This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / arch / m32r / kernel / irq.c
diff --git a/arch/m32r/kernel/irq.c b/arch/m32r/kernel/irq.c
new file mode 100644 (file)
index 0000000..ba13577
--- /dev/null
@@ -0,0 +1,1020 @@
+/*
+ * linux/arch/m32r/kernel/irq.c
+ *
+ *  Copyright (c) 2003, 2004 Hitoshi Yamamoto
+ *
+ *  Taken from i386 2.6.4 version.
+ */
+
+/*
+ *     linux/arch/i386/kernel/irq.c
+ *
+ *     Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the code used by various IRQ handling routines:
+ * asking for different IRQ's should be done through these routines
+ * instead of just grabbing them. Thus setups with different IRQ numbers
+ * shouldn't result in any weird surprises, and installing new handlers
+ * should be easier.
+ */
+
+/*
+ * (mostly architecture independent, will move to kernel/irq.c in 2.5.)
+ *
+ * IRQs are in fact implemented a bit like signal handlers for the kernel.
+ * Naturally it's not a 1:1 relation, but there are similarities.
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/irq.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+
+#include <asm/atomic.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+#include <asm/delay.h>
+#include <asm/irq.h>
+
+/*
+ * Linux has a controller-independent x86 interrupt architecture.
+ * every controller has a 'controller-template', that is used
+ * by the main code to do the right thing. Each driver-visible
+ * interrupt source is transparently wired to the apropriate
+ * controller. Thus drivers need not be aware of the
+ * interrupt-controller.
+ *
+ * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
+ * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
+ * (IO-APICs assumed to be messaging to Pentium local-APICs)
+ *
+ * the code is designed to be easily extended with new/different
+ * interrupt controllers, without having to do assembly magic.
+ */
+
+/*
+ * Controller mappings for all interrupt sources:
+ */
+irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
+       [0 ... NR_IRQS-1] = {
+               .handler = &no_irq_type,
+               .lock = SPIN_LOCK_UNLOCKED
+       }
+};
+
+static void register_irq_proc (unsigned int irq);
+
+/*
+ * Special irq handlers.
+ */
+
+irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
+{ return IRQ_NONE; }
+
+/*
+ * Generic no controller code
+ */
+
+static void enable_none(unsigned int irq) { }
+static unsigned int startup_none(unsigned int irq) { return 0; }
+static void disable_none(unsigned int irq) { }
+static void ack_none(unsigned int irq)
+{
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves, it doesn't deserve
+ * a generic callback i think.
+ */
+       printk("unexpected IRQ trap at vector %02x\n", irq);
+}
+
+/* startup is the same as "enable", shutdown is same as "disable" */
+#define shutdown_none  disable_none
+#define end_none       enable_none
+
+struct hw_interrupt_type no_irq_type = {
+       "none",
+       startup_none,
+       shutdown_none,
+       enable_none,
+       disable_none,
+       ack_none,
+       end_none
+};
+
+atomic_t irq_err_count;
+atomic_t irq_mis_count;
+
+/*
+ * Generic, controller-independent functions:
+ */
+
+int show_interrupts(struct seq_file *p, void *v)
+{
+       int i = *(loff_t *) v, j;
+       struct irqaction * action;
+       unsigned long flags;
+
+       if (i == 0) {
+               seq_printf(p, "           ");
+               for (j=0; j<NR_CPUS; j++)
+                       if (cpu_online(j))
+                               seq_printf(p, "CPU%d       ",j);
+               seq_putc(p, '\n');
+       }
+
+       if (i < NR_IRQS) {
+               spin_lock_irqsave(&irq_desc[i].lock, flags);
+               action = irq_desc[i].action;
+               if (!action)
+                       goto skip;
+               seq_printf(p, "%3d: ",i);
+#ifndef CONFIG_SMP
+               seq_printf(p, "%10u ", kstat_irqs(i));
+#else
+               for (j = 0; j < NR_CPUS; j++)
+                       if (cpu_online(j))
+                               seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
+#endif
+               seq_printf(p, " %14s", irq_desc[i].handler->typename);
+               seq_printf(p, "  %s", action->name);
+
+               for (action=action->next; action; action = action->next)
+                       seq_printf(p, ", %s", action->name);
+
+               seq_putc(p, '\n');
+skip:
+               spin_unlock_irqrestore(&irq_desc[i].lock, flags);
+       } else if (i == NR_IRQS) {
+               seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
+               seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
+       }
+       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.
+ */
+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;
+               action = action->next;
+               retval |= ret;
+       } 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
+ * handlers).
+ */
+asmlinkage unsigned int do_IRQ(int irq, struct pt_regs *regs)
+{
+       /*
+        * We ack quickly, we don't want the irq controller
+        * thinking we're snobs just because some other CPU has
+        * disabled global interrupts (we have already done the
+        * INT_ACK cycles, it's too late to try to pretend to the
+        * controller that we aren't taking the interrupt).
+        *
+        * 0 return value means that this irq is already being
+        * handled by some other CPU. (or is disabled)
+        */
+       irq_desc_t *desc = irq_desc + irq;
+       struct irqaction * action;
+       unsigned int status;
+
+       irq_enter();
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+       /* FIXME M32R */
+#endif
+       kstat_this_cpu.irqs[irq]++;
+       spin_lock(&desc->lock);
+       desc->handler->ack(irq);
+       /*
+          REPLAY is when Linux resends an IRQ that was dropped earlier
+          WAITING is used by probe to mark irqs that are being tested
+          */
+       status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
+       status |= IRQ_PENDING; /* we _want_ to handle it */
+
+       /*
+        * If the IRQ is disabled for whatever reason, we cannot
+        * use the action we have.
+        */
+       action = NULL;
+       if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
+               action = desc->action;
+               status &= ~IRQ_PENDING; /* we commit to handling */
+               status |= IRQ_INPROGRESS; /* we are handling it */
+       }
+       desc->status = status;
+
+       /*
+        * If there is no IRQ handler or it was disabled, exit early.
+          Since we set PENDING, if another processor is handling
+          a different instance of this same irq, the other processor
+          will take care of it.
+        */
+       if (unlikely(!action))
+               goto out;
+
+       /*
+        * Edge triggered interrupts need to remember
+        * pending events.
+        * This applies to any hw interrupts that allow a second
+        * instance of the same irq to arrive while we are in do_IRQ
+        * or in the handler. But the code here only handles the _second_
+        * instance of the irq, not the third or fourth. So it is mostly
+        * useful for irq hardware that does not mask cleanly in an
+        * SMP environment.
+        */
+       for (;;) {
+               irqreturn_t action_ret;
+
+               spin_unlock(&desc->lock);
+               action_ret = handle_IRQ_event(irq, regs, action);
+               spin_lock(&desc->lock);
+               if (!noirqdebug)
+                       note_interrupt(irq, desc, action_ret);
+               if (likely(!(desc->status & IRQ_PENDING)))
+                       break;
+               desc->status &= ~IRQ_PENDING;
+       }
+       desc->status &= ~IRQ_INPROGRESS;
+
+out:
+       /*
+        * The ->end() handler has to deal with interrupts which got
+        * disabled while the handler was running.
+        */
+       desc->handler->end(irq);
+       spin_unlock(&desc->lock);
+
+       irq_exit();
+
+#if defined(CONFIG_SMP)
+       if (irq == M32R_IRQ_MFT2)
+               smp_send_timer();
+#endif /* CONFIG_SMP */
+
+       return 1;
+}
+
+int can_request_irq(unsigned int irq, unsigned long irqflags)
+{
+       struct irqaction *action;
+
+       if (irq >= NR_IRQS)
+               return 0;
+       action = irq_desc[irq].action;
+       if (action) {
+               if (irqflags & action->flags & SA_SHIRQ)
+                       action = NULL;
+       }
+       return !action;
+}
+
+/**
+ *     request_irq - allocate an interrupt line
+ *     @irq: Interrupt line to allocate
+ *     @handler: Function to be called when the IRQ occurs
+ *     @irqflags: Interrupt type flags
+ *     @devname: An ascii name for the claiming device
+ *     @dev_id: A cookie passed back to the handler function
+ *
+ *     This call allocates interrupt resources and enables the
+ *     interrupt line and IRQ handling. From the point this
+ *     call is made your handler function may be invoked. Since
+ *     your handler function must clear any interrupt the board
+ *     raises, you must take care both to initialise your hardware
+ *     and to set up the interrupt handler in the right order.
+ *
+ *     Dev_id must be globally unique. Normally the address of the
+ *     device data structure is used as the cookie. Since the handler
+ *     receives this value it makes sense to use it.
+ *
+ *     If your interrupt is shared you must pass a non NULL dev_id
+ *     as this is required when freeing the interrupt.
+ *
+ *     Flags:
+ *
+ *     SA_SHIRQ                Interrupt is shared
+ *
+ *     SA_INTERRUPT            Disable local interrupts while processing
+ *
+ *     SA_SAMPLE_RANDOM        The interrupt can be used for entropy
+ *
+ */
+
+int request_irq(unsigned int irq,
+               irqreturn_t (*handler)(int, void *, struct pt_regs *),
+               unsigned long irqflags,
+               const char * devname,
+               void *dev_id)
+{
+       int retval;
+       struct irqaction * action;
+
+#if 1
+       /*
+        * Sanity-check: shared interrupts should REALLY pass in
+        * a real dev-ID, otherwise we'll have trouble later trying
+        * to figure out which interrupt is which (messes up the
+        * interrupt freeing logic etc).
+        */
+       if (irqflags & SA_SHIRQ) {
+               if (!dev_id)
+                       printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n", devname, (&irq)[-1]);
+       }
+#endif
+
+       if (irq >= NR_IRQS)
+               return -EINVAL;
+       if (!handler)
+               return -EINVAL;
+
+       action = (struct irqaction *)
+                       kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
+       if (!action)
+               return -ENOMEM;
+
+       action->handler = handler;
+       action->flags = irqflags;
+       cpus_clear(action->mask);
+       action->name = devname;
+       action->next = NULL;
+       action->dev_id = dev_id;
+
+       retval = setup_irq(irq, action);
+       if (retval)
+               kfree(action);
+       return retval;
+}
+
+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..
+ *
+ * This depends on the fact that any interrupt that
+ * comes in on to an unassigned handler will get stuck
+ * with "IRQ_WAITING" cleared and the interrupt
+ * disabled.
+ */
+
+static DECLARE_MUTEX(probe_sem);
+
+/**
+ *     probe_irq_on    - begin an interrupt autodetect
+ *
+ *     Commence probing for an interrupt. The interrupts are scanned
+ *     and a mask of potential interrupt lines is returned.
+ *
+ */
+
+unsigned long probe_irq_on(void)
+{
+       unsigned int i;
+       irq_desc_t *desc;
+       unsigned long val;
+       unsigned long delay;
+
+       down(&probe_sem);
+       /*
+        * something may have generated an irq long ago and we want to
+        * flush such a longstanding irq before considering it as spurious.
+        */
+       for (i = NR_IRQS-1; i > 0; i--)  {
+               desc = irq_desc + i;
+
+               spin_lock_irq(&desc->lock);
+               if (!irq_desc[i].action)
+                       irq_desc[i].handler->startup(i);
+               spin_unlock_irq(&desc->lock);
+       }
+
+       /* Wait for longstanding interrupts to trigger. */
+       for (delay = jiffies + HZ/50; time_after(delay, jiffies); )
+               /* about 20ms delay */ barrier();
+
+       /*
+        * enable any unassigned irqs
+        * (we must startup again here because if a longstanding irq
+        * happened in the previous stage, it may have masked itself)
+        */
+       for (i = NR_IRQS-1; i > 0; i--) {
+               desc = irq_desc + i;
+
+               spin_lock_irq(&desc->lock);
+               if (!desc->action) {
+                       desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
+                       if (desc->handler->startup(i))
+                               desc->status |= IRQ_PENDING;
+               }
+               spin_unlock_irq(&desc->lock);
+       }
+
+       /*
+        * Wait for spurious interrupts to trigger
+        */
+       for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
+               /* about 100ms delay */ barrier();
+
+       /*
+        * Now filter out any obviously spurious interrupts
+        */
+       val = 0;
+       for (i = 0; i < NR_IRQS; i++) {
+               irq_desc_t *desc = irq_desc + i;
+               unsigned int status;
+
+               spin_lock_irq(&desc->lock);
+               status = desc->status;
+
+               if (status & IRQ_AUTODETECT) {
+                       /* It triggered already - consider it spurious. */
+                       if (!(status & IRQ_WAITING)) {
+                               desc->status = status & ~IRQ_AUTODETECT;
+                               desc->handler->shutdown(i);
+                       } else
+                               if (i < 32)
+                                       val |= 1 << i;
+               }
+               spin_unlock_irq(&desc->lock);
+       }
+
+       return val;
+}
+
+EXPORT_SYMBOL(probe_irq_on);
+
+/*
+ * Return a mask of triggered interrupts (this
+ * can handle only legacy ISA interrupts).
+ */
+
+/**
+ *     probe_irq_mask - scan a bitmap of interrupt lines
+ *     @val:   mask of interrupts to consider
+ *
+ *     Scan the ISA bus interrupt lines and return a bitmap of
+ *     active interrupts. The interrupt probe logic state is then
+ *     returned to its previous value.
+ *
+ *     Note: we need to scan all the irq's even though we will
+ *     only return ISA irq numbers - just so that we reset them
+ *     all to a known state.
+ */
+unsigned int probe_irq_mask(unsigned long val)
+{
+       int i;
+       unsigned int mask;
+
+       mask = 0;
+       for (i = 0; i < NR_IRQS; i++) {
+               irq_desc_t *desc = irq_desc + i;
+               unsigned int status;
+
+               spin_lock_irq(&desc->lock);
+               status = desc->status;
+
+               if (status & IRQ_AUTODETECT) {
+                       if (i < 16 && !(status & IRQ_WAITING))
+                               mask |= 1 << i;
+
+                       desc->status = status & ~IRQ_AUTODETECT;
+                       desc->handler->shutdown(i);
+               }
+               spin_unlock_irq(&desc->lock);
+       }
+       up(&probe_sem);
+
+       return mask & val;
+}
+
+/*
+ * Return the one interrupt that triggered (this can
+ * handle any interrupt source).
+ */
+
+/**
+ *     probe_irq_off   - end an interrupt autodetect
+ *     @val: mask of potential interrupts (unused)
+ *
+ *     Scans the unused interrupt lines and returns the line which
+ *     appears to have triggered the interrupt. If no interrupt was
+ *     found then zero is returned. If more than one interrupt is
+ *     found then minus the first candidate is returned to indicate
+ *     their is doubt.
+ *
+ *     The interrupt probe logic state is returned to its previous
+ *     value.
+ *
+ *     BUGS: When used in a module (which arguably shouldnt happen)
+ *     nothing prevents two IRQ probe callers from overlapping. The
+ *     results of this are non-optimal.
+ */
+
+int probe_irq_off(unsigned long val)
+{
+       int i, irq_found, nr_irqs;
+
+       nr_irqs = 0;
+       irq_found = 0;
+       for (i = 0; i < NR_IRQS; i++) {
+               irq_desc_t *desc = irq_desc + i;
+               unsigned int status;
+
+               spin_lock_irq(&desc->lock);
+               status = desc->status;
+
+               if (status & IRQ_AUTODETECT) {
+                       if (!(status & IRQ_WAITING)) {
+                               if (!nr_irqs)
+                                       irq_found = i;
+                               nr_irqs++;
+                       }
+                       desc->status = status & ~IRQ_AUTODETECT;
+                       desc->handler->shutdown(i);
+               }
+               spin_unlock_irq(&desc->lock);
+       }
+       up(&probe_sem);
+
+       if (nr_irqs > 1)
+               irq_found = -irq_found;
+       return irq_found;
+}
+
+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
+
+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
+}
+
+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);
+}
+