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x86: change FIRST_SYSTEM_VECTOR to a variable, fix
[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kernel / irq_32.c
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1da177e4 1/*
1da177e4
LT
2 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
3 *
4 * This file contains the lowest level x86-specific interrupt
5 * entry, irq-stacks and irq statistics code. All the remaining
6 * irq logic is done by the generic kernel/irq/ code and
7 * by the x86-specific irq controller code. (e.g. i8259.c and
8 * io_apic.c.)
9 */
10
1da177e4
LT
11#include <linux/module.h>
12#include <linux/seq_file.h>
13#include <linux/interrupt.h>
14#include <linux/kernel_stat.h>
f3705136
ZM
15#include <linux/notifier.h>
16#include <linux/cpu.h>
17#include <linux/delay.h>
1da177e4 18
e05d723f
TG
19#include <asm/apic.h>
20#include <asm/uaccess.h>
21
f34e3b61 22DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
1da177e4
LT
23EXPORT_PER_CPU_SYMBOL(irq_stat);
24
7c3576d2
JF
25DEFINE_PER_CPU(struct pt_regs *, irq_regs);
26EXPORT_PER_CPU_SYMBOL(irq_regs);
27
1da177e4
LT
28/*
29 * 'what should we do if we get a hw irq event on an illegal vector'.
30 * each architecture has to answer this themselves.
31 */
32void ack_bad_irq(unsigned int irq)
33{
e05d723f
TG
34 printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
35
36#ifdef CONFIG_X86_LOCAL_APIC
37 /*
38 * Currently unexpected vectors happen only on SMP and APIC.
39 * We _must_ ack these because every local APIC has only N
40 * irq slots per priority level, and a 'hanging, unacked' IRQ
41 * holds up an irq slot - in excessive cases (when multiple
42 * unexpected vectors occur) that might lock up the APIC
43 * completely.
44 * But only ack when the APIC is enabled -AK
45 */
46 if (cpu_has_apic)
47 ack_APIC_irq();
1da177e4 48#endif
e05d723f 49}
1da177e4
LT
50
51#ifdef CONFIG_4KSTACKS
52/*
53 * per-CPU IRQ handling contexts (thread information and stack)
54 */
55union irq_ctx {
56 struct thread_info tinfo;
57 u32 stack[THREAD_SIZE/sizeof(u32)];
58};
59
22722051
AM
60static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
61static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
1da177e4
LT
62#endif
63
64/*
65 * do_IRQ handles all normal device IRQ's (the special
66 * SMP cross-CPU interrupts have their own specific
67 * handlers).
68 */
75604d7f 69unsigned int do_IRQ(struct pt_regs *regs)
1da177e4 70{
7d12e780 71 struct pt_regs *old_regs;
19eadf98 72 /* high bit used in ret_from_ code */
65ea5b03 73 int irq = ~regs->orig_ax;
f5b9ed7a 74 struct irq_desc *desc = irq_desc + irq;
1da177e4
LT
75#ifdef CONFIG_4KSTACKS
76 union irq_ctx *curctx, *irqctx;
77 u32 *isp;
78#endif
79
a052b68b
AM
80 if (unlikely((unsigned)irq >= NR_IRQS)) {
81 printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
77bf90ed 82 __func__, irq);
a052b68b
AM
83 BUG();
84 }
85
7d12e780 86 old_regs = set_irq_regs(regs);
1da177e4
LT
87 irq_enter();
88#ifdef CONFIG_DEBUG_STACKOVERFLOW
89 /* Debugging check for stack overflow: is there less than 1KB free? */
90 {
65ea5b03 91 long sp;
1da177e4
LT
92
93 __asm__ __volatile__("andl %%esp,%0" :
65ea5b03
PA
94 "=r" (sp) : "0" (THREAD_SIZE - 1));
95 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
1da177e4 96 printk("do_IRQ: stack overflow: %ld\n",
65ea5b03 97 sp - sizeof(struct thread_info));
1da177e4
LT
98 dump_stack();
99 }
100 }
101#endif
102
103#ifdef CONFIG_4KSTACKS
104
105 curctx = (union irq_ctx *) current_thread_info();
106 irqctx = hardirq_ctx[smp_processor_id()];
107
108 /*
109 * this is where we switch to the IRQ stack. However, if we are
110 * already using the IRQ stack (because we interrupted a hardirq
111 * handler) we can't do that and just have to keep using the
112 * current stack (which is the irq stack already after all)
113 */
114 if (curctx != irqctx) {
65ea5b03 115 int arg1, arg2, bx;
1da177e4
LT
116
117 /* build the stack frame on the IRQ stack */
118 isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
119 irqctx->tinfo.task = curctx->tinfo.task;
120 irqctx->tinfo.previous_esp = current_stack_pointer;
121
a5d157e0
BS
122 /*
123 * Copy the softirq bits in preempt_count so that the
124 * softirq checks work in the hardirq context.
125 */
126 irqctx->tinfo.preempt_count =
91bf4602
AM
127 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
128 (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
a5d157e0 129
1da177e4 130 asm volatile(
65ea5b03
PA
131 " xchgl %%ebx,%%esp \n"
132 " call *%%edi \n"
133 " movl %%ebx,%%esp \n"
134 : "=a" (arg1), "=d" (arg2), "=b" (bx)
7d12e780 135 : "0" (irq), "1" (desc), "2" (isp),
f5b9ed7a 136 "D" (desc->handle_irq)
5065dbaf 137 : "memory", "cc", "ecx"
1da177e4
LT
138 );
139 } else
140#endif
7d12e780 141 desc->handle_irq(irq, desc);
1da177e4
LT
142
143 irq_exit();
7d12e780 144 set_irq_regs(old_regs);
1da177e4
LT
145 return 1;
146}
147
148#ifdef CONFIG_4KSTACKS
149
1da177e4 150static char softirq_stack[NR_CPUS * THREAD_SIZE]
09fce8a1 151 __attribute__((__section__(".bss.page_aligned")));
1da177e4
LT
152
153static char hardirq_stack[NR_CPUS * THREAD_SIZE]
09fce8a1 154 __attribute__((__section__(".bss.page_aligned")));
1da177e4
LT
155
156/*
157 * allocate per-cpu stacks for hardirq and for softirq processing
158 */
159void irq_ctx_init(int cpu)
160{
161 union irq_ctx *irqctx;
162
163 if (hardirq_ctx[cpu])
164 return;
165
166 irqctx = (union irq_ctx*) &hardirq_stack[cpu*THREAD_SIZE];
167 irqctx->tinfo.task = NULL;
168 irqctx->tinfo.exec_domain = NULL;
169 irqctx->tinfo.cpu = cpu;
170 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
171 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
172
173 hardirq_ctx[cpu] = irqctx;
174
175 irqctx = (union irq_ctx*) &softirq_stack[cpu*THREAD_SIZE];
176 irqctx->tinfo.task = NULL;
177 irqctx->tinfo.exec_domain = NULL;
178 irqctx->tinfo.cpu = cpu;
55f327fa 179 irqctx->tinfo.preempt_count = 0;
1da177e4
LT
180 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
181
182 softirq_ctx[cpu] = irqctx;
183
184 printk("CPU %u irqstacks, hard=%p soft=%p\n",
185 cpu,hardirq_ctx[cpu],softirq_ctx[cpu]);
186}
187
e1367daf
LS
188void irq_ctx_exit(int cpu)
189{
190 hardirq_ctx[cpu] = NULL;
191}
192
1da177e4
LT
193asmlinkage void do_softirq(void)
194{
195 unsigned long flags;
196 struct thread_info *curctx;
197 union irq_ctx *irqctx;
198 u32 *isp;
199
200 if (in_interrupt())
201 return;
202
203 local_irq_save(flags);
204
205 if (local_softirq_pending()) {
206 curctx = current_thread_info();
207 irqctx = softirq_ctx[smp_processor_id()];
208 irqctx->tinfo.task = curctx->task;
209 irqctx->tinfo.previous_esp = current_stack_pointer;
210
211 /* build the stack frame on the softirq stack */
212 isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
213
214 asm volatile(
215 " xchgl %%ebx,%%esp \n"
216 " call __do_softirq \n"
217 " movl %%ebx,%%esp \n"
218 : "=b"(isp)
219 : "0"(isp)
220 : "memory", "cc", "edx", "ecx", "eax"
221 );
55f327fa
IM
222 /*
223 * Shouldnt happen, we returned above if in_interrupt():
224 */
225 WARN_ON_ONCE(softirq_count());
1da177e4
LT
226 }
227
228 local_irq_restore(flags);
229}
1da177e4
LT
230#endif
231
232/*
233 * Interrupt statistics:
234 */
235
236atomic_t irq_err_count;
237
238/*
239 * /proc/interrupts printing:
240 */
241
242int show_interrupts(struct seq_file *p, void *v)
243{
244 int i = *(loff_t *) v, j;
245 struct irqaction * action;
246 unsigned long flags;
247
248 if (i == 0) {
249 seq_printf(p, " ");
9f40a72a 250 for_each_online_cpu(j)
bdbdaa79 251 seq_printf(p, "CPU%-8d",j);
1da177e4
LT
252 seq_putc(p, '\n');
253 }
254
255 if (i < NR_IRQS) {
072f5d82
JB
256 unsigned any_count = 0;
257
1da177e4 258 spin_lock_irqsave(&irq_desc[i].lock, flags);
072f5d82
JB
259#ifndef CONFIG_SMP
260 any_count = kstat_irqs(i);
261#else
262 for_each_online_cpu(j)
263 any_count |= kstat_cpu(j).irqs[i];
264#endif
1da177e4 265 action = irq_desc[i].action;
072f5d82 266 if (!action && !any_count)
1da177e4
LT
267 goto skip;
268 seq_printf(p, "%3d: ",i);
269#ifndef CONFIG_SMP
270 seq_printf(p, "%10u ", kstat_irqs(i));
271#else
9f40a72a 272 for_each_online_cpu(j)
f3705136 273 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
1da177e4 274#endif
f5b9ed7a 275 seq_printf(p, " %8s", irq_desc[i].chip->name);
a460e745 276 seq_printf(p, "-%-8s", irq_desc[i].name);
1da177e4 277
072f5d82
JB
278 if (action) {
279 seq_printf(p, " %s", action->name);
280 while ((action = action->next) != NULL)
281 seq_printf(p, ", %s", action->name);
282 }
1da177e4
LT
283
284 seq_putc(p, '\n');
285skip:
286 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
287 } else if (i == NR_IRQS) {
288 seq_printf(p, "NMI: ");
9f40a72a 289 for_each_online_cpu(j)
f3705136 290 seq_printf(p, "%10u ", nmi_count(j));
38e760a1 291 seq_printf(p, " Non-maskable interrupts\n");
1da177e4
LT
292#ifdef CONFIG_X86_LOCAL_APIC
293 seq_printf(p, "LOC: ");
9f40a72a 294 for_each_online_cpu(j)
f3705136
ZM
295 seq_printf(p, "%10u ",
296 per_cpu(irq_stat,j).apic_timer_irqs);
38e760a1 297 seq_printf(p, " Local timer interrupts\n");
1da177e4 298#endif
38e760a1
JK
299#ifdef CONFIG_SMP
300 seq_printf(p, "RES: ");
301 for_each_online_cpu(j)
302 seq_printf(p, "%10u ",
303 per_cpu(irq_stat,j).irq_resched_count);
304 seq_printf(p, " Rescheduling interrupts\n");
305 seq_printf(p, "CAL: ");
306 for_each_online_cpu(j)
307 seq_printf(p, "%10u ",
308 per_cpu(irq_stat,j).irq_call_count);
309 seq_printf(p, " function call interrupts\n");
310 seq_printf(p, "TLB: ");
311 for_each_online_cpu(j)
312 seq_printf(p, "%10u ",
313 per_cpu(irq_stat,j).irq_tlb_count);
314 seq_printf(p, " TLB shootdowns\n");
315#endif
316 seq_printf(p, "TRM: ");
317 for_each_online_cpu(j)
318 seq_printf(p, "%10u ",
319 per_cpu(irq_stat,j).irq_thermal_count);
320 seq_printf(p, " Thermal event interrupts\n");
321 seq_printf(p, "SPU: ");
322 for_each_online_cpu(j)
323 seq_printf(p, "%10u ",
324 per_cpu(irq_stat,j).irq_spurious_count);
325 seq_printf(p, " Spurious interrupts\n");
1da177e4
LT
326 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
327#if defined(CONFIG_X86_IO_APIC)
328 seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
329#endif
330 }
331 return 0;
332}
f3705136
ZM
333
334#ifdef CONFIG_HOTPLUG_CPU
335#include <mach_apic.h>
336
337void fixup_irqs(cpumask_t map)
338{
339 unsigned int irq;
340 static int warned;
341
342 for (irq = 0; irq < NR_IRQS; irq++) {
343 cpumask_t mask;
344 if (irq == 2)
345 continue;
346
a53da52f 347 cpus_and(mask, irq_desc[irq].affinity, map);
f3705136
ZM
348 if (any_online_cpu(mask) == NR_CPUS) {
349 printk("Breaking affinity for irq %i\n", irq);
350 mask = map;
351 }
d1bef4ed
IM
352 if (irq_desc[irq].chip->set_affinity)
353 irq_desc[irq].chip->set_affinity(irq, mask);
f3705136
ZM
354 else if (irq_desc[irq].action && !(warned++))
355 printk("Cannot set affinity for irq %i\n", irq);
356 }
357
358#if 0
359 barrier();
360 /* Ingo Molnar says: "after the IO-APIC masks have been redirected
361 [note the nop - the interrupt-enable boundary on x86 is two
362 instructions from sti] - to flush out pending hardirqs and
363 IPIs. After this point nothing is supposed to reach this CPU." */
364 __asm__ __volatile__("sti; nop; cli");
365 barrier();
366#else
367 /* That doesn't seem sufficient. Give it 1ms. */
368 local_irq_enable();
369 mdelay(1);
370 local_irq_disable();
371#endif
372}
373#endif
374