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/malloc.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>
38 #include <asm/system.h>
39 #include <asm/bitops.h>
40 #include <asm/uaccess.h>
41 #include <asm/pgalloc.h>
42 #include <asm/delay.h>
49 * Linux has a controller-independent x86 interrupt architecture.
50 * every controller has a 'controller-template', that is used
51 * by the main code to do the right thing. Each driver-visible
52 * interrupt source is transparently wired to the apropriate
53 * controller. Thus drivers need not be aware of the
54 * interrupt-controller.
56 * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
57 * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
58 * (IO-APICs assumed to be messaging to Pentium local-APICs)
60 * the code is designed to be easily extended with new/different
61 * interrupt controllers, without having to do assembly magic.
64 irq_cpustat_t irq_stat
[NR_CPUS
];
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 volatile unsigned long irq_err_count
;
127 * Generic, controller-independent functions:
130 int get_irq_list(char *buf
)
133 struct irqaction
* action
;
136 p
+= sprintf(p
, " ");
137 for (j
=0; j
<smp_num_cpus
; j
++)
138 p
+= sprintf(p
, "CPU%d ",j
);
141 for (i
= 0 ; i
< NR_IRQS
; i
++) {
142 action
= irq_desc
[i
].action
;
145 p
+= sprintf(p
, "%3d: ",i
);
147 p
+= sprintf(p
, "%10u ", kstat_irqs(i
));
149 for (j
= 0; j
< smp_num_cpus
; j
++)
150 p
+= sprintf(p
, "%10u ",
151 kstat
.irqs
[cpu_logical_map(j
)][i
]);
153 p
+= sprintf(p
, " %14s", irq_desc
[i
].handler
->typename
);
154 p
+= sprintf(p
, " %s", action
->name
);
156 for (action
=action
->next
; action
; action
= action
->next
)
157 p
+= sprintf(p
, ", %s", action
->name
);
160 p
+= sprintf(p
, "NMI: ");
161 for (j
= 0; j
< smp_num_cpus
; j
++)
162 p
+= sprintf(p
, "%10u ",
163 atomic_read(&nmi_counter(cpu_logical_map(j
))));
164 p
+= sprintf(p
, "\n");
166 p
+= sprintf(p
, "LOC: ");
167 for (j
= 0; j
< smp_num_cpus
; j
++)
168 p
+= sprintf(p
, "%10u ",
169 apic_timer_irqs
[cpu_logical_map(j
)]);
170 p
+= sprintf(p
, "\n");
172 p
+= sprintf(p
, "ERR: %10lu\n", irq_err_count
);
178 * Global interrupt locks for SMP. Allow interrupts to come in on any
179 * CPU, yet make cli/sti act globally to protect critical regions..
183 unsigned char global_irq_holder
= NO_PROC_ID
;
184 unsigned volatile int global_irq_lock
;
186 extern void show_stack(unsigned long* esp
);
188 static void show(char * str
)
191 int cpu
= smp_processor_id();
193 printk("\n%s, CPU %d:\n", str
, cpu
);
194 printk("irq: %d [",irqs_running());
195 for(i
=0;i
< smp_num_cpus
;i
++)
196 printk(" %d",local_irq_count(i
));
197 printk(" ]\nbh: %d [",spin_is_locked(&global_bh_lock
) ? 1 : 0);
198 for(i
=0;i
< smp_num_cpus
;i
++)
199 printk(" %d",local_bh_count(i
));
201 printk(" ]\nStack dumps:");
202 for(i
= 0; i
< smp_num_cpus
; i
++) {
206 printk("\nCPU %d:",i
);
207 esp
= init_tss
[i
].esp0
;
209 /* tss->esp0 is set to NULL in cpu_init(),
210 * it's initialized when the cpu returns to user
213 printk(" <unknown> ");
216 esp
&= ~(THREAD_SIZE
-1);
217 esp
+= sizeof(struct task_struct
);
218 show_stack((void*)esp
);
220 printk("\nCPU %d:",cpu
);
225 #define MAXCOUNT 100000000
228 * I had a lockup scenario where a tight loop doing
229 * spin_unlock()/spin_lock() on CPU#1 was racing with
230 * spin_lock() on CPU#0. CPU#0 should have noticed spin_unlock(), but
231 * apparently the spin_unlock() information did not make it
232 * through to CPU#0 ... nasty, is this by design, do we have to limit
233 * 'memory update oscillation frequency' artificially like here?
235 * Such 'high frequency update' races can be avoided by careful design, but
236 * some of our major constructs like spinlocks use similar techniques,
237 * it would be nice to clarify this issue. Set this define to 0 if you
238 * want to check whether your system freezes. I suspect the delay done
239 * by SYNC_OTHER_CORES() is in correlation with 'snooping latency', but
240 * i thought that such things are guaranteed by design, since we use
243 #define SUSPECTED_CPU_OR_CHIPSET_BUG_WORKAROUND 0
245 #if SUSPECTED_CPU_OR_CHIPSET_BUG_WORKAROUND
246 # define SYNC_OTHER_CORES(x) udelay(x+1)
249 * We have to allow irqs to arrive between __sti and __cli
251 # define SYNC_OTHER_CORES(x) __asm__ __volatile__ ("nop")
254 static inline void wait_on_irq(int cpu
)
256 int count
= MAXCOUNT
;
261 * Wait until all interrupts are gone. Wait
262 * for bottom half handlers unless we're
263 * already executing in one..
266 if (local_bh_count(cpu
) || !spin_is_locked(&global_bh_lock
))
269 /* Duh, we have to loop. Release the lock to avoid deadlocks */
270 clear_bit(0,&global_irq_lock
);
278 SYNC_OTHER_CORES(cpu
);
284 if (!local_bh_count(cpu
) && spin_is_locked(&global_bh_lock
))
286 if (!test_and_set_bit(0,&global_irq_lock
))
293 * This is called when we want to synchronize with
294 * interrupts. We may for example tell a device to
295 * stop sending interrupts: but to make sure there
296 * are no interrupts that are executing on another
297 * CPU we need to call this function.
299 void synchronize_irq(void)
301 if (irqs_running()) {
302 /* Stupid approach */
308 static inline void get_irqlock(int cpu
)
310 if (test_and_set_bit(0,&global_irq_lock
)) {
311 /* do we already hold the lock? */
312 if ((unsigned char) cpu
== global_irq_holder
)
314 /* Uhhuh.. Somebody else got it. Wait.. */
317 } while (test_bit(0,&global_irq_lock
));
318 } while (test_and_set_bit(0,&global_irq_lock
));
321 * We also to make sure that nobody else is running
322 * in an interrupt context.
329 global_irq_holder
= cpu
;
332 #define EFLAGS_IF_SHIFT 9
335 * A global "cli()" while in an interrupt context
336 * turns into just a local cli(). Interrupts
337 * should use spinlocks for the (very unlikely)
338 * case that they ever want to protect against
341 * If we already have local interrupts disabled,
342 * this will not turn a local disable into a
343 * global one (problems with spinlocks: this makes
344 * save_flags+cli+sti usable inside a spinlock).
346 void __global_cli(void)
351 if (flags
& (1 << EFLAGS_IF_SHIFT
)) {
352 int cpu
= smp_processor_id();
354 if (!local_irq_count(cpu
))
359 void __global_sti(void)
361 int cpu
= smp_processor_id();
363 if (!local_irq_count(cpu
))
364 release_irqlock(cpu
);
369 * SMP flags value to restore to:
375 unsigned long __global_save_flags(void)
380 int cpu
= smp_processor_id();
383 local_enabled
= (flags
>> EFLAGS_IF_SHIFT
) & 1;
384 /* default to local */
385 retval
= 2 + local_enabled
;
387 /* check for global flags if we're not in an interrupt */
388 if (!local_irq_count(cpu
)) {
391 if (global_irq_holder
== cpu
)
397 void __global_restore_flags(unsigned long flags
)
413 printk("global_restore_flags: %08lx (%08lx)\n",
414 flags
, (&flags
)[-1]);
421 * This should really return information about whether
422 * we should do bottom half handling etc. Right now we
423 * end up _always_ checking the bottom half, which is a
424 * waste of time and is not what some drivers would
427 int handle_IRQ_event(unsigned int irq
, struct pt_regs
* regs
, struct irqaction
* action
)
430 int cpu
= smp_processor_id();
434 status
= 1; /* Force the "do bottom halves" bit */
436 if (!(action
->flags
& SA_INTERRUPT
))
440 status
|= action
->flags
;
441 action
->handler(irq
, action
->dev_id
, regs
);
442 action
= action
->next
;
444 if (status
& SA_SAMPLE_RANDOM
)
445 add_interrupt_randomness(irq
);
454 * Generic enable/disable code: this just calls
455 * down into the PIC-specific version for the actual
456 * hardware disable after having gotten the irq
461 * disable_irq_nosync - disable an irq without waiting
462 * @irq: Interrupt to disable
464 * Disable the selected interrupt line. Disables of an interrupt
465 * stack. Unlike disable_irq(), this function does not ensure existing
466 * instances of the IRQ handler have completed before returning.
468 * This function may be called from IRQ context.
471 void inline disable_irq_nosync(unsigned int irq
)
473 irq_desc_t
*desc
= irq_desc
+ irq
;
476 spin_lock_irqsave(&desc
->lock
, flags
);
477 if (!desc
->depth
++) {
478 desc
->status
|= IRQ_DISABLED
;
479 desc
->handler
->disable(irq
);
481 spin_unlock_irqrestore(&desc
->lock
, flags
);
485 * disable_irq - disable an irq and wait for completion
486 * @irq: Interrupt to disable
488 * Disable the selected interrupt line. Disables of an interrupt
489 * stack. That is for two disables you need two enables. This
490 * function waits for any pending IRQ handlers for this interrupt
491 * to complete before returning. If you use this function while
492 * holding a resource the IRQ handler may need you will deadlock.
494 * This function may be called - with care - from IRQ context.
497 void disable_irq(unsigned int irq
)
499 disable_irq_nosync(irq
);
501 if (!local_irq_count(smp_processor_id())) {
504 } while (irq_desc
[irq
].status
& IRQ_INPROGRESS
);
509 * enable_irq - enable interrupt handling on an irq
510 * @irq: Interrupt to enable
512 * Re-enables the processing of interrupts on this IRQ line
513 * providing no disable_irq calls are now in effect.
515 * This function may be called from IRQ context.
518 void enable_irq(unsigned int irq
)
520 irq_desc_t
*desc
= irq_desc
+ irq
;
523 spin_lock_irqsave(&desc
->lock
, flags
);
524 switch (desc
->depth
) {
526 unsigned int status
= desc
->status
& ~IRQ_DISABLED
;
527 desc
->status
= status
;
528 if ((status
& (IRQ_PENDING
| IRQ_REPLAY
)) == IRQ_PENDING
) {
529 desc
->status
= status
| IRQ_REPLAY
;
530 hw_resend_irq(desc
->handler
,irq
);
532 desc
->handler
->enable(irq
);
539 printk("enable_irq() unbalanced from %p\n",
540 __builtin_return_address(0));
542 spin_unlock_irqrestore(&desc
->lock
, flags
);
546 * do_IRQ handles all normal device IRQ's (the special
547 * SMP cross-CPU interrupts have their own specific
550 asmlinkage
unsigned int do_IRQ(struct pt_regs regs
)
553 * We ack quickly, we don't want the irq controller
554 * thinking we're snobs just because some other CPU has
555 * disabled global interrupts (we have already done the
556 * INT_ACK cycles, it's too late to try to pretend to the
557 * controller that we aren't taking the interrupt).
559 * 0 return value means that this irq is already being
560 * handled by some other CPU. (or is disabled)
562 int irq
= regs
.orig_eax
& 0xff; /* high bits used in ret_from_ code */
563 int cpu
= smp_processor_id();
564 irq_desc_t
*desc
= irq_desc
+ irq
;
565 struct irqaction
* action
;
568 kstat
.irqs
[cpu
][irq
]++;
569 spin_lock(&desc
->lock
);
570 desc
->handler
->ack(irq
);
572 REPLAY is when Linux resends an IRQ that was dropped earlier
573 WAITING is used by probe to mark irqs that are being tested
575 status
= desc
->status
& ~(IRQ_REPLAY
| IRQ_WAITING
);
576 status
|= IRQ_PENDING
; /* we _want_ to handle it */
579 * If the IRQ is disabled for whatever reason, we cannot
580 * use the action we have.
583 if (!(status
& (IRQ_DISABLED
| IRQ_INPROGRESS
))) {
584 action
= desc
->action
;
585 status
&= ~IRQ_PENDING
; /* we commit to handling */
586 status
|= IRQ_INPROGRESS
; /* we are handling it */
588 desc
->status
= status
;
591 * If there is no IRQ handler or it was disabled, exit early.
592 Since we set PENDING, if another processor is handling
593 a different instance of this same irq, the other processor
594 will take care of it.
600 * Edge triggered interrupts need to remember
602 * This applies to any hw interrupts that allow a second
603 * instance of the same irq to arrive while we are in do_IRQ
604 * or in the handler. But the code here only handles the _second_
605 * instance of the irq, not the third or fourth. So it is mostly
606 * useful for irq hardware that does not mask cleanly in an
610 spin_unlock(&desc
->lock
);
611 handle_IRQ_event(irq
, ®s
, action
);
612 spin_lock(&desc
->lock
);
614 if (!(desc
->status
& IRQ_PENDING
))
616 desc
->status
&= ~IRQ_PENDING
;
618 desc
->status
&= ~IRQ_INPROGRESS
;
621 * The ->end() handler has to deal with interrupts which got
622 * disabled while the handler was running.
624 desc
->handler
->end(irq
);
625 spin_unlock(&desc
->lock
);
627 if (softirq_state
[cpu
].active
& softirq_state
[cpu
].mask
)
633 * request_irq - allocate an interrupt line
634 * @irq: Interrupt line to allocate
635 * @handler: Function to be called when the IRQ occurs
636 * @irqflags: Interrupt type flags
637 * @devname: An ascii name for the claiming device
638 * @dev_id: A cookie passed back to the handler function
640 * This call allocates interrupt resources and enables the
641 * interrupt line and IRQ handling. From the point this
642 * call is made your handler function may be invoked. Since
643 * your handler function must clear any interrupt the board
644 * raises, you must take care both to initialise your hardware
645 * and to set up the interrupt handler in the right order.
647 * Dev_id must be globally unique. Normally the address of the
648 * device data structure is used as the cookie. Since the handler
649 * receives this value it makes sense to use it.
651 * If your interrupt is shared you must pass a non NULL dev_id
652 * as this is required when freeing the interrupt.
656 * SA_SHIRQ Interrupt is shared
658 * SA_INTERRUPT Disable local interrupts while processing
660 * SA_SAMPLE_RANDOM The interrupt can be used for entropy
664 int request_irq(unsigned int irq
,
665 void (*handler
)(int, void *, struct pt_regs
*),
666 unsigned long irqflags
,
667 const char * devname
,
671 struct irqaction
* action
;
675 * Sanity-check: shared interrupts should REALLY pass in
676 * a real dev-ID, otherwise we'll have trouble later trying
677 * to figure out which interrupt is which (messes up the
678 * interrupt freeing logic etc).
680 if (irqflags
& SA_SHIRQ
) {
682 printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n", devname
, (&irq
)[-1]);
691 action
= (struct irqaction
*)
692 kmalloc(sizeof(struct irqaction
), GFP_KERNEL
);
696 action
->handler
= handler
;
697 action
->flags
= irqflags
;
699 action
->name
= devname
;
701 action
->dev_id
= dev_id
;
703 retval
= setup_irq(irq
, action
);
710 * free_irq - free an interrupt
711 * @irq: Interrupt line to free
712 * @dev_id: Device identity to free
714 * Remove an interrupt handler. The handler is removed and if the
715 * interrupt line is no longer in use by any driver it is disabled.
716 * On a shared IRQ the caller must ensure the interrupt is disabled
717 * on the card it drives before calling this function. The function
718 * does not return until any executing interrupts for this IRQ
721 * This function may be called from interrupt context.
723 * Bugs: Attempting to free an irq in a handler for the same irq hangs
727 void free_irq(unsigned int irq
, void *dev_id
)
730 struct irqaction
**p
;
736 desc
= irq_desc
+ irq
;
737 spin_lock_irqsave(&desc
->lock
,flags
);
740 struct irqaction
* action
= *p
;
742 struct irqaction
**pp
= p
;
744 if (action
->dev_id
!= dev_id
)
747 /* Found it - now remove it from the list of entries */
750 desc
->status
|= IRQ_DISABLED
;
751 desc
->handler
->shutdown(irq
);
753 spin_unlock_irqrestore(&desc
->lock
,flags
);
756 /* Wait to make sure it's not being used on another CPU */
757 while (desc
->status
& IRQ_INPROGRESS
)
763 printk("Trying to free free IRQ%d\n",irq
);
764 spin_unlock_irqrestore(&desc
->lock
,flags
);
770 * IRQ autodetection code..
772 * This depends on the fact that any interrupt that
773 * comes in on to an unassigned handler will get stuck
774 * with "IRQ_WAITING" cleared and the interrupt
779 * probe_irq_on - begin an interrupt autodetect
781 * Commence probing for an interrupt. The interrupts are scanned
782 * and a mask of potential interrupt lines is returned.
786 unsigned long probe_irq_on(void)
794 * something may have generated an irq long ago and we want to
795 * flush such a longstanding irq before considering it as spurious.
797 for (i
= NR_IRQS
-1; i
> 0; i
--) {
800 spin_lock_irq(&desc
->lock
);
801 if (!irq_desc
[i
].action
)
802 irq_desc
[i
].handler
->startup(i
);
803 spin_unlock_irq(&desc
->lock
);
806 /* Wait for longstanding interrupts to trigger. */
807 for (delay
= jiffies
+ HZ
/50; time_after(delay
, jiffies
); )
808 /* about 20ms delay */ synchronize_irq();
811 * enable any unassigned irqs
812 * (we must startup again here because if a longstanding irq
813 * happened in the previous stage, it may have masked itself)
815 for (i
= NR_IRQS
-1; i
> 0; i
--) {
818 spin_lock_irq(&desc
->lock
);
820 desc
->status
|= IRQ_AUTODETECT
| IRQ_WAITING
;
821 if (desc
->handler
->startup(i
))
822 desc
->status
|= IRQ_PENDING
;
824 spin_unlock_irq(&desc
->lock
);
828 * Wait for spurious interrupts to trigger
830 for (delay
= jiffies
+ HZ
/10; time_after(delay
, jiffies
); )
831 /* about 100ms delay */ synchronize_irq();
834 * Now filter out any obviously spurious interrupts
837 for (i
= 0; i
< NR_IRQS
; i
++) {
838 irq_desc_t
*desc
= irq_desc
+ i
;
841 spin_lock_irq(&desc
->lock
);
842 status
= desc
->status
;
844 if (status
& IRQ_AUTODETECT
) {
845 /* It triggered already - consider it spurious. */
846 if (!(status
& IRQ_WAITING
)) {
847 desc
->status
= status
& ~IRQ_AUTODETECT
;
848 desc
->handler
->shutdown(i
);
853 spin_unlock_irq(&desc
->lock
);
860 * Return a mask of triggered interrupts (this
861 * can handle only legacy ISA interrupts).
865 * probe_irq_mask - scan a bitmap of interrupt lines
866 * @val: mask of interrupts to consider
868 * Scan the ISA bus interrupt lines and return a bitmap of
869 * active interrupts. The interrupt probe logic state is then
870 * returned to its previous value.
873 unsigned int probe_irq_mask(unsigned long val
)
879 for (i
= 0; i
< 16; i
++) {
880 irq_desc_t
*desc
= irq_desc
+ i
;
883 spin_lock_irq(&desc
->lock
);
884 status
= desc
->status
;
886 if (status
& IRQ_AUTODETECT
) {
887 if (!(status
& IRQ_WAITING
))
890 desc
->status
= status
& ~IRQ_AUTODETECT
;
891 desc
->handler
->shutdown(i
);
893 spin_unlock_irq(&desc
->lock
);
900 * Return the one interrupt that triggered (this can
901 * handle any interrupt source).
905 * probe_irq_off - end an interrupt autodetect
906 * @val: mask of potential interrupts (unused)
908 * Scans the unused interrupt lines and returns the line which
909 * appears to have triggered the interrupt. If no interrupt was
910 * found then zero is returned. If more than one interrupt is
911 * found then minus the first candidate is returned to indicate
914 * The interrupt probe logic state is returned to its previous
917 * BUGS: When used in a module (which arguably shouldnt happen)
918 * nothing prevents two IRQ probe callers from overlapping. The
919 * results of this are non-optimal.
922 int probe_irq_off(unsigned long val
)
924 int i
, irq_found
, nr_irqs
;
928 for (i
= 0; i
< NR_IRQS
; i
++) {
929 irq_desc_t
*desc
= irq_desc
+ i
;
932 spin_lock_irq(&desc
->lock
);
933 status
= desc
->status
;
935 if (status
& IRQ_AUTODETECT
) {
936 if (!(status
& IRQ_WAITING
)) {
941 desc
->status
= status
& ~IRQ_AUTODETECT
;
942 desc
->handler
->shutdown(i
);
944 spin_unlock_irq(&desc
->lock
);
948 irq_found
= -irq_found
;
952 /* this was setup_x86_irq but it seems pretty generic */
953 int setup_irq(unsigned int irq
, struct irqaction
* new)
957 struct irqaction
*old
, **p
;
958 irq_desc_t
*desc
= irq_desc
+ irq
;
961 * Some drivers like serial.c use request_irq() heavily,
962 * so we have to be careful not to interfere with a
965 if (new->flags
& SA_SAMPLE_RANDOM
) {
967 * This function might sleep, we want to call it first,
968 * outside of the atomic block.
969 * Yes, this might clear the entropy pool if the wrong
970 * driver is attempted to be loaded, without actually
971 * installing a new handler, but is this really a problem,
972 * only the sysadmin is able to do this.
974 rand_initialize_irq(irq
);
978 * The following block of code has to be executed atomically
980 spin_lock_irqsave(&desc
->lock
,flags
);
982 if ((old
= *p
) != NULL
) {
983 /* Can't share interrupts unless both agree to */
984 if (!(old
->flags
& new->flags
& SA_SHIRQ
)) {
985 spin_unlock_irqrestore(&desc
->lock
,flags
);
989 /* add new interrupt at end of irq queue */
1001 desc
->status
&= ~IRQ_DISABLED
;
1002 desc
->handler
->startup(irq
);
1004 spin_unlock_irqrestore(&desc
->lock
,flags
);
1006 register_irq_proc(irq
);
1010 static struct proc_dir_entry
* root_irq_dir
;
1011 static struct proc_dir_entry
* irq_dir
[NR_IRQS
];
1012 static struct proc_dir_entry
* smp_affinity_entry
[NR_IRQS
];
1014 static unsigned long irq_affinity
[NR_IRQS
] = { [0 ... NR_IRQS
-1] = ~0UL };
1016 #define HEX_DIGITS 8
1018 static int irq_affinity_read_proc (char *page
, char **start
, off_t off
,
1019 int count
, int *eof
, void *data
)
1021 if (count
< HEX_DIGITS
+1)
1023 return sprintf (page
, "%08lx\n", irq_affinity
[(long)data
]);
1026 static unsigned int parse_hex_value (const char *buffer
,
1027 unsigned long count
, unsigned long *ret
)
1029 unsigned char hexnum
[HEX_DIGITS
];
1030 unsigned long value
;
1035 if (count
> HEX_DIGITS
)
1037 if (copy_from_user(hexnum
, buffer
, count
))
1041 * Parse the first 8 characters as a hex string, any non-hex char
1042 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
1046 for (i
= 0; i
< count
; i
++) {
1047 unsigned int c
= hexnum
[i
];
1050 case '0' ... '9': c
-= '0'; break;
1051 case 'a' ... 'f': c
-= 'a'-10; break;
1052 case 'A' ... 'F': c
-= 'A'-10; break;
1056 value
= (value
<< 4) | c
;
1063 static int irq_affinity_write_proc (struct file
*file
, const char *buffer
,
1064 unsigned long count
, void *data
)
1066 int irq
= (long) data
, full_count
= count
, err
;
1067 unsigned long new_value
;
1069 if (!irq_desc
[irq
].handler
->set_affinity
)
1072 err
= parse_hex_value(buffer
, count
, &new_value
);
1076 * Do not allow disabling IRQs completely - it's a too easy
1077 * way to make the system unusable accidentally :-) At least
1078 * one online CPU still has to be targeted.
1080 if (!(new_value
& cpu_online_map
))
1084 irq_affinity
[irq
] = new_value
;
1085 irq_desc
[irq
].handler
->set_affinity(irq
, new_value
);
1090 static int prof_cpu_mask_read_proc (char *page
, char **start
, off_t off
,
1091 int count
, int *eof
, void *data
)
1093 unsigned long *mask
= (unsigned long *) data
;
1094 if (count
< HEX_DIGITS
+1)
1096 return sprintf (page
, "%08lx\n", *mask
);
1099 static int prof_cpu_mask_write_proc (struct file
*file
, const char *buffer
,
1100 unsigned long count
, void *data
)
1102 unsigned long *mask
= (unsigned long *) data
, full_count
= count
, err
;
1103 unsigned long new_value
;
1105 err
= parse_hex_value(buffer
, count
, &new_value
);
1113 #define MAX_NAMELEN 10
1115 static void register_irq_proc (unsigned int irq
)
1117 struct proc_dir_entry
*entry
;
1118 char name
[MAX_NAMELEN
];
1120 if (!root_irq_dir
|| (irq_desc
[irq
].handler
== &no_irq_type
) ||
1124 memset(name
, 0, MAX_NAMELEN
);
1125 sprintf(name
, "%d", irq
);
1127 /* create /proc/irq/1234 */
1128 irq_dir
[irq
] = proc_mkdir(name
, root_irq_dir
);
1130 /* create /proc/irq/1234/smp_affinity */
1131 entry
= create_proc_entry("smp_affinity", 0600, irq_dir
[irq
]);
1134 entry
->data
= (void *)(long)irq
;
1135 entry
->read_proc
= irq_affinity_read_proc
;
1136 entry
->write_proc
= irq_affinity_write_proc
;
1138 smp_affinity_entry
[irq
] = entry
;
1141 unsigned long prof_cpu_mask
= -1;
1143 void init_irq_proc (void)
1145 struct proc_dir_entry
*entry
;
1148 /* create /proc/irq */
1149 root_irq_dir
= proc_mkdir("irq", 0);
1151 /* create /proc/irq/prof_cpu_mask */
1152 entry
= create_proc_entry("prof_cpu_mask", 0600, root_irq_dir
);
1155 entry
->data
= (void *)&prof_cpu_mask
;
1156 entry
->read_proc
= prof_cpu_mask_read_proc
;
1157 entry
->write_proc
= prof_cpu_mask_write_proc
;
1160 * Create entries for all existing IRQs.
1162 for (i
= 0; i
< NR_IRQS
; i
++)
1163 register_irq_proc(i
);