1 files changed, 519 insertions, 0 deletions

diff --git a/arch/ppc64/kernel/irq.c b/arch/ppc64/kernel/irq.c
new file mode 100644
index 000000000000..4fd7f203c1e3
--- /dev/null
+++ b/arch/ppc64/kernel/irq.c
@@ -0,0 +1,519 @@
+/*
+ *  arch/ppc/kernel/irq.c
+ *
+ *  Derived from arch/i386/kernel/irq.c
+ *    Copyright (C) 1992 Linus Torvalds
+ *  Adapted from arch/i386 by Gary Thomas
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *  Updated and modified by Cort Dougan (cort@cs.nmt.edu)
+ *    Copyright (C) 1996 Cort Dougan
+ *  Adapted for Power Macintosh by Paul Mackerras
+ *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
+ *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/threads.h>
+#include <linux/kernel_stat.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/proc_fs.h>
+#include <linux/random.h>
+#include <linux/kallsyms.h>
+#include <linux/profile.h>
+#include <linux/bitops.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/irq.h>
+#include <asm/cache.h>
+#include <asm/prom.h>
+#include <asm/ptrace.h>
+#include <asm/iSeries/LparData.h>
+#include <asm/machdep.h>
+#include <asm/paca.h>
+
+#ifdef CONFIG_SMP
+extern void iSeries_smp_message_recv( struct pt_regs * );
+#endif
+
+extern irq_desc_t irq_desc[NR_IRQS];
+EXPORT_SYMBOL(irq_desc);
+
+int distribute_irqs = 1;
+int __irq_offset_value;
+int ppc_spurious_interrupts;
+unsigned long lpevent_count;
+u64 ppc64_interrupt_controller;
+
+int show_interrupts(struct seq_file *p, void *v)
+{
+        int i = *(loff_t *) v, j;
+        struct irqaction * action;
+        irq_desc_t *desc;
+        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) {
+                desc = get_irq_desc(i);
+                spin_lock_irqsave(&desc->lock, flags);
+                action = desc->action;
+                if (!action || !action->handler)
+                        goto skip;
+                seq_printf(p, "%3d: ", i);
+#ifdef CONFIG_SMP
+                for (j = 0; j < NR_CPUS; j++) {
+                        if (cpu_online(j))
+                                seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
+                }
+#else
+                seq_printf(p, "%10u ", kstat_irqs(i));
+#endif /* CONFIG_SMP */
+                if (desc->handler)
+                        seq_printf(p, " %s ", desc->handler->typename );
+                else
+                        seq_printf(p, "  None      ");
+                seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
+                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(&desc->lock, flags);
+        } else if (i == NR_IRQS)
+                seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
+        return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void fixup_irqs(cpumask_t map)
+{
+        unsigned int irq;
+        static int warned;
+
+        for_each_irq(irq) {
+                cpumask_t mask;
+
+                if (irq_desc[irq].status & IRQ_PER_CPU)
+                        continue;
+
+                cpus_and(mask, irq_affinity[irq], map);
+                if (any_online_cpu(mask) == NR_CPUS) {
+                        printk("Breaking affinity for irq %i\n", irq);
+                        mask = map;
+                }
+                if (irq_desc[irq].handler->set_affinity)
+                        irq_desc[irq].handler->set_affinity(irq, mask);
+                else if (irq_desc[irq].action && !(warned++))
+                        printk("Cannot set affinity for irq %i\n", irq);
+        }
+
+        local_irq_enable();
+        mdelay(1);
+        local_irq_disable();
+}
+#endif
+
+extern int noirqdebug;
+
+/*
+ * Eventually, this should take an array of interrupts and an array size
+ * so it can dispatch multiple interrupts.
+ */
+void ppc_irq_dispatch_handler(struct pt_regs *regs, int irq)
+{
+        int status;
+        struct irqaction *action;
+        int cpu = smp_processor_id();
+        irq_desc_t *desc = get_irq_desc(irq);
+        irqreturn_t action_ret;
+#ifdef CONFIG_IRQSTACKS
+        struct thread_info *curtp, *irqtp;
+#endif
+
+        kstat_cpu(cpu).irqs[irq]++;
+
+        if (desc->status & IRQ_PER_CPU) {
+                /* no locking required for CPU-local interrupts: */
+                ack_irq(irq);
+                action_ret = handle_IRQ_event(irq, regs, desc->action);
+                desc->handler->end(irq);
+                return;
+        }
+
+        spin_lock(&desc->lock);
+        ack_irq(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;
+                if (!action || !action->handler) {
+                        ppc_spurious_interrupts++;
+                        printk(KERN_DEBUG "Unhandled interrupt %x, disabled\n", irq);
+                        /* We can't call disable_irq here, it would deadlock */
+                        if (!desc->depth)
+                                desc->depth = 1;
+                        desc->status |= IRQ_DISABLED;
+                        /* This is not a real spurrious interrupt, we
+                         * have to eoi it, so we jump to out
+                         */
+                        mask_irq(irq);
+                        goto out;
+                }
+                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 (;;) {
+                spin_unlock(&desc->lock);
+
+#ifdef CONFIG_IRQSTACKS
+                /* Switch to the irq stack to handle this */
+                curtp = current_thread_info();
+                irqtp = hardirq_ctx[smp_processor_id()];
+                if (curtp != irqtp) {
+                        irqtp->task = curtp->task;
+                        irqtp->flags = 0;
+                        action_ret = call_handle_IRQ_event(irq, regs, action, irqtp);
+                        irqtp->task = NULL;
+                        if (irqtp->flags)
+                                set_bits(irqtp->flags, &curtp->flags);
+                } else
+#endif
+                        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;
+        }
+out:
+        desc->status &= ~IRQ_INPROGRESS;
+        /*
+         * The ->end() handler has to deal with interrupts which got
+         * disabled while the handler was running.
+         */
+        if (desc->handler) {
+                if (desc->handler->end)
+                        desc->handler->end(irq);
+                else if (desc->handler->enable)
+                        desc->handler->enable(irq);
+        }
+        spin_unlock(&desc->lock);
+}
+
+#ifdef CONFIG_PPC_ISERIES
+void do_IRQ(struct pt_regs *regs)
+{
+        struct paca_struct *lpaca;
+        struct ItLpQueue *lpq;
+
+        irq_enter();
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+        /* Debugging check for stack overflow: is there less than 2KB free? */
+        {
+                long sp;
+
+                sp = __get_SP() & (THREAD_SIZE-1);
+
+                if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
+                        printk("do_IRQ: stack overflow: %ld\n",
+                                sp - sizeof(struct thread_info));
+                        dump_stack();
+                }
+        }
+#endif
+
+        lpaca = get_paca();
+#ifdef CONFIG_SMP
+        if (lpaca->lppaca.int_dword.fields.ipi_cnt) {
+                lpaca->lppaca.int_dword.fields.ipi_cnt = 0;
+                iSeries_smp_message_recv(regs);
+        }
+#endif /* CONFIG_SMP */
+        lpq = lpaca->lpqueue_ptr;
+        if (lpq && ItLpQueue_isLpIntPending(lpq))
+                lpevent_count += ItLpQueue_process(lpq, regs);
+
+        irq_exit();
+
+        if (lpaca->lppaca.int_dword.fields.decr_int) {
+                lpaca->lppaca.int_dword.fields.decr_int = 0;
+                /* Signal a fake decrementer interrupt */
+                timer_interrupt(regs);
+        }
+}
+
+#else   /* CONFIG_PPC_ISERIES */
+
+void do_IRQ(struct pt_regs *regs)
+{
+        int irq;
+
+        irq_enter();
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+        /* Debugging check for stack overflow: is there less than 2KB free? */
+        {
+                long sp;
+
+                sp = __get_SP() & (THREAD_SIZE-1);
+
+                if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
+                        printk("do_IRQ: stack overflow: %ld\n",
+                                sp - sizeof(struct thread_info));
+                        dump_stack();
+                }
+        }
+#endif
+
+        irq = ppc_md.get_irq(regs);
+
+        if (irq >= 0)
+                ppc_irq_dispatch_handler(regs, irq);
+        else
+                /* That's not SMP safe ... but who cares ? */
+                ppc_spurious_interrupts++;
+
+        irq_exit();
+}
+#endif  /* CONFIG_PPC_ISERIES */
+
+void __init init_IRQ(void)
+{
+        static int once = 0;
+
+        if (once)
+                return;
+
+        once++;
+
+        ppc_md.init_IRQ();
+        irq_ctx_init();
+}
+
+#ifndef CONFIG_PPC_ISERIES
+/*
+ * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
+ */
+
+#define UNDEFINED_IRQ 0xffffffff
+unsigned int virt_irq_to_real_map[NR_IRQS];
+
+/*
+ * Don't use virtual irqs 0, 1, 2 for devices.
+ * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
+ * and 2 is the XICS IPI interrupt.
+ * We limit virtual irqs to 17 less than NR_IRQS so that when we
+ * offset them by 16 (to reserve the first 16 for ISA interrupts)
+ * we don't end up with an interrupt number >= NR_IRQS.
+ */
+#define MIN_VIRT_IRQ    3
+#define MAX_VIRT_IRQ    (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
+#define NR_VIRT_IRQS    (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
+
+void
+virt_irq_init(void)
+{
+        int i;
+        for (i = 0; i < NR_IRQS; i++)
+                virt_irq_to_real_map[i] = UNDEFINED_IRQ;
+}
+
+/* Create a mapping for a real_irq if it doesn't already exist.
+ * Return the virtual irq as a convenience.
+ */
+int virt_irq_create_mapping(unsigned int real_irq)
+{
+        unsigned int virq, first_virq;
+        static int warned;
+
+        if (ppc64_interrupt_controller == IC_OPEN_PIC)
+                return real_irq;        /* no mapping for openpic (for now) */
+
+        /* don't map interrupts < MIN_VIRT_IRQ */
+        if (real_irq < MIN_VIRT_IRQ) {
+                virt_irq_to_real_map[real_irq] = real_irq;
+                return real_irq;
+        }
+
+        /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
+        virq = real_irq;
+        if (virq > MAX_VIRT_IRQ)
+                virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
+
+        /* search for this number or a free slot */
+        first_virq = virq;
+        while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
+                if (virt_irq_to_real_map[virq] == real_irq)
+                        return virq;
+                if (++virq > MAX_VIRT_IRQ)
+                        virq = MIN_VIRT_IRQ;
+                if (virq == first_virq)
+                        goto nospace;   /* oops, no free slots */
+        }
+
+        virt_irq_to_real_map[virq] = real_irq;
+        return virq;
+
+ nospace:
+        if (!warned) {
+                printk(KERN_CRIT "Interrupt table is full\n");
+                printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
+                       "in your kernel sources and rebuild.\n", NR_IRQS);
+                warned = 1;
+        }
+        return NO_IRQ;
+}
+
+/*
+ * In most cases will get a hit on the very first slot checked in the
+ * virt_irq_to_real_map.  Only when there are a large number of
+ * IRQs will this be expensive.
+ */
+unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
+{
+        unsigned int virq;
+        unsigned int first_virq;
+
+        virq = real_irq;
+
+        if (virq > MAX_VIRT_IRQ)
+                virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
+
+        first_virq = virq;
+
+        do {
+                if (virt_irq_to_real_map[virq] == real_irq)
+                        return virq;
+
+                virq++;
+
+                if (virq >= MAX_VIRT_IRQ)
+                        virq = 0;
+
+        } while (first_virq != virq);
+
+        return NO_IRQ;
+
+}
+
+#endif /* CONFIG_PPC_ISERIES */
+
+#ifdef CONFIG_IRQSTACKS
+struct thread_info *softirq_ctx[NR_CPUS];
+struct thread_info *hardirq_ctx[NR_CPUS];
+
+void irq_ctx_init(void)
+{
+        struct thread_info *tp;
+        int i;
+
+        for_each_cpu(i) {
+                memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
+                tp = softirq_ctx[i];
+                tp->cpu = i;
+                tp->preempt_count = SOFTIRQ_OFFSET;
+
+                memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
+                tp = hardirq_ctx[i];
+                tp->cpu = i;
+                tp->preempt_count = HARDIRQ_OFFSET;
+        }
+}
+
+void do_softirq(void)
+{
+        unsigned long flags;
+        struct thread_info *curtp, *irqtp;
+
+        if (in_interrupt())
+                return;
+
+        local_irq_save(flags);
+
+        if (local_softirq_pending()) {
+                curtp = current_thread_info();
+                irqtp = softirq_ctx[smp_processor_id()];
+                irqtp->task = curtp->task;
+                call_do_softirq(irqtp);
+                irqtp->task = NULL;
+        }
+
+        local_irq_restore(flags);
+}
+EXPORT_SYMBOL(do_softirq);
+
+#endif /* CONFIG_IRQSTACKS */
+
+static int __init setup_noirqdistrib(char *str)
+{
+        distribute_irqs = 0;
+        return 1;
+}
+
+__setup("noirqdistrib", setup_noirqdistrib);