1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5
6#include <linux/init.h>
7#include <linux/kernel.h>
8#include <linux/interrupt.h>
9#include <linux/irq.h>
10#include <linux/irqchip.h>
11#include <linux/irqdomain.h>
12
13#include <asm/loongarch.h>
14#include <asm/setup.h>
15
16static struct irq_domain *irq_domain;
17struct fwnode_handle *cpuintc_handle;
18
19static u32 lpic_gsi_to_irq(u32 gsi)
20{
21	/* Only pch irqdomain transferring is required for LoongArch. */
22	if (gsi >= GSI_MIN_PCH_IRQ && gsi <= GSI_MAX_PCH_IRQ)
23		return acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH);
24
25	return 0;
26}
27
28static struct fwnode_handle *lpic_get_gsi_domain_id(u32 gsi)
29{
30	int id;
31	struct fwnode_handle *domain_handle = NULL;
32
33	switch (gsi) {
34	case GSI_MIN_CPU_IRQ ... GSI_MAX_CPU_IRQ:
35		if (liointc_handle)
36			domain_handle = liointc_handle;
37		break;
38
39	case GSI_MIN_LPC_IRQ ... GSI_MAX_LPC_IRQ:
40		if (pch_lpc_handle)
41			domain_handle = pch_lpc_handle;
42		break;
43
44	case GSI_MIN_PCH_IRQ ... GSI_MAX_PCH_IRQ:
45		id = find_pch_pic(gsi);
46		if (id >= 0 && pch_pic_handle[id])
47			domain_handle = pch_pic_handle[id];
48		break;
49	}
50
51	return domain_handle;
52}
53
54static void mask_loongarch_irq(struct irq_data *d)
55{
56	clear_csr_ecfg(ECFGF(d->hwirq));
57}
58
59static void unmask_loongarch_irq(struct irq_data *d)
60{
61	set_csr_ecfg(ECFGF(d->hwirq));
62}
63
64static struct irq_chip cpu_irq_controller = {
65	.name		= "CPUINTC",
66	.irq_mask	= mask_loongarch_irq,
67	.irq_unmask	= unmask_loongarch_irq,
68};
69
70static void handle_cpu_irq(struct pt_regs *regs)
71{
72	int hwirq;
73	unsigned int estat = read_csr_estat() & CSR_ESTAT_IS;
74
75	while ((hwirq = ffs(estat))) {
76		estat &= ~BIT(hwirq - 1);
77		generic_handle_domain_irq(irq_domain, hwirq - 1);
78	}
79}
80
81static int loongarch_cpu_intc_map(struct irq_domain *d, unsigned int irq,
82			     irq_hw_number_t hwirq)
83{
84	irq_set_noprobe(irq);
85	irq_set_chip_and_handler(irq, &cpu_irq_controller, handle_percpu_irq);
86
87	return 0;
88}
89
90static const struct irq_domain_ops loongarch_cpu_intc_irq_domain_ops = {
91	.map = loongarch_cpu_intc_map,
92	.xlate = irq_domain_xlate_onecell,
93};
94
95#ifdef CONFIG_OF
96static int __init cpuintc_of_init(struct device_node *of_node,
97				struct device_node *parent)
98{
99	cpuintc_handle = of_node_to_fwnode(of_node);
100
101	irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
102				&loongarch_cpu_intc_irq_domain_ops, NULL);
103	if (!irq_domain)
104		panic("Failed to add irqdomain for loongarch CPU");
105
106	set_handle_irq(&handle_cpu_irq);
107
108	return 0;
109}
110IRQCHIP_DECLARE(cpu_intc, "loongson,cpu-interrupt-controller", cpuintc_of_init);
111#endif
112
113static int __init liointc_parse_madt(union acpi_subtable_headers *header,
114					const unsigned long end)
115{
116	struct acpi_madt_lio_pic *liointc_entry = (struct acpi_madt_lio_pic *)header;
117
118	return liointc_acpi_init(irq_domain, liointc_entry);
119}
120
121static int __init eiointc_parse_madt(union acpi_subtable_headers *header,
122					const unsigned long end)
123{
124	struct acpi_madt_eio_pic *eiointc_entry = (struct acpi_madt_eio_pic *)header;
125
126	return eiointc_acpi_init(irq_domain, eiointc_entry);
127}
128
129static int __init acpi_cascade_irqdomain_init(void)
130{
131	int r;
132
133	r = acpi_table_parse_madt(ACPI_MADT_TYPE_LIO_PIC, liointc_parse_madt, 0);
134	if (r < 0)
135		return r;
136
137	r = acpi_table_parse_madt(ACPI_MADT_TYPE_EIO_PIC, eiointc_parse_madt, 0);
138	if (r < 0)
139		return r;
140
141	return 0;
142}
143
144static int __init cpuintc_acpi_init(union acpi_subtable_headers *header,
145				   const unsigned long end)
146{
147	int ret;
148
149	if (irq_domain)
150		return 0;
151
152	/* Mask interrupts. */
153	clear_csr_ecfg(ECFG0_IM);
154	clear_csr_estat(ESTATF_IP);
155
156	cpuintc_handle = irq_domain_alloc_named_fwnode("CPUINTC");
157	irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
158					&loongarch_cpu_intc_irq_domain_ops, NULL);
159
160	if (!irq_domain)
161		panic("Failed to add irqdomain for LoongArch CPU");
162
163	set_handle_irq(&handle_cpu_irq);
164	acpi_set_irq_model(ACPI_IRQ_MODEL_LPIC, lpic_get_gsi_domain_id);
165	acpi_set_gsi_to_irq_fallback(lpic_gsi_to_irq);
166	ret = acpi_cascade_irqdomain_init();
167
168	return ret;
169}
170
171IRQCHIP_ACPI_DECLARE(cpuintc_v1, ACPI_MADT_TYPE_CORE_PIC,
172		NULL, ACPI_MADT_CORE_PIC_VERSION_V1, cpuintc_acpi_init);
173