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 static struct irq_domain *irq_domain;
17 struct fwnode_handle *cpuintc_handle;
18
lpic_gsi_to_irq(u32 gsi)19 static 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
lpic_get_gsi_domain_id(u32 gsi)28 static 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
mask_loongarch_irq(struct irq_data * d)54 static void mask_loongarch_irq(struct irq_data *d)
55 {
56 clear_csr_ecfg(ECFGF(d->hwirq));
57 }
58
unmask_loongarch_irq(struct irq_data * d)59 static void unmask_loongarch_irq(struct irq_data *d)
60 {
61 set_csr_ecfg(ECFGF(d->hwirq));
62 }
63
64 static struct irq_chip cpu_irq_controller = {
65 .name = "CPUINTC",
66 .irq_mask = mask_loongarch_irq,
67 .irq_unmask = unmask_loongarch_irq,
68 };
69
handle_cpu_irq(struct pt_regs * regs)70 static 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
loongarch_cpu_intc_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)81 static 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
90 static 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
liointc_parse_madt(union acpi_subtable_headers * header,const unsigned long end)95 static int __init liointc_parse_madt(union acpi_subtable_headers *header,
96 const unsigned long end)
97 {
98 struct acpi_madt_lio_pic *liointc_entry = (struct acpi_madt_lio_pic *)header;
99
100 return liointc_acpi_init(irq_domain, liointc_entry);
101 }
102
eiointc_parse_madt(union acpi_subtable_headers * header,const unsigned long end)103 static int __init eiointc_parse_madt(union acpi_subtable_headers *header,
104 const unsigned long end)
105 {
106 struct acpi_madt_eio_pic *eiointc_entry = (struct acpi_madt_eio_pic *)header;
107
108 return eiointc_acpi_init(irq_domain, eiointc_entry);
109 }
110
acpi_cascade_irqdomain_init(void)111 static int __init acpi_cascade_irqdomain_init(void)
112 {
113 int r;
114
115 r = acpi_table_parse_madt(ACPI_MADT_TYPE_LIO_PIC, liointc_parse_madt, 0);
116 if (r < 0)
117 return r;
118
119 r = acpi_table_parse_madt(ACPI_MADT_TYPE_EIO_PIC, eiointc_parse_madt, 0);
120 if (r < 0)
121 return r;
122
123 return 0;
124 }
125
cpuintc_acpi_init(union acpi_subtable_headers * header,const unsigned long end)126 static int __init cpuintc_acpi_init(union acpi_subtable_headers *header,
127 const unsigned long end)
128 {
129 int ret;
130
131 if (irq_domain)
132 return 0;
133
134 /* Mask interrupts. */
135 clear_csr_ecfg(ECFG0_IM);
136 clear_csr_estat(ESTATF_IP);
137
138 cpuintc_handle = irq_domain_alloc_named_fwnode("CPUINTC");
139 irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
140 &loongarch_cpu_intc_irq_domain_ops, NULL);
141
142 if (!irq_domain)
143 panic("Failed to add irqdomain for LoongArch CPU");
144
145 set_handle_irq(&handle_cpu_irq);
146 acpi_set_irq_model(ACPI_IRQ_MODEL_LPIC, lpic_get_gsi_domain_id);
147 acpi_set_gsi_to_irq_fallback(lpic_gsi_to_irq);
148 ret = acpi_cascade_irqdomain_init();
149
150 return ret;
151 }
152
153 IRQCHIP_ACPI_DECLARE(cpuintc_v1, ACPI_MADT_TYPE_CORE_PIC,
154 NULL, ACPI_MADT_CORE_PIC_VERSION_V1, cpuintc_acpi_init);
155