1 // SPDX-License-Identifier: GPL-2.0-only
7  *  Copyright (C) 2007-2008 Novell
18  *  a 2 dimensional bitmap (the first for priority class, the second for CPUs
27  * p->rt_priority   p->prio   newpri   cpupri
29  *				  -1       -1 (CPUPRI_INVALID)
48 		cpupri = CPUPRI_INVALID;	/* -1 */  in convert_prio()
52 		cpupri = MAX_RT_PRIO-1 - prio;	/* 1 ... 99 */  in convert_prio()
55 	case MAX_RT_PRIO-1:  in convert_prio()
70 	struct cpupri_vec *vec  = &cp->pri_to_cpu[idx];  in __cpupri_find()
73 	if (!atomic_read(&(vec)->count))  in __cpupri_find()
99 	if (cpumask_any_and(&p->cpus_mask, vec->mask) >= nr_cpu_ids)  in __cpupri_find()
103 		cpumask_and(lowest_mask, &p->cpus_mask, vec->mask);  in __cpupri_find()
109 		 * second reads of vec->mask.  If we hit this  in __cpupri_find()
127  * cpupri_find_fitness - find the best (lowest-pri) CPU in the system
141  * Return: (int)bool - CPUs were found
147 	int task_pri = convert_prio(p->prio);  in cpupri_find_fitness()
185 	 * The cost of this trade-off is not entirely clear and will probably  in cpupri_find_fitness()
188 	 * The main idea here is that if some CPUs were over-committed, we try  in cpupri_find_fitness()
200  * cpupri_set - update the CPU priority setting
203  * @newpri: The priority (INVALID,NORMAL,RT1-RT99,HIGHER) to assign to this CPU
205  * Note: Assumes cpu_rq(cpu)->lock is locked
211 	int *currpri = &cp->cpu_to_pri[cpu];  in cpupri_set()
229 		struct cpupri_vec *vec = &cp->pri_to_cpu[newpri];  in cpupri_set()
231 		cpumask_set_cpu(cpu, vec->mask);  in cpupri_set()
238 		atomic_inc(&(vec)->count);  in cpupri_set()
242 		struct cpupri_vec *vec  = &cp->pri_to_cpu[oldpri];  in cpupri_set()
245 		 * Because the order of modification of the vec->count  in cpupri_set()
263 		atomic_dec(&(vec)->count);  in cpupri_set()
265 		cpumask_clear_cpu(cpu, vec->mask);  in cpupri_set()
272  * cpupri_init - initialize the cpupri structure
275  * Return: -ENOMEM on memory allocation failure.
282 		struct cpupri_vec *vec = &cp->pri_to_cpu[i];  in cpupri_init()
284 		atomic_set(&vec->count, 0);  in cpupri_init()
285 		if (!zalloc_cpumask_var(&vec->mask, GFP_KERNEL))  in cpupri_init()
289 	cp->cpu_to_pri = kcalloc(nr_cpu_ids, sizeof(int), GFP_KERNEL);  in cpupri_init()
290 	if (!cp->cpu_to_pri)  in cpupri_init()
294 		cp->cpu_to_pri[i] = CPUPRI_INVALID;  in cpupri_init()
299 	for (i--; i >= 0; i--)  in cpupri_init()
300 		free_cpumask_var(cp->pri_to_cpu[i].mask);  in cpupri_init()
301 	return -ENOMEM;  in cpupri_init()
305  * cpupri_cleanup - clean up the cpupri structure
312 	kfree(cp->cpu_to_pri);  in cpupri_cleanup()
314 		free_cpumask_var(cp->pri_to_cpu[i].mask);  in cpupri_cleanup()