ceph/src/dpdk/lib/librte_eal/common/include/rte_launch.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  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
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #ifndef _RTE_LAUNCH_H_
  35 #define _RTE_LAUNCH_H_
  36
  37 /**
  38  * @file
  39  *
  40  * Launch tasks on other lcores
  41  */
  42
  43 #ifdef __cplusplus
  44 extern "C" {
  45 #endif
  46
  47 /**
  48  * State of an lcore.
  49  */
  50 enum rte_lcore_state_t {
  51         WAIT,       /**< waiting a new command */
  52         RUNNING,    /**< executing command */
  53         FINISHED,   /**< command executed */
  54 };
  55
  56 /**
  57  * Definition of a remote launch function.
  58  */
  59 typedef int (lcore_function_t)(void *);
  60
  61 /**
  62  * Launch a function on another lcore.
  63  *
  64  * To be executed on the MASTER lcore only.
  65  *
  66  * Sends a message to a slave lcore (identified by the slave_id) that
  67  * is in the WAIT state (this is true after the first call to
  68  * rte_eal_init()). This can be checked by first calling
  69  * rte_eal_wait_lcore(slave_id).
  70  *
  71  * When the remote lcore receives the message, it switches to
  72  * the RUNNING state, then calls the function f with argument arg. Once the
  73  * execution is done, the remote lcore switches to a FINISHED state and
  74  * the return value of f is stored in a local variable to be read using
  75  * rte_eal_wait_lcore().
  76  *
  77  * The MASTER lcore returns as soon as the message is sent and knows
  78  * nothing about the completion of f.
  79  *
  80  * Note: This function is not designed to offer optimum
  81  * performance. It is just a practical way to launch a function on
  82  * another lcore at initialization time.
  83  *
  84  * @param f
  85  *   The function to be called.
  86  * @param arg
  87  *   The argument for the function.
  88  * @param slave_id
  89  *   The identifier of the lcore on which the function should be executed.
  90  * @return
  91  *   - 0: Success. Execution of function f started on the remote lcore.
  92  *   - (-EBUSY): The remote lcore is not in a WAIT state.
  93  */
  94 int rte_eal_remote_launch(lcore_function_t *f, void *arg, unsigned slave_id);
  95
  96 /**
  97  * This enum indicates whether the master core must execute the handler
  98  * launched on all logical cores.
  99  */
 100 enum rte_rmt_call_master_t {
 101         SKIP_MASTER = 0, /**< lcore handler not executed by master core. */
 102         CALL_MASTER,     /**< lcore handler executed by master core. */
 103 };
 104
 105 /**
 106  * Launch a function on all lcores.
 107  *
 108  * Check that each SLAVE lcore is in a WAIT state, then call
 109  * rte_eal_remote_launch() for each lcore.
 110  *
 111  * @param f
 112  *   The function to be called.
 113  * @param arg
 114  *   The argument for the function.
 115  * @param call_master
 116  *   If call_master set to SKIP_MASTER, the MASTER lcore does not call
 117  *   the function. If call_master is set to CALL_MASTER, the function
 118  *   is also called on master before returning. In any case, the master
 119  *   lcore returns as soon as it finished its job and knows nothing
 120  *   about the completion of f on the other lcores.
 121  * @return
 122  *   - 0: Success. Execution of function f started on all remote lcores.
 123  *   - (-EBUSY): At least one remote lcore is not in a WAIT state. In this
 124  *     case, no message is sent to any of the lcores.
 125  */
 126 int rte_eal_mp_remote_launch(lcore_function_t *f, void *arg,
 127                              enum rte_rmt_call_master_t call_master);
 128
 129 /**
 130  * Get the state of the lcore identified by slave_id.
 131  *
 132  * To be executed on the MASTER lcore only.
 133  *
 134  * @param slave_id
 135  *   The identifier of the lcore.
 136  * @return
 137  *   The state of the lcore.
 138  */
 139 enum rte_lcore_state_t rte_eal_get_lcore_state(unsigned slave_id);
 140
 141 /**
 142  * Wait until an lcore finishes its job.
 143  *
 144  * To be executed on the MASTER lcore only.
 145  *
 146  * If the slave lcore identified by the slave_id is in a FINISHED state,
 147  * switch to the WAIT state. If the lcore is in RUNNING state, wait until
 148  * the lcore finishes its job and moves to the FINISHED state.
 149  *
 150  * @param slave_id
 151  *   The identifier of the lcore.
 152  * @return
 153  *   - 0: If the lcore identified by the slave_id is in a WAIT state.
 154  *   - The value that was returned by the previous remote launch
 155  *     function call if the lcore identified by the slave_id was in a
 156  *     FINISHED or RUNNING state. In this case, it changes the state
 157  *     of the lcore to WAIT.
 158  */
 159 int rte_eal_wait_lcore(unsigned slave_id);
 160
 161 /**
 162  * Wait until all lcores finish their jobs.
 163  *
 164  * To be executed on the MASTER lcore only. Issue an
 165  * rte_eal_wait_lcore() for every lcore. The return values are
 166  * ignored.
 167  *
 168  * After a call to rte_eal_mp_wait_lcore(), the caller can assume
 169  * that all slave lcores are in a WAIT state.
 170  */
 171 void rte_eal_mp_wait_lcore(void);
 172
 173 #ifdef __cplusplus
 174 }
 175 #endif
 176
 177 #endif /* _RTE_LAUNCH_H_ */