[patch] generic-hardirqs-2.6.9-rc1-mm4.patch

Ingo Molnar
2004-09-08T21:16:00Z

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* Ingo Molnar <mingo@elte.hu> wrote:

> latest patch attached - this should compile on every architecture.
> It's basically what Christoph suggested first time around :-)
> Compiles/boots on x86. Any other observations?

i've attached generic-hardirqs-2.6.9-rc1-mm4.patch which is a merge
against -mm4. x86 and x64 compiles & boots fine. Since there are zero
changes to non-x86 architectures it should build fine on all platforms.

Ingo

[-- Attachment #2: generic-hardirqs-2.6.9-rc1-mm4.patch --]
[-- Type: text/plain, Size: 27918 bytes --]

--- linux/arch/i386/kernel/irq.c.orig
+++ linux/arch/i386/kernel/irq.c
@@ -73,8 +73,6 @@ irq_desc_t irq_desc[NR_IRQS] __cacheline
}
};

-static void register_irq_proc (unsigned int irq);
-
/*
* per-CPU IRQ handling stacks
*/
@@ -196,89 +194,6 @@ 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(KERN_INFO "IRQ lockup detection disabled\n");
- return 1;
-}
-
-__setup("noirqdebug", noirqdebug_setup);
-
static int irqfixup;

static int __init irqfixup_setup(char *str)
@@ -380,7 +295,7 @@ static asmlinkage int misrouted_irq(int
*
* Called under desc->lock
*/
-static void note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret, struct pt_regs *regs)
+static void x86_note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret, struct pt_regs *regs)
{
if (action_ret != IRQ_HANDLED) {
desc->irqs_unhandled++;
@@ -464,97 +379,6 @@ static void note_interrupt(int irq, 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);
-}
-
#ifdef CONFIG_HOTPLUG_CPU
static int irqs_stabilizing;

@@ -695,7 +519,7 @@ asmlinkage unsigned int do_IRQ(struct pt
}
spin_lock(&desc->lock);
if (!noirqdebug)
- note_interrupt(irq, desc, action_ret, &regs);
+ x86_note_interrupt(irq, desc, action_ret, &regs);
if (curctx != irqctx)
irqctx->tinfo.task = NULL;
if (likely(!(desc->status & IRQ_PENDING)))
@@ -714,7 +538,7 @@ asmlinkage unsigned int do_IRQ(struct pt

spin_lock(&desc->lock);
if (!noirqdebug)
- note_interrupt(irq, desc, action_ret, &regs);
+ x86_note_interrupt(irq, desc, action_ret, &regs);
if (likely(!(desc->status & IRQ_PENDING)))
break;
desc->status &= ~IRQ_PENDING;
@@ -830,62 +654,6 @@ 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..
*
@@ -1081,115 +849,6 @@ 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
-
#ifdef CONFIG_HOTPLUG_CPU
#include <mach_apic.h>

@@ -1234,55 +893,6 @@ void fixup_irqs(void)
#endif
}
#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
/*
--- linux/arch/i386/kernel/i386_ksyms.c.orig
+++ linux/arch/i386/kernel/i386_ksyms.c
@@ -76,9 +76,6 @@ 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);
@@ -146,7 +143,6 @@ 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/Kconfig.orig
+++ linux/arch/i386/Kconfig
@@ -1226,6 +1226,10 @@ source "crypto/Kconfig"

source "lib/Kconfig"

+config GENERIC_HARDIRQS
+ bool
+ default y
+
config X86_SMP
bool
depends on SMP && !X86_VOYAGER
--- 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>
@@ -71,7 +74,24 @@ 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 int setup_irq(unsigned int irq, struct irqaction * new);
+
+#ifdef CONFIG_GENERIC_HARDIRQS
+extern asmlinkage int handle_IRQ_event(unsigned int irq, struct pt_regs *regs, struct irqaction *action);
+extern void synchronize_irq(unsigned int irq);
+extern void free_irq(unsigned int irq, void *dev_id);
+extern void disable_irq_nosync(unsigned int irq);
+extern void disable_irq(unsigned int irq);
+extern void enable_irq(unsigned int irq);
+extern void note_interrupt(int irq, irq_desc_t *desc, int action_ret);
+extern void __report_bad_irq(int irq, irq_desc_t *desc, int action_ret);
+extern void report_bad_irq(int irq, irq_desc_t *desc, int action_ret);
+extern void init_irq_proc(void);
+
+extern int noirqdebug;
+
+#endif

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

--- 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/kernel/Makefile.orig
+++ linux/kernel/Makefile
@@ -12,6 +12,7 @@ obj-y = sched.o fork.o exec_domain.o
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += cpu.o spinlock.o
+obj-$(CONFIG_GENERIC_HARDIRQS) += hardirq.o
obj-$(CONFIG_UID16) += uid16.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_KALLSYMS) += kallsyms.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 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;
+}
+
+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;
+ }
+}
+
+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 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 synchronize_irq(unsigned int irq)
+{
+ struct irq_desc *desc = irq_desc + irq;
+
+ while (desc->status & IRQ_INPROGRESS)
+ cpu_relax();
+}
+
+EXPORT_SYMBOL(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 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(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 disable_irq(unsigned int irq)
+{
+ irq_desc_t *desc = irq_desc + irq;
+ disable_irq_nosync(irq);
+ if (desc->action)
+ synchronize_irq(irq);
+}
+
+EXPORT_SYMBOL(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 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(enable_irq);
+
+int 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;
+}
+
+/**
+ * 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)
+{
+ 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(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 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);
+}