xref: /openbmc/linux/arch/loongarch/kernel/irq.c (revision dff03381)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4  */
5 #include <linux/kernel.h>
6 #include <linux/acpi.h>
7 #include <linux/atomic.h>
8 #include <linux/delay.h>
9 #include <linux/init.h>
10 #include <linux/interrupt.h>
11 #include <linux/irqchip.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/proc_fs.h>
14 #include <linux/mm.h>
15 #include <linux/sched.h>
16 #include <linux/seq_file.h>
17 #include <linux/kallsyms.h>
18 #include <linux/uaccess.h>
19 
20 #include <asm/irq.h>
21 #include <asm/loongson.h>
22 #include <asm/setup.h>
23 
24 DEFINE_PER_CPU(unsigned long, irq_stack);
25 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
26 EXPORT_PER_CPU_SYMBOL(irq_stat);
27 
28 struct acpi_vector_group pch_group[MAX_IO_PICS];
29 struct acpi_vector_group msi_group[MAX_IO_PICS];
30 /*
31  * 'what should we do if we get a hw irq event on an illegal vector'.
32  * each architecture has to answer this themselves.
33  */
34 void ack_bad_irq(unsigned int irq)
35 {
36 	pr_warn("Unexpected IRQ # %d\n", irq);
37 }
38 
39 atomic_t irq_err_count;
40 
41 asmlinkage void spurious_interrupt(void)
42 {
43 	atomic_inc(&irq_err_count);
44 }
45 
46 int arch_show_interrupts(struct seq_file *p, int prec)
47 {
48 #ifdef CONFIG_SMP
49 	show_ipi_list(p, prec);
50 #endif
51 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
52 	return 0;
53 }
54 
55 static int __init early_pci_mcfg_parse(struct acpi_table_header *header)
56 {
57 	struct acpi_table_mcfg *mcfg;
58 	struct acpi_mcfg_allocation *mptr;
59 	int i, n;
60 
61 	if (header->length < sizeof(struct acpi_table_mcfg))
62 		return -EINVAL;
63 
64 	n = (header->length - sizeof(struct acpi_table_mcfg)) /
65 					sizeof(struct acpi_mcfg_allocation);
66 	mcfg = (struct acpi_table_mcfg *)header;
67 	mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
68 
69 	for (i = 0; i < n; i++, mptr++) {
70 		msi_group[i].pci_segment = mptr->pci_segment;
71 		pch_group[i].node = msi_group[i].node = (mptr->address >> 44) & 0xf;
72 	}
73 
74 	return 0;
75 }
76 
77 static void __init init_vec_parent_group(void)
78 {
79 	int i;
80 
81 	for (i = 0; i < MAX_IO_PICS; i++) {
82 		msi_group[i].pci_segment = -1;
83 		msi_group[i].node = -1;
84 		pch_group[i].node = -1;
85 	}
86 
87 	acpi_table_parse(ACPI_SIG_MCFG, early_pci_mcfg_parse);
88 }
89 
90 static int __init get_ipi_irq(void)
91 {
92 	struct irq_domain *d = irq_find_matching_fwnode(cpuintc_handle, DOMAIN_BUS_ANY);
93 
94 	if (d)
95 		return irq_create_mapping(d, EXCCODE_IPI - EXCCODE_INT_START);
96 
97 	return -EINVAL;
98 }
99 
100 void __init init_IRQ(void)
101 {
102 	int i;
103 #ifdef CONFIG_SMP
104 	int r, ipi_irq;
105 	static int ipi_dummy_dev;
106 #endif
107 	unsigned int order = get_order(IRQ_STACK_SIZE);
108 	struct page *page;
109 
110 	clear_csr_ecfg(ECFG0_IM);
111 	clear_csr_estat(ESTATF_IP);
112 
113 	init_vec_parent_group();
114 	irqchip_init();
115 #ifdef CONFIG_SMP
116 	ipi_irq = get_ipi_irq();
117 	if (ipi_irq < 0)
118 		panic("IPI IRQ mapping failed\n");
119 	irq_set_percpu_devid(ipi_irq);
120 	r = request_percpu_irq(ipi_irq, loongson3_ipi_interrupt, "IPI", &ipi_dummy_dev);
121 	if (r < 0)
122 		panic("IPI IRQ request failed\n");
123 #endif
124 
125 	for (i = 0; i < NR_IRQS; i++)
126 		irq_set_noprobe(i);
127 
128 	for_each_possible_cpu(i) {
129 		page = alloc_pages_node(cpu_to_node(i), GFP_KERNEL, order);
130 
131 		per_cpu(irq_stack, i) = (unsigned long)page_address(page);
132 		pr_debug("CPU%d IRQ stack at 0x%lx - 0x%lx\n", i,
133 			per_cpu(irq_stack, i), per_cpu(irq_stack, i) + IRQ_STACK_SIZE);
134 	}
135 
136 	set_csr_ecfg(ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | ECFGF_IPI | ECFGF_PMC);
137 }
138