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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * A general-purpose cyclic execution infrastructure, to allow "small"
- * (run-time wise) functions to be executed at a specified frequency.
- * Things like LED blinking or watchdog triggering are examples for such
- * tasks.
- *
- * Copyright (C) 2022 Stefan Roese <sr@denx.de>
- */
- #include <cyclic.h>
- #include <log.h>
- #include <malloc.h>
- #include <time.h>
- #include <linux/errno.h>
- #include <linux/list.h>
- #include <asm/global_data.h>
- DECLARE_GLOBAL_DATA_PTR;
- void hw_watchdog_reset(void);
- struct hlist_head *cyclic_get_list(void)
- {
- /* Silence "discards 'volatile' qualifier" warning. */
- return (struct hlist_head *)&gd->cyclic_list;
- }
- struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
- const char *name, void *ctx)
- {
- struct cyclic_info *cyclic;
- cyclic = calloc(1, sizeof(struct cyclic_info));
- if (!cyclic) {
- pr_debug("Memory allocation error\n");
- return NULL;
- }
- /* Store values in struct */
- cyclic->func = func;
- cyclic->ctx = ctx;
- cyclic->name = strdup(name);
- cyclic->delay_us = delay_us;
- cyclic->start_time_us = timer_get_us();
- hlist_add_head(&cyclic->list, cyclic_get_list());
- return cyclic;
- }
- int cyclic_unregister(struct cyclic_info *cyclic)
- {
- hlist_del(&cyclic->list);
- free(cyclic);
- return 0;
- }
- void cyclic_run(void)
- {
- struct cyclic_info *cyclic;
- struct hlist_node *tmp;
- uint64_t now, cpu_time;
- /* Prevent recursion */
- if (gd->flags & GD_FLG_CYCLIC_RUNNING)
- return;
- gd->flags |= GD_FLG_CYCLIC_RUNNING;
- hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list) {
- /*
- * Check if this cyclic function needs to get called, e.g.
- * do not call the cyclic func too often
- */
- now = timer_get_us();
- if (time_after_eq64(now, cyclic->next_call)) {
- /* Call cyclic function and account it's cpu-time */
- cyclic->next_call = now + cyclic->delay_us;
- cyclic->func(cyclic->ctx);
- cyclic->run_cnt++;
- cpu_time = timer_get_us() - now;
- cyclic->cpu_time_us += cpu_time;
- /* Check if cpu-time exceeds max allowed time */
- if ((cpu_time > CONFIG_CYCLIC_MAX_CPU_TIME_US) &&
- (!cyclic->already_warned)) {
- pr_err("cyclic function %s took too long: %lldus vs %dus max\n",
- cyclic->name, cpu_time,
- CONFIG_CYCLIC_MAX_CPU_TIME_US);
- /*
- * Don't disable this function, just warn once
- * about this exceeding CPU time usage
- */
- cyclic->already_warned = true;
- }
- }
- }
- gd->flags &= ~GD_FLG_CYCLIC_RUNNING;
- }
- void schedule(void)
- {
- /* The HW watchdog is not integrated into the cyclic IF (yet) */
- if (IS_ENABLED(CONFIG_HW_WATCHDOG))
- hw_watchdog_reset();
- /*
- * schedule() might get called very early before the cyclic IF is
- * ready. Make sure to only call cyclic_run() when it's initalized.
- */
- if (gd)
- cyclic_run();
- }
- int cyclic_unregister_all(void)
- {
- struct cyclic_info *cyclic;
- struct hlist_node *tmp;
- hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list)
- cyclic_unregister(cyclic);
- return 0;
- }
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