2 * Derived from arch/i386/kernel/irq.c
3 * Copyright (C) 1992 Linus Torvalds
4 * Adapted from arch/i386 by Gary Thomas
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 * Updated and modified by Cort Dougan <cort@fsmlabs.com>
7 * Copyright (C) 1996-2001 Cort Dougan
8 * Adapted for Power Macintosh by Paul Mackerras
9 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
16 * This file contains the code used by various IRQ handling routines:
17 * asking for different IRQ's should be done through these routines
18 * instead of just grabbing them. Thus setups with different IRQ numbers
19 * shouldn't result in any weird surprises, and installing new handlers
22 * The MPC8xx has an interrupt mask in the SIU. If a bit is set, the
23 * interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit
24 * mask register (of which only 16 are defined), hence the weird shifting
25 * and complement of the cached_irq_mask. I want to be able to stuff
26 * this right into the SIU SMASK register.
27 * Many of the prep/chrp functions are conditional compiled on CONFIG_PPC_8xx
28 * to reduce code space and undefined function references.
33 #include <linux/export.h>
34 #include <linux/threads.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/signal.h>
37 #include <linux/sched.h>
38 #include <linux/ptrace.h>
39 #include <linux/ioport.h>
40 #include <linux/interrupt.h>
41 #include <linux/timex.h>
42 #include <linux/init.h>
43 #include <linux/slab.h>
44 #include <linux/delay.h>
45 #include <linux/irq.h>
46 #include <linux/seq_file.h>
47 #include <linux/cpumask.h>
48 #include <linux/profile.h>
49 #include <linux/bitops.h>
50 #include <linux/list.h>
51 #include <linux/radix-tree.h>
52 #include <linux/mutex.h>
53 #include <linux/pci.h>
54 #include <linux/debugfs.h>
56 #include <linux/of_irq.h>
58 #include <linux/uaccess.h>
60 #include <asm/pgtable.h>
62 #include <asm/cache.h>
64 #include <asm/ptrace.h>
65 #include <asm/machdep.h>
68 #include <asm/livepatch.h>
69 #include <asm/asm-prototypes.h>
73 #include <asm/firmware.h>
74 #include <asm/lv1call.h>
76 #define CREATE_TRACE_POINTS
77 #include <asm/trace.h>
78 #include <asm/cpu_has_feature.h>
80 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
81 EXPORT_PER_CPU_SYMBOL(irq_stat);
83 int __irq_offset_value;
86 EXPORT_SYMBOL(__irq_offset_value);
87 atomic_t ppc_n_lost_interrupts;
90 extern int tau_initialized;
91 extern int tau_interrupts(int);
93 #endif /* CONFIG_PPC32 */
97 int distribute_irqs = 1;
99 static inline notrace unsigned long get_irq_happened(void)
101 unsigned long happened;
103 __asm__ __volatile__("lbz %0,%1(13)"
104 : "=r" (happened) : "i" (offsetof(struct paca_struct, irq_happened)));
109 static inline notrace void set_soft_enabled(unsigned long enable)
111 __asm__ __volatile__("stb %0,%1(13)"
112 : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
115 static inline notrace int decrementer_check_overflow(void)
117 u64 now = get_tb_or_rtc();
118 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
120 return now >= *next_tb;
123 /* This is called whenever we are re-enabling interrupts
124 * and returns either 0 (nothing to do) or 500/900/280/a00/e80 if
125 * there's an EE, DEC or DBELL to generate.
127 * This is called in two contexts: From arch_local_irq_restore()
128 * before soft-enabling interrupts, and from the exception exit
129 * path when returning from an interrupt from a soft-disabled to
130 * a soft enabled context. In both case we have interrupts hard
133 * We take care of only clearing the bits we handled in the
134 * PACA irq_happened field since we can only re-emit one at a
135 * time and we don't want to "lose" one.
137 notrace unsigned int __check_irq_replay(void)
140 * We use local_paca rather than get_paca() to avoid all
141 * the debug_smp_processor_id() business in this low level
144 unsigned char happened = local_paca->irq_happened;
146 if (happened & PACA_IRQ_HARD_DIS) {
147 /* Clear bit 0 which we wouldn't clear otherwise */
148 local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
151 * We may have missed a decrementer interrupt if hard disabled.
152 * Check the decrementer register in case we had a rollover
153 * while hard disabled.
155 if (!(happened & PACA_IRQ_DEC)) {
156 if (decrementer_check_overflow()) {
157 local_paca->irq_happened |= PACA_IRQ_DEC;
158 happened |= PACA_IRQ_DEC;
164 * Force the delivery of pending soft-disabled interrupts on PS3.
165 * Any HV call will have this side effect.
167 if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
169 lv1_get_version_info(&tmp, &tmp2);
173 * Check if an hypervisor Maintenance interrupt happened.
174 * This is a higher priority interrupt than the others, so
177 if (happened & PACA_IRQ_HMI) {
178 local_paca->irq_happened &= ~PACA_IRQ_HMI;
182 if (happened & PACA_IRQ_DEC) {
183 local_paca->irq_happened &= ~PACA_IRQ_DEC;
187 if (happened & PACA_IRQ_EE) {
188 local_paca->irq_happened &= ~PACA_IRQ_EE;
192 #ifdef CONFIG_PPC_BOOK3E
194 * Check if an EPR external interrupt happened this bit is typically
195 * set if we need to handle another "edge" interrupt from within the
196 * MPIC "EPR" handler.
198 if (happened & PACA_IRQ_EE_EDGE) {
199 local_paca->irq_happened &= ~PACA_IRQ_EE_EDGE;
203 if (happened & PACA_IRQ_DBELL) {
204 local_paca->irq_happened &= ~PACA_IRQ_DBELL;
208 if (happened & PACA_IRQ_DBELL) {
209 local_paca->irq_happened &= ~PACA_IRQ_DBELL;
212 #endif /* CONFIG_PPC_BOOK3E */
214 /* There should be nothing left ! */
215 BUG_ON(local_paca->irq_happened != 0);
220 notrace void arch_local_irq_restore(unsigned long en)
222 unsigned char irq_happened;
225 /* Write the new soft-enabled value */
226 set_soft_enabled(en);
230 * From this point onward, we can take interrupts, preempt,
231 * etc... unless we got hard-disabled. We check if an event
232 * happened. If none happened, we know we can just return.
234 * We may have preempted before the check below, in which case
235 * we are checking the "new" CPU instead of the old one. This
236 * is only a problem if an event happened on the "old" CPU.
238 * External interrupt events will have caused interrupts to
239 * be hard-disabled, so there is no problem, we
240 * cannot have preempted.
242 irq_happened = get_irq_happened();
247 * We need to hard disable to get a trusted value from
248 * __check_irq_replay(). We also need to soft-disable
249 * again to avoid warnings in there due to the use of
252 * We know that if the value in irq_happened is exactly 0x01
253 * then we are already hard disabled (there are other less
254 * common cases that we'll ignore for now), so we skip the
255 * (expensive) mtmsrd.
257 if (unlikely(irq_happened != PACA_IRQ_HARD_DIS))
258 __hard_irq_disable();
259 #ifdef CONFIG_TRACE_IRQFLAGS
262 * We should already be hard disabled here. We had bugs
263 * where that wasn't the case so let's dbl check it and
264 * warn if we are wrong. Only do that when IRQ tracing
265 * is enabled as mfmsr() can be costly.
267 if (WARN_ON(mfmsr() & MSR_EE))
268 __hard_irq_disable();
270 #endif /* CONFIG_TRACE_IRQFLAGS */
275 * Check if anything needs to be re-emitted. We haven't
276 * soft-enabled yet to avoid warnings in decrementer_check_overflow
277 * accessing per-cpu variables
279 replay = __check_irq_replay();
281 /* We can soft-enable now */
285 * And replay if we have to. This will return with interrupts
289 __replay_interrupt(replay);
293 /* Finally, let's ensure we are hard enabled */
296 EXPORT_SYMBOL(arch_local_irq_restore);
299 * This is specifically called by assembly code to re-enable interrupts
300 * if they are currently disabled. This is typically called before
301 * schedule() or do_signal() when returning to userspace. We do it
302 * in C to avoid the burden of dealing with lockdep etc...
304 * NOTE: This is called with interrupts hard disabled but not marked
305 * as such in paca->irq_happened, so we need to resync this.
307 void notrace restore_interrupts(void)
309 if (irqs_disabled()) {
310 local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
317 * This is a helper to use when about to go into idle low-power
318 * when the latter has the side effect of re-enabling interrupts
319 * (such as calling H_CEDE under pHyp).
321 * You call this function with interrupts soft-disabled (this is
322 * already the case when ppc_md.power_save is called). The function
323 * will return whether to enter power save or just return.
325 * In the former case, it will have notified lockdep of interrupts
326 * being re-enabled and generally sanitized the lazy irq state,
327 * and in the latter case it will leave with interrupts hard
328 * disabled and marked as such, so the local_irq_enable() call
329 * in arch_cpu_idle() will properly re-enable everything.
331 bool prep_irq_for_idle(void)
334 * First we need to hard disable to ensure no interrupt
335 * occurs before we effectively enter the low power state
337 __hard_irq_disable();
338 local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
341 * If anything happened while we were soft-disabled,
342 * we return now and do not enter the low power state.
344 if (lazy_irq_pending())
347 /* Tell lockdep we are about to re-enable */
351 * Mark interrupts as soft-enabled and clear the
352 * PACA_IRQ_HARD_DIS from the pending mask since we
353 * are about to hard enable as well as a side effect
354 * of entering the low power state.
356 local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
357 local_paca->soft_enabled = 1;
359 /* Tell the caller to enter the low power state */
363 #ifdef CONFIG_PPC_BOOK3S
365 * This is for idle sequences that return with IRQs off, but the
366 * idle state itself wakes on interrupt. Tell the irq tracer that
367 * IRQs are enabled for the duration of idle so it does not get long
368 * off times. Must be paired with fini_irq_for_idle_irqsoff.
370 bool prep_irq_for_idle_irqsoff(void)
372 WARN_ON(!irqs_disabled());
375 * First we need to hard disable to ensure no interrupt
376 * occurs before we effectively enter the low power state
378 __hard_irq_disable();
379 local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
382 * If anything happened while we were soft-disabled,
383 * we return now and do not enter the low power state.
385 if (lazy_irq_pending())
388 /* Tell lockdep we are about to re-enable */
395 * Take the SRR1 wakeup reason, index into this table to find the
396 * appropriate irq_happened bit.
398 static const u8 srr1_to_lazyirq[0x10] = {
410 void irq_set_pending_from_srr1(unsigned long srr1)
412 unsigned int idx = (srr1 & SRR1_WAKEMASK_P8) >> 18;
415 * The 0 index (SRR1[42:45]=b0000) must always evaluate to 0,
416 * so this can be called unconditionally with srr1 wake reason.
418 local_paca->irq_happened |= srr1_to_lazyirq[idx];
420 #endif /* CONFIG_PPC_BOOK3S */
423 * Force a replay of the external interrupt handler on this CPU.
425 void force_external_irq_replay(void)
428 * This must only be called with interrupts soft-disabled,
429 * the replay will happen when re-enabling.
431 WARN_ON(!arch_irqs_disabled());
434 * Interrupts must always be hard disabled before irq_happened is
435 * modified (to prevent lost update in case of interrupt between
438 __hard_irq_disable();
439 local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
441 /* Indicate in the PACA that we have an interrupt to replay */
442 local_paca->irq_happened |= PACA_IRQ_EE;
445 #endif /* CONFIG_PPC64 */
447 int arch_show_interrupts(struct seq_file *p, int prec)
451 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
452 if (tau_initialized) {
453 seq_printf(p, "%*s: ", prec, "TAU");
454 for_each_online_cpu(j)
455 seq_printf(p, "%10u ", tau_interrupts(j));
456 seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n");
458 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
460 seq_printf(p, "%*s: ", prec, "LOC");
461 for_each_online_cpu(j)
462 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_event);
463 seq_printf(p, " Local timer interrupts for timer event device\n");
465 seq_printf(p, "%*s: ", prec, "LOC");
466 for_each_online_cpu(j)
467 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_others);
468 seq_printf(p, " Local timer interrupts for others\n");
470 seq_printf(p, "%*s: ", prec, "SPU");
471 for_each_online_cpu(j)
472 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
473 seq_printf(p, " Spurious interrupts\n");
475 seq_printf(p, "%*s: ", prec, "PMI");
476 for_each_online_cpu(j)
477 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
478 seq_printf(p, " Performance monitoring interrupts\n");
480 seq_printf(p, "%*s: ", prec, "MCE");
481 for_each_online_cpu(j)
482 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
483 seq_printf(p, " Machine check exceptions\n");
485 if (cpu_has_feature(CPU_FTR_HVMODE)) {
486 seq_printf(p, "%*s: ", prec, "HMI");
487 for_each_online_cpu(j)
488 seq_printf(p, "%10u ",
489 per_cpu(irq_stat, j).hmi_exceptions);
490 seq_printf(p, " Hypervisor Maintenance Interrupts\n");
493 seq_printf(p, "%*s: ", prec, "NMI");
494 for_each_online_cpu(j)
495 seq_printf(p, "%10u ", per_cpu(irq_stat, j).sreset_irqs);
496 seq_printf(p, " System Reset interrupts\n");
498 #ifdef CONFIG_PPC_WATCHDOG
499 seq_printf(p, "%*s: ", prec, "WDG");
500 for_each_online_cpu(j)
501 seq_printf(p, "%10u ", per_cpu(irq_stat, j).soft_nmi_irqs);
502 seq_printf(p, " Watchdog soft-NMI interrupts\n");
505 #ifdef CONFIG_PPC_DOORBELL
506 if (cpu_has_feature(CPU_FTR_DBELL)) {
507 seq_printf(p, "%*s: ", prec, "DBL");
508 for_each_online_cpu(j)
509 seq_printf(p, "%10u ", per_cpu(irq_stat, j).doorbell_irqs);
510 seq_printf(p, " Doorbell interrupts\n");
520 u64 arch_irq_stat_cpu(unsigned int cpu)
522 u64 sum = per_cpu(irq_stat, cpu).timer_irqs_event;
524 sum += per_cpu(irq_stat, cpu).pmu_irqs;
525 sum += per_cpu(irq_stat, cpu).mce_exceptions;
526 sum += per_cpu(irq_stat, cpu).spurious_irqs;
527 sum += per_cpu(irq_stat, cpu).timer_irqs_others;
528 sum += per_cpu(irq_stat, cpu).hmi_exceptions;
529 sum += per_cpu(irq_stat, cpu).sreset_irqs;
530 #ifdef CONFIG_PPC_WATCHDOG
531 sum += per_cpu(irq_stat, cpu).soft_nmi_irqs;
533 #ifdef CONFIG_PPC_DOORBELL
534 sum += per_cpu(irq_stat, cpu).doorbell_irqs;
540 static inline void check_stack_overflow(void)
542 #ifdef CONFIG_DEBUG_STACKOVERFLOW
545 sp = current_stack_pointer() & (THREAD_SIZE-1);
547 /* check for stack overflow: is there less than 2KB free? */
548 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
549 pr_err("do_IRQ: stack overflow: %ld\n",
550 sp - sizeof(struct thread_info));
556 void __do_irq(struct pt_regs *regs)
562 trace_irq_entry(regs);
565 * Query the platform PIC for the interrupt & ack it.
567 * This will typically lower the interrupt line to the CPU
569 irq = ppc_md.get_irq();
571 /* We can hard enable interrupts now to allow perf interrupts */
572 may_hard_irq_enable();
574 /* And finally process it */
576 __this_cpu_inc(irq_stat.spurious_irqs);
578 generic_handle_irq(irq);
580 trace_irq_exit(regs);
585 void do_IRQ(struct pt_regs *regs)
587 struct pt_regs *old_regs = set_irq_regs(regs);
588 struct thread_info *curtp, *irqtp, *sirqtp;
590 /* Switch to the irq stack to handle this */
591 curtp = current_thread_info();
592 irqtp = hardirq_ctx[raw_smp_processor_id()];
593 sirqtp = softirq_ctx[raw_smp_processor_id()];
595 check_stack_overflow();
597 /* Already there ? */
598 if (unlikely(curtp == irqtp || curtp == sirqtp)) {
600 set_irq_regs(old_regs);
604 /* Prepare the thread_info in the irq stack */
605 irqtp->task = curtp->task;
608 /* Copy the preempt_count so that the [soft]irq checks work. */
609 irqtp->preempt_count = curtp->preempt_count;
611 /* Switch stack and call */
612 call_do_irq(regs, irqtp);
614 /* Restore stack limit */
617 /* Copy back updates to the thread_info */
619 set_bits(irqtp->flags, &curtp->flags);
621 set_irq_regs(old_regs);
624 void __init init_IRQ(void)
634 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
635 struct thread_info *critirq_ctx[NR_CPUS] __read_mostly;
636 struct thread_info *dbgirq_ctx[NR_CPUS] __read_mostly;
637 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
639 void exc_lvl_ctx_init(void)
641 struct thread_info *tp;
644 for_each_possible_cpu(i) {
649 cpu_nr = get_hard_smp_processor_id(i);
655 memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
656 tp = critirq_ctx[cpu_nr];
658 tp->preempt_count = 0;
661 memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
662 tp = dbgirq_ctx[cpu_nr];
664 tp->preempt_count = 0;
666 memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
667 tp = mcheckirq_ctx[cpu_nr];
669 tp->preempt_count = HARDIRQ_OFFSET;
675 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
676 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
678 void irq_ctx_init(void)
680 struct thread_info *tp;
683 for_each_possible_cpu(i) {
684 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
687 klp_init_thread_info(tp);
689 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
692 klp_init_thread_info(tp);
696 void do_softirq_own_stack(void)
698 struct thread_info *curtp, *irqtp;
700 curtp = current_thread_info();
701 irqtp = softirq_ctx[smp_processor_id()];
702 irqtp->task = curtp->task;
704 call_do_softirq(irqtp);
707 /* Set any flag that may have been set on the
711 set_bits(irqtp->flags, &curtp->flags);
714 irq_hw_number_t virq_to_hw(unsigned int virq)
716 struct irq_data *irq_data = irq_get_irq_data(virq);
717 return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
719 EXPORT_SYMBOL_GPL(virq_to_hw);
722 int irq_choose_cpu(const struct cpumask *mask)
726 if (cpumask_equal(mask, cpu_online_mask)) {
727 static int irq_rover;
728 static DEFINE_RAW_SPINLOCK(irq_rover_lock);
731 /* Round-robin distribution... */
733 raw_spin_lock_irqsave(&irq_rover_lock, flags);
735 irq_rover = cpumask_next(irq_rover, cpu_online_mask);
736 if (irq_rover >= nr_cpu_ids)
737 irq_rover = cpumask_first(cpu_online_mask);
741 raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
743 cpuid = cpumask_first_and(mask, cpu_online_mask);
744 if (cpuid >= nr_cpu_ids)
748 return get_hard_smp_processor_id(cpuid);
751 int irq_choose_cpu(const struct cpumask *mask)
753 return hard_smp_processor_id();
757 int arch_early_irq_init(void)
763 static int __init setup_noirqdistrib(char *str)
769 __setup("noirqdistrib", setup_noirqdistrib);
770 #endif /* CONFIG_PPC64 */