[patch] generic-hardirqs.patch, 2.6.9-rc1-bk14

Ingo Molnar
2004-09-08T12:08:59Z

[-- Attachment #1: Type: text/plain, Size: 973 bytes --]

the attached patch moves generic hardirq handling bits to
kernel/hardirq.c. It is not a replacement for any of the existing IRQ
functions, so architectures can use their existing hardirq code in an
unmodified form. It is a library of generic functions that an
architecture can make use of optionally.

I've fully converted x86's irq.c to use the new functions, and Scott
Wood has done the same for ppc/ppc64 as well. (the arch-ppc* changes are
not included in this patch because i couldnt test them myself in the
current port of this patch - but the generic bits were tested on ppc.)

i have test-compiled and test-booted the patch on x86 and x64, on SMP &&
PREEMPT and !SMP && !PREEMPT kernels. x64 needed only a single change (a
setup_irq() prototype) to work fine, which makes me believe that the
patch will not break other architectures either.

(a more complex version of this patch has been tested for weeks as part
of the voluntary-preempt patches as well.)

Ingo

[-- Attachment #2: generic-hardirqs.patch --]
[-- Type: text/plain, Size: 31992 bytes --]

the attached patch moves generic hardirq handling bits into
kernel/hardirq.c. It is not a replacement for any of the existing IRQ
functions, so architectures can use their existing hardirq code in an
unmodified form. It is a library of generic functions that an
architecture can make use of optionally.

I've fully converted x86's irq.c to use the new functions - and Scott
Wood has done the same for ppc/ppc64 as well. (the arch-ppc* changes are
not included in this patch because i couldnt test them myself in the
current port of this patch - but the generic bits were tested on ppc)

i have test-compiled the patch on x86 and x64, on SMP && PREEMPT and
!SMP && !PREEMPT. x64 needed only a single change - a setup_irq()
prototype, to work fine, which makes me believe that the patch will not
break any other architectures either.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

--- linux/arch/i386/kernel/i386_ksyms.c.orig
+++ linux/arch/i386/kernel/i386_ksyms.c
@@ -77,9 +77,6 @@ EXPORT_SYMBOL_GPL(kernel_fpu_begin);
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(ioremap_nocache);
EXPORT_SYMBOL(iounmap);
-EXPORT_SYMBOL(enable_irq);
-EXPORT_SYMBOL(disable_irq);
-EXPORT_SYMBOL(disable_irq_nosync);
EXPORT_SYMBOL(probe_irq_mask);
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(pm_idle);
@@ -147,7 +144,6 @@ EXPORT_SYMBOL_NOVERS(__write_lock_failed
EXPORT_SYMBOL_NOVERS(__read_lock_failed);

/* Global SMP stuff */
-EXPORT_SYMBOL(synchronize_irq);
EXPORT_SYMBOL(smp_call_function);

/* TLB flushing */
--- linux/arch/i386/kernel/irq.c.orig
+++ linux/arch/i386/kernel/irq.c
@@ -71,8 +71,6 @@ irq_desc_t irq_desc[NR_IRQS] __cacheline
}
};

-static void register_irq_proc (unsigned int irq);
-
/*
* per-CPU IRQ handling stacks
*/
@@ -198,218 +196,6 @@ skip:
return 0;
}

-
-
-
-#ifdef CONFIG_SMP
-inline void synchronize_irq(unsigned int irq)
-{
- while (irq_desc[irq].status & IRQ_INPROGRESS)
- cpu_relax();
-}
-#endif
-
-/*
- * This should really return information about whether
- * we should do bottom half handling etc. Right now we
- * end up _always_ checking the bottom half, which is a
- * waste of time and is not what some drivers would
- * prefer.
- */
-asmlinkage int handle_IRQ_event(unsigned int irq,
- struct pt_regs *regs, struct irqaction *action)
-{
- int status = 1; /* Force the "do bottom halves" bit */
- int ret, retval = 0;
-
- if (!(action->flags & SA_INTERRUPT))
- local_irq_enable();
-
- do {
- ret = action->handler(irq, action->dev_id, regs);
- if (ret == IRQ_HANDLED)
- status |= action->flags;
- retval |= ret;
- action = action->next;
- } while (action);
- if (status & SA_SAMPLE_RANDOM)
- add_interrupt_randomness(irq);
- local_irq_disable();
- return retval;
-}
-
-static void __report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
-{
- struct irqaction *action;
-
- if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
- printk(KERN_ERR "irq event %d: bogus return value %x\n",
- irq, action_ret);
- } else {
- printk(KERN_ERR "irq %d: nobody cared!\n", irq);
- }
- dump_stack();
- printk(KERN_ERR "handlers:\n");
- action = desc->action;
- do {
- printk(KERN_ERR "[<%p>]", action->handler);
- print_symbol(" (%s)",
- (unsigned long)action->handler);
- printk("\n");
- action = action->next;
- } while (action);
-}
-
-static void report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
-{
- static int count = 100;
-
- if (count) {
- count--;
- __report_bad_irq(irq, desc, action_ret);
- }
-}
-
-static int noirqdebug;
-
-static int __init noirqdebug_setup(char *str)
-{
- noirqdebug = 1;
- printk("IRQ lockup detection disabled\n");
- return 1;
-}
-
-__setup("noirqdebug", noirqdebug_setup);
-
-/*
- * If 99,900 of the previous 100,000 interrupts have not been handled then
- * assume that the IRQ is stuck in some manner. Drop a diagnostic and try to
- * turn the IRQ off.
- *
- * (The other 100-of-100,000 interrupts may have been a correctly-functioning
- * device sharing an IRQ with the failing one)
- *
- * Called under desc->lock
- */
-static void note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret)
-{
- if (action_ret != IRQ_HANDLED) {
- desc->irqs_unhandled++;
- if (action_ret != IRQ_NONE)
- report_bad_irq(irq, desc, action_ret);
- }
-
- desc->irq_count++;
- if (desc->irq_count < 100000)
- return;
-
- desc->irq_count = 0;
- if (desc->irqs_unhandled > 99900) {
- /*
- * The interrupt is stuck
- */
- __report_bad_irq(irq, desc, action_ret);
- /*
- * Now kill the IRQ
- */
- printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
- desc->status |= IRQ_DISABLED;
- desc->handler->disable(irq);
- }
- desc->irqs_unhandled = 0;
-}
-
-/*
- * Generic enable/disable code: this just calls
- * down into the PIC-specific version for the actual
- * hardware disable after having gotten the irq
- * controller lock.
- */
-
-/**
- * disable_irq_nosync - disable an irq without waiting
- * @irq: Interrupt to disable
- *
- * Disable the selected interrupt line. Disables and Enables are
- * nested.
- * Unlike disable_irq(), this function does not ensure existing
- * instances of the IRQ handler have completed before returning.
- *
- * This function may be called from IRQ context.
- */
-
-inline void disable_irq_nosync(unsigned int irq)
-{
- irq_desc_t *desc = irq_desc + irq;
- unsigned long flags;
-
- spin_lock_irqsave(&desc->lock, flags);
- if (!desc->depth++) {
- desc->status |= IRQ_DISABLED;
- desc->handler->disable(irq);
- }
- spin_unlock_irqrestore(&desc->lock, flags);
-}
-
-/**
- * disable_irq - disable an irq and wait for completion
- * @irq: Interrupt to disable
- *
- * Disable the selected interrupt line. Enables and Disables are
- * nested.
- * This function waits for any pending IRQ handlers for this interrupt
- * to complete before returning. If you use this function while
- * holding a resource the IRQ handler may need you will deadlock.
- *
- * This function may be called - with care - from IRQ context.
- */
-
-void disable_irq(unsigned int irq)
-{
- irq_desc_t *desc = irq_desc + irq;
- disable_irq_nosync(irq);
- if (desc->action)
- synchronize_irq(irq);
-}
-
-/**
- * enable_irq - enable handling of an irq
- * @irq: Interrupt to enable
- *
- * Undoes the effect of one call to disable_irq(). If this
- * matches the last disable, processing of interrupts on this
- * IRQ line is re-enabled.
- *
- * This function may be called from IRQ context.
- */
-
-void enable_irq(unsigned int irq)
-{
- irq_desc_t *desc = irq_desc + irq;
- unsigned long flags;
-
- spin_lock_irqsave(&desc->lock, flags);
- switch (desc->depth) {
- case 1: {
- unsigned int status = desc->status & ~IRQ_DISABLED;
- desc->status = status;
- if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
- desc->status = status | IRQ_REPLAY;
- hw_resend_irq(desc->handler,irq);
- }
- desc->handler->enable(irq);
- /* fall-through */
- }
- default:
- desc->depth--;
- break;
- case 0:
- printk("enable_irq(%u) unbalanced from %p\n", irq,
- __builtin_return_address(0));
- }
- spin_unlock_irqrestore(&desc->lock, flags);
-}
-
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
@@ -510,7 +296,7 @@ asmlinkage unsigned int do_IRQ(struct pt
*/

if (curctx == irqctx)
- action_ret = handle_IRQ_event(irq, &regs, action);
+ action_ret = generic_handle_IRQ_event(irq, &regs, action);
else {
/* build the stack frame on the IRQ stack */
isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
@@ -523,7 +309,7 @@ asmlinkage unsigned int do_IRQ(struct pt

asm volatile(
" xchgl %%ebx,%%esp \n"
- " call handle_IRQ_event \n"
+ " call generic_handle_IRQ_event \n"
" xchgl %%ebx,%%esp \n"
: "=a"(action_ret)
: "b"(isp)
@@ -534,7 +320,7 @@ asmlinkage unsigned int do_IRQ(struct pt
}
spin_lock(&desc->lock);
if (!noirqdebug)
- note_interrupt(irq, desc, action_ret);
+ generic_note_interrupt(irq, desc, action_ret);
if (curctx != irqctx)
irqctx->tinfo.task = NULL;
if (likely(!(desc->status & IRQ_PENDING)))
@@ -549,11 +335,11 @@ asmlinkage unsigned int do_IRQ(struct pt

spin_unlock(&desc->lock);

- action_ret = handle_IRQ_event(irq, &regs, action);
+ action_ret = generic_handle_IRQ_event(irq, &regs, action);

spin_lock(&desc->lock);
if (!noirqdebug)
- note_interrupt(irq, desc, action_ret);
+ generic_note_interrupt(irq, desc, action_ret);
if (likely(!(desc->status & IRQ_PENDING)))
break;
desc->status &= ~IRQ_PENDING;
@@ -659,7 +445,7 @@ int request_irq(unsigned int irq,
action->next = NULL;
action->dev_id = dev_id;

- retval = setup_irq(irq, action);
+ retval = generic_setup_irq(irq, action);
if (retval)
kfree(action);
return retval;
@@ -667,62 +453,6 @@ int request_irq(unsigned int irq,

EXPORT_SYMBOL(request_irq);

-/**
- * free_irq - free an interrupt
- * @irq: Interrupt line to free
- * @dev_id: Device identity to free
- *
- * Remove an interrupt handler. The handler is removed and if the
- * interrupt line is no longer in use by any driver it is disabled.
- * On a shared IRQ the caller must ensure the interrupt is disabled
- * on the card it drives before calling this function. The function
- * does not return until any executing interrupts for this IRQ
- * have completed.
- *
- * This function must not be called from interrupt context.
- */
-
-void free_irq(unsigned int irq, void *dev_id)
-{
- irq_desc_t *desc;
- struct irqaction **p;
- unsigned long flags;
-
- if (irq >= NR_IRQS)
- return;
-
- desc = irq_desc + irq;
- spin_lock_irqsave(&desc->lock,flags);
- p = &desc->action;
- for (;;) {
- struct irqaction * action = *p;
- if (action) {
- struct irqaction **pp = p;
- p = &action->next;
- if (action->dev_id != dev_id)
- continue;
-
- /* Found it - now remove it from the list of entries */
- *pp = action->next;
- if (!desc->action) {
- desc->status |= IRQ_DISABLED;
- desc->handler->shutdown(irq);
- }
- spin_unlock_irqrestore(&desc->lock,flags);
-
- /* Wait to make sure it's not being used on another CPU */
- synchronize_irq(irq);
- kfree(action);
- return;
- }
- printk("Trying to free free IRQ%d\n",irq);
- spin_unlock_irqrestore(&desc->lock,flags);
- return;
- }
-}
-
-EXPORT_SYMBOL(free_irq);
-
/*
* IRQ autodetection code..
*
@@ -918,165 +648,6 @@ int probe_irq_off(unsigned long val)

EXPORT_SYMBOL(probe_irq_off);

-/* this was setup_x86_irq but it seems pretty generic */
-int setup_irq(unsigned int irq, struct irqaction * new)
-{
- int shared = 0;
- unsigned long flags;
- struct irqaction *old, **p;
- irq_desc_t *desc = irq_desc + irq;
-
- if (desc->handler == &no_irq_type)
- return -ENOSYS;
- /*
- * Some drivers like serial.c use request_irq() heavily,
- * so we have to be careful not to interfere with a
- * running system.
- */
- if (new->flags & SA_SAMPLE_RANDOM) {
- /*
- * This function might sleep, we want to call it first,
- * outside of the atomic block.
- * Yes, this might clear the entropy pool if the wrong
- * driver is attempted to be loaded, without actually
- * installing a new handler, but is this really a problem,
- * only the sysadmin is able to do this.
- */
- rand_initialize_irq(irq);
- }
-
- /*
- * The following block of code has to be executed atomically
- */
- spin_lock_irqsave(&desc->lock,flags);
- p = &desc->action;
- if ((old = *p) != NULL) {
- /* Can't share interrupts unless both agree to */
- if (!(old->flags & new->flags & SA_SHIRQ)) {
- spin_unlock_irqrestore(&desc->lock,flags);
- return -EBUSY;
- }
-
- /* add new interrupt at end of irq queue */
- do {
- p = &old->next;
- old = *p;
- } while (old);
- shared = 1;
- }
-
- *p = new;
-
- if (!shared) {
- desc->depth = 0;
- desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
- desc->handler->startup(irq);
- }
- spin_unlock_irqrestore(&desc->lock,flags);
-
- register_irq_proc(irq);
- return 0;
-}
-
-static struct proc_dir_entry * root_irq_dir;
-static struct proc_dir_entry * irq_dir [NR_IRQS];
-
-#ifdef CONFIG_SMP
-
-static struct proc_dir_entry *smp_affinity_entry[NR_IRQS];
-
-cpumask_t irq_affinity[NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
-
-static int irq_affinity_read_proc(char *page, char **start, off_t off,
- int count, int *eof, void *data)
-{
- int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]);
- if (count - len < 2)
- return -EINVAL;
- len += sprintf(page + len, "\n");
- return len;
-}
-
-static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
- unsigned long count, void *data)
-{
- int irq = (long)data, full_count = count, err;
- cpumask_t new_value, tmp;
-
- if (!irq_desc[irq].handler->set_affinity)
- return -EIO;
-
- err = cpumask_parse(buffer, count, new_value);
- if (err)
- return err;
-
- /*
- * Do not allow disabling IRQs completely - it's a too easy
- * way to make the system unusable accidentally :-) At least
- * one online CPU still has to be targeted.
- */
- cpus_and(tmp, new_value, cpu_online_map);
- if (cpus_empty(tmp))
- return -EINVAL;
-
- irq_affinity[irq] = new_value;
- irq_desc[irq].handler->set_affinity(irq,
- cpumask_of_cpu(first_cpu(new_value)));
-
- return full_count;
-}
-
-#endif
-#define MAX_NAMELEN 10
-
-static void register_irq_proc (unsigned int irq)
-{
- char name [MAX_NAMELEN];
-
- if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) ||
- irq_dir[irq])
- return;
-
- memset(name, 0, MAX_NAMELEN);
- sprintf(name, "%d", irq);
-
- /* create /proc/irq/1234 */
- irq_dir[irq] = proc_mkdir(name, root_irq_dir);
-
-#ifdef CONFIG_SMP
- {
- struct proc_dir_entry *entry;
-
- /* create /proc/irq/1234/smp_affinity */
- entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
-
- if (entry) {
- entry->nlink = 1;
- entry->data = (void *)(long)irq;
- entry->read_proc = irq_affinity_read_proc;
- entry->write_proc = irq_affinity_write_proc;
- }
-
- smp_affinity_entry[irq] = entry;
- }
-#endif
-}
-
-void init_irq_proc (void)
-{
- int i;
-
- /* create /proc/irq */
- root_irq_dir = proc_mkdir("irq", NULL);
- create_prof_cpu_mask(root_irq_dir);
- /*
- * Create entries for all existing IRQs.
- */
- for (i = 0; i < NR_IRQS; i++)
- register_irq_proc(i);
-}
-
-
#ifdef CONFIG_4KSTACKS
/*
* These should really be __section__(".bss.page_aligned") as well, but
--- linux/include/asm-x86_64/hardirq.h.orig
+++ linux/include/asm-x86_64/hardirq.h
@@ -25,8 +25,8 @@
* - ( bit 26 is the PREEMPT_ACTIVE flag. )
*
* PREEMPT_MASK: 0x000000ff
- * HARDIRQ_MASK: 0x0000ff00
- * SOFTIRQ_MASK: 0x00ff0000
+ * SOFTIRQ_MASK: 0x0000ff00
+ * HARDIRQ_MASK: 0x00ff0000
*/

#define PREEMPT_BITS 8
@@ -99,4 +99,6 @@ do { \
extern void synchronize_irq(unsigned int irq);
#endif /* CONFIG_SMP */

+extern int setup_irq(unsigned int irq, struct irqaction * new);
+
#endif /* __ASM_HARDIRQ_H */
--- linux/include/linux/irq.h.orig
+++ linux/include/linux/irq.h
@@ -10,12 +10,15 @@
*/

#include <linux/config.h>
+#include <linux/linkage.h>

#if !defined(CONFIG_ARCH_S390)

#include <linux/cache.h>
#include <linux/spinlock.h>
#include <linux/cpumask.h>
+#include <linux/wait.h>
+#include <linux/signal.h>

#include <asm/irq.h>
#include <asm/ptrace.h>
@@ -71,10 +74,21 @@ extern irq_desc_t irq_desc [NR_IRQS];

#include <asm/hw_irq.h> /* the arch dependent stuff */

-extern int setup_irq(unsigned int , struct irqaction * );
+
+extern asmlinkage int generic_handle_IRQ_event(unsigned int irq, struct pt_regs *regs, struct irqaction *action);
+extern void generic_synchronize_irq(unsigned int irq);
+extern int generic_setup_irq(unsigned int irq, struct irqaction * new);
+extern void generic_free_irq(unsigned int irq, void *dev_id);
+extern void generic_disable_irq_nosync(unsigned int irq);
+extern void generic_disable_irq(unsigned int irq);
+extern void generic_enable_irq(unsigned int irq);
+extern void generic_note_interrupt(int irq, irq_desc_t *desc, int action_ret);
+extern void generic_init_irq_proc(void);

extern hw_irq_controller no_irq_type; /* needed in every arch ? */

+extern int noirqdebug;
+
#endif

#endif /* __irq_h */
--- linux/include/linux/interrupt.h.orig
+++ linux/include/linux/interrupt.h
@@ -40,6 +40,8 @@ struct irqaction {
const char *name;
void *dev_id;
struct irqaction *next;
+ int irq;
+ struct proc_dir_entry *dir;
};

extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
--- linux/include/asm-i386/irq.h.orig
+++ linux/include/asm-i386/irq.h
@@ -21,9 +21,6 @@ static __inline__ int irq_canonicalize(i
return ((irq == 2) ? 9 : irq);
}

-extern void disable_irq(unsigned int);
-extern void disable_irq_nosync(unsigned int);
-extern void enable_irq(unsigned int);
extern void release_x86_irqs(struct task_struct *);
extern int can_request_irq(unsigned int, unsigned long flags);

--- linux/include/asm-i386/hardirq.h.orig
+++ linux/include/asm-i386/hardirq.h
@@ -68,10 +68,6 @@ typedef struct {
#define in_softirq() (softirq_count())
#define in_interrupt() (irq_count())

-
-#define hardirq_trylock() (!in_interrupt())
-#define hardirq_endlock() do { } while (0)
-
#define irq_enter() (preempt_count() += HARDIRQ_OFFSET)
#define nmi_enter() (irq_enter())
#define nmi_exit() (preempt_count() -= HARDIRQ_OFFSET)
@@ -92,10 +88,39 @@ do { \
preempt_enable_no_resched(); \
} while (0)

-#ifndef CONFIG_SMP
-# define synchronize_irq(irq) barrier()
-#else
- extern void synchronize_irq(unsigned int irq);
-#endif /* CONFIG_SMP */
+static inline void synchronize_irq(unsigned int irq)
+{
+ generic_synchronize_irq(irq);
+}
+
+static inline void free_irq(unsigned int irq, void *dev_id)
+{
+ generic_free_irq(irq, dev_id);
+}
+
+static inline void disable_irq_nosync(unsigned int irq)
+{
+ generic_disable_irq_nosync(irq);
+}
+
+static inline void disable_irq(unsigned int irq)
+{
+ generic_disable_irq(irq);
+}
+
+static inline void enable_irq(unsigned int irq)
+{
+ generic_enable_irq(irq);
+}
+
+static inline int setup_irq(unsigned int irq, struct irqaction *new)
+{
+ return generic_setup_irq(irq, new);
+}
+
+static inline void init_irq_proc(void)
+{
+ generic_init_irq_proc();
+}

#endif /* __ASM_HARDIRQ_H */
--- linux/kernel/Makefile.orig
+++ linux/kernel/Makefile
@@ -3,7 +3,7 @@
#

obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
- exit.o itimer.o time.o softirq.o resource.o \
+ exit.o itimer.o time.o softirq.o hardirq.o resource.o \
sysctl.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o intermodule.o extable.o params.o posix-timers.o \
--- linux/kernel/hardirq.c.orig
+++ linux/kernel/hardirq.c
@@ -0,0 +1,529 @@
+/*
+ * linux/kernel/hardirq.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the generic code used by various IRQ handling
+ * routines.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/kallsyms.h>
+#include <linux/proc_fs.h>
+#include <linux/irq.h>
+#include <linux/wait.h>
+#include <asm/uaccess.h>
+
+int noirqdebug;
+
+extern struct irq_desc irq_desc[NR_IRQS];
+
+static struct proc_dir_entry * root_irq_dir;
+static struct proc_dir_entry * irq_dir [NR_IRQS];
+
+static void register_irq_proc(unsigned int irq);
+static void register_handler_proc(unsigned int irq, struct irqaction *action);
+
+/*
+ * This should really return information about whether
+ * we should do bottom half handling etc. Right now we
+ * end up _always_ checking the bottom half, which is a
+ * waste of time and is not what some drivers would
+ * prefer.
+ */
+asmlinkage int generic_handle_IRQ_event(unsigned int irq,
+ struct pt_regs *regs, struct irqaction *action)
+{
+ int status = 1; /* Force the "do bottom halves" bit */
+ int ret, retval = 0;
+
+ if (!(action->flags & SA_INTERRUPT))
+ local_irq_enable();
+
+ do {
+ ret = action->handler(irq, action->dev_id, regs);
+ if (ret == IRQ_HANDLED)
+ status |= action->flags;
+ retval |= ret;
+ action = action->next;
+ } while (action);
+
+ if (status & SA_SAMPLE_RANDOM)
+ add_interrupt_randomness(irq);
+ local_irq_disable();
+
+ return retval;
+}
+
+static void __report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
+{
+ struct irqaction *action;
+
+ if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
+ printk(KERN_ERR "irq event %d: bogus return value %x\n",
+ irq, action_ret);
+ } else {
+ printk(KERN_ERR "irq %d: nobody cared!\n", irq);
+ }
+ dump_stack();
+ printk(KERN_ERR "handlers:\n");
+ action = desc->action;
+ while (action) {
+ printk(KERN_ERR "[<%p>]", action->handler);
+ print_symbol(" (%s)",
+ (unsigned long)action->handler);
+ printk("\n");
+ action = action->next;
+ }
+}
+
+static void report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
+{
+ static int count = 100;
+
+ if (count) {
+ count--;
+ __report_bad_irq(irq, desc, action_ret);
+ }
+}
+
+
+static int __init noirqdebug_setup(char *str)
+{
+ noirqdebug = 1;
+ printk("IRQ lockup detection disabled\n");
+ return 1;
+}
+
+__setup("noirqdebug", noirqdebug_setup);
+
+/*
+ * If 99,900 of the previous 100,000 interrupts have not been handled then
+ * assume that the IRQ is stuck in some manner. Drop a diagnostic and try to
+ * turn the IRQ off.
+ *
+ * (The other 100-of-100,000 interrupts may have been a correctly-functioning
+ * device sharing an IRQ with the failing one)
+ *
+ * Called under desc->lock
+ */
+void generic_note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret)
+{
+ if (action_ret != IRQ_HANDLED) {
+ desc->irqs_unhandled++;
+ if (action_ret != IRQ_NONE)
+ report_bad_irq(irq, desc, action_ret);
+ }
+
+ desc->irq_count++;
+ if (desc->irq_count < 100000)
+ return;
+
+ desc->irq_count = 0;
+ if (desc->irqs_unhandled > 99900) {
+ /*
+ * The interrupt is stuck
+ */
+ __report_bad_irq(irq, desc, action_ret);
+ /*
+ * Now kill the IRQ
+ */
+ printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
+ desc->status |= IRQ_DISABLED;
+ desc->handler->disable(irq);
+ }
+ desc->irqs_unhandled = 0;
+}
+
+void generic_synchronize_irq(unsigned int irq)
+{
+ struct irq_desc *desc = irq_desc + irq;
+
+ while (desc->status & IRQ_INPROGRESS)
+ cpu_relax();
+}
+
+EXPORT_SYMBOL(generic_synchronize_irq);
+
+/*
+ * Generic enable/disable code: this just calls
+ * down into the PIC-specific version for the actual
+ * hardware disable after having gotten the irq
+ * controller lock.
+ */
+
+/**
+ * disable_irq_nosync - disable an irq without waiting
+ * @irq: Interrupt to disable
+ *
+ * Disable the selected interrupt line. Disables and Enables are
+ * nested.
+ * Unlike disable_irq(), this function does not ensure existing
+ * instances of the IRQ handler have completed before returning.
+ *
+ * This function may be called from IRQ context.
+ */
+
+void generic_disable_irq_nosync(unsigned int irq)
+{
+ irq_desc_t *desc = irq_desc + irq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ if (!desc->depth++) {
+ desc->status |= IRQ_DISABLED;
+ desc->handler->disable(irq);
+ }
+ spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+EXPORT_SYMBOL(generic_disable_irq_nosync);
+
+/**
+ * disable_irq - disable an irq and wait for completion
+ * @irq: Interrupt to disable
+ *
+ * Disable the selected interrupt line. Enables and Disables are
+ * nested.
+ * This function waits for any pending IRQ handlers for this interrupt
+ * to complete before returning. If you use this function while
+ * holding a resource the IRQ handler may need you will deadlock.
+ *
+ * This function may be called - with care - from IRQ context.
+ */
+
+void generic_disable_irq(unsigned int irq)
+{
+ irq_desc_t *desc = irq_desc + irq;
+ generic_disable_irq_nosync(irq);
+ if (desc->action)
+ synchronize_irq(irq);
+}
+
+EXPORT_SYMBOL(generic_disable_irq);
+
+/**
+ * enable_irq - enable handling of an irq
+ * @irq: Interrupt to enable
+ *
+ * Undoes the effect of one call to disable_irq(). If this
+ * matches the last disable, processing of interrupts on this
+ * IRQ line is re-enabled.
+ *
+ * This function may be called from IRQ context.
+ */
+
+void generic_enable_irq(unsigned int irq)
+{
+ irq_desc_t *desc = irq_desc + irq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ switch (desc->depth) {
+ case 1: {
+ unsigned int status = desc->status & ~IRQ_DISABLED;
+ desc->status = status;
+ if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
+ desc->status = status | IRQ_REPLAY;
+ hw_resend_irq(desc->handler,irq);
+ }
+ desc->handler->enable(irq);
+ /* fall-through */
+ }
+ default:
+ desc->depth--;
+ break;
+ case 0:
+ printk("enable_irq(%u) unbalanced from %p\n", irq,
+ __builtin_return_address(0));
+ }
+ spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+EXPORT_SYMBOL(generic_enable_irq);
+
+int generic_setup_irq(unsigned int irq, struct irqaction * new)
+{
+ int shared = 0;
+ unsigned long flags;
+ struct irqaction *old, **p;
+ struct irq_desc *desc = irq_desc + irq;
+
+ if (desc->handler == &no_irq_type)
+ return -ENOSYS;
+ /*
+ * Some drivers like serial.c use request_irq() heavily,
+ * so we have to be careful not to interfere with a
+ * running system.
+ */
+ if (new->flags & SA_SAMPLE_RANDOM) {
+ /*
+ * This function might sleep, we want to call it first,
+ * outside of the atomic block.
+ * Yes, this might clear the entropy pool if the wrong
+ * driver is attempted to be loaded, without actually
+ * installing a new handler, but is this really a problem,
+ * only the sysadmin is able to do this.
+ */
+ rand_initialize_irq(irq);
+ }
+
+ /*
+ * The following block of code has to be executed atomically
+ */
+ spin_lock_irqsave(&desc->lock,flags);
+ p = &desc->action;
+ if ((old = *p) != NULL) {
+ /* Can't share interrupts unless both agree to */
+ if (!(old->flags & new->flags & SA_SHIRQ)) {
+ spin_unlock_irqrestore(&desc->lock,flags);
+ return -EBUSY;
+ }
+
+ /* add new interrupt at end of irq queue */
+ do {
+ p = &old->next;
+ old = *p;
+ } while (old);
+ shared = 1;
+ }
+
+ *p = new;
+
+ if (!shared) {
+ desc->depth = 0;
+ desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
+ if (desc->handler->startup)
+ desc->handler->startup(irq);
+ else
+ desc->handler->enable(irq);
+ }
+ spin_unlock_irqrestore(&desc->lock,flags);
+
+ new->irq = irq;
+ register_irq_proc(irq);
+ new->dir = NULL;
+ register_handler_proc(irq, new);
+
+ return 0;
+}
+
+/**
+ * generic_free_irq - free an interrupt
+ * @irq: Interrupt line to free
+ * @dev_id: Device identity to free
+ *
+ * Remove an interrupt handler. The handler is removed and if the
+ * interrupt line is no longer in use by any driver it is disabled.
+ * On a shared IRQ the caller must ensure the interrupt is disabled
+ * on the card it drives before calling this function. The function
+ * does not return until any executing interrupts for this IRQ
+ * have completed.
+ *
+ * This function must not be called from interrupt context.
+ */
+
+void generic_free_irq(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc;
+ struct irqaction **p;
+ unsigned long flags;
+
+ if (irq >= NR_IRQS)
+ return;
+
+ desc = irq_desc + irq;
+ spin_lock_irqsave(&desc->lock,flags);
+ p = &desc->action;
+ for (;;) {
+ struct irqaction * action = *p;
+ if (action) {
+ struct irqaction **pp = p;
+ p = &action->next;
+ if (action->dev_id != dev_id)
+ continue;
+
+ /* Found it - now remove it from the list of entries */
+ *pp = action->next;
+ if (!desc->action) {
+ desc->status |= IRQ_DISABLED;
+ if (desc->handler->shutdown)
+ desc->handler->shutdown(irq);
+ else
+ desc->handler->disable(irq);
+ }
+ spin_unlock_irqrestore(&desc->lock,flags);
+ if (action->dir)
+ remove_proc_entry(action->dir->name, irq_dir[irq]);
+
+ /* Wait to make sure it's not being used on another CPU */
+ synchronize_irq(irq);
+ kfree(action);
+ return;
+ }
+ printk("Trying to free free IRQ%d\n",irq);
+ spin_unlock_irqrestore(&desc->lock,flags);
+ return;
+ }
+}
+
+EXPORT_SYMBOL(generic_free_irq);
+
+#ifdef CONFIG_SMP
+
+static struct proc_dir_entry *smp_affinity_entry[NR_IRQS];
+
+cpumask_t irq_affinity[NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
+
+static int irq_affinity_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]);
+ if (count - len < 2)
+ return -EINVAL;
+ len += sprintf(page + len, "\n");
+ return len;
+}
+
+static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ int irq = (long)data, full_count = count, err;
+ cpumask_t new_value, tmp;
+
+ if (!irq_desc[irq].handler->set_affinity)
+ return -EIO;
+
+ err = cpumask_parse(buffer, count, new_value);
+ if (err)
+ return err;
+
+ /*
+ * Do not allow disabling IRQs completely - it's a too easy
+ * way to make the system unusable accidentally :-) At least
+ * one online CPU still has to be targeted.
+ */
+ cpus_and(tmp, new_value, cpu_online_map);
+ if (cpus_empty(tmp))
+ return -EINVAL;
+
+ irq_affinity[irq] = new_value;
+ irq_desc[irq].handler->set_affinity(irq,
+ cpumask_of_cpu(first_cpu(new_value)));
+
+ return full_count;
+}
+
+#endif
+
+static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = cpumask_scnprintf(page, count, *(cpumask_t *)data);
+ if (count - len < 2)
+ return -EINVAL;
+ len += sprintf(page + len, "\n");
+ return len;
+}
+
+static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ cpumask_t *mask = (cpumask_t *)data;
+ unsigned long full_count = count, err;
+ cpumask_t new_value;
+
+ err = cpumask_parse(buffer, count, new_value);
+ if (err)
+ return err;
+
+ *mask = new_value;
+ return full_count;
+}
+
+#define MAX_NAMELEN 10
+
+static void register_irq_proc(unsigned int irq)
+{
+ char name [MAX_NAMELEN];
+
+ if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) ||
+ irq_dir[irq])
+ return;
+
+ memset(name, 0, MAX_NAMELEN);
+ sprintf(name, "%d", irq);
+
+ /* create /proc/irq/1234 */
+ irq_dir[irq] = proc_mkdir(name, root_irq_dir);
+
+#ifdef CONFIG_SMP
+ {
+ struct proc_dir_entry *entry;
+
+ /* create /proc/irq/1234/smp_affinity */
+ entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
+
+ if (entry) {
+ entry->nlink = 1;
+ entry->data = (void *)(long)irq;
+ entry->read_proc = irq_affinity_read_proc;
+ entry->write_proc = irq_affinity_write_proc;
+ }
+
+ smp_affinity_entry[irq] = entry;
+ }
+#endif
+}
+
+#undef MAX_NAMELEN
+
+#define MAX_NAMELEN 128
+
+static void register_handler_proc(unsigned int irq, struct irqaction *action)
+{
+ char name [MAX_NAMELEN];
+
+ if (!irq_dir[irq] || action->dir || !action->name)
+ return;
+
+ memset(name, 0, MAX_NAMELEN);
+ snprintf(name, MAX_NAMELEN, "%s", action->name);
+
+ /* create /proc/irq/1234/handler/ */
+ action->dir = proc_mkdir(name, irq_dir[irq]);
+}
+
+
+unsigned long prof_cpu_mask = -1;
+
+void generic_init_irq_proc(void)
+{
+ struct proc_dir_entry *entry;
+ int i;
+
+ /* create /proc/irq */
+ root_irq_dir = proc_mkdir("irq", NULL);
+
+ /* create /proc/irq/prof_cpu_mask */
+ entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
+
+ if (!entry)
+ return;
+
+ entry->nlink = 1;
+ entry->data = (void *)&prof_cpu_mask;
+ entry->read_proc = prof_cpu_mask_read_proc;
+ entry->write_proc = prof_cpu_mask_write_proc;
+
+ /*
+ * Create entries for all existing IRQs.
+ */
+ for (i = 0; i < NR_IRQS; i++)
+ register_irq_proc(i);
+}