2 * linux/arch/i386/kernel/irq.c
4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
6 * This file contains the code used by various IRQ handling routines:
7 * asking for different IRQ's should be done through these routines
8 * instead of just grabbing them. Thus setups with different IRQ numbers
9 * shouldn't result in any weird surprises, and installing new handlers
14 * (mostly architecture independent, will move to kernel/irq.c in 2.5.)
16 * IRQs are in fact implemented a bit like signal handlers for the kernel.
17 * Naturally it's not a 1:1 relation, but there are similarities.
20 #include <linux/config.h>
21 #include <linux/ptrace.h>
22 #include <linux/errno.h>
23 #include <linux/signal.h>
24 #include <linux/sched.h>
25 #include <linux/ioport.h>
26 #include <linux/interrupt.h>
27 #include <linux/timex.h>
28 #include <linux/slab.h>
29 #include <linux/random.h>
30 #include <linux/smp_lock.h>
31 #include <linux/init.h>
32 #include <linux/kernel_stat.h>
33 #include <linux/irq.h>
34 #include <linux/proc_fs.h>
35 #include <linux/seq_file.h>
37 #include <asm/atomic.h>
40 #include <asm/system.h>
41 #include <asm/bitops.h>
42 #include <asm/uaccess.h>
43 #include <asm/pgalloc.h>
44 #include <asm/delay.h>
51 * Linux has a controller-independent x86 interrupt architecture.
52 * every controller has a 'controller-template', that is used
53 * by the main code to do the right thing. Each driver-visible
54 * interrupt source is transparently wired to the apropriate
55 * controller. Thus drivers need not be aware of the
56 * interrupt-controller.
58 * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
59 * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
60 * (IO-APICs assumed to be messaging to Pentium local-APICs)
62 * the code is designed to be easily extended with new/different
63 * interrupt controllers, without having to do assembly magic.
67 * Controller mappings for all interrupt sources:
69 irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned =
70 { [0 ... NR_IRQS-1] = { 0, &no_irq_type, NULL, 0, SPIN_LOCK_UNLOCKED}};
72 static void register_irq_proc (unsigned int irq);
75 * Special irq handlers.
78 void no_action(int cpl, void *dev_id, struct pt_regs *regs) { }
81 * Generic no controller code
84 static void enable_none(unsigned int irq) { }
85 static unsigned int startup_none(unsigned int irq) { return 0; }
86 static void disable_none(unsigned int irq) { }
87 static void ack_none(unsigned int irq)
90 * 'what should we do if we get a hw irq event on an illegal vector'.
91 * each architecture has to answer this themselves, it doesnt deserve
92 * a generic callback i think.
95 printk("unexpected IRQ trap at vector %02x\n", irq);
96 #ifdef CONFIG_X86_LOCAL_APIC
98 * Currently unexpected vectors happen only on SMP and APIC.
99 * We _must_ ack these because every local APIC has only N
100 * irq slots per priority level, and a 'hanging, unacked' IRQ
101 * holds up an irq slot - in excessive cases (when multiple
102 * unexpected vectors occur) that might lock up the APIC
110 /* startup is the same as "enable", shutdown is same as "disable" */
111 #define shutdown_none disable_none
112 #define end_none enable_none
114 struct hw_interrupt_type no_irq_type = {
124 atomic_t irq_err_count;
125 #ifdef CONFIG_X86_IO_APIC
126 #ifdef APIC_MISMATCH_DEBUG
127 atomic_t irq_mis_count;
132 * Generic, controller-independent functions:
135 int show_interrupts(struct seq_file *p, void *v)
138 struct irqaction * action;
141 for (j=0; j<smp_num_cpus; j++)
142 seq_printf(p, "CPU%d ",j);
145 for (i = 0 ; i < NR_IRQS ; i++) {
146 action = irq_desc[i].action;
149 seq_printf(p, "%3d: ",i);
151 seq_printf(p, "%10u ", kstat_irqs(i));
153 for (j = 0; j < smp_num_cpus; j++)
154 seq_printf(p, "%10u ",
155 kstat.irqs[cpu_logical_map(j)][i]);
157 seq_printf(p, " %14s", irq_desc[i].handler->typename);
158 seq_printf(p, " %s", action->name);
160 for (action=action->next; action; action = action->next)
161 seq_printf(p, ", %s", action->name);
164 seq_printf(p, "NMI: ");
165 for (j = 0; j < smp_num_cpus; j++)
166 seq_printf(p, "%10u ",
167 nmi_count(cpu_logical_map(j)));
169 #if CONFIG_X86_LOCAL_APIC
170 seq_printf(p, "LOC: ");
171 for (j = 0; j < smp_num_cpus; j++)
172 seq_printf(p, "%10u ",
173 apic_timer_irqs[cpu_logical_map(j)]);
176 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
177 #ifdef CONFIG_X86_IO_APIC
178 #ifdef APIC_MISMATCH_DEBUG
179 seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
188 * Global interrupt locks for SMP. Allow interrupts to come in on any
189 * CPU, yet make cli/sti act globally to protect critical regions..
193 unsigned char global_irq_holder = NO_PROC_ID;
194 unsigned volatile long global_irq_lock; /* pendantic: long for set_bit --RR */
196 extern void show_stack(unsigned long* esp);
198 static void show(char * str)
201 int cpu = smp_processor_id();
203 printk("\n%s, CPU %d:\n", str, cpu);
204 printk("irq: %d [",irqs_running());
205 for(i=0;i < smp_num_cpus;i++)
206 printk(" %d",local_irq_count(i));
207 printk(" ]\nbh: %d [",spin_is_locked(&global_bh_lock) ? 1 : 0);
208 for(i=0;i < smp_num_cpus;i++)
209 printk(" %d",local_bh_count(i));
211 printk(" ]\nStack dumps:");
212 for(i = 0; i < smp_num_cpus; i++) {
216 printk("\nCPU %d:",i);
217 esp = init_tss[i].esp0;
219 /* tss->esp0 is set to NULL in cpu_init(),
220 * it's initialized when the cpu returns to user
223 printk(" <unknown> ");
226 esp &= ~(THREAD_SIZE-1);
227 esp += sizeof(struct task_struct);
228 show_stack((void*)esp);
230 printk("\nCPU %d:",cpu);
235 #define MAXCOUNT 100000000
238 * I had a lockup scenario where a tight loop doing
239 * spin_unlock()/spin_lock() on CPU#1 was racing with
240 * spin_lock() on CPU#0. CPU#0 should have noticed spin_unlock(), but
241 * apparently the spin_unlock() information did not make it
242 * through to CPU#0 ... nasty, is this by design, do we have to limit
243 * 'memory update oscillation frequency' artificially like here?
245 * Such 'high frequency update' races can be avoided by careful design, but
246 * some of our major constructs like spinlocks use similar techniques,
247 * it would be nice to clarify this issue. Set this define to 0 if you
248 * want to check whether your system freezes. I suspect the delay done
249 * by SYNC_OTHER_CORES() is in correlation with 'snooping latency', but
250 * i thought that such things are guaranteed by design, since we use
253 #define SUSPECTED_CPU_OR_CHIPSET_BUG_WORKAROUND 0
255 #if SUSPECTED_CPU_OR_CHIPSET_BUG_WORKAROUND
256 # define SYNC_OTHER_CORES(x) udelay(x+1)
259 * We have to allow irqs to arrive between __sti and __cli
261 # define SYNC_OTHER_CORES(x) __asm__ __volatile__ ("nop")
264 static inline void wait_on_irq(int cpu)
266 int count = MAXCOUNT;
271 * Wait until all interrupts are gone. Wait
272 * for bottom half handlers unless we're
273 * already executing in one..
276 if (local_bh_count(cpu) || !spin_is_locked(&global_bh_lock))
279 /* Duh, we have to loop. Release the lock to avoid deadlocks */
280 clear_bit(0,&global_irq_lock);
288 SYNC_OTHER_CORES(cpu);
294 if (!local_bh_count(cpu) && spin_is_locked(&global_bh_lock))
296 if (!test_and_set_bit(0,&global_irq_lock))
303 * This is called when we want to synchronize with
304 * interrupts. We may for example tell a device to
305 * stop sending interrupts: but to make sure there
306 * are no interrupts that are executing on another
307 * CPU we need to call this function.
309 void synchronize_irq(void)
311 if (irqs_running()) {
312 /* Stupid approach */
318 static inline void get_irqlock(int cpu)
320 if (test_and_set_bit(0,&global_irq_lock)) {
321 /* do we already hold the lock? */
322 if ((unsigned char) cpu == global_irq_holder)
324 /* Uhhuh.. Somebody else got it. Wait.. */
328 } while (test_bit(0,&global_irq_lock));
329 } while (test_and_set_bit(0,&global_irq_lock));
332 * We also to make sure that nobody else is running
333 * in an interrupt context.
340 global_irq_holder = cpu;
343 #define EFLAGS_IF_SHIFT 9
346 * A global "cli()" while in an interrupt context
347 * turns into just a local cli(). Interrupts
348 * should use spinlocks for the (very unlikely)
349 * case that they ever want to protect against
352 * If we already have local interrupts disabled,
353 * this will not turn a local disable into a
354 * global one (problems with spinlocks: this makes
355 * save_flags+cli+sti usable inside a spinlock).
357 void __global_cli(void)
362 if (flags & (1 << EFLAGS_IF_SHIFT)) {
363 int cpu = smp_processor_id();
365 if (!local_irq_count(cpu))
370 void __global_sti(void)
372 int cpu = smp_processor_id();
374 if (!local_irq_count(cpu))
375 release_irqlock(cpu);
380 * SMP flags value to restore to:
386 unsigned long __global_save_flags(void)
391 int cpu = smp_processor_id();
394 local_enabled = (flags >> EFLAGS_IF_SHIFT) & 1;
395 /* default to local */
396 retval = 2 + local_enabled;
398 /* check for global flags if we're not in an interrupt */
399 if (!local_irq_count(cpu)) {
402 if (global_irq_holder == cpu)
408 void __global_restore_flags(unsigned long flags)
424 printk("global_restore_flags: %08lx (%08lx)\n",
425 flags, (&flags)[-1]);
432 * This should really return information about whether
433 * we should do bottom half handling etc. Right now we
434 * end up _always_ checking the bottom half, which is a
435 * waste of time and is not what some drivers would
438 int handle_IRQ_event(unsigned int irq, struct pt_regs * regs, struct irqaction * action)
441 int cpu = smp_processor_id();
445 status = 1; /* Force the "do bottom halves" bit */
447 if (!(action->flags & SA_INTERRUPT))
451 status |= action->flags;
452 action->handler(irq, action->dev_id, regs);
453 action = action->next;
455 if (status & SA_SAMPLE_RANDOM)
456 add_interrupt_randomness(irq);
465 * Generic enable/disable code: this just calls
466 * down into the PIC-specific version for the actual
467 * hardware disable after having gotten the irq
472 * disable_irq_nosync - disable an irq without waiting
473 * @irq: Interrupt to disable
475 * Disable the selected interrupt line. Disables and Enables are
477 * Unlike disable_irq(), this function does not ensure existing
478 * instances of the IRQ handler have completed before returning.
480 * This function may be called from IRQ context.
483 inline void disable_irq_nosync(unsigned int irq)
485 irq_desc_t *desc = irq_desc + irq;
488 spin_lock_irqsave(&desc->lock, flags);
489 if (!desc->depth++) {
490 desc->status |= IRQ_DISABLED;
491 desc->handler->disable(irq);
493 spin_unlock_irqrestore(&desc->lock, flags);
497 * disable_irq - disable an irq and wait for completion
498 * @irq: Interrupt to disable
500 * Disable the selected interrupt line. Enables and Disables are
502 * This function waits for any pending IRQ handlers for this interrupt
503 * to complete before returning. If you use this function while
504 * holding a resource the IRQ handler may need you will deadlock.
506 * This function may be called - with care - from IRQ context.
509 void disable_irq(unsigned int irq)
511 disable_irq_nosync(irq);
513 if (!local_irq_count(smp_processor_id())) {
517 } while (irq_desc[irq].status & IRQ_INPROGRESS);
522 * enable_irq - enable handling of an irq
523 * @irq: Interrupt to enable
525 * Undoes the effect of one call to disable_irq(). If this
526 * matches the last disable, processing of interrupts on this
527 * IRQ line is re-enabled.
529 * This function may be called from IRQ context.
532 void enable_irq(unsigned int irq)
534 irq_desc_t *desc = irq_desc + irq;
537 spin_lock_irqsave(&desc->lock, flags);
538 switch (desc->depth) {
540 unsigned int status = desc->status & ~IRQ_DISABLED;
541 desc->status = status;
542 if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
543 desc->status = status | IRQ_REPLAY;
544 hw_resend_irq(desc->handler,irq);
546 desc->handler->enable(irq);
553 printk("enable_irq(%u) unbalanced from %p\n", irq,
554 __builtin_return_address(0));
556 spin_unlock_irqrestore(&desc->lock, flags);
560 * do_IRQ handles all normal device IRQ's (the special
561 * SMP cross-CPU interrupts have their own specific
564 asmlinkage unsigned int do_IRQ(struct pt_regs regs)
567 * We ack quickly, we don't want the irq controller
568 * thinking we're snobs just because some other CPU has
569 * disabled global interrupts (we have already done the
570 * INT_ACK cycles, it's too late to try to pretend to the
571 * controller that we aren't taking the interrupt).
573 * 0 return value means that this irq is already being
574 * handled by some other CPU. (or is disabled)
576 int irq = regs.orig_eax & 0xff; /* high bits used in ret_from_ code */
577 int cpu = smp_processor_id();
578 irq_desc_t *desc = irq_desc + irq;
579 struct irqaction * action;
581 #ifdef CONFIG_DEBUG_STACKOVERFLOW
584 /* Debugging check for stack overflow: is there less than 1KB free? */
585 __asm__ __volatile__("andl %%esp,%0" : "=r" (esp) : "0" (8191));
586 if (unlikely(esp < (sizeof(struct task_struct) + 1024))) {
587 extern void show_stack(unsigned long *);
589 printk("do_IRQ: stack overflow: %ld\n",
590 esp - sizeof(struct task_struct));
591 __asm__ __volatile__("movl %%esp,%0" : "=r" (esp));
592 show_stack((void *)esp);
596 kstat.irqs[cpu][irq]++;
597 spin_lock(&desc->lock);
598 desc->handler->ack(irq);
600 REPLAY is when Linux resends an IRQ that was dropped earlier
601 WAITING is used by probe to mark irqs that are being tested
603 status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
604 status |= IRQ_PENDING; /* we _want_ to handle it */
607 * If the IRQ is disabled for whatever reason, we cannot
608 * use the action we have.
611 if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
612 action = desc->action;
613 status &= ~IRQ_PENDING; /* we commit to handling */
614 status |= IRQ_INPROGRESS; /* we are handling it */
616 desc->status = status;
619 * If there is no IRQ handler or it was disabled, exit early.
620 Since we set PENDING, if another processor is handling
621 a different instance of this same irq, the other processor
622 will take care of it.
628 * Edge triggered interrupts need to remember
630 * This applies to any hw interrupts that allow a second
631 * instance of the same irq to arrive while we are in do_IRQ
632 * or in the handler. But the code here only handles the _second_
633 * instance of the irq, not the third or fourth. So it is mostly
634 * useful for irq hardware that does not mask cleanly in an
638 spin_unlock(&desc->lock);
639 handle_IRQ_event(irq, ®s, action);
640 spin_lock(&desc->lock);
642 if (!(desc->status & IRQ_PENDING))
644 desc->status &= ~IRQ_PENDING;
646 desc->status &= ~IRQ_INPROGRESS;
649 * The ->end() handler has to deal with interrupts which got
650 * disabled while the handler was running.
652 desc->handler->end(irq);
653 spin_unlock(&desc->lock);
655 if (softirq_pending(cpu))
661 * request_irq - allocate an interrupt line
662 * @irq: Interrupt line to allocate
663 * @handler: Function to be called when the IRQ occurs
664 * @irqflags: Interrupt type flags
665 * @devname: An ascii name for the claiming device
666 * @dev_id: A cookie passed back to the handler function
668 * This call allocates interrupt resources and enables the
669 * interrupt line and IRQ handling. From the point this
670 * call is made your handler function may be invoked. Since
671 * your handler function must clear any interrupt the board
672 * raises, you must take care both to initialise your hardware
673 * and to set up the interrupt handler in the right order.
675 * Dev_id must be globally unique. Normally the address of the
676 * device data structure is used as the cookie. Since the handler
677 * receives this value it makes sense to use it.
679 * If your interrupt is shared you must pass a non NULL dev_id
680 * as this is required when freeing the interrupt.
684 * SA_SHIRQ Interrupt is shared
686 * SA_INTERRUPT Disable local interrupts while processing
688 * SA_SAMPLE_RANDOM The interrupt can be used for entropy
692 int request_irq(unsigned int irq,
693 void (*handler)(int, void *, struct pt_regs *),
694 unsigned long irqflags,
695 const char * devname,
699 struct irqaction * action;
703 * Sanity-check: shared interrupts should REALLY pass in
704 * a real dev-ID, otherwise we'll have trouble later trying
705 * to figure out which interrupt is which (messes up the
706 * interrupt freeing logic etc).
708 if (irqflags & SA_SHIRQ) {
710 printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n", devname, (&irq)[-1]);
719 action = (struct irqaction *)
720 kmalloc(sizeof(struct irqaction), GFP_KERNEL);
724 action->handler = handler;
725 action->flags = irqflags;
727 action->name = devname;
729 action->dev_id = dev_id;
731 retval = setup_irq(irq, action);
738 * free_irq - free an interrupt
739 * @irq: Interrupt line to free
740 * @dev_id: Device identity to free
742 * Remove an interrupt handler. The handler is removed and if the
743 * interrupt line is no longer in use by any driver it is disabled.
744 * On a shared IRQ the caller must ensure the interrupt is disabled
745 * on the card it drives before calling this function. The function
746 * does not return until any executing interrupts for this IRQ
749 * This function may be called from interrupt context.
751 * Bugs: Attempting to free an irq in a handler for the same irq hangs
755 void free_irq(unsigned int irq, void *dev_id)
758 struct irqaction **p;
764 desc = irq_desc + irq;
765 spin_lock_irqsave(&desc->lock,flags);
768 struct irqaction * action = *p;
770 struct irqaction **pp = p;
772 if (action->dev_id != dev_id)
775 /* Found it - now remove it from the list of entries */
778 desc->status |= IRQ_DISABLED;
779 desc->handler->shutdown(irq);
781 spin_unlock_irqrestore(&desc->lock,flags);
784 /* Wait to make sure it's not being used on another CPU */
785 while (desc->status & IRQ_INPROGRESS) {
793 printk("Trying to free free IRQ%d\n",irq);
794 spin_unlock_irqrestore(&desc->lock,flags);
800 * IRQ autodetection code..
802 * This depends on the fact that any interrupt that
803 * comes in on to an unassigned handler will get stuck
804 * with "IRQ_WAITING" cleared and the interrupt
808 static DECLARE_MUTEX(probe_sem);
811 * probe_irq_on - begin an interrupt autodetect
813 * Commence probing for an interrupt. The interrupts are scanned
814 * and a mask of potential interrupt lines is returned.
818 unsigned long probe_irq_on(void)
827 * something may have generated an irq long ago and we want to
828 * flush such a longstanding irq before considering it as spurious.
830 for (i = NR_IRQS-1; i > 0; i--) {
833 spin_lock_irq(&desc->lock);
834 if (!irq_desc[i].action)
835 irq_desc[i].handler->startup(i);
836 spin_unlock_irq(&desc->lock);
839 /* Wait for longstanding interrupts to trigger. */
840 for (delay = jiffies + HZ/50; time_after(delay, jiffies); )
841 /* about 20ms delay */ synchronize_irq();
844 * enable any unassigned irqs
845 * (we must startup again here because if a longstanding irq
846 * happened in the previous stage, it may have masked itself)
848 for (i = NR_IRQS-1; i > 0; i--) {
851 spin_lock_irq(&desc->lock);
853 desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
854 if (desc->handler->startup(i))
855 desc->status |= IRQ_PENDING;
857 spin_unlock_irq(&desc->lock);
861 * Wait for spurious interrupts to trigger
863 for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
864 /* about 100ms delay */ synchronize_irq();
867 * Now filter out any obviously spurious interrupts
870 for (i = 0; i < NR_IRQS; i++) {
871 irq_desc_t *desc = irq_desc + i;
874 spin_lock_irq(&desc->lock);
875 status = desc->status;
877 if (status & IRQ_AUTODETECT) {
878 /* It triggered already - consider it spurious. */
879 if (!(status & IRQ_WAITING)) {
880 desc->status = status & ~IRQ_AUTODETECT;
881 desc->handler->shutdown(i);
886 spin_unlock_irq(&desc->lock);
893 * Return a mask of triggered interrupts (this
894 * can handle only legacy ISA interrupts).
898 * probe_irq_mask - scan a bitmap of interrupt lines
899 * @val: mask of interrupts to consider
901 * Scan the ISA bus interrupt lines and return a bitmap of
902 * active interrupts. The interrupt probe logic state is then
903 * returned to its previous value.
905 * Note: we need to scan all the irq's even though we will
906 * only return ISA irq numbers - just so that we reset them
907 * all to a known state.
909 unsigned int probe_irq_mask(unsigned long val)
915 for (i = 0; i < NR_IRQS; i++) {
916 irq_desc_t *desc = irq_desc + i;
919 spin_lock_irq(&desc->lock);
920 status = desc->status;
922 if (status & IRQ_AUTODETECT) {
923 if (i < 16 && !(status & IRQ_WAITING))
926 desc->status = status & ~IRQ_AUTODETECT;
927 desc->handler->shutdown(i);
929 spin_unlock_irq(&desc->lock);
937 * Return the one interrupt that triggered (this can
938 * handle any interrupt source).
942 * probe_irq_off - end an interrupt autodetect
943 * @val: mask of potential interrupts (unused)
945 * Scans the unused interrupt lines and returns the line which
946 * appears to have triggered the interrupt. If no interrupt was
947 * found then zero is returned. If more than one interrupt is
948 * found then minus the first candidate is returned to indicate
951 * The interrupt probe logic state is returned to its previous
954 * BUGS: When used in a module (which arguably shouldnt happen)
955 * nothing prevents two IRQ probe callers from overlapping. The
956 * results of this are non-optimal.
959 int probe_irq_off(unsigned long val)
961 int i, irq_found, nr_irqs;
965 for (i = 0; i < NR_IRQS; i++) {
966 irq_desc_t *desc = irq_desc + i;
969 spin_lock_irq(&desc->lock);
970 status = desc->status;
972 if (status & IRQ_AUTODETECT) {
973 if (!(status & IRQ_WAITING)) {
978 desc->status = status & ~IRQ_AUTODETECT;
979 desc->handler->shutdown(i);
981 spin_unlock_irq(&desc->lock);
986 irq_found = -irq_found;
990 /* this was setup_x86_irq but it seems pretty generic */
991 int setup_irq(unsigned int irq, struct irqaction * new)
995 struct irqaction *old, **p;
996 irq_desc_t *desc = irq_desc + irq;
999 * Some drivers like serial.c use request_irq() heavily,
1000 * so we have to be careful not to interfere with a
1003 if (new->flags & SA_SAMPLE_RANDOM) {
1005 * This function might sleep, we want to call it first,
1006 * outside of the atomic block.
1007 * Yes, this might clear the entropy pool if the wrong
1008 * driver is attempted to be loaded, without actually
1009 * installing a new handler, but is this really a problem,
1010 * only the sysadmin is able to do this.
1012 rand_initialize_irq(irq);
1016 * The following block of code has to be executed atomically
1018 spin_lock_irqsave(&desc->lock,flags);
1020 if ((old = *p) != NULL) {
1021 /* Can't share interrupts unless both agree to */
1022 if (!(old->flags & new->flags & SA_SHIRQ)) {
1023 spin_unlock_irqrestore(&desc->lock,flags);
1027 /* add new interrupt at end of irq queue */
1039 desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
1040 desc->handler->startup(irq);
1042 spin_unlock_irqrestore(&desc->lock,flags);
1044 register_irq_proc(irq);
1048 static struct proc_dir_entry * root_irq_dir;
1049 static struct proc_dir_entry * irq_dir [NR_IRQS];
1051 #define HEX_DIGITS 8
1053 static unsigned int parse_hex_value (const char *buffer,
1054 unsigned long count, unsigned long *ret)
1056 unsigned char hexnum [HEX_DIGITS];
1057 unsigned long value;
1062 if (count > HEX_DIGITS)
1064 if (copy_from_user(hexnum, buffer, count))
1068 * Parse the first 8 characters as a hex string, any non-hex char
1069 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
1073 for (i = 0; i < count; i++) {
1074 unsigned int c = hexnum[i];
1077 case '0' ... '9': c -= '0'; break;
1078 case 'a' ... 'f': c -= 'a'-10; break;
1079 case 'A' ... 'F': c -= 'A'-10; break;
1083 value = (value << 4) | c;
1092 static struct proc_dir_entry * smp_affinity_entry [NR_IRQS];
1094 static unsigned long irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = ~0UL };
1095 static int irq_affinity_read_proc (char *page, char **start, off_t off,
1096 int count, int *eof, void *data)
1098 if (count < HEX_DIGITS+1)
1100 return sprintf (page, "%08lx\n", irq_affinity[(long)data]);
1103 static int irq_affinity_write_proc (struct file *file, const char *buffer,
1104 unsigned long count, void *data)
1106 int irq = (long) data, full_count = count, err;
1107 unsigned long new_value;
1109 if (!irq_desc[irq].handler->set_affinity)
1112 err = parse_hex_value(buffer, count, &new_value);
1115 * Do not allow disabling IRQs completely - it's a too easy
1116 * way to make the system unusable accidentally :-) At least
1117 * one online CPU still has to be targeted.
1119 if (!(new_value & cpu_online_map))
1122 irq_affinity[irq] = new_value;
1123 irq_desc[irq].handler->set_affinity(irq, new_value);
1130 static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
1131 int count, int *eof, void *data)
1133 unsigned long *mask = (unsigned long *) data;
1134 if (count < HEX_DIGITS+1)
1136 return sprintf (page, "%08lx\n", *mask);
1139 static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
1140 unsigned long count, void *data)
1142 unsigned long *mask = (unsigned long *) data, full_count = count, err;
1143 unsigned long new_value;
1145 err = parse_hex_value(buffer, count, &new_value);
1153 #define MAX_NAMELEN 10
1155 static void register_irq_proc (unsigned int irq)
1157 char name [MAX_NAMELEN];
1159 if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) ||
1163 memset(name, 0, MAX_NAMELEN);
1164 sprintf(name, "%d", irq);
1166 /* create /proc/irq/1234 */
1167 irq_dir[irq] = proc_mkdir(name, root_irq_dir);
1171 struct proc_dir_entry *entry;
1173 /* create /proc/irq/1234/smp_affinity */
1174 entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
1178 entry->data = (void *)(long)irq;
1179 entry->read_proc = irq_affinity_read_proc;
1180 entry->write_proc = irq_affinity_write_proc;
1183 smp_affinity_entry[irq] = entry;
1188 unsigned long prof_cpu_mask = -1;
1190 void init_irq_proc (void)
1192 struct proc_dir_entry *entry;
1195 /* create /proc/irq */
1196 root_irq_dir = proc_mkdir("irq", 0);
1198 /* create /proc/irq/prof_cpu_mask */
1199 entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
1205 entry->data = (void *)&prof_cpu_mask;
1206 entry->read_proc = prof_cpu_mask_read_proc;
1207 entry->write_proc = prof_cpu_mask_write_proc;
1210 * Create entries for all existing IRQs.
1212 for (i = 0; i < NR_IRQS; i++)
1213 register_irq_proc(i);