Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  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@fsmlabs.com>

 *    Copyright (C) 1996-2001 Cort Dougan

 *  Adapted for Power Macintosh by Paul Mackerras

 *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)

 *

 * 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.

 *

 * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the

 * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit

 * mask register (of which only 16 are defined), hence the weird shifting

 * and complement of the cached_irq_mask.  I want to be able to stuff

 * this right into the SIU SMASK register.

 * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx

 * to reduce code space and undefined function references.

 */

#undef DEBUG

#include <linux/module.h>

#include <linux/threads.h>

#include <linux/kernel_stat.h>

#include <linux/signal.h>

#include <linux/sched.h>

#include <linux/ptrace.h>

#include <linux/ioport.h>

#include <linux/interrupt.h>

#include <linux/timex.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/delay.h>

#include <linux/irq.h>

#include <linux/seq_file.h>

#include <linux/cpumask.h>

#include <linux/profile.h>

#include <linux/bitops.h>

#include <linux/list.h>

#include <linux/radix-tree.h>

#include <linux/mutex.h>

#include <linux/bootmem.h>

#include <linux/pci.h>

#include <linux/debugfs.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/machdep.h>

#include <asm/udbg.h>

#ifdef CONFIG_PPC64

#include <asm/paca.h>

#include <asm/firmware.h>

#include <asm/lv1call.h>

#endif

int __irq_offset_value;

static int ppc_spurious_interrupts;

#ifdef CONFIG_PPC32

EXPORT_SYMBOL(__irq_offset_value);

atomic_t ppc_n_lost_interrupts;

#ifndef CONFIG_PPC_MERGE

#define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)

unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];

#endif

#ifdef CONFIG_TAU_INT

extern int tau_initialized;

extern int tau_interrupts(int);

#endif

#endif /* CONFIG_PPC32 */

#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)

extern atomic_t ipi_recv;

extern atomic_t ipi_sent;

#endif

#ifdef CONFIG_PPC64

EXPORT_SYMBOL(irq_desc);

int distribute_irqs = 1;

static inline unsigned long get_hard_enabled(void)

{

        unsigned long enabled;

        __asm__ __volatile__("lbz %0,%1(13)"

        : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));

        return enabled;

}

static inline void set_soft_enabled(unsigned long enable)

{

        __asm__ __volatile__("stb %0,%1(13)"

        : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));

}

void local_irq_restore(unsigned long en)

{

        /*

         * get_paca()->soft_enabled = en;

         * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?

         * That was allowed before, and in such a case we do need to take care

         * that gcc will set soft_enabled directly via r13, not choose to use

         * an intermediate register, lest we're preempted to a different cpu.

         */

        set_soft_enabled(en);

        if (!en)

                return;

        if (firmware_has_feature(FW_FEATURE_ISERIES)) {

                /*

                 * Do we need to disable preemption here?  Not really: in the

                 * unlikely event that we're preempted to a different cpu in

                 * between getting r13, loading its lppaca_ptr, and loading

                 * its any_int, we might call iseries_handle_interrupts without

                 * an interrupt pending on the new cpu, but that's no disaster,

                 * is it?  And the business of preempting us off the old cpu

                 * would itself involve a local_irq_restore which handles the

                 * interrupt to that cpu.

                 *

                 * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"

                 * to avoid any preemption checking added into get_paca().

                 */

                if (local_paca->lppaca_ptr->int_dword.any_int)

                        iseries_handle_interrupts();

                return;

        }

        /*

         * if (get_paca()->hard_enabled) return;

         * But again we need to take care that gcc gets hard_enabled directly

         * via r13, not choose to use an intermediate register, lest we're

         * preempted to a different cpu in between the two instructions.

         */

        if (get_hard_enabled())

                return;

        /*

         * Need to hard-enable interrupts here.  Since currently disabled,

         * no need to take further asm precautions against preemption; but

         * use local_paca instead of get_paca() to avoid preemption checking.

         */

        local_paca->hard_enabled = en;

        if ((int)mfspr(SPRN_DEC) < 0)

                mtspr(SPRN_DEC, 1);

        /*

         * Force the delivery of pending soft-disabled interrupts on PS3.

         * Any HV call will have this side effect.

         */

        if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {

                u64 tmp;

                lv1_get_version_info(&tmp);

        }

        __hard_irq_enable();

}

#endif /* CONFIG_PPC64 */

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_puts(p, "           ");

                for_each_online_cpu(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_each_online_cpu(j)

                        seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);

#else

                seq_printf(p, "%10u ", kstat_irqs(i));

#endif /* CONFIG_SMP */

                if (desc->chip)

                        seq_printf(p, " %s ", desc->chip->typename);

                else

                        seq_puts(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) {

#ifdef CONFIG_PPC32

#ifdef CONFIG_TAU_INT

                if (tau_initialized){

                        seq_puts(p, "TAU: ");

                        for_each_online_cpu(j)

                                seq_printf(p, "%10u ", tau_interrupts(j));

                        seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");

                }

#endif

#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)

                /* should this be per processor send/receive? */

                seq_printf(p, "IPI (recv/sent): %10u/%u\n",

                                atomic_read(&ipi_recv), atomic_read(&ipi_sent));

#endif

#endif /* CONFIG_PPC32 */

                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_desc[irq].affinity, map);

                if (any_online_cpu(mask) == NR_CPUS) {

                        printk("Breaking affinity for irq %i\n", irq);

                        mask = map;

                }

                if (irq_desc[irq].chip->set_affinity)

                        irq_desc[irq].chip->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

void do_IRQ(struct pt_regs *regs)

{

        struct pt_regs *old_regs = set_irq_regs(regs);

        unsigned int irq;

#ifdef CONFIG_IRQSTACKS

        struct thread_info *curtp, *irqtp;

#endif

        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

        /*

         * Every platform is required to implement ppc_md.get_irq.

         * This function will either return an irq number or NO_IRQ to

         * indicate there are no more pending.

         * The value NO_IRQ_IGNORE is for buggy hardware and means that this

         * IRQ has already been handled. -- Tom

         */

        irq = ppc_md.get_irq();

        if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {

#ifdef CONFIG_IRQSTACKS

                /* Switch to the irq stack to handle this */

                curtp = current_thread_info();

                irqtp = hardirq_ctx[smp_processor_id()];

                if (curtp != irqtp) {

                        struct irq_desc *desc = irq_desc + irq;

                        void *handler = desc->handle_irq;

                        if (handler == NULL)

                                handler = &__do_IRQ;

                        irqtp->task = curtp->task;

                        irqtp->flags = 0;

                        call_handle_irq(irq, desc, irqtp, handler);

                        irqtp->task = NULL;

                        if (irqtp->flags)

                                set_bits(irqtp->flags, &curtp->flags);

                } else

#endif

                        generic_handle_irq(irq);

        } else if (irq != NO_IRQ_IGNORE)

                /* That's not SMP safe ... but who cares ? */

                ppc_spurious_interrupts++;

        irq_exit();

        set_irq_regs(old_regs);

#ifdef CONFIG_PPC_ISERIES

        if (firmware_has_feature(FW_FEATURE_ISERIES) &&

                        get_lppaca()->int_dword.fields.decr_int) {

                get_lppaca()->int_dword.fields.decr_int = 0;

                /* Signal a fake decrementer interrupt */

                timer_interrupt(regs);

        }

#endif

}

void __init init_IRQ(void)

{

        if (ppc_md.init_IRQ)

                ppc_md.init_IRQ();

#ifdef CONFIG_PPC64

        irq_ctx_init();

#endif

}

#ifdef CONFIG_IRQSTACKS

struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;

struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;

void irq_ctx_init(void)

{

        struct thread_info *tp;

        int i;

        for_each_possible_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;

        }

}

static inline void do_softirq_onstack(void)

{

        struct thread_info *curtp, *irqtp;

        curtp = current_thread_info();

        irqtp = softirq_ctx[smp_processor_id()];

        irqtp->task = curtp->task;

        call_do_softirq(irqtp);

        irqtp->task = NULL;

}

#else

#define do_softirq_onstack()    __do_softirq()

#endif /* CONFIG_IRQSTACKS */

void do_softirq(void)

{

        unsigned long flags;

        if (in_interrupt())

                return;

        local_irq_save(flags);

        if (local_softirq_pending())

                do_softirq_onstack();

        local_irq_restore(flags);

}

/*

 * IRQ controller and virtual interrupts

 */

#ifdef CONFIG_PPC_MERGE

static LIST_HEAD(irq_hosts);

static DEFINE_SPINLOCK(irq_big_lock);

static DEFINE_PER_CPU(unsigned int, irq_radix_reader);

static unsigned int irq_radix_writer;

struct irq_map_entry irq_map[NR_IRQS];

static unsigned int irq_virq_count = NR_IRQS;

static struct irq_host *irq_default_host;

irq_hw_number_t virq_to_hw(unsigned int virq)

{

        return irq_map[virq].hwirq;

}

EXPORT_SYMBOL_GPL(virq_to_hw);

static int default_irq_host_match(struct irq_host *h, struct device_node *np)

{

        return h->of_node != NULL && h->of_node == np;

}

struct irq_host *irq_alloc_host(struct device_node *of_node,

                                unsigned int revmap_type,

                                unsigned int revmap_arg,

                                struct irq_host_ops *ops,

                                irq_hw_number_t inval_irq)

{

        struct irq_host *host;

        unsigned int size = sizeof(struct irq_host);

        unsigned int i;

        unsigned int *rmap;

        unsigned long flags;

        /* Allocate structure and revmap table if using linear mapping */

        if (revmap_type == IRQ_HOST_MAP_LINEAR)

                size += revmap_arg * sizeof(unsigned int);

        host = zalloc_maybe_bootmem(size, GFP_KERNEL);

        if (host == NULL)

                return NULL;

        /* Fill structure */

        host->revmap_type = revmap_type;

        host->inval_irq = inval_irq;

        host->ops = ops;

        host->of_node = of_node;

        if (host->ops->match == NULL)

                host->ops->match = default_irq_host_match;

        spin_lock_irqsave(&irq_big_lock, flags);

        /* If it's a legacy controller, check for duplicates and

         * mark it as allocated (we use irq 0 host pointer for that

         */

        if (revmap_type == IRQ_HOST_MAP_LEGACY) {

                if (irq_map[0].host != NULL) {

                        spin_unlock_irqrestore(&irq_big_lock, flags);

                        /* If we are early boot, we can't free the structure,

                         * too bad...

                         * this will be fixed once slab is made available early

                         * instead of the current cruft

                         */

                        if (mem_init_done)

                                kfree(host);

                        return NULL;

                }

                irq_map[0].host = host;

        }

        list_add(&host->link, &irq_hosts);

        spin_unlock_irqrestore(&irq_big_lock, flags);

        /* Additional setups per revmap type */

        switch(revmap_type) {

        case IRQ_HOST_MAP_LEGACY:

                /* 0 is always the invalid number for legacy */

                host->inval_irq = 0;

                /* setup us as the host for all legacy interrupts */

                for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {

                        irq_map[i].hwirq = i;

                        smp_wmb();

                        irq_map[i].host = host;

                        smp_wmb();

                        /* Clear norequest flags */

                        get_irq_desc(i)->status &= ~IRQ_NOREQUEST;

                        /* Legacy flags are left to default at this point,

                         * one can then use irq_create_mapping() to

                         * explicitly change them

                         */

                        ops->map(host, i, i);

                }

                break;

        case IRQ_HOST_MAP_LINEAR:

                rmap = (unsigned int *)(host + 1);

                for (i = 0; i < revmap_arg; i++)

                        rmap[i] = NO_IRQ;

                host->revmap_data.linear.size = revmap_arg;

                smp_wmb();

                host->revmap_data.linear.revmap = rmap;

                break;

        default:

                break;

        }

        pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);

        return host;

}

struct irq_host *irq_find_host(struct device_node *node)

{

        struct irq_host *h, *found = NULL;

        unsigned long flags;

        /* We might want to match the legacy controller last since

         * it might potentially be set to match all interrupts in

         * the absence of a device node. This isn't a problem so far

         * yet though...

         */

        spin_lock_irqsave(&irq_big_lock, flags);

        list_for_each_entry(h, &irq_hosts, link)

                if (h->ops->match(h, node)) {

                        found = h;

                        break;

                }

        spin_unlock_irqrestore(&irq_big_lock, flags);

        return found;

}

EXPORT_SYMBOL_GPL(irq_find_host);

void irq_set_default_host(struct irq_host *host)

{

        pr_debug("irq: Default host set to @0x%p\n", host);

        irq_default_host = host;

}

void irq_set_virq_count(unsigned int count)

{

        pr_debug("irq: Trying to set virq count to %d\n", count);

        BUG_ON(count < NUM_ISA_INTERRUPTS);

        if (count < NR_IRQS)

                irq_virq_count = count;

}

/* radix tree not lockless safe ! we use a brlock-type mecanism

 * for now, until we can use a lockless radix tree

 */

static void irq_radix_wrlock(unsigned long *flags)

{

        unsigned int cpu, ok;

        spin_lock_irqsave(&irq_big_lock, *flags);

        irq_radix_writer = 1;

        smp_mb();

        do {

                barrier();

                ok = 1;

                for_each_possible_cpu(cpu) {

                        if (per_cpu(irq_radix_reader, cpu)) {

                                ok = 0;

                                break;

                        }

                }

                if (!ok)

                        cpu_relax();

        } while(!ok);

}

static void irq_radix_wrunlock(unsigned long flags)

{

        smp_wmb();

        irq_radix_writer = 0;

        spin_unlock_irqrestore(&irq_big_lock, flags);

}

static void irq_radix_rdlock(unsigned long *flags)

{

        local_irq_save(*flags);

        __get_cpu_var(irq_radix_reader) = 1;

        smp_mb();

        if (likely(irq_radix_writer == 0))

                return;

        __get_cpu_var(irq_radix_reader) = 0;

        smp_wmb();

        spin_lock(&irq_big_lock);

        __get_cpu_var(irq_radix_reader) = 1;

        spin_unlock(&irq_big_lock);

}

static void irq_radix_rdunlock(unsigned long flags)

{

        __get_cpu_var(irq_radix_reader) = 0;

        local_irq_restore(flags);

}

static int irq_setup_virq(struct irq_host *host, unsigned int virq,

                            irq_hw_number_t hwirq)

{

        /* Clear IRQ_NOREQUEST flag */

        get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;

        /* map it */

        smp_wmb();

        irq_map[virq].hwirq = hwirq;

        smp_mb();

        if (host->ops->map(host, virq, hwirq)) {

                pr_debug("irq: -> mapping failed, freeing\n");

                irq_free_virt(virq, 1);

                return -1;

        }

        return 0;

}

unsigned int irq_create_direct_mapping(struct irq_host *host)

{

        unsigned int virq;

        if (host == NULL)

                host = irq_default_host;

        BUG_ON(host == NULL);

        WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);

        virq = irq_alloc_virt(host, 1, 0);

        if (virq == NO_IRQ) {

                pr_debug("irq: create_direct virq allocation failed\n");

                return NO_IRQ;

        }

        pr_debug("irq: create_direct obtained virq %d\n", virq);

        if (irq_setup_virq(host, virq, virq))

                return NO_IRQ;

        return virq;

}

unsigned int irq_create_mapping(struct irq_host *host,

                                irq_hw_number_t hwirq)

{

        unsigned int virq, hint;

        pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);

        /* Look for default host if nececssary */

        if (host == NULL)

                host = irq_default_host;

        if (host == NULL) {

                printk(KERN_WARNING "irq_create_mapping called for"

                       " NULL host, hwirq=%lx\n", hwirq);

                WARN_ON(1);

                return NO_IRQ;

        }

        pr_debug("irq: -> using host @%p\n", host);

        /* Check if mapping already exist, if it does, call

         * host->ops->map() to update the flags

         */

        virq = irq_find_mapping(host, hwirq);

        if (virq != NO_IRQ) {

                if (host->ops->remap)

                        host->ops->remap(host, virq, hwirq);

                pr_debug("irq: -> existing mapping on virq %d\n", virq);

                return virq;

        }

        /* Get a virtual interrupt number */

        if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {

                /* Handle legacy */

                virq = (unsigned int)hwirq;

                if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)

                        return NO_IRQ;

                return virq;

        } else {

                /* Allocate a virtual interrupt number */

                hint = hwirq % irq_virq_count;

                virq = irq_alloc_virt(host, 1, hint);

                if (virq == NO_IRQ) {

                        pr_debug("irq: -> virq allocation failed\n");

                        return NO_IRQ;

                }

        }