xref: /openbmc/linux/arch/xtensa/kernel/irq.c (revision c4e78957)
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 #ifdef CONFIG_DEBUG_STACKOVERFLOW
37 	/* Debugging check for stack overflow: is there less than 1KB free? */
38 	{
39 		unsigned long sp = current_stack_pointer;
40 
41 		sp &= THREAD_SIZE - 1;
42 
43 		if (unlikely(sp < (sizeof(thread_info) + 1024)))
44 			printk("Stack overflow in do_IRQ: %ld\n",
45 			       sp - sizeof(struct thread_info));
46 	}
47 #endif
48 	generic_handle_domain_irq(NULL, hwirq);
49 }
50 
51 int arch_show_interrupts(struct seq_file *p, int prec)
52 {
53 	unsigned cpu __maybe_unused;
54 #ifdef CONFIG_SMP
55 	show_ipi_list(p, prec);
56 #endif
57 #if XTENSA_FAKE_NMI
58 	seq_printf(p, "%*s:", prec, "NMI");
59 	for_each_online_cpu(cpu)
60 		seq_printf(p, " %10lu", per_cpu(nmi_count, cpu));
61 	seq_puts(p, "   Non-maskable interrupts\n");
62 #endif
63 	return 0;
64 }
65 
66 int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize,
67 		unsigned long int_irq, unsigned long ext_irq,
68 		unsigned long *out_hwirq, unsigned int *out_type)
69 {
70 	if (WARN_ON(intsize < 1 || intsize > 2))
71 		return -EINVAL;
72 	if (intsize == 2 && intspec[1] == 1) {
73 		int_irq = xtensa_map_ext_irq(ext_irq);
74 		if (int_irq < XCHAL_NUM_INTERRUPTS)
75 			*out_hwirq = int_irq;
76 		else
77 			return -EINVAL;
78 	} else {
79 		*out_hwirq = int_irq;
80 	}
81 	*out_type = IRQ_TYPE_NONE;
82 	return 0;
83 }
84 
85 int xtensa_irq_map(struct irq_domain *d, unsigned int irq,
86 		irq_hw_number_t hw)
87 {
88 	struct irq_chip *irq_chip = d->host_data;
89 	u32 mask = 1 << hw;
90 
91 	if (mask & XCHAL_INTTYPE_MASK_SOFTWARE) {
92 		irq_set_chip_and_handler_name(irq, irq_chip,
93 				handle_simple_irq, "level");
94 		irq_set_status_flags(irq, IRQ_LEVEL);
95 	} else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE) {
96 		irq_set_chip_and_handler_name(irq, irq_chip,
97 				handle_edge_irq, "edge");
98 		irq_clear_status_flags(irq, IRQ_LEVEL);
99 	} else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL) {
100 		irq_set_chip_and_handler_name(irq, irq_chip,
101 				handle_level_irq, "level");
102 		irq_set_status_flags(irq, IRQ_LEVEL);
103 	} else if (mask & XCHAL_INTTYPE_MASK_TIMER) {
104 		irq_set_chip_and_handler_name(irq, irq_chip,
105 				handle_percpu_irq, "timer");
106 		irq_clear_status_flags(irq, IRQ_LEVEL);
107 #ifdef XCHAL_INTTYPE_MASK_PROFILING
108 	} else if (mask & XCHAL_INTTYPE_MASK_PROFILING) {
109 		irq_set_chip_and_handler_name(irq, irq_chip,
110 				handle_percpu_irq, "profiling");
111 		irq_set_status_flags(irq, IRQ_LEVEL);
112 #endif
113 	} else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */
114 		/* XCHAL_INTTYPE_MASK_NMI */
115 		irq_set_chip_and_handler_name(irq, irq_chip,
116 				handle_level_irq, "level");
117 		irq_set_status_flags(irq, IRQ_LEVEL);
118 	}
119 	return 0;
120 }
121 
122 unsigned xtensa_map_ext_irq(unsigned ext_irq)
123 {
124 	unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE |
125 		XCHAL_INTTYPE_MASK_EXTERN_LEVEL;
126 	unsigned i;
127 
128 	for (i = 0; mask; ++i, mask >>= 1) {
129 		if ((mask & 1) && ext_irq-- == 0)
130 			return i;
131 	}
132 	return XCHAL_NUM_INTERRUPTS;
133 }
134 
135 unsigned xtensa_get_ext_irq_no(unsigned irq)
136 {
137 	unsigned mask = (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
138 		XCHAL_INTTYPE_MASK_EXTERN_LEVEL) &
139 		((1u << irq) - 1);
140 	return hweight32(mask);
141 }
142 
143 void __init init_IRQ(void)
144 {
145 #ifdef CONFIG_USE_OF
146 	irqchip_init();
147 #else
148 #ifdef CONFIG_HAVE_SMP
149 	xtensa_mx_init_legacy(NULL);
150 #else
151 	xtensa_pic_init_legacy(NULL);
152 #endif
153 #endif
154 
155 #ifdef CONFIG_SMP
156 	ipi_init();
157 #endif
158 }
159 
160 #ifdef CONFIG_HOTPLUG_CPU
161 /*
162  * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
163  * the affinity settings do not allow other CPUs, force them onto any
164  * available CPU.
165  */
166 void migrate_irqs(void)
167 {
168 	unsigned int i, cpu = smp_processor_id();
169 
170 	for_each_active_irq(i) {
171 		struct irq_data *data = irq_get_irq_data(i);
172 		struct cpumask *mask;
173 		unsigned int newcpu;
174 
175 		if (irqd_is_per_cpu(data))
176 			continue;
177 
178 		mask = irq_data_get_affinity_mask(data);
179 		if (!cpumask_test_cpu(cpu, mask))
180 			continue;
181 
182 		newcpu = cpumask_any_and(mask, cpu_online_mask);
183 
184 		if (newcpu >= nr_cpu_ids) {
185 			pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
186 					    i, cpu);
187 
188 			cpumask_setall(mask);
189 		}
190 		irq_set_affinity(i, mask);
191 	}
192 }
193 #endif /* CONFIG_HOTPLUG_CPU */
194