1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
4 * Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@baylibre.com>
5 */
6
7#include <linux/cleanup.h>
8#include <linux/interrupt.h>
9#include <linux/irq.h>
10#include <linux/irq_sim.h>
11#include <linux/irq_work.h>
12#include <linux/slab.h>
13
14struct irq_sim_work_ctx {
15 struct irq_work work;
16 int irq_base;
17 unsigned int irq_count;
18 unsigned long *pending;
19 struct irq_domain *domain;
20};
21
22struct irq_sim_irq_ctx {
23 bool enabled;
24 struct irq_sim_work_ctx *work_ctx;
25};
26
27static void irq_sim_irqmask(struct irq_data *data)
28{
29 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(d: data);
30
31 irq_ctx->enabled = false;
32}
33
34static void irq_sim_irqunmask(struct irq_data *data)
35{
36 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(d: data);
37
38 irq_ctx->enabled = true;
39}
40
41static int irq_sim_set_type(struct irq_data *data, unsigned int type)
42{
43 /* We only support rising and falling edge trigger types. */
44 if (type & ~IRQ_TYPE_EDGE_BOTH)
45 return -EINVAL;
46
47 irqd_set_trigger_type(d: data, type);
48
49 return 0;
50}
51
52static int irq_sim_get_irqchip_state(struct irq_data *data,
53 enum irqchip_irq_state which, bool *state)
54{
55 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(d: data);
56 irq_hw_number_t hwirq = irqd_to_hwirq(d: data);
57
58 switch (which) {
59 case IRQCHIP_STATE_PENDING:
60 if (irq_ctx->enabled)
61 *state = test_bit(hwirq, irq_ctx->work_ctx->pending);
62 break;
63 default:
64 return -EINVAL;
65 }
66
67 return 0;
68}
69
70static int irq_sim_set_irqchip_state(struct irq_data *data,
71 enum irqchip_irq_state which, bool state)
72{
73 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(d: data);
74 irq_hw_number_t hwirq = irqd_to_hwirq(d: data);
75
76 switch (which) {
77 case IRQCHIP_STATE_PENDING:
78 if (irq_ctx->enabled) {
79 assign_bit(nr: hwirq, addr: irq_ctx->work_ctx->pending, value: state);
80 if (state)
81 irq_work_queue(work: &irq_ctx->work_ctx->work);
82 }
83 break;
84 default:
85 return -EINVAL;
86 }
87
88 return 0;
89}
90
91static struct irq_chip irq_sim_irqchip = {
92 .name = "irq_sim",
93 .irq_mask = irq_sim_irqmask,
94 .irq_unmask = irq_sim_irqunmask,
95 .irq_set_type = irq_sim_set_type,
96 .irq_get_irqchip_state = irq_sim_get_irqchip_state,
97 .irq_set_irqchip_state = irq_sim_set_irqchip_state,
98};
99
100static void irq_sim_handle_irq(struct irq_work *work)
101{
102 struct irq_sim_work_ctx *work_ctx;
103 unsigned int offset = 0;
104 int irqnum;
105
106 work_ctx = container_of(work, struct irq_sim_work_ctx, work);
107
108 while (!bitmap_empty(src: work_ctx->pending, nbits: work_ctx->irq_count)) {
109 offset = find_next_bit(addr: work_ctx->pending,
110 size: work_ctx->irq_count, offset);
111 clear_bit(nr: offset, addr: work_ctx->pending);
112 irqnum = irq_find_mapping(domain: work_ctx->domain, hwirq: offset);
113 handle_simple_irq(desc: irq_to_desc(irq: irqnum));
114 }
115}
116
117static int irq_sim_domain_map(struct irq_domain *domain,
118 unsigned int virq, irq_hw_number_t hw)
119{
120 struct irq_sim_work_ctx *work_ctx = domain->host_data;
121 struct irq_sim_irq_ctx *irq_ctx;
122
123 irq_ctx = kzalloc(size: sizeof(*irq_ctx), GFP_KERNEL);
124 if (!irq_ctx)
125 return -ENOMEM;
126
127 irq_set_chip(irq: virq, chip: &irq_sim_irqchip);
128 irq_set_chip_data(irq: virq, data: irq_ctx);
129 irq_set_handler(irq: virq, handle: handle_simple_irq);
130 irq_modify_status(irq: virq, clr: IRQ_NOREQUEST | IRQ_NOAUTOEN, set: IRQ_NOPROBE);
131 irq_ctx->work_ctx = work_ctx;
132
133 return 0;
134}
135
136static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
137{
138 struct irq_sim_irq_ctx *irq_ctx;
139 struct irq_data *irqd;
140
141 irqd = irq_domain_get_irq_data(domain, virq);
142 irq_ctx = irq_data_get_irq_chip_data(d: irqd);
143
144 irq_set_handler(irq: virq, NULL);
145 irq_domain_reset_irq_data(irq_data: irqd);
146 kfree(objp: irq_ctx);
147}
148
149static const struct irq_domain_ops irq_sim_domain_ops = {
150 .map = irq_sim_domain_map,
151 .unmap = irq_sim_domain_unmap,
152};
153
154/**
155 * irq_domain_create_sim - Create a new interrupt simulator irq_domain and
156 * allocate a range of dummy interrupts.
157 *
158 * @fwnode: struct fwnode_handle to be associated with this domain.
159 * @num_irqs: Number of interrupts to allocate.
160 *
161 * On success: return a new irq_domain object.
162 * On failure: a negative errno wrapped with ERR_PTR().
163 */
164struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
165 unsigned int num_irqs)
166{
167 struct irq_sim_work_ctx *work_ctx __free(kfree) =
168 kmalloc(size: sizeof(*work_ctx), GFP_KERNEL);
169
170 if (!work_ctx)
171 return ERR_PTR(error: -ENOMEM);
172
173 unsigned long *pending __free(bitmap) = bitmap_zalloc(nbits: num_irqs, GFP_KERNEL);
174 if (!pending)
175 return ERR_PTR(error: -ENOMEM);
176
177 work_ctx->domain = irq_domain_create_linear(fwnode, size: num_irqs,
178 ops: &irq_sim_domain_ops,
179 host_data: work_ctx);
180 if (!work_ctx->domain)
181 return ERR_PTR(error: -ENOMEM);
182
183 work_ctx->irq_count = num_irqs;
184 work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
185 work_ctx->pending = no_free_ptr(pending);
186
187 return no_free_ptr(work_ctx)->domain;
188}
189EXPORT_SYMBOL_GPL(irq_domain_create_sim);
190
191/**
192 * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
193 * the interrupt descriptors and allocated memory.
194 *
195 * @domain: The interrupt simulator domain to tear down.
196 */
197void irq_domain_remove_sim(struct irq_domain *domain)
198{
199 struct irq_sim_work_ctx *work_ctx = domain->host_data;
200
201 irq_work_sync(work: &work_ctx->work);
202 bitmap_free(bitmap: work_ctx->pending);
203 kfree(objp: work_ctx);
204
205 irq_domain_remove(host: domain);
206}
207EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
208
209static void devm_irq_domain_remove_sim(void *data)
210{
211 struct irq_domain *domain = data;
212
213 irq_domain_remove_sim(domain);
214}
215
216/**
217 * devm_irq_domain_create_sim - Create a new interrupt simulator for
218 * a managed device.
219 *
220 * @dev: Device to initialize the simulator object for.
221 * @fwnode: struct fwnode_handle to be associated with this domain.
222 * @num_irqs: Number of interrupts to allocate
223 *
224 * On success: return a new irq_domain object.
225 * On failure: a negative errno wrapped with ERR_PTR().
226 */
227struct irq_domain *devm_irq_domain_create_sim(struct device *dev,
228 struct fwnode_handle *fwnode,
229 unsigned int num_irqs)
230{
231 struct irq_domain *domain;
232 int ret;
233
234 domain = irq_domain_create_sim(fwnode, num_irqs);
235 if (IS_ERR(ptr: domain))
236 return domain;
237
238 ret = devm_add_action_or_reset(dev, devm_irq_domain_remove_sim, domain);
239 if (ret)
240 return ERR_PTR(error: ret);
241
242 return domain;
243}
244EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);
245

source code of linux/kernel/irq/irq_sim.c