xref: /openbmc/linux/arch/x86/kernel/irqinit.c (revision 8a26af30)
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 	const char *name = chip->name;
74 	int i;
75 
76 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
77 	init_bsp_APIC();
78 #endif
79 	legacy_pic->init(0);
80 
81 	for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
82 		irq_set_chip_and_handler_name(i, chip, handle_level_irq, name);
83 }
84 
85 void __init init_IRQ(void)
86 {
87 	int i;
88 
89 	/*
90 	 * We probably need a better place for this, but it works for
91 	 * now ...
92 	 */
93 	x86_add_irq_domains();
94 
95 	/*
96 	 * On cpu 0, Assign IRQ0_VECTOR..IRQ15_VECTOR's to IRQ 0..15.
97 	 * If these IRQ's are handled by legacy interrupt-controllers like PIC,
98 	 * then this configuration will likely be static after the boot. If
99 	 * these IRQ's are handled by more mordern controllers like IO-APIC,
100 	 * then this vector space can be freed and re-used dynamically as the
101 	 * irq's migrate etc.
102 	 */
103 	for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
104 		per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i;
105 
106 	x86_init.irqs.intr_init();
107 }
108 
109 /*
110  * Setup the vector to irq mappings.
111  */
112 void setup_vector_irq(int cpu)
113 {
114 #ifndef CONFIG_X86_IO_APIC
115 	int irq;
116 
117 	/*
118 	 * On most of the platforms, legacy PIC delivers the interrupts on the
119 	 * boot cpu. But there are certain platforms where PIC interrupts are
120 	 * delivered to multiple cpu's. If the legacy IRQ is handled by the
121 	 * legacy PIC, for the new cpu that is coming online, setup the static
122 	 * legacy vector to irq mapping:
123 	 */
124 	for (irq = 0; irq < legacy_pic->nr_legacy_irqs; irq++)
125 		per_cpu(vector_irq, cpu)[IRQ0_VECTOR + irq] = irq;
126 #endif
127 
128 	__setup_vector_irq(cpu);
129 }
130 
131 static void __init smp_intr_init(void)
132 {
133 #ifdef CONFIG_SMP
134 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
135 	/*
136 	 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
137 	 * IPI, driven by wakeup.
138 	 */
139 	alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
140 
141 	/* IPI for generic function call */
142 	alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
143 
144 	/* IPI for generic single function call */
145 	alloc_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,
146 			call_function_single_interrupt);
147 
148 	/* Low priority IPI to cleanup after moving an irq */
149 	set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
150 	set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
151 
152 	/* IPI used for rebooting/stopping */
153 	alloc_intr_gate(REBOOT_VECTOR, reboot_interrupt);
154 #endif
155 #endif /* CONFIG_SMP */
156 }
157 
158 static void __init apic_intr_init(void)
159 {
160 	smp_intr_init();
161 
162 #ifdef CONFIG_X86_THERMAL_VECTOR
163 	alloc_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
164 #endif
165 #ifdef CONFIG_X86_MCE_THRESHOLD
166 	alloc_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
167 #endif
168 
169 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
170 	/* self generated IPI for local APIC timer */
171 	alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
172 
173 	/* IPI for X86 platform specific use */
174 	alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi);
175 #ifdef CONFIG_HAVE_KVM
176 	/* IPI for KVM to deliver posted interrupt */
177 	alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi);
178 #endif
179 
180 	/* IPI vectors for APIC spurious and error interrupts */
181 	alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
182 	alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
183 
184 	/* IRQ work interrupts: */
185 # ifdef CONFIG_IRQ_WORK
186 	alloc_intr_gate(IRQ_WORK_VECTOR, irq_work_interrupt);
187 # endif
188 
189 #endif
190 }
191 
192 void __init native_init_IRQ(void)
193 {
194 	int i;
195 
196 	/* Execute any quirks before the call gates are initialised: */
197 	x86_init.irqs.pre_vector_init();
198 
199 	apic_intr_init();
200 
201 	/*
202 	 * Cover the whole vector space, no vector can escape
203 	 * us. (some of these will be overridden and become
204 	 * 'special' SMP interrupts)
205 	 */
206 	i = FIRST_EXTERNAL_VECTOR;
207 	for_each_clear_bit_from(i, used_vectors, NR_VECTORS) {
208 		/* IA32_SYSCALL_VECTOR could be used in trap_init already. */
209 		set_intr_gate(i, interrupt[i - FIRST_EXTERNAL_VECTOR]);
210 	}
211 
212 	if (!acpi_ioapic && !of_ioapic)
213 		setup_irq(2, &irq2);
214 
215 #ifdef CONFIG_X86_32
216 	irq_ctx_init(smp_processor_id());
217 #endif
218 }
219