xref: /openbmc/linux/arch/xtensa/kernel/irq.c (revision ae213c44)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/arch/xtensa/kernel/irq.c
4  *
5  * Xtensa built-in interrupt controller and some generic functions copied
6  * from i386.
7  *
8  * Copyright (C) 2002 - 2013 Tensilica, Inc.
9  * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
10  *
11  *
12  * Chris Zankel <chris@zankel.net>
13  * Kevin Chea
14  *
15  */
16 
17 #include <linux/module.h>
18 #include <linux/seq_file.h>
19 #include <linux/interrupt.h>
20 #include <linux/irq.h>
21 #include <linux/kernel_stat.h>
22 #include <linux/irqchip.h>
23 #include <linux/irqchip/xtensa-mx.h>
24 #include <linux/irqchip/xtensa-pic.h>
25 #include <linux/irqdomain.h>
26 #include <linux/of.h>
27 
28 #include <asm/mxregs.h>
29 #include <linux/uaccess.h>
30 #include <asm/platform.h>
31 
32 DECLARE_PER_CPU(unsigned long, nmi_count);
33 
34 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
35 {
36 	int irq = irq_find_mapping(NULL, hwirq);
37 
38 #ifdef CONFIG_DEBUG_STACKOVERFLOW
39 	/* Debugging check for stack overflow: is there less than 1KB free? */
40 	{
41 		unsigned long sp;
42 
43 		__asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
44 		sp &= THREAD_SIZE - 1;
45 
46 		if (unlikely(sp < (sizeof(thread_info) + 1024)))
47 			printk("Stack overflow in do_IRQ: %ld\n",
48 			       sp - sizeof(struct thread_info));
49 	}
50 #endif
51 	generic_handle_irq(irq);
52 }
53 
54 int arch_show_interrupts(struct seq_file *p, int prec)
55 {
56 	unsigned cpu __maybe_unused;
57 #ifdef CONFIG_SMP
58 	show_ipi_list(p, prec);
59 #endif
60 #if XTENSA_FAKE_NMI
61 	seq_printf(p, "%*s:", prec, "NMI");
62 	for_each_online_cpu(cpu)
63 		seq_printf(p, " %10lu", per_cpu(nmi_count, cpu));
64 	seq_puts(p, "   Non-maskable interrupts\n");
65 #endif
66 	return 0;
67 }
68 
69 int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize,
70 		unsigned long int_irq, unsigned long ext_irq,
71 		unsigned long *out_hwirq, unsigned int *out_type)
72 {
73 	if (WARN_ON(intsize < 1 || intsize > 2))
74 		return -EINVAL;
75 	if (intsize == 2 && intspec[1] == 1) {
76 		int_irq = xtensa_map_ext_irq(ext_irq);
77 		if (int_irq < XCHAL_NUM_INTERRUPTS)
78 			*out_hwirq = int_irq;
79 		else
80 			return -EINVAL;
81 	} else {
82 		*out_hwirq = int_irq;
83 	}
84 	*out_type = IRQ_TYPE_NONE;
85 	return 0;
86 }
87 
88 int xtensa_irq_map(struct irq_domain *d, unsigned int irq,
89 		irq_hw_number_t hw)
90 {
91 	struct irq_chip *irq_chip = d->host_data;
92 	u32 mask = 1 << hw;
93 
94 	if (mask & XCHAL_INTTYPE_MASK_SOFTWARE) {
95 		irq_set_chip_and_handler_name(irq, irq_chip,
96 				handle_simple_irq, "level");
97 		irq_set_status_flags(irq, IRQ_LEVEL);
98 	} else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE) {
99 		irq_set_chip_and_handler_name(irq, irq_chip,
100 				handle_edge_irq, "edge");
101 		irq_clear_status_flags(irq, IRQ_LEVEL);
102 	} else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL) {
103 		irq_set_chip_and_handler_name(irq, irq_chip,
104 				handle_level_irq, "level");
105 		irq_set_status_flags(irq, IRQ_LEVEL);
106 	} else if (mask & XCHAL_INTTYPE_MASK_TIMER) {
107 		irq_set_chip_and_handler_name(irq, irq_chip,
108 				handle_percpu_irq, "timer");
109 		irq_clear_status_flags(irq, IRQ_LEVEL);
110 #ifdef XCHAL_INTTYPE_MASK_PROFILING
111 	} else if (mask & XCHAL_INTTYPE_MASK_PROFILING) {
112 		irq_set_chip_and_handler_name(irq, irq_chip,
113 				handle_percpu_irq, "profiling");
114 		irq_set_status_flags(irq, IRQ_LEVEL);
115 #endif
116 	} else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */
117 		/* XCHAL_INTTYPE_MASK_NMI */
118 		irq_set_chip_and_handler_name(irq, irq_chip,
119 				handle_level_irq, "level");
120 		irq_set_status_flags(irq, IRQ_LEVEL);
121 	}
122 	return 0;
123 }
124 
125 unsigned xtensa_map_ext_irq(unsigned ext_irq)
126 {
127 	unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE |
128 		XCHAL_INTTYPE_MASK_EXTERN_LEVEL;
129 	unsigned i;
130 
131 	for (i = 0; mask; ++i, mask >>= 1) {
132 		if ((mask & 1) && ext_irq-- == 0)
133 			return i;
134 	}
135 	return XCHAL_NUM_INTERRUPTS;
136 }
137 
138 unsigned xtensa_get_ext_irq_no(unsigned irq)
139 {
140 	unsigned mask = (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
141 		XCHAL_INTTYPE_MASK_EXTERN_LEVEL) &
142 		((1u << irq) - 1);
143 	return hweight32(mask);
144 }
145 
146 void __init init_IRQ(void)
147 {
148 #ifdef CONFIG_OF
149 	irqchip_init();
150 #else
151 #ifdef CONFIG_HAVE_SMP
152 	xtensa_mx_init_legacy(NULL);
153 #else
154 	xtensa_pic_init_legacy(NULL);
155 #endif
156 #endif
157 
158 #ifdef CONFIG_SMP
159 	ipi_init();
160 #endif
161 }
162 
163 #ifdef CONFIG_HOTPLUG_CPU
164 /*
165  * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
166  * the affinity settings do not allow other CPUs, force them onto any
167  * available CPU.
168  */
169 void migrate_irqs(void)
170 {
171 	unsigned int i, cpu = smp_processor_id();
172 
173 	for_each_active_irq(i) {
174 		struct irq_data *data = irq_get_irq_data(i);
175 		struct cpumask *mask;
176 		unsigned int newcpu;
177 
178 		if (irqd_is_per_cpu(data))
179 			continue;
180 
181 		mask = irq_data_get_affinity_mask(data);
182 		if (!cpumask_test_cpu(cpu, mask))
183 			continue;
184 
185 		newcpu = cpumask_any_and(mask, cpu_online_mask);
186 
187 		if (newcpu >= nr_cpu_ids) {
188 			pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
189 					    i, cpu);
190 
191 			cpumask_setall(mask);
192 		}
193 		irq_set_affinity(i, mask);
194 	}
195 }
196 #endif /* CONFIG_HOTPLUG_CPU */
197