1 // SPDX-License-Identifier: GPL-2.0
3  * Generic cpu hotunplug interrupt migration code copied from the
12 #include <linux/interrupt.h>
20 /* For !GENERIC_IRQ_EFFECTIVE_AFF_MASK this looks at general affinity mask */
28 	 * The cpumask_empty() check is a workaround for interrupt chips,  in irq_needs_fixup()
29 	 * which do not implement effective affinity, but the architecture has  in irq_needs_fixup()
30 	 * enabled the config switch. Use the general affinity mask instead.  in irq_needs_fixup()
46 		pr_warn("Eff. affinity %*pbl of IRQ %u contains only offline CPUs after offlining CPU %u\n",  in irq_needs_fixup()
47 			cpumask_pr_args(m), d->irq, cpu);  in irq_needs_fixup()
59 	const struct cpumask *affinity;  in migrate_one_irq()  local
68 	 * still in the radix tree. Also if the chip has no affinity setter,  in migrate_one_irq()
71 	if (!chip || !chip->irq_set_affinity) {  in migrate_one_irq()
72 		pr_debug("IRQ %u: Unable to migrate away\n", d->irq);  in migrate_one_irq()
78 	 * - Interrupt is per cpu  in migrate_one_irq()
79 	 * - Interrupt is not started  in migrate_one_irq()
80 	 * - Affinity mask does not include this CPU.  in migrate_one_irq()
82 	 * Note: Do not check desc->action as this might be a chained  in migrate_one_irq()
83 	 * interrupt.  in migrate_one_irq()
96 	 * interrupt was moved in hard irq context, then the vectors need  in migrate_one_irq()
97 	 * to be cleaned up. It can't wait until this interrupt actually  in migrate_one_irq()
104 	 * mask, so the last change of the affinity does not get lost. If  in migrate_one_irq()
106 	 * any online CPU, use the current affinity mask.  in migrate_one_irq()
109 		affinity = irq_desc_get_pending_mask(desc);  in migrate_one_irq()
111 		affinity = irq_data_get_affinity_mask(d);  in migrate_one_irq()
114 	if (maskchip && chip->irq_mask)  in migrate_one_irq()
115 		chip->irq_mask(d);  in migrate_one_irq()
118 	cpumask_copy(&available_cpus, affinity);  in migrate_one_irq()
120 	affinity = &available_cpus;  in migrate_one_irq()
123 	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {  in migrate_one_irq()
129 		 * If the interrupt is managed, then shut it down and leave  in migrate_one_irq()
130 		 * the affinity untouched.  in migrate_one_irq()
139 		default_affinity = desc->affinity_hint ? : irq_default_affinity;  in migrate_one_irq()
143 		 * (1) online and un-isolated CPU from default affinity  in migrate_one_irq()
144 		 * (2) online and un-isolated CPU  in migrate_one_irq()
153 			affinity = cpu_online_mask;  in migrate_one_irq()
156 		 * We are overriding the affinity with all online and  in migrate_one_irq()
157 		 * un-isolated cpus. irq_set_affinity_locked() call  in migrate_one_irq()
158 		 * below notify this mask to PM QOS affinity listener.  in migrate_one_irq()
161 		 * level irqchip driver sets the affinity of an irq  in migrate_one_irq()
163 		 * prepared mask while overriding the user affinity.  in migrate_one_irq()
165 		affinity = cpumask_of(cpumask_any(affinity));  in migrate_one_irq()
167 		affinity = cpu_online_mask;  in migrate_one_irq()
173 	 * disables the masking of offline CPUs from the supplied affinity  in migrate_one_irq()
178 	err = irq_set_affinity_locked(d, affinity, false);  in migrate_one_irq()
180 	err = irq_do_set_affinity(d, affinity, false);  in migrate_one_irq()
183 		pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",  in migrate_one_irq()
184 				    d->irq, err);  in migrate_one_irq()
188 	if (maskchip && chip->irq_unmask)  in migrate_one_irq()
189 		chip->irq_unmask(d);  in migrate_one_irq()
195  * irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu
198  * If the affinity settings do not allow other CPUs, force them onto any
213 		raw_spin_lock(&desc->lock);  in irq_migrate_all_off_this_cpu()
215 		raw_spin_unlock(&desc->lock);  in irq_migrate_all_off_this_cpu()
241 	const struct cpumask *affinity = irq_data_get_affinity_mask(data);  in irq_restore_affinity_of_irq()  local
243 	if (!irqd_affinity_is_managed(data) || !desc->action ||  in irq_restore_affinity_of_irq()
244 	    !irq_data_get_irq_chip(data) || !cpumask_test_cpu(cpu, affinity))  in irq_restore_affinity_of_irq()
253 	 * If the interrupt can only be directed to a single target  in irq_restore_affinity_of_irq()
254 	 * CPU then it is already assigned to a CPU in the affinity  in irq_restore_affinity_of_irq()
260 		irq_set_affinity_locked(data, affinity, false);  in irq_restore_affinity_of_irq()
264  * irq_affinity_online_cpu - Restore affinity for managed interrupts
275 		raw_spin_lock_irq(&desc->lock);  in irq_affinity_online_cpu()
277 		raw_spin_unlock_irq(&desc->lock);  in irq_affinity_online_cpu()