ceph/src/dpdk/lib/librte_distributor/rte_distributor.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
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   7  *   Redistribution and use in source and binary forms, with or without
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  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
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  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  32  */
  33
  34 #ifndef _RTE_DISTRIBUTE_H_
  35 #define _RTE_DISTRIBUTE_H_
  36
  37 /**
  38  * @file
  39  * RTE distributor
  40  *
  41  * The distributor is a component which is designed to pass packets
  42  * one-at-a-time to workers, with dynamic load balancing.
  43  */
  44
  45 #ifdef __cplusplus
  46 extern "C" {
  47 #endif
  48
  49 #define RTE_DISTRIBUTOR_NAMESIZE 32 /**< Length of name for instance */
  50
  51 struct rte_distributor;
  52 struct rte_mbuf;
  53
  54 /**
  55  * Function to create a new distributor instance
  56  *
  57  * Reserves the memory needed for the distributor operation and
  58  * initializes the distributor to work with the configured number of workers.
  59  *
  60  * @param name
  61  *   The name to be given to the distributor instance.
  62  * @param socket_id
  63  *   The NUMA node on which the memory is to be allocated
  64  * @param num_workers
  65  *   The maximum number of workers that will request packets from this
  66  *   distributor
  67  * @return
  68  *   The newly created distributor instance
  69  */
  70 struct rte_distributor *
  71 rte_distributor_create(const char *name, unsigned socket_id,
  72                 unsigned num_workers);
  73
  74 /*  *** APIS to be called on the distributor lcore ***  */
  75 /*
  76  * The following APIs are the public APIs which are designed for use on a
  77  * single lcore which acts as the distributor lcore for a given distributor
  78  * instance. These functions cannot be called on multiple cores simultaneously
  79  * without using locking to protect access to the internals of the distributor.
  80  *
  81  * NOTE: a given lcore cannot act as both a distributor lcore and a worker lcore
  82  * for the same distributor instance, otherwise deadlock will result.
  83  */
  84
  85 /**
  86  * Process a set of packets by distributing them among workers that request
  87  * packets. The distributor will ensure that no two packets that have the
  88  * same flow id, or tag, in the mbuf will be procesed at the same time.
  89  *
  90  * The user is advocated to set tag for each mbuf before calling this function.
  91  * If user doesn't set the tag, the tag value can be various values depending on
  92  * driver implementation and configuration.
  93  *
  94  * This is not multi-thread safe and should only be called on a single lcore.
  95  *
  96  * @param d
  97  *   The distributor instance to be used
  98  * @param mbufs
  99  *   The mbufs to be distributed
 100  * @param num_mbufs
 101  *   The number of mbufs in the mbufs array
 102  * @return
 103  *   The number of mbufs processed.
 104  */
 105 int
 106 rte_distributor_process(struct rte_distributor *d,
 107                 struct rte_mbuf **mbufs, unsigned num_mbufs);
 108
 109 /**
 110  * Get a set of mbufs that have been returned to the distributor by workers
 111  *
 112  * This should only be called on the same lcore as rte_distributor_process()
 113  *
 114  * @param d
 115  *   The distributor instance to be used
 116  * @param mbufs
 117  *   The mbufs pointer array to be filled in
 118  * @param max_mbufs
 119  *   The size of the mbufs array
 120  * @return
 121  *   The number of mbufs returned in the mbufs array.
 122  */
 123 int
 124 rte_distributor_returned_pkts(struct rte_distributor *d,
 125                 struct rte_mbuf **mbufs, unsigned max_mbufs);
 126
 127 /**
 128  * Flush the distributor component, so that there are no in-flight or
 129  * backlogged packets awaiting processing
 130  *
 131  * This should only be called on the same lcore as rte_distributor_process()
 132  *
 133  * @param d
 134  *   The distributor instance to be used
 135  * @return
 136  *   The number of queued/in-flight packets that were completed by this call.
 137  */
 138 int
 139 rte_distributor_flush(struct rte_distributor *d);
 140
 141 /**
 142  * Clears the array of returned packets used as the source for the
 143  * rte_distributor_returned_pkts() API call.
 144  *
 145  * This should only be called on the same lcore as rte_distributor_process()
 146  *
 147  * @param d
 148  *   The distributor instance to be used
 149  */
 150 void
 151 rte_distributor_clear_returns(struct rte_distributor *d);
 152
 153 /*  *** APIS to be called on the worker lcores ***  */
 154 /*
 155  * The following APIs are the public APIs which are designed for use on
 156  * multiple lcores which act as workers for a distributor. Each lcore should use
 157  * a unique worker id when requesting packets.
 158  *
 159  * NOTE: a given lcore cannot act as both a distributor lcore and a worker lcore
 160  * for the same distributor instance, otherwise deadlock will result.
 161  */
 162
 163 /**
 164  * API called by a worker to get a new packet to process. Any previous packet
 165  * given to the worker is assumed to have completed processing, and may be
 166  * optionally returned to the distributor via the oldpkt parameter.
 167  *
 168  * @param d
 169  *   The distributor instance to be used
 170  * @param worker_id
 171  *   The worker instance number to use - must be less that num_workers passed
 172  *   at distributor creation time.
 173  * @param oldpkt
 174  *   The previous packet, if any, being processed by the worker
 175  *
 176  * @return
 177  *   A new packet to be processed by the worker thread.
 178  */
 179 struct rte_mbuf *
 180 rte_distributor_get_pkt(struct rte_distributor *d,
 181                 unsigned worker_id, struct rte_mbuf *oldpkt);
 182
 183 /**
 184  * API called by a worker to return a completed packet without requesting a
 185  * new packet, for example, because a worker thread is shutting down
 186  *
 187  * @param d
 188  *   The distributor instance to be used
 189  * @param worker_id
 190  *   The worker instance number to use - must be less that num_workers passed
 191  *   at distributor creation time.
 192  * @param mbuf
 193  *   The previous packet being processed by the worker
 194  */
 195 int
 196 rte_distributor_return_pkt(struct rte_distributor *d, unsigned worker_id,
 197                 struct rte_mbuf *mbuf);
 198
 199 /**
 200  * API called by a worker to request a new packet to process.
 201  * Any previous packet given to the worker is assumed to have completed
 202  * processing, and may be optionally returned to the distributor via
 203  * the oldpkt parameter.
 204  * Unlike rte_distributor_get_pkt(), this function does not wait for a new
 205  * packet to be provided by the distributor.
 206  *
 207  * NOTE: after calling this function, rte_distributor_poll_pkt() should
 208  * be used to poll for the packet requested. The rte_distributor_get_pkt()
 209  * API should *not* be used to try and retrieve the new packet.
 210  *
 211  * @param d
 212  *   The distributor instance to be used
 213  * @param worker_id
 214  *   The worker instance number to use - must be less that num_workers passed
 215  *   at distributor creation time.
 216  * @param oldpkt
 217  *   The previous packet, if any, being processed by the worker
 218  */
 219 void
 220 rte_distributor_request_pkt(struct rte_distributor *d,
 221                 unsigned worker_id, struct rte_mbuf *oldpkt);
 222
 223 /**
 224  * API called by a worker to check for a new packet that was previously
 225  * requested by a call to rte_distributor_request_pkt(). It does not wait
 226  * for the new packet to be available, but returns NULL if the request has
 227  * not yet been fulfilled by the distributor.
 228  *
 229  * @param d
 230  *   The distributor instance to be used
 231  * @param worker_id
 232  *   The worker instance number to use - must be less that num_workers passed
 233  *   at distributor creation time.
 234  *
 235  * @return
 236  *   A new packet to be processed by the worker thread, or NULL if no
 237  *   packet is yet available.
 238  */
 239 struct rte_mbuf *
 240 rte_distributor_poll_pkt(struct rte_distributor *d,
 241                 unsigned worker_id);
 242
 243 #ifdef __cplusplus
 244 }
 245 #endif
 246
 247 #endif