// SPDX-License-Identifier: GPL-2.0-only/* *  Housekeeping management. Manage the targets for routine code that can run on *  any CPU: unbound workqueues, timers, kthreads and any offloadable work. * * Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker * Copyright (C) 2017-2018 SUSE, Frederic Weisbecker * */ enum hk_flags {	HK_FLAG_TIMER		= BIT(HK_TYPE_TIMER),	HK_FLAG_RCU		= BIT(HK_TYPE_RCU),	HK_FLAG_MISC		= BIT(HK_TYPE_MISC),	HK_FLAG_SCHED		= BIT(HK_TYPE_SCHED),	HK_FLAG_TICK		= BIT(HK_TYPE_TICK),	HK_FLAG_DOMAIN		= BIT(HK_TYPE_DOMAIN),	HK_FLAG_WQ		= BIT(HK_TYPE_WQ),	HK_FLAG_MANAGED_IRQ	= BIT(HK_TYPE_MANAGED_IRQ),	HK_FLAG_KTHREAD		= BIT(HK_TYPE_KTHREAD),}; DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);EXPORT_SYMBOL_GPL(housekeeping_overridden); struct housekeeping {	cpumask_var_t cpumasks[HK_TYPE_MAX];	unsigned long flags;}; static struct housekeeping housekeeping; bool housekeeping_enabled(enum hk_type type){	return !!(housekeeping.flags & BIT(type));}EXPORT_SYMBOL_GPL(housekeeping_enabled); int housekeeping_any_cpu(enum hk_type type){	int cpu; 	if (static_branch_unlikely(&housekeeping_overridden)) {		if (housekeeping.flags & BIT(type)) {			cpu = sched_numa_find_closest(housekeeping.cpumasks[type], smp_processor_id());			if (cpu < nr_cpu_ids)				return cpu; 			cpu = cpumask_any_and(housekeeping.cpumasks[type], cpu_online_mask);			if (likely(cpu < nr_cpu_ids))				return cpu;			/*			 * Unless we have another problem this can only happen			 * at boot time before start_secondary() brings the 1st			 * housekeeping CPU up.			 */			WARN_ON_ONCE(system_state == SYSTEM_RUNNING ||				     type != HK_TYPE_TIMER);		}	}	return smp_processor_id();}EXPORT_SYMBOL_GPL(housekeeping_any_cpu); const struct cpumask *housekeeping_cpumask(enum hk_type type){	if (static_branch_unlikely(&housekeeping_overridden))		if (housekeeping.flags & BIT(type))			return housekeeping.cpumasks[type];	return cpu_possible_mask;}EXPORT_SYMBOL_GPL(housekeeping_cpumask); void housekeeping_affine(struct task_struct *t, enum hk_type type){	if (static_branch_unlikely(&housekeeping_overridden))		if (housekeeping.flags & BIT(type))			set_cpus_allowed_ptr(t, housekeeping.cpumasks[type]);}EXPORT_SYMBOL_GPL(housekeeping_affine); bool housekeeping_test_cpu(int cpu, enum hk_type type){	if (static_branch_unlikely(&housekeeping_overridden))		if (housekeeping.flags & BIT(type))			return cpumask_test_cpu(cpu, housekeeping.cpumasks[type]);	return true;}EXPORT_SYMBOL_GPL(housekeeping_test_cpu); void __init housekeeping_init(void){	enum hk_type type; 	if (!housekeeping.flags)		return; 	static_branch_enable(&housekeeping_overridden); 	if (housekeeping.flags & HK_FLAG_TICK)		sched_tick_offload_init(); 	for_each_set_bit(type, &housekeeping.flags, HK_TYPE_MAX) {		/* We need at least one CPU to handle housekeeping work */		WARN_ON_ONCE(cpumask_empty(housekeeping.cpumasks[type]));	}} static void __init housekeeping_setup_type(enum hk_type type,					   cpumask_var_t housekeeping_staging){ 	alloc_bootmem_cpumask_var(&housekeeping.cpumasks[type]);	cpumask_copy(housekeeping.cpumasks[type],		     housekeeping_staging);} static int __init housekeeping_setup(char *str, unsigned long flags){	cpumask_var_t non_housekeeping_mask, housekeeping_staging;	unsigned int first_cpu;	int err = 0; 	if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) {		if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) {			pr_warn("Housekeeping: nohz unsupported."				" Build with CONFIG_NO_HZ_FULL\n");			return 0;		}	} 	alloc_bootmem_cpumask_var(&non_housekeeping_mask);	if (cpulist_parse(str, non_housekeeping_mask) < 0) {		pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n");		goto free_non_housekeeping_mask;	} 	alloc_bootmem_cpumask_var(&housekeeping_staging);	cpumask_andnot(housekeeping_staging,		       cpu_possible_mask, non_housekeeping_mask); 	first_cpu = cpumask_first_and(cpu_present_mask, housekeeping_staging);	if (first_cpu >= nr_cpu_ids || first_cpu >= setup_max_cpus) {		__cpumask_set_cpu(smp_processor_id(), housekeeping_staging);		__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);		if (!housekeeping.flags) {			pr_warn("Housekeeping: must include one present CPU, "				"using boot CPU:%d\n", smp_processor_id());		}	} 	if (cpumask_empty(non_housekeeping_mask))		goto free_housekeeping_staging; 	if (!housekeeping.flags) {		/* First setup call ("nohz_full=" or "isolcpus=") */		enum hk_type type; 		for_each_set_bit(type, &flags, HK_TYPE_MAX)			housekeeping_setup_type(type, housekeeping_staging);	} else {		/* Second setup call ("nohz_full=" after "isolcpus=" or the reverse) */		enum hk_type type;		unsigned long iter_flags = flags & housekeeping.flags; 		for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) {			if (!cpumask_equal(housekeeping_staging,					   housekeeping.cpumasks[type])) {				pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");				goto free_housekeeping_staging;			}		} 		iter_flags = flags & ~housekeeping.flags; 		for_each_set_bit(type, &iter_flags, HK_TYPE_MAX)			housekeeping_setup_type(type, housekeeping_staging);	} 	if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK))		tick_nohz_full_setup(non_housekeeping_mask); 	housekeeping.flags |= flags;	err = 1; free_housekeeping_staging:	free_bootmem_cpumask_var(housekeeping_staging);free_non_housekeeping_mask:	free_bootmem_cpumask_var(non_housekeeping_mask); 	return err;} static int __init housekeeping_nohz_full_setup(char *str){	unsigned long flags; 	flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |		HK_FLAG_MISC | HK_FLAG_KTHREAD; 	return housekeeping_setup(str, flags);}__setup("nohz_full=", housekeeping_nohz_full_setup); static int __init housekeeping_isolcpus_setup(char *str){	unsigned long flags = 0;	bool illegal = false;	char *par;	int len; 	while (isalpha(*str)) {		if (!strncmp(str, "nohz,", 5)) {			str += 5;			flags |= HK_FLAG_TICK;			continue;		} 		if (!strncmp(str, "domain,", 7)) {			str += 7;			flags |= HK_FLAG_DOMAIN;			continue;		} 		if (!strncmp(str, "managed_irq,", 12)) {			str += 12;			flags |= HK_FLAG_MANAGED_IRQ;			continue;		} 		/*		 * Skip unknown sub-parameter and validate that it is not		 * containing an invalid character.		 */		for (par = str, len = 0; *str && *str != ','; str++, len++) {			if (!isalpha(*str) && *str != '_')				illegal = true;		} 		if (illegal) {			pr_warn("isolcpus: Invalid flag %.*s\n", len, par);			return 0;		} 		pr_info("isolcpus: Skipped unknown flag %.*s\n", len, par);		str++;	} 	/* Default behaviour for isolcpus without flags */	if (!flags)		flags |= HK_FLAG_DOMAIN; 	return housekeeping_setup(str, flags);}__setup("isolcpus=", housekeeping_isolcpus_setup);