Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 349 insertions, 0 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
new file mode 100644
index 000000000000..5202e4c4a5b6
--- /dev/null
+++ b/kernel/irq/manage.c
@@ -0,0 +1,349 @@
+/*
+ * linux/kernel/irq/manage.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains driver APIs to the irq subsystem.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
+
+#ifdef CONFIG_SMP
+
+cpumask_t irq_affinity[NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
+
+/**
+ *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
+ *
+ *      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 synchronize_irq(unsigned int irq)
+{
+        struct irq_desc *desc = irq_desc + irq;
+
+        while (desc->status & IRQ_INPROGRESS)
+                cpu_relax();
+}
+
+EXPORT_SYMBOL(synchronize_irq);
+
+#endif
+
+/**
+ *      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 0:
+                WARN_ON(1);
+                break;
+        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--;
+        }
+        spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+EXPORT_SYMBOL(enable_irq);
+
+/*
+ * Internal function that tells the architecture code whether a
+ * particular irq has been exclusively allocated or is available
+ * for driver use.
+ */
+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;
+}
+
+/*
+ * Internal function to register an irqaction - typically used to
+ * allocate special interrupts that are part of the architecture.
+ */
+int setup_irq(unsigned int irq, struct irqaction * new)
+{
+        struct irq_desc *desc = irq_desc + irq;
+        struct irqaction *old, **p;
+        unsigned long flags;
+        int shared = 0;
+
+        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);
+                        unregister_handler_proc(irq, action);
+
+                        /* Make sure it's not being used on another CPU */
+                        synchronize_irq(irq);
+                        kfree(action);
+                        return;
+                }
+                printk(KERN_ERR "Trying to free free IRQ%d\n",irq);
+                spin_unlock_irqrestore(&desc->lock,flags);
+                return;
+        }
+}
+
+EXPORT_SYMBOL(free_irq);
+
+/**
+ *      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)
+{
+        struct irqaction * action;
+        int retval;
+
+        /*
+         * Sanity-check: shared interrupts must 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) && !dev_id)
+                return -EINVAL;
+        if (irq >= NR_IRQS)
+                return -EINVAL;
+        if (!handler)
+                return -EINVAL;
+
+        action = 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);
+