lib/eal/common/eal_common_launch.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <errno.h>
   6
   7 #include <rte_launch.h>
   8 #include <rte_eal_trace.h>
   9 #include <rte_atomic.h>
  10 #include <rte_pause.h>
  11 #include <rte_lcore.h>
  12
  13 #include "eal_private.h"
  14 #include "eal_thread.h"
  15
  16 /*
  17  * Wait until a lcore finished its job.
  18  */
  19 int
  20 rte_eal_wait_lcore(unsigned worker_id)
  21 {
  22         while (__atomic_load_n(&lcore_config[worker_id].state,
  23                         __ATOMIC_ACQUIRE) != WAIT)
  24                 rte_pause();
  25
  26         return lcore_config[worker_id].ret;
  27 }
  28
  29 /*
  30  * Send a message to a worker lcore identified by worker_id to call a
  31  * function f with argument arg. Once the execution is done, the
  32  * remote lcore switches to WAIT state.
  33  */
  34 int
  35 rte_eal_remote_launch(lcore_function_t *f, void *arg, unsigned int worker_id)
  36 {
  37         int rc = -EBUSY;
  38
  39         /* Check if the worker is in 'WAIT' state. Use acquire order
  40          * since 'state' variable is used as the guard variable.
  41          */
  42         if (__atomic_load_n(&lcore_config[worker_id].state,
  43                         __ATOMIC_ACQUIRE) != WAIT)
  44                 goto finish;
  45
  46         lcore_config[worker_id].arg = arg;
  47         /* Ensure that all the memory operations are completed
  48          * before the worker thread starts running the function.
  49          * Use worker thread function as the guard variable.
  50          */
  51         __atomic_store_n(&lcore_config[worker_id].f, f, __ATOMIC_RELEASE);
  52
  53         eal_thread_wake_worker(worker_id);
  54         rc = 0;
  55
  56 finish:
  57         rte_eal_trace_thread_remote_launch(f, arg, worker_id, rc);
  58         return rc;
  59 }
  60
  61 /*
  62  * Check that every WORKER lcores are in WAIT state, then call
  63  * rte_eal_remote_launch() for all of them. If call_main is true
  64  * (set to CALL_MAIN), also call the function on the main lcore.
  65  */
  66 int
  67 rte_eal_mp_remote_launch(int (*f)(void *), void *arg,
  68                          enum rte_rmt_call_main_t call_main)
  69 {
  70         int lcore_id;
  71         int main_lcore = rte_get_main_lcore();
  72
  73         /* check state of lcores */
  74         RTE_LCORE_FOREACH_WORKER(lcore_id) {
  75                 if (lcore_config[lcore_id].state != WAIT)
  76                         return -EBUSY;
  77         }
  78
  79         /* send messages to cores */
  80         RTE_LCORE_FOREACH_WORKER(lcore_id) {
  81                 rte_eal_remote_launch(f, arg, lcore_id);
  82         }
  83
  84         if (call_main == CALL_MAIN) {
  85                 lcore_config[main_lcore].ret = f(arg);
  86                 lcore_config[main_lcore].state = WAIT;
  87         }
  88
  89         return 0;
  90 }
  91
  92 /*
  93  * Return the state of the lcore identified by worker_id.
  94  */
  95 enum rte_lcore_state_t
  96 rte_eal_get_lcore_state(unsigned lcore_id)
  97 {
  98         return lcore_config[lcore_id].state;
  99 }
 100
 101 /*
 102  * Do a rte_eal_wait_lcore() for every lcore. The return values are
 103  * ignored.
 104  */
 105 void
 106 rte_eal_mp_wait_lcore(void)
 107 {
 108         unsigned lcore_id;
 109
 110         RTE_LCORE_FOREACH_WORKER(lcore_id) {
 111                 rte_eal_wait_lcore(lcore_id);
 112         }
 113 }