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 
16 struct 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 
25 static 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 
31 static 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 
42 static 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 
53 static 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 
68 static 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 
83 static 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 
95 static 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 
104 static 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 
113 static 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 		generic_handle_domain_irq(part->domain, hwirq);
131 
132 	chained_irq_exit(chip, desc);
133 }
134 
135 static int partition_domain_alloc(struct irq_domain *domain, unsigned int virq,
136 				  unsigned int nr_irqs, void *arg)
137 {
138 	int ret;
139 	irq_hw_number_t hwirq;
140 	unsigned int type;
141 	struct irq_fwspec *fwspec = arg;
142 	struct partition_desc *part;
143 
144 	BUG_ON(nr_irqs != 1);
145 	ret = domain->ops->translate(domain, fwspec, &hwirq, &type);
146 	if (ret)
147 		return ret;
148 
149 	part = domain->host_data;
150 
151 	set_bit(hwirq, part->bitmap);
152 	irq_set_chained_handler_and_data(irq_desc_get_irq(part->chained_desc),
153 					 partition_handle_irq, part);
154 	irq_set_percpu_devid_partition(virq, &part->parts[hwirq].mask);
155 	irq_domain_set_info(domain, virq, hwirq, &partition_irq_chip, part,
156 			    handle_percpu_devid_irq, NULL, NULL);
157 	irq_set_status_flags(virq, IRQ_NOAUTOEN);
158 
159 	return 0;
160 }
161 
162 static void partition_domain_free(struct irq_domain *domain, unsigned int virq,
163 				  unsigned int nr_irqs)
164 {
165 	struct irq_data *d;
166 
167 	BUG_ON(nr_irqs != 1);
168 
169 	d = irq_domain_get_irq_data(domain, virq);
170 	irq_set_handler(virq, NULL);
171 	irq_domain_reset_irq_data(d);
172 }
173 
174 int partition_translate_id(struct partition_desc *desc, void *partition_id)
175 {
176 	struct partition_affinity *part = NULL;
177 	int i;
178 
179 	for (i = 0; i < desc->nr_parts; i++) {
180 		if (desc->parts[i].partition_id == partition_id) {
181 			part = &desc->parts[i];
182 			break;
183 		}
184 	}
185 
186 	if (WARN_ON(!part)) {
187 		pr_err("Failed to find partition\n");
188 		return -EINVAL;
189 	}
190 
191 	return i;
192 }
193 
194 struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
195 					     struct partition_affinity *parts,
196 					     int nr_parts,
197 					     int chained_irq,
198 					     const struct irq_domain_ops *ops)
199 {
200 	struct partition_desc *desc;
201 	struct irq_domain *d;
202 
203 	BUG_ON(!ops->select || !ops->translate);
204 
205 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
206 	if (!desc)
207 		return NULL;
208 
209 	desc->ops = *ops;
210 	desc->ops.free = partition_domain_free;
211 	desc->ops.alloc = partition_domain_alloc;
212 
213 	d = irq_domain_create_linear(fwnode, nr_parts, &desc->ops, desc);
214 	if (!d)
215 		goto out;
216 	desc->domain = d;
217 
218 	desc->bitmap = bitmap_zalloc(nr_parts, GFP_KERNEL);
219 	if (WARN_ON(!desc->bitmap))
220 		goto out;
221 
222 	desc->chained_desc = irq_to_desc(chained_irq);
223 	desc->nr_parts = nr_parts;
224 	desc->parts = parts;
225 
226 	return desc;
227 out:
228 	if (d)
229 		irq_domain_remove(d);
230 	kfree(desc);
231 
232 	return NULL;
233 }
234 
235 struct irq_domain *partition_get_domain(struct partition_desc *dsc)
236 {
237 	if (dsc)
238 		return dsc->domain;
239 
240 	return NULL;
241 }
242