1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2016 ARM Limited, All Rights Reserved.
  4 * Author: Marc Zyngier <marc.zyngier@arm.com>
  5 */
  6
  7#include <linux/bitops.h>
  8#include <linux/interrupt.h>
  9#include <linux/irqchip.h>
 10#include <linux/irqchip/chained_irq.h>
 11#include <linux/irqchip/irq-partition-percpu.h>
 12#include <linux/irqdomain.h>
 13#include <linux/seq_file.h>
 14#include <linux/slab.h>
 15
 16struct partition_desc {
 17	int				nr_parts;
 18	struct partition_affinity	*parts;
 19	struct irq_domain		*domain;
 20	struct irq_desc			*chained_desc;
 21	unsigned long			*bitmap;
 22	struct irq_domain_ops		ops;
 23};
 24
 25static bool partition_check_cpu(struct partition_desc *part,
 26				unsigned int cpu, unsigned int hwirq)
 27{
 28	return cpumask_test_cpu(cpu, &part->parts[hwirq].mask);
 29}
 30
 31static void partition_irq_mask(struct irq_data *d)
 32{
 33	struct partition_desc *part = irq_data_get_irq_chip_data(d);
 34	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 35	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
 36
 37	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
 38	    chip->irq_mask)
 39		chip->irq_mask(data);
 40}
 41
 42static void partition_irq_unmask(struct irq_data *d)
 43{
 44	struct partition_desc *part = irq_data_get_irq_chip_data(d);
 45	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 46	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
 47
 48	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
 49	    chip->irq_unmask)
 50		chip->irq_unmask(data);
 51}
 52
 53static int partition_irq_set_irqchip_state(struct irq_data *d,
 54					   enum irqchip_irq_state which,
 55					   bool val)
 56{
 57	struct partition_desc *part = irq_data_get_irq_chip_data(d);
 58	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 59	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
 60
 61	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
 62	    chip->irq_set_irqchip_state)
 63		return chip->irq_set_irqchip_state(data, which, val);
 64
 65	return -EINVAL;
 66}
 67
 68static int partition_irq_get_irqchip_state(struct irq_data *d,
 69					   enum irqchip_irq_state which,
 70					   bool *val)
 71{
 72	struct partition_desc *part = irq_data_get_irq_chip_data(d);
 73	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 74	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
 75
 76	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
 77	    chip->irq_get_irqchip_state)
 78		return chip->irq_get_irqchip_state(data, which, val);
 79
 80	return -EINVAL;
 81}
 82
 83static int partition_irq_set_type(struct irq_data *d, unsigned int type)
 84{
 85	struct partition_desc *part = irq_data_get_irq_chip_data(d);
 86	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 87	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
 88
 89	if (chip->irq_set_type)
 90		return chip->irq_set_type(data, type);
 91
 92	return -EINVAL;
 93}
 94
 95static void partition_irq_print_chip(struct irq_data *d, struct seq_file *p)
 96{
 97	struct partition_desc *part = irq_data_get_irq_chip_data(d);
 98	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 99	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
100
101	seq_printf(p, " %5s-%lu", chip->name, data->hwirq);
102}
103
104static struct irq_chip partition_irq_chip = {
105	.irq_mask		= partition_irq_mask,
106	.irq_unmask		= partition_irq_unmask,
107	.irq_set_type		= partition_irq_set_type,
108	.irq_get_irqchip_state	= partition_irq_get_irqchip_state,
109	.irq_set_irqchip_state	= partition_irq_set_irqchip_state,
110	.irq_print_chip		= partition_irq_print_chip,
111};
112
113static void partition_handle_irq(struct irq_desc *desc)
114{
115	struct partition_desc *part = irq_desc_get_handler_data(desc);
116	struct irq_chip *chip = irq_desc_get_chip(desc);
117	int cpu = smp_processor_id();
118	int hwirq;
119
120	chained_irq_enter(chip, desc);
121
122	for_each_set_bit(hwirq, part->bitmap, part->nr_parts) {
123		if (partition_check_cpu(part, cpu, hwirq))
124			break;
125	}
126
127	if (unlikely(hwirq == part->nr_parts)) {
128		handle_bad_irq(desc);
129	} else {
130		unsigned int irq;
131		irq = irq_find_mapping(part->domain, hwirq);
132		generic_handle_irq(irq);
133	}
134
135	chained_irq_exit(chip, desc);
136}
137
138static int partition_domain_alloc(struct irq_domain *domain, unsigned int virq,
139				  unsigned int nr_irqs, void *arg)
140{
141	int ret;
142	irq_hw_number_t hwirq;
143	unsigned int type;
144	struct irq_fwspec *fwspec = arg;
145	struct partition_desc *part;
146
147	BUG_ON(nr_irqs != 1);
148	ret = domain->ops->translate(domain, fwspec, &hwirq, &type);
149	if (ret)
150		return ret;
151
152	part = domain->host_data;
153
154	set_bit(hwirq, part->bitmap);
155	irq_set_chained_handler_and_data(irq_desc_get_irq(part->chained_desc),
156					 partition_handle_irq, part);
157	irq_set_percpu_devid_partition(virq, &part->parts[hwirq].mask);
158	irq_domain_set_info(domain, virq, hwirq, &partition_irq_chip, part,
159			    handle_percpu_devid_irq, NULL, NULL);
160	irq_set_status_flags(virq, IRQ_NOAUTOEN);
161
162	return 0;
163}
164
165static void partition_domain_free(struct irq_domain *domain, unsigned int virq,
166				  unsigned int nr_irqs)
167{
168	struct irq_data *d;
169
170	BUG_ON(nr_irqs != 1);
171
172	d = irq_domain_get_irq_data(domain, virq);
173	irq_set_handler(virq, NULL);
174	irq_domain_reset_irq_data(d);
175}
176
177int partition_translate_id(struct partition_desc *desc, void *partition_id)
178{
179	struct partition_affinity *part = NULL;
180	int i;
181
182	for (i = 0; i < desc->nr_parts; i++) {
183		if (desc->parts[i].partition_id == partition_id) {
184			part = &desc->parts[i];
185			break;
186		}
187	}
188
189	if (WARN_ON(!part)) {
190		pr_err("Failed to find partition\n");
191		return -EINVAL;
192	}
193
194	return i;
195}
196
197struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
198					     struct partition_affinity *parts,
199					     int nr_parts,
200					     int chained_irq,
201					     const struct irq_domain_ops *ops)
202{
203	struct partition_desc *desc;
204	struct irq_domain *d;
205
206	BUG_ON(!ops->select || !ops->translate);
207
208	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
209	if (!desc)
210		return NULL;
211
212	desc->ops = *ops;
213	desc->ops.free = partition_domain_free;
214	desc->ops.alloc = partition_domain_alloc;
215
216	d = irq_domain_create_linear(fwnode, nr_parts, &desc->ops, desc);
217	if (!d)
218		goto out;
219	desc->domain = d;
220
221	desc->bitmap = kcalloc(BITS_TO_LONGS(nr_parts), sizeof(long),
222			       GFP_KERNEL);
223	if (WARN_ON(!desc->bitmap))
224		goto out;
225
226	desc->chained_desc = irq_to_desc(chained_irq);
227	desc->nr_parts = nr_parts;
228	desc->parts = parts;
229
230	return desc;
231out:
232	if (d)
233		irq_domain_remove(d);
234	kfree(desc);
235
236	return NULL;
237}
238
239struct irq_domain *partition_get_domain(struct partition_desc *dsc)
240{
241	if (dsc)
242		return dsc->domain;
243
244	return NULL;
245}