2 * arch/ppc/kernel/irq.c
4 * Derived from arch/i386/kernel/irq.c
5 * Copyright (C) 1992 Linus Torvalds
6 * Adapted from arch/i386 by Gary Thomas
7 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
8 * Updated and modified by Cort Dougan (cort@cs.nmt.edu)
9 * Copyright (C) 1996 Cort Dougan
10 * Adapted for Power Macintosh by Paul Mackerras
11 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
12 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
19 * This file contains the code used by various IRQ handling routines:
20 * asking for different IRQ's should be done through these routines
21 * instead of just grabbing them. Thus setups with different IRQ numbers
22 * shouldn't result in any weird surprises, and installing new handlers
26 #include <linux/errno.h>
27 #include <linux/module.h>
28 #include <linux/threads.h>
29 #include <linux/kernel_stat.h>
30 #include <linux/signal.h>
31 #include <linux/sched.h>
32 #include <linux/ioport.h>
33 #include <linux/interrupt.h>
34 #include <linux/timex.h>
35 #include <linux/config.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/pci.h>
39 #include <linux/delay.h>
40 #include <linux/irq.h>
41 #include <linux/proc_fs.h>
42 #include <linux/random.h>
43 #include <linux/kallsyms.h>
44 #include <linux/profile.h>
45 #include <linux/bitops.h>
47 #include <asm/uaccess.h>
48 #include <asm/system.h>
50 #include <asm/pgtable.h>
52 #include <asm/cache.h>
54 #include <asm/ptrace.h>
55 #include <asm/iSeries/LparData.h>
56 #include <asm/machdep.h>
60 extern void iSeries_smp_message_recv( struct pt_regs * );
63 extern irq_desc_t irq_desc[NR_IRQS];
65 int distribute_irqs = 1;
66 int __irq_offset_value;
67 int ppc_spurious_interrupts;
68 unsigned long lpevent_count;
69 u64 ppc64_interrupt_controller;
71 int show_interrupts(struct seq_file *p, void *v)
73 int i = *(loff_t *) v, j;
74 struct irqaction * action;
80 for (j=0; j<NR_CPUS; j++) {
82 seq_printf(p, "CPU%d ",j);
88 desc = get_irq_desc(i);
89 spin_lock_irqsave(&desc->lock, flags);
90 action = desc->action;
91 if (!action || !action->handler)
93 seq_printf(p, "%3d: ", i);
95 for (j = 0; j < NR_CPUS; j++) {
97 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
100 seq_printf(p, "%10u ", kstat_irqs(i));
101 #endif /* CONFIG_SMP */
103 seq_printf(p, " %s ", desc->handler->typename );
105 seq_printf(p, " None ");
106 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge ");
107 seq_printf(p, " %s",action->name);
108 for (action=action->next; action; action = action->next)
109 seq_printf(p, ", %s", action->name);
112 spin_unlock_irqrestore(&desc->lock, flags);
113 } else if (i == NR_IRQS)
114 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
118 extern int noirqdebug;
121 * Eventually, this should take an array of interrupts and an array size
122 * so it can dispatch multiple interrupts.
124 void ppc_irq_dispatch_handler(struct pt_regs *regs, int irq)
127 struct irqaction *action;
128 int cpu = smp_processor_id();
129 irq_desc_t *desc = get_irq_desc(irq);
130 irqreturn_t action_ret;
131 #ifdef CONFIG_IRQSTACKS
132 struct thread_info *curtp, *irqtp;
135 kstat_cpu(cpu).irqs[irq]++;
137 if (desc->status & IRQ_PER_CPU) {
138 /* no locking required for CPU-local interrupts: */
140 action_ret = handle_IRQ_event(irq, regs, desc->action);
141 desc->handler->end(irq);
145 spin_lock(&desc->lock);
148 REPLAY is when Linux resends an IRQ that was dropped earlier
149 WAITING is used by probe to mark irqs that are being tested
151 status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
152 status |= IRQ_PENDING; /* we _want_ to handle it */
155 * If the IRQ is disabled for whatever reason, we cannot
156 * use the action we have.
159 if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
160 action = desc->action;
161 if (!action || !action->handler) {
162 ppc_spurious_interrupts++;
163 printk(KERN_DEBUG "Unhandled interrupt %x, disabled\n", irq);
164 /* We can't call disable_irq here, it would deadlock */
167 desc->status |= IRQ_DISABLED;
168 /* This is not a real spurrious interrupt, we
169 * have to eoi it, so we jump to out
174 status &= ~IRQ_PENDING; /* we commit to handling */
175 status |= IRQ_INPROGRESS; /* we are handling it */
177 desc->status = status;
180 * If there is no IRQ handler or it was disabled, exit early.
181 Since we set PENDING, if another processor is handling
182 a different instance of this same irq, the other processor
183 will take care of it.
185 if (unlikely(!action))
189 * Edge triggered interrupts need to remember
191 * This applies to any hw interrupts that allow a second
192 * instance of the same irq to arrive while we are in do_IRQ
193 * or in the handler. But the code here only handles the _second_
194 * instance of the irq, not the third or fourth. So it is mostly
195 * useful for irq hardware that does not mask cleanly in an
199 spin_unlock(&desc->lock);
201 #ifdef CONFIG_IRQSTACKS
202 /* Switch to the irq stack to handle this */
203 curtp = current_thread_info();
204 irqtp = hardirq_ctx[smp_processor_id()];
205 if (curtp != irqtp) {
206 irqtp->task = curtp->task;
208 action_ret = call_handle_IRQ_event(irq, regs, action, irqtp);
211 set_bits(irqtp->flags, &curtp->flags);
214 action_ret = handle_IRQ_event(irq, regs, action);
216 spin_lock(&desc->lock);
218 note_interrupt(irq, desc, action_ret);
219 if (likely(!(desc->status & IRQ_PENDING)))
221 desc->status &= ~IRQ_PENDING;
224 desc->status &= ~IRQ_INPROGRESS;
226 * The ->end() handler has to deal with interrupts which got
227 * disabled while the handler was running.
230 if (desc->handler->end)
231 desc->handler->end(irq);
232 else if (desc->handler->enable)
233 desc->handler->enable(irq);
235 spin_unlock(&desc->lock);
238 #ifdef CONFIG_PPC_ISERIES
239 void do_IRQ(struct pt_regs *regs)
241 struct paca_struct *lpaca;
242 struct ItLpQueue *lpq;
246 #ifdef CONFIG_DEBUG_STACKOVERFLOW
247 /* Debugging check for stack overflow: is there less than 2KB free? */
251 sp = __get_SP() & (THREAD_SIZE-1);
253 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
254 printk("do_IRQ: stack overflow: %ld\n",
255 sp - sizeof(struct thread_info));
263 if (lpaca->lppaca.int_dword.fields.ipi_cnt) {
264 lpaca->lppaca.int_dword.fields.ipi_cnt = 0;
265 iSeries_smp_message_recv(regs);
267 #endif /* CONFIG_SMP */
268 lpq = lpaca->lpqueue_ptr;
269 if (lpq && ItLpQueue_isLpIntPending(lpq))
270 lpevent_count += ItLpQueue_process(lpq, regs);
274 if (lpaca->lppaca.int_dword.fields.decr_int) {
275 lpaca->lppaca.int_dword.fields.decr_int = 0;
276 /* Signal a fake decrementer interrupt */
277 timer_interrupt(regs);
281 #else /* CONFIG_PPC_ISERIES */
283 void do_IRQ(struct pt_regs *regs)
289 #ifdef CONFIG_DEBUG_STACKOVERFLOW
290 /* Debugging check for stack overflow: is there less than 2KB free? */
294 sp = __get_SP() & (THREAD_SIZE-1);
296 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
297 printk("do_IRQ: stack overflow: %ld\n",
298 sp - sizeof(struct thread_info));
304 irq = ppc_md.get_irq(regs);
307 ppc_irq_dispatch_handler(regs, irq);
309 /* That's not SMP safe ... but who cares ? */
310 ppc_spurious_interrupts++;
314 #endif /* CONFIG_PPC_ISERIES */
316 void __init init_IRQ(void)
329 #ifndef CONFIG_PPC_ISERIES
331 * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
334 #define UNDEFINED_IRQ 0xffffffff
335 unsigned int virt_irq_to_real_map[NR_IRQS];
338 * Don't use virtual irqs 0, 1, 2 for devices.
339 * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
340 * and 2 is the XICS IPI interrupt.
341 * We limit virtual irqs to 17 less than NR_IRQS so that when we
342 * offset them by 16 (to reserve the first 16 for ISA interrupts)
343 * we don't end up with an interrupt number >= NR_IRQS.
345 #define MIN_VIRT_IRQ 3
346 #define MAX_VIRT_IRQ (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
347 #define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
353 for (i = 0; i < NR_IRQS; i++)
354 virt_irq_to_real_map[i] = UNDEFINED_IRQ;
357 /* Create a mapping for a real_irq if it doesn't already exist.
358 * Return the virtual irq as a convenience.
360 int virt_irq_create_mapping(unsigned int real_irq)
362 unsigned int virq, first_virq;
365 if (ppc64_interrupt_controller == IC_OPEN_PIC)
366 return real_irq; /* no mapping for openpic (for now) */
368 /* don't map interrupts < MIN_VIRT_IRQ */
369 if (real_irq < MIN_VIRT_IRQ) {
370 virt_irq_to_real_map[real_irq] = real_irq;
374 /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
376 if (virq > MAX_VIRT_IRQ)
377 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
379 /* search for this number or a free slot */
381 while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
382 if (virt_irq_to_real_map[virq] == real_irq)
384 if (++virq > MAX_VIRT_IRQ)
386 if (virq == first_virq)
387 goto nospace; /* oops, no free slots */
390 virt_irq_to_real_map[virq] = real_irq;
395 printk(KERN_CRIT "Interrupt table is full\n");
396 printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
397 "in your kernel sources and rebuild.\n", NR_IRQS);
404 * In most cases will get a hit on the very first slot checked in the
405 * virt_irq_to_real_map. Only when there are a large number of
406 * IRQs will this be expensive.
408 unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
411 unsigned int first_virq;
415 if (virq > MAX_VIRT_IRQ)
416 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
421 if (virt_irq_to_real_map[virq] == real_irq)
426 if (virq >= MAX_VIRT_IRQ)
429 } while (first_virq != virq);
435 #endif /* CONFIG_PPC_ISERIES */
437 #ifdef CONFIG_IRQSTACKS
438 struct thread_info *softirq_ctx[NR_CPUS];
439 struct thread_info *hardirq_ctx[NR_CPUS];
441 void irq_ctx_init(void)
443 struct thread_info *tp;
447 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
450 tp->preempt_count = SOFTIRQ_OFFSET;
452 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
455 tp->preempt_count = HARDIRQ_OFFSET;
459 void do_softirq(void)
462 struct thread_info *curtp, *irqtp;
467 local_irq_save(flags);
469 if (local_softirq_pending()) {
470 curtp = current_thread_info();
471 irqtp = softirq_ctx[smp_processor_id()];
472 irqtp->task = curtp->task;
473 call_do_softirq(irqtp);
477 local_irq_restore(flags);
479 EXPORT_SYMBOL(do_softirq);
481 #endif /* CONFIG_IRQSTACKS */
483 static int __init setup_noirqdistrib(char *str)
489 __setup("noirqdistrib", setup_noirqdistrib);