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);