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 		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 
138 static 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 
165 static 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 
177 int 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 
197 struct 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;
231 out:
232 	if (d)
233 		irq_domain_remove(d);
234 	kfree(desc);
235 
236 	return NULL;
237 }
238 
239 struct irq_domain *partition_get_domain(struct partition_desc *dsc)
240 {
241 	if (dsc)
242 		return dsc->domain;
243 
244 	return NULL;
245 }
246