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