanded.
+ */
+ uint64_t match = 0;
+ unsigned i;
+ /*
+ * to scan for a match use "xor" and "not" to get a 0/1
+ * value, then use shifting to merge to single "match"
+ * variable, where a one-bit indicates a match for the
+ * worker given by the bit-position
+ */
+ for (i = 0; i < d->num_workers; i++)
+ match |= (!(d->in_flight_tags[i] ^ new_tag)
+ << i);
+
+ /* Only turned-on bits are considered as match */
+ match &= d->in_flight_bitmask;
+
+ if (match) {
+ next_mb = NULL;
+ unsigned worker = __builtin_ctzl(match);
+ if (add_to_backlog(&d->backlog[worker],
+ next_value) < 0)
+ next_idx--;
+ }
+ }
+
+ if ((data & RTE_DISTRIB_GET_BUF) &&
+ (d->backlog[wkr].count || next_mb)) {
+
+ if (d->backlog[wkr].count)
+ d->bufs[wkr].bufptr64 =
+ backlog_pop(&d->backlog[wkr]);
+
+ else {
+ d->bufs[wkr].bufptr64 = next_value;
+ d->in_flight_tags[wkr] = new_tag;
+ d->in_flight_bitmask |= (1UL << wkr);
+ next_mb = NULL;
+ }
+ oldbuf = data >> RTE_DISTRIB_FLAG_BITS;
+ } else if (data & RTE_DISTRIB_RETURN_BUF) {
+ handle_worker_shutdown(d, wkr);
+ oldbuf = data >> RTE_DISTRIB_FLAG_BITS;
+ }
+
+ /* store returns in a circular buffer */
+ store_return(oldbuf, d, &ret_start, &ret_count);
+
+ if (++wkr == d->num_workers)
+ wkr = 0;
+ }
+ /* to finish, check all workers for backlog and schedule work for them
+ * if they are ready */
+ for (wkr = 0; wkr < d->num_workers; wkr++)
+ if (d->backlog[wkr].count &&
+ (d->bufs[wkr].bufptr64 & RTE_DISTRIB_GET_BUF)) {
+
+ int64_t oldbuf = d->bufs[wkr].bufptr64 >>
+ RTE_DISTRIB_FLAG_BITS;
+ store_return(oldbuf, d, &ret_start, &ret_count);
+
+ d->bufs[wkr].bufptr64 = backlog_pop(&d->backlog[wkr]);
+ }
+
+ d->returns.start = ret_start;
+ d->returns.count = ret_count;
+ return num_mbufs;
+}
+VERSION_SYMBOL(rte_distributor_process, _v20, 2.0);
+
+/* return to the caller, packets returned from workers */
+int
+rte_distributor_returned_pkts_v20(struct rte_distributor_v20 *d,
+ struct rte_mbuf **mbufs, unsigned max_mbufs)
+{
+ struct rte_distributor_returned_pkts *returns = &d->returns;
+ unsigned retval = (max_mbufs < returns->count) ?
+ max_mbufs : returns->count;
+ unsigned i;
+
+ for (i = 0; i < retval; i++) {
+ unsigned idx = (returns->start + i) & RTE_DISTRIB_RETURNS_MASK;
+ mbufs[i] = returns->mbufs[idx];
+ }
+ returns->start += i;
+ returns->count -= i;
+
+ return retval;
+}
+VERSION_SYMBOL(rte_distributor_returned_pkts, _v20, 2.0);
+
+/* return the number of packets in-flight in a distributor, i.e. packets
+ * being workered on or queued up in a backlog. */
+static inline unsigned
+total_outstanding(const struct rte_distributor_v20 *d)
+{
+ unsigned wkr, total_outstanding;
+
+ total_outstanding = __builtin_popcountl(d->in_flight_bitmask);
+
+ for (wkr = 0; wkr < d->num_workers; wkr++)
+ total_outstanding += d->backlog[wkr].count;
+
+ return total_outstanding;
+}
+
+/* flush the distributor, so that there are no outstanding packets in flight or
+ * queued up. */
+int
+rte_distributor_flush_v20(struct rte_distributor_v20 *d)
+{
+ const unsigned flushed = total_outstanding(d);
+
+ while (total_outstanding(d) > 0)
+ rte_distributor_process_v20(d, NULL, 0);
+
+ return flushed;
+}
+VERSION_SYMBOL(rte_distributor_flush, _v20, 2.0);
+
+/* clears the internal returns array in the distributor */
+void
+rte_distributor_clear_returns_v20(struct rte_distributor_v20 *d)
+{
+ d->returns.start = d->returns.count = 0;
+#ifndef __OPTIMIZE__
+ memset(d->returns.mbufs, 0, sizeof(d->returns.mbufs));
+#endif
+}
+VERSION_SYMBOL(rte_distributor_clear_returns, _v20, 2.0);
+
+/* creates a distributor instance */
+struct rte_distributor_v20 *
+rte_distributor_create_v20(const char *name,
+ unsigned socket_id,
+ unsigned num_workers)
+{
+ struct rte_distributor_v20 *d;
+ struct rte_distributor_list *distributor_list;
+ char mz_name[RTE_MEMZONE_NAMESIZE];
+ const struct rte_memzone *mz;
+
+ /* compilation-time checks */
+ RTE_BUILD_BUG_ON((sizeof(*d) & RTE_CACHE_LINE_MASK) != 0);
+ RTE_BUILD_BUG_ON((RTE_DISTRIB_MAX_WORKERS & 7) != 0);
+ RTE_BUILD_BUG_ON(RTE_DISTRIB_MAX_WORKERS >
+ sizeof(d->in_flight_bitmask) * CHAR_BIT);
+
+ if (name == NULL || num_workers >= RTE_DISTRIB_MAX_WORKERS) {
+ rte_errno = EINVAL;
+ return NULL;
+ }
+
+ snprintf(mz_name, sizeof(mz_name), RTE_DISTRIB_PREFIX"%s", name);
+ mz = rte_memzone_reserve(mz_name, sizeof(*d), socket_id, NO_FLAGS);
+ if (mz == NULL) {
+ rte_errno = ENOMEM;
+ return NULL;
+ }
+
+ d = mz->addr;
+ snprintf(d->name, sizeof(d->name), "%s", name);
+ d->num_workers = num_workers;
+
+ distributor_list = RTE_TAILQ_CAST(rte_distributor_tailq.head,
+ rte_distributor_list);
+
+ rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
+ TAILQ_INSERT_TAIL(distributor_list, d, next);
+ rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
+
+ return d;
+}
+VERSION_SYMBOL(rte_distributor_create, _v20, 2.0);
Code Review / deb_dpdk.git / blobdiff