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