// 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 * */#include "sched.h" DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);EXPORT_SYMBOL_GPL(housekeeping_overridden);static cpumask_var_t housekeeping_mask;static unsigned int housekeeping_flags; bool housekeeping_enabled(enum hk_flags flags){	return !!(housekeeping_flags & flags);}EXPORT_SYMBOL_GPL(housekeeping_enabled); int housekeeping_any_cpu(enum hk_flags flags){	int cpu; 	if (static_branch_unlikely(&housekeeping_overridden)) {		if (housekeeping_flags & flags) {			cpu = sched_numa_find_closest(housekeeping_mask, smp_processor_id());			if (cpu < nr_cpu_ids)				return cpu; 			return cpumask_any_and(housekeeping_mask, cpu_online_mask);		}	}	return smp_processor_id();}EXPORT_SYMBOL_GPL(housekeeping_any_cpu); const struct cpumask *housekeeping_cpumask(enum hk_flags flags){	if (static_branch_unlikely(&housekeeping_overridden))		if (housekeeping_flags & flags)			return housekeeping_mask;	return cpu_possible_mask;}EXPORT_SYMBOL_GPL(housekeeping_cpumask); void housekeeping_affine(struct task_struct *t, enum hk_flags flags){	if (static_branch_unlikely(&housekeeping_overridden))		if (housekeeping_flags & flags)			set_cpus_allowed_ptr(t, housekeeping_mask);}EXPORT_SYMBOL_GPL(housekeeping_affine); bool housekeeping_test_cpu(int cpu, enum hk_flags flags){	if (static_branch_unlikely(&housekeeping_overridden))		if (housekeeping_flags & flags)			return cpumask_test_cpu(cpu, housekeeping_mask);	return true;}EXPORT_SYMBOL_GPL(housekeeping_test_cpu); void __init housekeeping_init(void){	if (!housekeeping_flags)		return; 	static_branch_enable(&housekeeping_overridden); 	if (housekeeping_flags & HK_FLAG_TICK)		sched_tick_offload_init(); 	/* We need at least one CPU to handle housekeeping work */	WARN_ON_ONCE(cpumask_empty(housekeeping_mask));} static int __init housekeeping_setup(char *str, enum hk_flags flags){	cpumask_var_t non_housekeeping_mask;	cpumask_var_t tmp;	int err; 	alloc_bootmem_cpumask_var(&non_housekeeping_mask);	err = cpulist_parse(str, non_housekeeping_mask);	if (err < 0 || cpumask_last(non_housekeeping_mask) >= nr_cpu_ids) {		pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n");		free_bootmem_cpumask_var(non_housekeeping_mask);		return 0;	} 	alloc_bootmem_cpumask_var(&tmp);	if (!housekeeping_flags) {		alloc_bootmem_cpumask_var(&housekeeping_mask);		cpumask_andnot(housekeeping_mask,			       cpu_possible_mask, non_housekeeping_mask); 		cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);		if (cpumask_empty(tmp)) {			pr_warn("Housekeeping: must include one present CPU, "				"using boot CPU:%d\n", smp_processor_id());			__cpumask_set_cpu(smp_processor_id(), housekeeping_mask);			__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);		}	} else {		cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);		if (cpumask_empty(tmp))			__cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);		cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask);		if (!cpumask_equal(tmp, housekeeping_mask)) {			pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");			free_bootmem_cpumask_var(tmp);			free_bootmem_cpumask_var(non_housekeeping_mask);			return 0;		}	}	free_bootmem_cpumask_var(tmp); 	if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {		if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {			tick_nohz_full_setup(non_housekeeping_mask);		} else {			pr_warn("Housekeeping: nohz unsupported."				" Build with CONFIG_NO_HZ_FULL\n");			free_bootmem_cpumask_var(non_housekeeping_mask);			return 0;		}	} 	housekeeping_flags |= flags; 	free_bootmem_cpumask_var(non_housekeeping_mask); 	return 1;} static int __init housekeeping_nohz_full_setup(char *str){	unsigned int 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 int 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);