xref: /openbmc/linux/arch/x86/kernel/irqinit.c (revision 4f3db074)
1 #include <linux/linkage.h>
2 #include <linux/errno.h>
3 #include <linux/signal.h>
4 #include <linux/sched.h>
5 #include <linux/ioport.h>
6 #include <linux/interrupt.h>
7 #include <linux/timex.h>
8 #include <linux/random.h>
9 #include <linux/kprobes.h>
10 #include <linux/init.h>
11 #include <linux/kernel_stat.h>
12 #include <linux/device.h>
13 #include <linux/bitops.h>
14 #include <linux/acpi.h>
15 #include <linux/io.h>
16 #include <linux/delay.h>
17 
18 #include <linux/atomic.h>
19 #include <asm/timer.h>
20 #include <asm/hw_irq.h>
21 #include <asm/pgtable.h>
22 #include <asm/desc.h>
23 #include <asm/apic.h>
24 #include <asm/setup.h>
25 #include <asm/i8259.h>
26 #include <asm/traps.h>
27 #include <asm/prom.h>
28 
29 /*
30  * ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
31  * (these are usually mapped to vectors 0x30-0x3f)
32  */
33 
34 /*
35  * The IO-APIC gives us many more interrupt sources. Most of these
36  * are unused but an SMP system is supposed to have enough memory ...
37  * sometimes (mostly wrt. hw bugs) we get corrupted vectors all
38  * across the spectrum, so we really want to be prepared to get all
39  * of these. Plus, more powerful systems might have more than 64
40  * IO-APIC registers.
41  *
42  * (these are usually mapped into the 0x30-0xff vector range)
43  */
44 
45 /*
46  * IRQ2 is cascade interrupt to second interrupt controller
47  */
48 static struct irqaction irq2 = {
49 	.handler = no_action,
50 	.name = "cascade",
51 	.flags = IRQF_NO_THREAD,
52 };
53 
54 DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
55 	[0 ... NR_VECTORS - 1] = VECTOR_UNDEFINED,
56 };
57 
58 int vector_used_by_percpu_irq(unsigned int vector)
59 {
60 	int cpu;
61 
62 	for_each_online_cpu(cpu) {
63 		if (per_cpu(vector_irq, cpu)[vector] > VECTOR_UNDEFINED)
64 			return 1;
65 	}
66 
67 	return 0;
68 }
69 
70 void __init init_ISA_irqs(void)
71 {
72 	struct irq_chip *chip = legacy_pic->chip;
73 	int i;
74 
75 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
76 	init_bsp_APIC();
77 #endif
78 	legacy_pic->init(0);
79 
80 	for (i = 0; i < nr_legacy_irqs(); i++)
81 		irq_set_chip_and_handler(i, chip, handle_level_irq);
82 }
83 
84 void __init init_IRQ(void)
85 {
86 	int i;
87 
88 	/*
89 	 * On cpu 0, Assign IRQ0_VECTOR..IRQ15_VECTOR's to IRQ 0..15.
90 	 * If these IRQ's are handled by legacy interrupt-controllers like PIC,
91 	 * then this configuration will likely be static after the boot. If
92 	 * these IRQ's are handled by more mordern controllers like IO-APIC,
93 	 * then this vector space can be freed and re-used dynamically as the
94 	 * irq's migrate etc.
95 	 */
96 	for (i = 0; i < nr_legacy_irqs(); i++)
97 		per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i;
98 
99 	x86_init.irqs.intr_init();
100 }
101 
102 static void __init smp_intr_init(void)
103 {
104 #ifdef CONFIG_SMP
105 	/*
106 	 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
107 	 * IPI, driven by wakeup.
108 	 */
109 	alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
110 
111 	/* IPI for generic function call */
112 	alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
113 
114 	/* IPI for generic single function call */
115 	alloc_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,
116 			call_function_single_interrupt);
117 
118 	/* Low priority IPI to cleanup after moving an irq */
119 	set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
120 	set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
121 
122 	/* IPI used for rebooting/stopping */
123 	alloc_intr_gate(REBOOT_VECTOR, reboot_interrupt);
124 #endif /* CONFIG_SMP */
125 }
126 
127 static void __init apic_intr_init(void)
128 {
129 	smp_intr_init();
130 
131 #ifdef CONFIG_X86_THERMAL_VECTOR
132 	alloc_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
133 #endif
134 #ifdef CONFIG_X86_MCE_THRESHOLD
135 	alloc_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
136 #endif
137 
138 #ifdef CONFIG_X86_LOCAL_APIC
139 	/* self generated IPI for local APIC timer */
140 	alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
141 
142 	/* IPI for X86 platform specific use */
143 	alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi);
144 #ifdef CONFIG_HAVE_KVM
145 	/* IPI for KVM to deliver posted interrupt */
146 	alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi);
147 #endif
148 
149 	/* IPI vectors for APIC spurious and error interrupts */
150 	alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
151 	alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
152 
153 	/* IRQ work interrupts: */
154 # ifdef CONFIG_IRQ_WORK
155 	alloc_intr_gate(IRQ_WORK_VECTOR, irq_work_interrupt);
156 # endif
157 
158 #endif
159 }
160 
161 void __init native_init_IRQ(void)
162 {
163 	int i;
164 
165 	/* Execute any quirks before the call gates are initialised: */
166 	x86_init.irqs.pre_vector_init();
167 
168 	apic_intr_init();
169 
170 	/*
171 	 * Cover the whole vector space, no vector can escape
172 	 * us. (some of these will be overridden and become
173 	 * 'special' SMP interrupts)
174 	 */
175 	i = FIRST_EXTERNAL_VECTOR;
176 #ifndef CONFIG_X86_LOCAL_APIC
177 #define first_system_vector NR_VECTORS
178 #endif
179 	for_each_clear_bit_from(i, used_vectors, first_system_vector) {
180 		/* IA32_SYSCALL_VECTOR could be used in trap_init already. */
181 		set_intr_gate(i, irq_entries_start +
182 				8 * (i - FIRST_EXTERNAL_VECTOR));
183 	}
184 #ifdef CONFIG_X86_LOCAL_APIC
185 	for_each_clear_bit_from(i, used_vectors, NR_VECTORS)
186 		set_intr_gate(i, spurious_interrupt);
187 #endif
188 
189 	if (!acpi_ioapic && !of_ioapic && nr_legacy_irqs())
190 		setup_irq(2, &irq2);
191 
192 #ifdef CONFIG_X86_32
193 	irq_ctx_init(smp_processor_id());
194 #endif
195 }
196