1 files changed, 744 insertions, 0 deletions

diff --git a/arch/v850/kernel/irq.c b/arch/v850/kernel/irq.c
new file mode 100644
index 000000000000..336cbf21dc8f
--- /dev/null
+++ b/arch/v850/kernel/irq.c
@@ -0,0 +1,744 @@
+/*
+ * arch/v850/kernel/irq.c -- High-level interrupt handling
+ *
+ *  Copyright (C) 2001,02,03,04  NEC Electronics Corporation
+ *  Copyright (C) 2001,02,03,04  Miles Bader <miles@gnu.org>
+ *  Copyright (C) 1994-2000  Ralf Baechle
+ *  Copyright (C) 1992  Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ * This file was was derived from the mips version, arch/mips/kernel/irq.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/random.h>
+#include <linux/seq_file.h>
+
+#include <asm/system.h>
+
+/*
+ * 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
+        }
+};
+
+/*
+ * 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("received IRQ %d with unknown interrupt type\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
+};
+
+volatile unsigned long irq_err_count, spurious_count;
+
+/*
+ * Generic, controller-independent functions:
+ */
+
+int show_interrupts(struct seq_file *p, void *v)
+{
+        int i = *(loff_t *) v;
+        struct irqaction * action;
+        unsigned long flags;
+
+        if (i == 0) {
+                seq_puts(p, "           ");
+                for (i=0; i < 1 /*smp_num_cpus*/; i++)
+                        seq_printf(p, "CPU%d       ", i);
+                seq_putc(p, '\n');
+        }
+
+        if (i < NR_IRQS) {
+                int j, count, num;
+                const char *type_name = irq_desc[i].handler->typename;
+                spin_lock_irqsave(&irq_desc[j].lock, flags);
+                action = irq_desc[i].action;
+                if (!action) 
+                        goto skip;
+
+                count = 0;
+                num = -1;
+                for (j = 0; j < NR_IRQS; j++)
+                        if (irq_desc[j].handler->typename == type_name) {
+                                if (i == j)
+                                        num = count;
+                                count++;
+                        }
+
+                seq_printf(p, "%3d: ",i);
+                seq_printf(p, "%10u ", kstat_irqs(i));
+                if (count > 1) {
+                        int prec = (num >= 100 ? 3 : num >= 10 ? 2 : 1);
+                        seq_printf(p, " %*s%d", 14 - prec, type_name, num);
+                } else
+                        seq_printf(p, " %14s", type_name);
+                
+                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[j].lock, flags);
+        } else if (i == NR_IRQS)
+                seq_printf(p, "ERR: %10lu\n", irq_err_count);
+        return 0;
+}
+
+/*
+ * 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;
+
+        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;
+        } while (action);
+        if (status & SA_SAMPLE_RANDOM)
+                add_interrupt_randomness(irq);
+        local_irq_disable();
+
+        return status;
+}
+
+/*
+ * 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 of an interrupt
+ *      stack. 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 inline 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. Disables of an interrupt
+ *      stack. That is for two disables you need two enables. 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)
+{
+        disable_irq_nosync(irq);
+        synchronize_irq(irq);
+}
+
+/**
+ *      enable_irq - enable interrupt handling on an irq
+ *      @irq: Interrupt to enable
+ *
+ *      Re-enables the processing of interrupts on this IRQ line
+ *      providing no disable_irq calls are now in effect.
+ *
+ *      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);
+}
+
+/* Handle interrupt IRQ.  REGS are the registers at the time of ther
+   interrupt.  */
+unsigned int handle_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)
+         */
+        int cpu = smp_processor_id();
+        irq_desc_t *desc = irq_desc + irq;
+        struct irqaction * action;
+        unsigned int status;
+
+        irq_enter();
+        kstat_cpu(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 handle_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 (;;) {
+                spin_unlock(&desc->lock);
+                handle_IRQ_event(irq, regs, action);
+                spin_lock(&desc->lock);
+                
+                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();
+
+        return 1;
+}
+
+/**
+ *      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_KERNEL);
+        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 may be called from interrupt context. 
+ *
+ *      Bugs: Attempting to free an irq in a handler for the same irq hangs
+ *            the machine.
+ */
+ 
+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);
+
+                        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;
+
+        /*
+         * 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;
+}
+
+/* Initialize irq handling for IRQs.
+   BASE_IRQ, BASE_IRQ+INTERVAL, ..., BASE_IRQ+NUM*INTERVAL
+   to IRQ_TYPE.  An IRQ_TYPE of 0 means to use a generic interrupt type.  */
+void __init
+init_irq_handlers (int base_irq, int num, int interval,
+                   struct hw_interrupt_type *irq_type)
+{
+        while (num-- > 0) {
+                irq_desc[base_irq].status  = IRQ_DISABLED;
+                irq_desc[base_irq].action  = NULL;
+                irq_desc[base_irq].depth   = 1;
+                irq_desc[base_irq].handler = irq_type;
+                base_irq += interval;
+        }
+}
+
+#if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
+void init_irq_proc(void)
+{
+}
+#endif /* CONFIG_PROC_FS && CONFIG_SYSCTL */