pic.c

linux-2.6.15.6

/*
 *  Support for the interrupt controllers found on Power Macintosh,
 *  currently Apple's "Grand Central" interrupt controller in all
 *  it's incarnations. OpenPIC support used on newer machines is
 *  in a separate file
 *
 *  Copyright (C) 1997 Paul Mackerras ([e-mail])
 *
 *  Maintained by Benjamin Herrenschmidt ([e-mail])
 *
 *  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.
 *
 */

#include <linux/config.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/sysdev.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <linux/module.h>

#include <asm/sections.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/time.h>
#include <asm/pmac_feature.h>
#include <asm/mpic.h>

#include "pmac.h"

/*
 * XXX this should be in xmon.h, but putting it there means xmon.h
 * has to include <linux/interrupt.h> (to get irqreturn_t), which
 * causes all sorts of problems.  -- paulus
 */
extern irqreturn_t xmon_irq(int, void *, struct pt_regs *);

#ifdef CONFIG_PPC32
struct pmac_irq_hw {
        unsigned int    event;
        unsigned int    enable;
        unsigned int    ack;
        unsigned int    level;
};

/* Default addresses */
static volatile struct pmac_irq_hw *pmac_irq_hw[4] = {
        (struct pmac_irq_hw *) 0xf3000020,
        (struct pmac_irq_hw *) 0xf3000010,
        (struct pmac_irq_hw *) 0xf4000020,
        (struct pmac_irq_hw *) 0xf4000010,
};

#define GC_LEVEL_MASK		0x3ff00000
#define OHARE_LEVEL_MASK	0x1ff00000
#define HEATHROW_LEVEL_MASK	0x1ff00000

static int max_irqs;
static int max_real_irqs;
static u32 level_mask[4];

static DEFINE_SPINLOCK(pmac_pic_lock);

#define GATWICK_IRQ_POOL_SIZE        10
static struct interrupt_info gatwick_int_pool[GATWICK_IRQ_POOL_SIZE];

#define NR_MASK_WORDS	((NR_IRQS + 31) / 32)
static unsigned long ppc_lost_interrupts[NR_MASK_WORDS];

/*
 * Mark an irq as "lost".  This is only used on the pmac
 * since it can lose interrupts (see pmac_set_irq_mask).
 * -- Cort
 */
void
__set_lost(unsigned long irq_nr, int nokick)
{
	if (!test_and_set_bit(irq_nr, ppc_lost_interrupts)) {
		atomic_inc(&ppc_n_lost_interrupts);
		if (!nokick)
			set_dec(1);
	}
}

static void
pmac_mask_and_ack_irq(unsigned int irq_nr)
{
        unsigned long bit = 1UL << (irq_nr & 0x1f);
        int i = irq_nr >> 5;
        unsigned long flags;

        if ((unsigned)irq_nr >= max_irqs)
                return;

        clear_bit(irq_nr, ppc_cached_irq_mask);
        if (test_and_clear_bit(irq_nr, ppc_lost_interrupts))
                atomic_dec(&ppc_n_lost_interrupts);
	spin_lock_irqsave(&pmac_pic_lock, flags);
        out_le32(&pmac_irq_hw[i]->enable, ppc_cached_irq_mask[i]);
        out_le32(&pmac_irq_hw[i]->ack, bit);
        do {
                /* make sure ack gets to controller before we enable
                   interrupts */
                mb();
        } while((in_le32(&pmac_irq_hw[i]->enable) & bit)
                != (ppc_cached_irq_mask[i] & bit));
	spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

static void pmac_set_irq_mask(unsigned int irq_nr, int nokicklost)
{
        unsigned long bit = 1UL << (irq_nr & 0x1f);
        int i = irq_nr >> 5;
        unsigned long flags;

        if ((unsigned)irq_nr >= max_irqs)
                return;

	spin_lock_irqsave(&pmac_pic_lock, flags);
        /* enable unmasked interrupts */
        out_le32(&pmac_irq_hw[i]->enable, ppc_cached_irq_mask[i]);

        do {
                /* make sure mask gets to controller before we
                   return to user */
                mb();
        } while((in_le32(&pmac_irq_hw[i]->enable) & bit)
                != (ppc_cached_irq_mask[i] & bit));

        /*
         * Unfortunately, setting the bit in the enable register
         * when the device interrupt is already on *doesn't* set
         * the bit in the flag register or request another interrupt.
         */
        if (bit & ppc_cached_irq_mask[i] & in_le32(&pmac_irq_hw[i]->level))
		__set_lost((ulong)irq_nr, nokicklost);
	spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

/* When an irq gets requested for the first client, if it's an
 * edge interrupt, we clear any previous one on the controller
 */
static unsigned int pmac_startup_irq(unsigned int irq_nr)
{
        unsigned long bit = 1UL << (irq_nr & 0x1f);
        int i = irq_nr >> 5;

	if ((irq_desc[irq_nr].status & IRQ_LEVEL) == 0)
		out_le32(&pmac_irq_hw[i]->ack, bit);
        set_bit(irq_nr, ppc_cached_irq_mask);
        pmac_set_irq_mask(irq_nr, 0);

	return 0;
}

static void pmac_mask_irq(unsigned int irq_nr)
{
        clear_bit(irq_nr, ppc_cached_irq_mask);
        pmac_set_irq_mask(irq_nr, 0);
        mb();
}

static void pmac_unmask_irq(unsigned int irq_nr)
{
        set_bit(irq_nr, ppc_cached_irq_mask);
        pmac_set_irq_mask(irq_nr, 0);
}

static void pmac_end_irq(unsigned int irq_nr)
{
	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
	    && irq_desc[irq_nr].action) {
        	set_bit(irq_nr, ppc_cached_irq_mask);
	        pmac_set_irq_mask(irq_nr, 1);
	}
}


struct hw_interrupt_type pmac_pic = {
	.typename	= " PMAC-PIC ",
	.startup	= pmac_startup_irq,
	.enable		= pmac_unmask_irq,
	.disable	= pmac_mask_irq,
	.ack		= pmac_mask_and_ack_irq,
	.end		= pmac_end_irq,
};

struct hw_interrupt_type gatwick_pic = {
	.typename	= " GATWICK  ",
	.startup	= pmac_startup_irq,
	.enable		= pmac_unmask_irq,
	.disable	= pmac_mask_irq,
	.ack		= pmac_mask_and_ack_irq,
	.end		= pmac_end_irq,
};

static irqreturn_t gatwick_action(int cpl, void *dev_id, struct pt_regs *regs)
{
	int irq, bits;

	for (irq = max_irqs; (irq -= 32) >= max_real_irqs; ) {
		int i = irq >> 5;
		bits = in_le32(&pmac_irq_hw[i]->event) | ppc_lost_interrupts[i];
		/* We must read level interrupts from the level register */
		bits |= (in_le32(&pmac_irq_hw[i]->level) & level_mask[i]);
		bits &= ppc_cached_irq_mask[i];
		if (bits == 0)
			continue;
		irq += __ilog2(bits);
		__do_IRQ(irq, regs);
		return IRQ_HANDLED;
	}
	printk("gatwick irq not from gatwick pic\n");
	return IRQ_NONE;
}

int
pmac_get_irq(struct pt_regs *regs)
{
	int irq;
	unsigned long bits = 0;

#ifdef CONFIG_SMP
	void psurge_smp_message_recv(struct pt_regs *);

       	/* IPI's are a hack on the powersurge -- Cort */
       	if ( smp_processor_id() != 0 ) {
		psurge_smp_message_recv(regs);
		return -2;	/* ignore, already handled */
        }
#endif /* CONFIG_SMP */
	for (irq = max_real_irqs; (irq -= 32) >= 0; ) {
		int i = irq >> 5;
		bits = in_le32(&pmac_irq_hw[i]->event) | ppc_lost_interrupts[i];
		/* We must read level interrupts from the level register */
		bits |= (in_le32(&pmac_irq_hw[i]->level) & level_mask[i]);
		bits &= ppc_cached_irq_mask[i];
		if (bits == 0)
			continue;
		irq += __ilog2(bits);
		break;
	}

	return irq;
}

/* This routine will fix some missing interrupt values in the device tree
 * on the gatwick mac-io controller used by some PowerBooks
 */
static void __init
pmac_fix_gatwick_interrupts(struct device_node *gw, int irq_base)
{
	struct device_node *node;
	int count;

	memset(gatwick_int_pool, 0, sizeof(gatwick_int_pool));
	node = gw->child;
	count = 0;
	while(node)
	{
		/* Fix SCC */
		if (strcasecmp(node->name, "escc") == 0)
			if (node->child) {
				if (node->child->n_intrs < 3) {
					node->child->intrs = &gatwick_int_pool[count];
					count += 3;
				}
				node->child->n_intrs = 3;
				node->child->intrs[0].line = 15+irq_base;
				node->child->intrs[1].line =  4+irq_base;
				node->child->intrs[2].line =  5+irq_base;
				printk(KERN_INFO "irq: fixed SCC on second controller (%d,%d,%d)\n",
					node->child->intrs[0].line,
					node->child->intrs[1].line,
					node->child->intrs[2].line);
			}
		/* Fix media-bay & left SWIM */
		if (strcasecmp(node->name, "media-bay") == 0) {
			struct device_node* ya_node;

			if (node->n_intrs == 0)
				node->intrs = &gatwick_int_pool[count++];
			node->n_intrs = 1;
			node->intrs[0].line = 29+irq_base;
			printk(KERN_INFO "irq: fixed media-bay on second controller (%d)\n",
					node->intrs[0].line);

			ya_node = node->child;
			while(ya_node)
			{
				if (strcasecmp(ya_node->name, "floppy") == 0) {
					if (ya_node->n_intrs < 2) {
						ya_node->intrs = &gatwick_int_pool[count];
						count += 2;
					}
					ya_node->n_intrs = 2;
					ya_node->intrs[0].line = 19+irq_base;
					ya_node->intrs[1].line =  1+irq_base;
					printk(KERN_INFO "irq: fixed floppy on second controller (%d,%d)\n",
						ya_node->intrs[0].line, ya_node->intrs[1].line);
				}
				if (strcasecmp(ya_node->name, "ata4") == 0) {
					if (ya_node->n_intrs < 2) {
						ya_node->intrs = &gatwick_int_pool[count];
						count += 2;
					}
					ya_node->n_intrs = 2;
					ya_node->intrs[0].line = 14+irq_base;
					ya_node->intrs[1].line =  3+irq_base;
					printk(KERN_INFO "irq: fixed ide on second controller (%d,%d)\n",
						ya_node->intrs[0].line, ya_node->intrs[1].line);
				}
				ya_node = ya_node->sibling;
			}
		}
		node = node->sibling;
	}
	if (count > 10) {
		printk("WARNING !! Gatwick interrupt pool overflow\n");
		printk("  GATWICK_IRQ_POOL_SIZE = %d\n", GATWICK_IRQ_POOL_SIZE);
		printk("              requested = %d\n", count);
	}
}

/*
 * The PowerBook 3400/2400/3500 can have a combo ethernet/modem
 * card which includes an ohare chip that acts as a second interrupt
 * controller.  If we find this second ohare, set it up and fix the
 * interrupt value in the device tree for the ethernet chip.
 */
static int __init enable_second_ohare(void)