xref: /linux/drivers/irqchip/irq-loongarch-cpu.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
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 
16 #include "irq-loongson.h"
17 
18 static struct irq_domain *irq_domain;
19 struct fwnode_handle *cpuintc_handle;
20 
21 static u32 lpic_gsi_to_irq(u32 gsi)
22 {
23 	int irq = 0;
24 
25 	/* Only pch irqdomain transferring is required for LoongArch. */
26 	if (gsi >= GSI_MIN_PCH_IRQ && gsi <= GSI_MAX_PCH_IRQ)
27 		irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH);
28 
29 	return (irq > 0) ? irq : 0;
30 }
31 
32 static struct fwnode_handle *lpic_get_gsi_domain_id(u32 gsi)
33 {
34 	int id;
35 	struct fwnode_handle *domain_handle = NULL;
36 
37 	switch (gsi) {
38 	case GSI_MIN_CPU_IRQ ... GSI_MAX_CPU_IRQ:
39 		if (liointc_handle)
40 			domain_handle = liointc_handle;
41 		break;
42 
43 	case GSI_MIN_LPC_IRQ ... GSI_MAX_LPC_IRQ:
44 		if (pch_lpc_handle)
45 			domain_handle = pch_lpc_handle;
46 		break;
47 
48 	case GSI_MIN_PCH_IRQ ... GSI_MAX_PCH_IRQ:
49 		id = find_pch_pic(gsi);
50 		if (id >= 0 && pch_pic_handle[id])
51 			domain_handle = pch_pic_handle[id];
52 		break;
53 	}
54 
55 	return domain_handle;
56 }
57 
58 static void mask_loongarch_irq(struct irq_data *d)
59 {
60 	clear_csr_ecfg(ECFGF(d->hwirq));
61 }
62 
63 static void unmask_loongarch_irq(struct irq_data *d)
64 {
65 	set_csr_ecfg(ECFGF(d->hwirq));
66 }
67 
68 static struct irq_chip cpu_irq_controller = {
69 	.name		= "CPUINTC",
70 	.irq_mask	= mask_loongarch_irq,
71 	.irq_unmask	= unmask_loongarch_irq,
72 };
73 
74 static void handle_cpu_irq(struct pt_regs *regs)
75 {
76 	int hwirq;
77 	unsigned int estat = read_csr_estat() & CSR_ESTAT_IS;
78 
79 	while ((hwirq = ffs(estat))) {
80 		estat &= ~BIT(hwirq - 1);
81 		generic_handle_domain_irq(irq_domain, hwirq - 1);
82 	}
83 }
84 
85 static int loongarch_cpu_intc_map(struct irq_domain *d, unsigned int irq,
86 			     irq_hw_number_t hwirq)
87 {
88 	irq_set_noprobe(irq);
89 	irq_set_chip_and_handler(irq, &cpu_irq_controller, handle_percpu_irq);
90 
91 	return 0;
92 }
93 
94 static const struct irq_domain_ops loongarch_cpu_intc_irq_domain_ops = {
95 	.map = loongarch_cpu_intc_map,
96 	.xlate = irq_domain_xlate_onecell,
97 };
98 
99 #ifdef CONFIG_OF
100 static int __init cpuintc_of_init(struct device_node *of_node,
101 				struct device_node *parent)
102 {
103 	cpuintc_handle = of_node_to_fwnode(of_node);
104 
105 	irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
106 				&loongarch_cpu_intc_irq_domain_ops, NULL);
107 	if (!irq_domain)
108 		panic("Failed to add irqdomain for loongarch CPU");
109 
110 	set_handle_irq(&handle_cpu_irq);
111 
112 	return 0;
113 }
114 IRQCHIP_DECLARE(cpu_intc, "loongson,cpu-interrupt-controller", cpuintc_of_init);
115 #endif
116 
117 static int __init liointc_parse_madt(union acpi_subtable_headers *header,
118 					const unsigned long end)
119 {
120 	struct acpi_madt_lio_pic *liointc_entry = (struct acpi_madt_lio_pic *)header;
121 
122 	return liointc_acpi_init(irq_domain, liointc_entry);
123 }
124 
125 static int __init eiointc_parse_madt(union acpi_subtable_headers *header,
126 					const unsigned long end)
127 {
128 	struct acpi_madt_eio_pic *eiointc_entry = (struct acpi_madt_eio_pic *)header;
129 
130 	return eiointc_acpi_init(irq_domain, eiointc_entry);
131 }
132 
133 static int __init acpi_cascade_irqdomain_init(void)
134 {
135 	int r;
136 
137 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_LIO_PIC, liointc_parse_madt, 0);
138 	if (r < 0)
139 		return r;
140 
141 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_EIO_PIC, eiointc_parse_madt, 0);
142 	if (r < 0)
143 		return r;
144 
145 	if (cpu_has_avecint)
146 		r = avecintc_acpi_init(irq_domain);
147 
148 	return r;
149 }
150 
151 static int __init cpuintc_acpi_init(union acpi_subtable_headers *header,
152 				   const unsigned long end)
153 {
154 	int ret;
155 
156 	if (irq_domain)
157 		return 0;
158 
159 	/* Mask interrupts. */
160 	clear_csr_ecfg(ECFG0_IM);
161 	clear_csr_estat(ESTATF_IP);
162 
163 	cpuintc_handle = irq_domain_alloc_named_fwnode("CPUINTC");
164 	irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
165 					&loongarch_cpu_intc_irq_domain_ops, NULL);
166 
167 	if (!irq_domain)
168 		panic("Failed to add irqdomain for LoongArch CPU");
169 
170 	set_handle_irq(&handle_cpu_irq);
171 	acpi_set_irq_model(ACPI_IRQ_MODEL_LPIC, lpic_get_gsi_domain_id);
172 	acpi_set_gsi_to_irq_fallback(lpic_gsi_to_irq);
173 	ret = acpi_cascade_irqdomain_init();
174 
175 	return ret;
176 }
177 
178 IRQCHIP_ACPI_DECLARE(cpuintc_v1, ACPI_MADT_TYPE_CORE_PIC,
179 		NULL, ACPI_MADT_CORE_PIC_VERSION_V1, cpuintc_acpi_init);
180