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@fsmlabs.com>
9 * Copyright (C) 1996-2001 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
25 * The MPC8xx has an interrupt mask in the SIU. If a bit is set, the
26 * interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit
27 * mask register (of which only 16 are defined), hence the weird shifting
28 * and complement of the cached_irq_mask. I want to be able to stuff
29 * this right into the SIU SMASK register.
30 * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
31 * to reduce code space and undefined function references.
34 #include <linux/errno.h>
35 #include <linux/module.h>
36 #include <linux/threads.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/signal.h>
39 #include <linux/sched.h>
40 #include <linux/ptrace.h>
41 #include <linux/ioport.h>
42 #include <linux/interrupt.h>
43 #include <linux/timex.h>
44 #include <linux/config.h>
45 #include <linux/init.h>
46 #include <linux/slab.h>
47 #include <linux/pci.h>
48 #include <linux/delay.h>
49 #include <linux/irq.h>
50 #include <linux/proc_fs.h>
51 #include <linux/random.h>
52 #include <linux/seq_file.h>
53 #include <linux/cpumask.h>
54 #include <linux/profile.h>
55 #include <linux/bitops.h>
57 #include <linux/kallsyms.h>
60 #include <asm/uaccess.h>
61 #include <asm/system.h>
63 #include <asm/pgtable.h>
65 #include <asm/cache.h>
67 #include <asm/ptrace.h>
68 #include <asm/machdep.h>
70 #include <asm/iseries/it_lp_queue.h>
74 int __irq_offset_value;
76 EXPORT_SYMBOL(__irq_offset_value);
79 static int ppc_spurious_interrupts;
82 #define NR_MASK_WORDS ((NR_IRQS + 31) / 32)
84 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
85 atomic_t ppc_n_lost_interrupts;
88 extern int tau_initialized;
89 extern int tau_interrupts(int);
92 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
93 extern atomic_t ipi_recv;
94 extern atomic_t ipi_sent;
96 #endif /* CONFIG_PPC32 */
99 EXPORT_SYMBOL(irq_desc);
101 int distribute_irqs = 1;
102 u64 ppc64_interrupt_controller;
103 #endif /* CONFIG_PPC64 */
105 int show_interrupts(struct seq_file *p, void *v)
107 int i = *(loff_t *)v, j;
108 struct irqaction *action;
114 for_each_online_cpu(j)
115 seq_printf(p, "CPU%d ", j);
120 desc = get_irq_desc(i);
121 spin_lock_irqsave(&desc->lock, flags);
122 action = desc->action;
123 if (!action || !action->handler)
125 seq_printf(p, "%3d: ", i);
127 for_each_online_cpu(j)
128 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
130 seq_printf(p, "%10u ", kstat_irqs(i));
131 #endif /* CONFIG_SMP */
133 seq_printf(p, " %s ", desc->handler->typename);
135 seq_puts(p, " None ");
136 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge ");
137 seq_printf(p, " %s", action->name);
138 for (action = action->next; action; action = action->next)
139 seq_printf(p, ", %s", action->name);
142 spin_unlock_irqrestore(&desc->lock, flags);
143 } else if (i == NR_IRQS) {
145 #ifdef CONFIG_TAU_INT
146 if (tau_initialized){
147 seq_puts(p, "TAU: ");
148 for (j = 0; j < NR_CPUS; j++)
150 seq_printf(p, "%10u ", tau_interrupts(j));
151 seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n");
154 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
155 /* should this be per processor send/receive? */
156 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
157 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
159 #endif /* CONFIG_PPC32 */
160 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
165 #ifdef CONFIG_HOTPLUG_CPU
166 void fixup_irqs(cpumask_t map)
174 if (irq_desc[irq].status & IRQ_PER_CPU)
177 cpus_and(mask, irq_affinity[irq], map);
178 if (any_online_cpu(mask) == NR_CPUS) {
179 printk("Breaking affinity for irq %i\n", irq);
182 if (irq_desc[irq].handler->set_affinity)
183 irq_desc[irq].handler->set_affinity(irq, mask);
184 else if (irq_desc[irq].action && !(warned++))
185 printk("Cannot set affinity for irq %i\n", irq);
194 void do_IRQ(struct pt_regs *regs)
197 #ifdef CONFIG_IRQSTACKS
198 struct thread_info *curtp, *irqtp;
203 #ifdef CONFIG_DEBUG_STACKOVERFLOW
204 /* Debugging check for stack overflow: is there less than 2KB free? */
208 sp = __get_SP() & (THREAD_SIZE-1);
210 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
211 printk("do_IRQ: stack overflow: %ld\n",
212 sp - sizeof(struct thread_info));
219 * Every platform is required to implement ppc_md.get_irq.
220 * This function will either return an irq number or -1 to
221 * indicate there are no more pending.
222 * The value -2 is for buggy hardware and means that this IRQ
223 * has already been handled. -- Tom
225 irq = ppc_md.get_irq(regs);
228 #ifdef CONFIG_IRQSTACKS
229 /* Switch to the irq stack to handle this */
230 curtp = current_thread_info();
231 irqtp = hardirq_ctx[smp_processor_id()];
232 if (curtp != irqtp) {
233 irqtp->task = curtp->task;
235 call___do_IRQ(irq, regs, irqtp);
238 set_bits(irqtp->flags, &curtp->flags);
242 } else if (irq != -2)
243 /* That's not SMP safe ... but who cares ? */
244 ppc_spurious_interrupts++;
248 #ifdef CONFIG_PPC_ISERIES
250 struct paca_struct *lpaca = get_paca();
252 if (lpaca->lppaca.int_dword.fields.decr_int) {
253 lpaca->lppaca.int_dword.fields.decr_int = 0;
254 /* Signal a fake decrementer interrupt */
255 timer_interrupt(regs);
261 void __init init_IRQ(void)
280 * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
283 #define UNDEFINED_IRQ 0xffffffff
284 unsigned int virt_irq_to_real_map[NR_IRQS];
287 * Don't use virtual irqs 0, 1, 2 for devices.
288 * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
289 * and 2 is the XICS IPI interrupt.
290 * We limit virtual irqs to 17 less than NR_IRQS so that when we
291 * offset them by 16 (to reserve the first 16 for ISA interrupts)
292 * we don't end up with an interrupt number >= NR_IRQS.
294 #define MIN_VIRT_IRQ 3
295 #define MAX_VIRT_IRQ (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
296 #define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
302 for (i = 0; i < NR_IRQS; i++)
303 virt_irq_to_real_map[i] = UNDEFINED_IRQ;
306 /* Create a mapping for a real_irq if it doesn't already exist.
307 * Return the virtual irq as a convenience.
309 int virt_irq_create_mapping(unsigned int real_irq)
311 unsigned int virq, first_virq;
314 if (ppc64_interrupt_controller == IC_OPEN_PIC)
315 return real_irq; /* no mapping for openpic (for now) */
317 if (ppc64_interrupt_controller == IC_CELL_PIC)
318 return real_irq; /* no mapping for iic either */
320 /* don't map interrupts < MIN_VIRT_IRQ */
321 if (real_irq < MIN_VIRT_IRQ) {
322 virt_irq_to_real_map[real_irq] = real_irq;
326 /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
328 if (virq > MAX_VIRT_IRQ)
329 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
331 /* search for this number or a free slot */
333 while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
334 if (virt_irq_to_real_map[virq] == real_irq)
336 if (++virq > MAX_VIRT_IRQ)
338 if (virq == first_virq)
339 goto nospace; /* oops, no free slots */
342 virt_irq_to_real_map[virq] = real_irq;
347 printk(KERN_CRIT "Interrupt table is full\n");
348 printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
349 "in your kernel sources and rebuild.\n", NR_IRQS);
356 * In most cases will get a hit on the very first slot checked in the
357 * virt_irq_to_real_map. Only when there are a large number of
358 * IRQs will this be expensive.
360 unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
363 unsigned int first_virq;
367 if (virq > MAX_VIRT_IRQ)
368 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
373 if (virt_irq_to_real_map[virq] == real_irq)
378 if (virq >= MAX_VIRT_IRQ)
381 } while (first_virq != virq);
387 #ifdef CONFIG_IRQSTACKS
388 struct thread_info *softirq_ctx[NR_CPUS];
389 struct thread_info *hardirq_ctx[NR_CPUS];
391 void irq_ctx_init(void)
393 struct thread_info *tp;
397 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
400 tp->preempt_count = SOFTIRQ_OFFSET;
402 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
405 tp->preempt_count = HARDIRQ_OFFSET;
409 void do_softirq(void)
412 struct thread_info *curtp, *irqtp;
417 local_irq_save(flags);
419 if (local_softirq_pending()) {
420 curtp = current_thread_info();
421 irqtp = softirq_ctx[smp_processor_id()];
422 irqtp->task = curtp->task;
423 call_do_softirq(irqtp);
427 local_irq_restore(flags);
429 EXPORT_SYMBOL(do_softirq);
431 #endif /* CONFIG_IRQSTACKS */
433 static int __init setup_noirqdistrib(char *str)
439 __setup("noirqdistrib", setup_noirqdistrib);
440 #endif /* CONFIG_PPC64 */