/* irq.c: UltraSparc IRQ handling/init/registry.
 *
 * Copyright (C) 1997, 2007, 2008 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1998  Eddie C. Dost    (ecd@skynet.be)
 * Copyright (C) 1998  Jakub Jelinek    (jj@ultra.linux.cz)
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/linkage.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/irq.h>

#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/iommu.h>
#include <asm/upa.h>
#include <asm/oplib.h>
#include <asm/prom.h>
#include <asm/timer.h>
#include <asm/smp.h>
#include <asm/starfire.h>
#include <asm/uaccess.h>
#include <asm/cache.h>
#include <asm/cpudata.h>
#include <asm/auxio.h>
#include <asm/head.h>
#include <asm/hypervisor.h>
#include <asm/cacheflush.h>

#include "entry.h"
#include "cpumap.h"

#define NUM_IVECS       (IMAP_INR + 1)

struct ino_bucket *ivector_table;
unsigned long ivector_table_pa;

/* On several sun4u processors, it is illegal to mix bypass and
 * non-bypass accesses.  Therefore we access all INO buckets
 * using bypass accesses only.
 */
static unsigned long bucket_get_chain_pa(unsigned long bucket_pa)
{
        unsigned long ret;

        __asm__ __volatile__("ldxa      [%1] %2, %0"
                             : "=&r" (ret)
                             : "r" (bucket_pa +
                                    offsetof(struct ino_bucket,
                                             __irq_chain_pa)),
                               "i" (ASI_PHYS_USE_EC));

        return ret;
}

static void bucket_clear_chain_pa(unsigned long bucket_pa)
{
        __asm__ __volatile__("stxa      %%g0, [%0] %1"
                             : /* no outputs */
                             : "r" (bucket_pa +
                                    offsetof(struct ino_bucket,
                                             __irq_chain_pa)),
                               "i" (ASI_PHYS_USE_EC));
}

static unsigned int bucket_get_virt_irq(unsigned long bucket_pa)
{
        unsigned int ret;

        __asm__ __volatile__("lduwa     [%1] %2, %0"
                             : "=&r" (ret)
                             : "r" (bucket_pa +
                                    offsetof(struct ino_bucket,
                                             __virt_irq)),
                               "i" (ASI_PHYS_USE_EC));

        return ret;
}

static void bucket_set_virt_irq(unsigned long bucket_pa,
                                unsigned int virt_irq)
{
        __asm__ __volatile__("stwa      %0, [%1] %2"
                             : /* no outputs */
                             : "r" (virt_irq),
                               "r" (bucket_pa +
                                    offsetof(struct ino_bucket,
                                             __virt_irq)),
                               "i" (ASI_PHYS_USE_EC));
}

#define irq_work_pa(__cpu)      &(trap_block[(__cpu)].irq_worklist_pa)

static struct {
        unsigned int dev_handle;
        unsigned int dev_ino;
        unsigned int in_use;
} virt_irq_table[NR_IRQS];
static DEFINE_SPINLOCK(virt_irq_alloc_lock);

unsigned char virt_irq_alloc(unsigned int dev_handle,
                             unsigned int dev_ino)
{
        unsigned long flags;
        unsigned char ent;

        BUILD_BUG_ON(NR_IRQS >= 256);

        spin_lock_irqsave(&virt_irq_alloc_lock, flags);

        for (ent = 1; ent < NR_IRQS; ent++) {
                if (!virt_irq_table[ent].in_use)
                        break;
        }
        if (ent >= NR_IRQS) {
                printk(KERN_ERR "IRQ: Out of virtual IRQs.\n");
                ent = 0;
        } else {
                virt_irq_table[ent].dev_handle = dev_handle;
                virt_irq_table[ent].dev_ino = dev_ino;
                virt_irq_table[ent].in_use = 1;
        }

        spin_unlock_irqrestore(&virt_irq_alloc_lock, flags);

        return ent;
}

#ifdef CONFIG_PCI_MSI
void virt_irq_free(unsigned int virt_irq)
{
        unsigned long flags;

        if (virt_irq >= NR_IRQS)
                return;

        spin_lock_irqsave(&virt_irq_alloc_lock, flags);

        virt_irq_table[virt_irq].in_use = 0;

        spin_unlock_irqrestore(&virt_irq_alloc_lock, flags);
}
#endif

/*
 * /proc/interrupts printing:
 */

int show_interrupts(struct seq_file *p, void *v)
{
        int i = *(loff_t *) v, j;
        struct irqaction * action;
        unsigned long flags;

        if (i == 0) {
                seq_printf(p, "           ");
                for_each_online_cpu(j)
                        seq_printf(p, "CPU%d       ",j);
                seq_putc(p, '\n');
        }

        if (i < NR_IRQS) {
                spin_lock_irqsave(&irq_desc[i].lock, flags);
                action = irq_desc[i].action;
                if (!action)
                        goto skip;
                seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
                seq_printf(p, "%10u ", kstat_irqs(i));
#else
                for_each_online_cpu(j)
                        seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
#endif
                seq_printf(p, " %9s", irq_desc[i].chip->typename);
                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[i].lock, flags);
        } else if (i == NR_IRQS) {
                seq_printf(p, "NMI: ");
                for_each_online_cpu(j)
                        seq_printf(p, "%10u ", cpu_data(j).__nmi_count);
                seq_printf(p, "     Non-maskable interrupts\n");
        }
        return 0;
}

static unsigned int sun4u_compute_tid(unsigned long imap, unsigned long cpuid)
{
        unsigned int tid;

        if (this_is_starfire) {
                tid = starfire_translate(imap, cpuid);
                tid <<= IMAP_TID_SHIFT;
                tid &= IMAP_TID_UPA;
        } else {
                if (tlb_type == cheetah || tlb_type == cheetah_plus) {
                        unsigned long ver;

                        __asm__ ("rdpr %%ver, %0" : "=r" (ver));
                        if ((ver >> 32UL) == __JALAPENO_ID ||
                            (ver >> 32UL) == __SERRANO_ID) {
                                tid = cpuid << IMAP_TID_SHIFT;
                                tid &= IMAP_TID_JBUS;
                        } else {
                                unsigned int a = cpuid & 0x1f;
                                unsigned int n = (cpuid >> 5) & 0x1f;

                                tid = ((a << IMAP_AID_SHIFT) |
                                       (n << IMAP_NID_SHIFT));
                                tid &= (IMAP_AID_SAFARI |
                                        IMAP_NID_SAFARI);
                        }
                } else {
                        tid = cpuid << IMAP_TID_SHIFT;
                        tid &= IMAP_TID_UPA;
                }
        }

        return tid;
}

struct irq_handler_data {
        unsigned long   iclr;
        unsigned long   imap;

        void            (*pre_handler)(unsigned int, void *, void *);
        void            *arg1;
        void            *arg2;
};

#ifdef CONFIG_SMP
static int irq_choose_cpu(unsigned int virt_irq)
{
        cpumask_t mask;
        int cpuid;

        cpumask_copy(&mask, irq_desc[virt_irq].affinity);
        if (cpus_equal(mask, cpu_online_map)) {
                cpuid = map_to_cpu(virt_irq);
        } else {
                cpumask_t tmp;

                cpus_and(tmp, cpu_online_map, mask);
                cpuid = cpus_empty(tmp) ? map_to_cpu(virt_irq) : first_cpu(tmp);
        }

        return cpuid;
}
#else
static int irq_choose_cpu(unsigned int virt_irq)
{
        return real_hard_smp_processor_id();
}
#endif

static void sun4u_irq_enable(unsigned int virt_irq)
{
        struct irq_handler_data *data = get_irq_chip_data(virt_irq);

        if (likely(data)) {
                unsigned long cpuid, imap, val;
                unsigned int tid;

                cpuid = irq_choose_cpu(virt_irq);
                imap = data->imap;

                tid = sun4u_compute_tid(imap, cpuid);

                val = upa_readq(imap);
                val &= ~(IMAP_TID_UPA | IMAP_TID_JBUS |
                         IMAP_AID_SAFARI | IMAP_NID_SAFARI);
                val |= tid | IMAP_VALID;
                upa_writeq(val, imap);
                upa_writeq(ICLR_IDLE, data->iclr);
        }
}

static int sun4u_set_affinity(unsigned int virt_irq,
                               const struct cpumask *mask)
{
        sun4u_irq_enable(virt_irq);

        return 0;
}

/* Don't do anything.  The desc->status check for IRQ_DISABLED in
 * handler_irq() will skip the handler call and that will leave the
 * interrupt in the sent state.  The next ->enable() call will hit the
 * ICLR register to reset the state machine.
 *
 * This scheme is necessary, instead of clearing the Valid bit in the
 * IMAP register, to handle the case of IMAP registers being shared by
 * multiple INOs (and thus ICLR registers).  Since we use a different
 * virtual IRQ for each shared IMAP instance, the generic code thinks
 * there is only one user so it prematurely calls ->disable() on
 * free_irq().
 *
 * We have to provide an explicit ->disable() method instead of using
 * NULL to get the default.  The reason is that if the generic code
 * sees that, it also hooks up a default ->shutdown method which
 * invokes ->mask() which we do not want.  See irq_chip_set_defaults().
 */
static void sun4u_irq_disable(unsigned int virt_irq)
{
}

static void sun4u_irq_eoi(unsigned int virt_irq)
{
        struct irq_handler_data *data = get_irq_chip_data(virt_irq);
        struct irq_desc *desc = irq_desc + virt_irq;

        if (unlikely(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                return;

        if (likely(data))
                upa_writeq(ICLR_IDLE, data->iclr);
}

static void sun4v_irq_enable(unsigned int virt_irq)
{
        unsigned int ino = virt_irq_table[virt_irq].dev_ino;
        unsigned long cpuid = irq_choose_cpu(virt_irq);
        int err;

        err = sun4v_intr_settarget(ino, cpuid);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_intr_settarget(%x,%lu): "
                       "err(%d)\n", ino, cpuid, err);
        err = sun4v_intr_setstate(ino, HV_INTR_STATE_IDLE);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_intr_setstate(%x): "
                       "err(%d)\n", ino, err);
        err = sun4v_intr_setenabled(ino, HV_INTR_ENABLED);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_intr_setenabled(%x): err(%d)\n",
                       ino, err);
}

static int sun4v_set_affinity(unsigned int virt_irq,
                               const struct cpumask *mask)
{
        unsigned int ino = virt_irq_table[virt_irq].dev_ino;
        unsigned long cpuid = irq_choose_cpu(virt_irq);
        int err;

        err = sun4v_intr_settarget(ino, cpuid);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_intr_settarget(%x,%lu): "
                       "err(%d)\n", ino, cpuid, err);

        return 0;
}

static void sun4v_irq_disable(unsigned int virt_irq)
{
        unsigned int ino = virt_irq_table[virt_irq].dev_ino;
        int err;

        err = sun4v_intr_setenabled(ino, HV_INTR_DISABLED);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_intr_setenabled(%x): "
                       "err(%d)\n", ino, err);
}

static void sun4v_irq_eoi(unsigned int virt_irq)
{
        unsigned int ino = virt_irq_table[virt_irq].dev_ino;
        struct irq_desc *desc = irq_desc + virt_irq;
        int err;

        if (unlikely(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                return;

        err = sun4v_intr_setstate(ino, HV_INTR_STATE_IDLE);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_intr_setstate(%x): "
                       "err(%d)\n", ino, err);
}

static void sun4v_virq_enable(unsigned int virt_irq)
{
        unsigned long cpuid, dev_handle, dev_ino;
        int err;

        cpuid = irq_choose_cpu(virt_irq);

        dev_handle = virt_irq_table[virt_irq].dev_handle;
        dev_ino = virt_irq_table[virt_irq].dev_ino;

        err = sun4v_vintr_set_target(dev_handle, dev_ino, cpuid);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_vintr_set_target(%lx,%lx,%lu): "
                       "err(%d)\n",
                       dev_handle, dev_ino, cpuid, err);
        err = sun4v_vintr_set_state(dev_handle, dev_ino,
                                    HV_INTR_STATE_IDLE);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_vintr_set_state(%lx,%lx,"
                       "HV_INTR_STATE_IDLE): err(%d)\n",
                       dev_handle, dev_ino, err);
        err = sun4v_vintr_set_valid(dev_handle, dev_ino,
                                    HV_INTR_ENABLED);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_vintr_set_state(%lx,%lx,"
                       "HV_INTR_ENABLED): err(%d)\n",
                       dev_handle, dev_ino, err);
}

static int sun4v_virt_set_affinity(unsigned int virt_irq,
                                    const struct cpumask *mask)
{
        unsigned long cpuid, dev_handle, dev_ino;
        int err;

        cpuid = irq_choose_cpu(virt_irq);

        dev_handle = virt_irq_table[virt_irq].dev_handle;
        dev_ino = virt_irq_table[virt_irq].dev_ino;

        err = sun4v_vintr_set_target(dev_handle, dev_ino, cpuid);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_vintr_set_target(%lx,%lx,%lu): "
                       "err(%d)\n",
                       dev_handle, dev_ino, cpuid, err);

        return 0;
}

static void sun4v_virq_disable(unsigned int virt_irq)
{
        unsigned long dev_handle, dev_ino;
        int err;

        dev_handle = virt_irq_table[virt_irq].dev_handle;
        dev_ino = virt_irq_table[virt_irq].dev_ino;

        err = sun4v_vintr_set_valid(dev_handle, dev_ino,
                                    HV_INTR_DISABLED);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_vintr_set_state(%lx,%lx,"
                       "HV_INTR_DISABLED): err(%d)\n",
                       dev_handle, dev_ino, err);
}

static void sun4v_virq_eoi(unsigned int virt_irq)
{
        struct irq_desc *desc = irq_desc + virt_irq;
        unsigned long dev_handle, dev_ino;
        int err;

        if (unlikely(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                return;

        dev_handle = virt_irq_table[virt_irq].dev_handle;
        dev_ino = virt_irq_table[virt_irq].dev_ino;

        err = sun4v_vintr_set_state(dev_handle, dev_ino,
                                    HV_INTR_STATE_IDLE);
        if (err != HV_EOK)
                printk(KERN_ERR "sun4v_vintr_set_state(%lx,%lx,"
                       "HV_INTR_STATE_IDLE): err(%d)\n",
                       dev_handle, dev_ino, err);
}

static struct irq_chip sun4u_irq = {
        .typename       = "sun4u",
        .enable         = sun4u_irq_enable,
        .disable        = sun4u_irq_disable,
        .eoi            = sun4u_irq_eoi,
        .set_affinity   = sun4u_set_affinity,
};

static struct irq_chip sun4v_irq = {
        .typename       = "sun4v",
        .enable         = sun4v_irq_enable,
        .disable        = sun4v_irq_disable,
        .eoi            = sun4v_irq_eoi,
        .set_affinity   = sun4v_set_affinity,
};

static struct irq_chip sun4v_virq = {
        .typename       = "vsun4v",
        .enable         = sun4v_virq_enable,
        .disable        = sun4v_virq_disable,
        .eoi            = sun4v_virq_eoi,
        .set_affinity   = sun4v_virt_set_affinity,
};

static void pre_flow_handler(unsigned int virt_irq,
                                      struct irq_desc *desc)
{
        struct irq_handler_data *data = get_irq_chip_data(virt_irq);
        unsigned int ino = virt_irq_table[virt_irq].dev_ino;

        data->pre_handler(ino, data->arg1, data->arg2);

        handle_fasteoi_irq(virt_irq, desc);
}

void irq_install_pre_handler(int virt_irq,
                             void (*func)(unsigned int, void *, void *),
                             void *arg1, void *arg2)
{
        struct irq_handler_data *data = get_irq_chip_data(virt_irq);
        struct irq_desc *desc = irq_desc + virt_irq;

        data->pre_handler = func;
        data->arg1 = arg1;
        data->arg2 = arg2;

        desc->handle_irq = pre_flow_handler;
}

unsigned int build_irq(int inofixup, unsigned long iclr, unsigned long imap)
{
        struct ino_bucket *bucket;
        struct irq_handler_data *data;
        unsigned int virt_irq;
        int ino;

        BUG_ON(tlb_type == hypervisor);

        ino = (upa_readq(imap) & (IMAP_IGN | IMAP_INO)) + inofixup;
        bucket = &ivector_table[ino];
        virt_irq = bucket_get_virt_irq(__pa(bucket));
        if (!virt_irq) {
                virt_irq = virt_irq_alloc(0, ino);
                bucket_set_virt_irq(__pa(bucket), virt_irq);
                set_irq_chip_and_handler_name(virt_irq,
                                              &sun4u_irq,
                                              handle_fasteoi_irq,
                                              "IVEC");
        }

        data = get_irq_chip_data(virt_irq);
        if (unlikely(data))
                goto out;

        data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
        if (unlikely(!data)) {
                prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
                prom_halt();
        }
        set_irq_chip_data(virt_irq, data);

        data->imap  = imap;
        data->iclr  = iclr;

out:
        return virt_irq;
}

static unsigned int sun4v_build_common(unsigned long sysino,
                                       struct irq_chip *chip)
{
        struct ino_bucket *bucket;
        struct irq_handler_data *data;
        unsigned int virt_irq;

        BUG_ON(tlb_type != hypervisor);

        bucket = &ivector_table[sysino];
        virt_irq = bucket_get_virt_irq(__pa(bucket));
        if (!virt_irq) {
                virt_irq = virt_irq_alloc(0, sysino);
                bucket_set_virt_irq(__pa(bucket), virt_irq);
                set_irq_chip_and_handler_name(virt_irq, chip,
                                              handle_fasteoi_irq,
                                              "IVEC");
        }

        data = get_irq_chip_data(virt_irq);
        if (unlikely(data))
                goto out;

        data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
        if (unlikely(!data)) {
                prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
                prom_halt();
        }
        set_irq_chip_data(virt_irq, data);

        /* Catch accidental accesses to these things.  IMAP/ICLR handling
         * is done by hypervisor calls on sun4v platforms, not by direct
         * register accesses.
         */
        data->imap = ~0UL;
        data->iclr = ~0UL;

out:
        return virt_irq;
}

unsigned int sun4v_build_irq(u32 devhandle, unsigned int devino)
{
        unsigned long sysino = sun4v_devino_to_sysino(devhandle, devino);

        return sun4v_build_common(sysino, &sun4v_irq);
}

unsigned int sun4v_build_virq(u32 devhandle, unsigned int devino)
{
        struct irq_handler_data *data;
        unsigned long hv_err, cookie;
        struct ino_bucket *bucket;
        struct irq_desc *desc;
        unsigned int virt_irq;

        bucket = kzalloc(sizeof(struct ino_bucket), GFP_ATOMIC);
        if (unlikely(!bucket))
                return 0;
        __flush_dcache_range((unsigned long) bucket,
                             ((unsigned long) bucket +
                              sizeof(struct ino_bucket)));

        virt_irq = virt_irq_alloc(devhandle, devino);
        bucket_set_virt_irq(__pa(bucket), virt_irq);

        set_irq_chip_and_handler_name(virt_irq, &sun4v_virq,
                                      handle_fasteoi_irq,
                                      "IVEC");

        data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
        if (unlikely(!data))
                return 0;

        /* In order to make the LDC channel startup sequence easier,
         * especially wrt. locking, we do not let request_irq() enable
         * the interrupt.
         */
        desc = irq_desc + virt_irq;
        desc->status |= IRQ_NOAUTOEN;

        set_irq_chip_data(virt_irq, data);

        /* Catch accidental accesses to these things.  IMAP/ICLR handling
         * is done by hypervisor calls on sun4v platforms, not by direct
         * register accesses.
         */
        data->imap = ~0UL;
        data->iclr = ~0UL;

        cookie = ~__pa(bucket);
        hv_err = sun4v_vintr_set_cookie(devhandle, devino, cookie);
        if (hv_err) {
                prom_printf("IRQ: Fatal, cannot set cookie for [%x:%x] "
                            "err=%lu\n", devhandle, devino, hv_err);
                prom_halt();
        }

        return virt_irq;
}

void ack_bad_irq(unsigned int virt_irq)
{
        unsigned int ino = virt_irq_table[virt_irq].dev_ino;

        if (!ino)
                ino = 0xdeadbeef;

        printk(KERN_CRIT "Unexpected IRQ from ino[%x] virt_irq[%u]\n",
               ino, virt_irq);
}

void *hardirq_stack[NR_CPUS];
void *softirq_stack[NR_CPUS];

static __attribute__((always_inline)) void *set_hardirq_stack(void)
{
        void *orig_sp, *sp = hardirq_stack[smp_processor_id()];

        __asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
        if (orig_sp < sp ||
            orig_sp > (sp + THREAD_SIZE)) {
                sp += THREAD_SIZE - 192 - STACK_BIAS;
                __asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
        }

        return orig_sp;
}
static __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
{
        __asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
}

void handler_irq(int irq, struct pt_regs *regs)
{
        unsigned long pstate, bucket_pa;
        struct pt_regs *old_regs;
        void *orig_sp;

        clear_softint(1 << irq);

        old_regs = set_irq_regs(regs);
        irq_enter();

        /* Grab an atomic snapshot of the pending IVECs.  */
        __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
                             "wrpr      %0, %3, %%pstate\n\t"
                             "ldx       [%2], %1\n\t"
                             "stx       %%g0, [%2]\n\t"
                             "wrpr      %0, 0x0, %%pstate\n\t"
                             : "=&r" (pstate), "=&r" (bucket_pa)
                             : "r" (irq_work_pa(smp_processor_id())),
                               "i" (PSTATE_IE)
                             : "memory");

        orig_sp = set_hardirq_stack();

        while (bucket_pa) {
                struct irq_desc *desc;
                unsigned long next_pa;
                unsigned int virt_irq;

                next_pa = bucket_get_chain_pa(bucket_pa);
                virt_irq = bucket_get_virt_irq(bucket_pa);
                bucket_clear_chain_pa(bucket_pa);

                desc = irq_desc + virt_irq;

                if (!(desc->status & IRQ_DISABLED))
                        desc->handle_irq(virt_irq, desc);

                bucket_pa = next_pa;
        }

        restore_hardirq_stack(orig_sp);

        irq_exit();
        set_irq_regs(old_regs);
}

void do_softirq(void)
{
        unsigned long flags;

        if (in_interrupt())
                return;

        local_irq_save(flags);

        if (local_softirq_pending()) {
                void *orig_sp, *sp = softirq_stack[smp_processor_id()];

                sp += THREAD_SIZE - 192 - STACK_BIAS;

                __asm__ __volatile__("mov %%sp, %0\n\t"
                                     "mov %1, %%sp"
                                     : "=&r" (orig_sp)
                                     : "r" (sp));
                __do_softirq();
                __asm__ __volatile__("mov %0, %%sp"
                                     : : "r" (orig_sp));
        }

        local_irq_restore(flags);
}

#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(void)
{
        unsigned int irq;

        for (irq = 0; irq < NR_IRQS; irq++) {
                unsigned long flags;

                spin_lock_irqsave(&irq_desc[irq].lock, flags);
                if (irq_desc[irq].action &&
                    !(irq_desc[irq].status & IRQ_PER_CPU)) {
                        if (irq_desc[irq].chip->set_affinity)
                                irq_desc[irq].chip->set_affinity(irq,
                                        irq_desc[irq].affinity);
                }
                spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
        }

        tick_ops->disable_irq();
}
#endif

struct sun5_timer {
        u64     count0;
        u64     limit0;
        u64     count1;
        u64     limit1;
};

static struct sun5_timer *prom_timers;
static u64 prom_limit0, prom_limit1;

static void map_prom_timers(void)
{
        struct device_node *dp;
        const unsigned int *addr;

        /* PROM timer node hangs out in the top level of device siblings... */
        dp = of_find_node_by_path("/");
        dp = dp->child;
        while (dp) {
                if (!strcmp(dp->name, "counter-timer"))
                        break;
                dp = dp->sibling;
        }

        /* Assume if node is not present, PROM uses different tick mechanism
         * which we should not care about.
         */
        if (!dp) {
                prom_timers = (struct sun5_timer *) 0;
                return;
        }

        /* If PROM is really using this, it must be mapped by him. */
        addr = of_get_property(dp, "address", NULL);
        if (!addr) {
                prom_printf("PROM does not have timer mapped, trying to continue.\n");
                prom_timers = (struct sun5_timer *) 0;
                return;
        }
        prom_timers = (struct sun5_timer *) ((unsigned long)addr[0]);
}

static void kill_prom_timer(void)
{
        if (!prom_timers)
                return;

        /* Save them away for later. */
        prom_limit0 = prom_timers->limit0;
        prom_limit1 = prom_timers->limit1;

        /* Just as in sun4c/sun4m PROM uses timer which ticks at IRQ 14.
         * We turn both off here just to be paranoid.
         */
        prom_timers->limit0 = 0;
        prom_timers->limit1 = 0;

        /* Wheee, eat the interrupt packet too... */
        __asm__ __volatile__(
"       mov     0x40, %%g2\n"
"       ldxa    [%%g0] %0, %%g1\n"
"       ldxa    [%%g2] %1, %%g1\n"
"       stxa    %%g0, [%%g0] %0\n"
"       membar  #Sync\n"
        : /* no outputs */
        : "i" (ASI_INTR_RECEIVE), "i" (ASI_INTR_R)
        : "g1", "g2");
}

void notrace init_irqwork_curcpu(void)
{
        int cpu = hard_smp_processor_id();

        trap_block[cpu].irq_worklist_pa = 0UL;
}

/* Please be very careful with register_one_mondo() and
 * sun4v_register_mondo_queues().
 *
 * On SMP this gets invoked from the CPU trampoline before
 * the cpu has fully taken over the trap table from OBP,
 * and it's kernel stack + %g6 thread register state is
 * not fully cooked yet.
 *
 * Therefore you cannot make any OBP calls, not even prom_printf,
 * from these two routines.
 */
static void __cpuinit notrace register_one_mondo(unsigned long paddr, unsigned long type, unsigned long qmask)
{
        unsigned long num_entries = (qmask + 1) / 64;
        unsigned long status;

        status = sun4v_cpu_qconf(type, paddr, num_entries);
        if (status != HV_EOK) {
                prom_printf("SUN4V: sun4v_cpu_qconf(%lu:%lx:%lu) failed, "
                            "err %lu\n", type, paddr, num_entries, status);
                prom_halt();
        }
}

void __cpuinit notrace sun4v_register_mondo_queues(int this_cpu)
{
        struct trap_per_cpu *tb = &trap_block[this_cpu];

        register_one_mondo(tb->cpu_mondo_pa, HV_CPU_QUEUE_CPU_MONDO,
                           tb->cpu_mondo_qmask);
        register_one_mondo(tb->dev_mondo_pa, HV_CPU_QUEUE_DEVICE_MONDO,
                           tb->dev_mondo_qmask);
        register_one_mondo(tb->resum_mondo_pa, HV_CPU_QUEUE_RES_ERROR,
                           tb->resum_qmask);
        register_one_mondo(tb->nonresum_mondo_pa, HV_CPU_QUEUE_NONRES_ERROR,
                           tb->nonresum_qmask);
}

/* Each queue region must be a power of 2 multiple of 64 bytes in
 * size.  The base real address must be aligned to the size of the
 * region.  Thus, an 8KB queue must be 8KB aligned, for example.
 */
static void __init alloc_one_queue(unsigned long *pa_ptr, unsigned long qmask)
{
        unsigned long size = PAGE_ALIGN(qmask + 1);
        unsigned long order = get_order(size);
        unsigned long p;

        p = __get_free_pages(GFP_KERNEL, order);
        if (!p) {
                prom_printf("SUN4V: Error, cannot allocate queue.\n");
                prom_halt();
        }

        *pa_ptr = __pa(p);
}

static void __init init_cpu_send_mondo_info(struct trap_per_cpu *tb)
{
#ifdef CONFIG_SMP
        unsigned long page;

        BUILD_BUG_ON((NR_CPUS * sizeof(u16)) > (PAGE_SIZE - 64));

        page = get_zeroed_page(GFP_KERNEL);
        if (!page) {
                prom_printf("SUN4V: Error, cannot allocate cpu mondo page.\n");
                prom_halt();
        }

        tb->cpu_mondo_block_pa = __pa(page);
        tb->cpu_list_pa = __pa(page + 64);
#endif
}

/* Allocate mondo and error queues for all possible cpus.  */
static void __init sun4v_init_mondo_queues(void)
{
        int cpu;

        for_each_possible_cpu(cpu) {
                struct trap_per_cpu *tb = &trap_block[cpu];

                alloc_one_queue(&tb->cpu_mondo_pa, tb->cpu_mondo_qmask);
                alloc_one_queue(&tb->dev_mondo_pa, tb->dev_mondo_qmask);
                alloc_one_queue(&tb->resum_mondo_pa, tb->resum_qmask);
                alloc_one_queue(&tb->resum_kernel_buf_pa, tb->resum_qmask);
                alloc_one_queue(&tb->nonresum_mondo_pa, tb->nonresum_qmask);
                alloc_one_queue(&tb->nonresum_kernel_buf_pa,
                                tb->nonresum_qmask);
        }
}

static void __init init_send_mondo_info(void)
{
        int cpu;

        for_each_possible_cpu(cpu) {
                struct trap_per_cpu *tb = &trap_block[cpu];

                init_cpu_send_mondo_info(tb);
        }
}

static struct irqaction timer_irq_action = {
        .name = "timer",
};

/* Only invoked on boot processor. */
void __init init_IRQ(void)
{
        unsigned long size;

        map_prom_timers();
        kill_prom_timer();

        size = sizeof(struct ino_bucket) * NUM_IVECS;
        ivector_table = kzalloc(size, GFP_KERNEL);
        if (!ivector_table) {
                prom_printf("Fatal error, cannot allocate ivector_table\n");
                prom_halt();
        }
        __flush_dcache_range((unsigned long) ivector_table,

                             ((unsigned long) ivector_table) + size);

        ivector_table_pa = __pa(ivector_table);

        if (tlb_type == hypervisor)
                sun4v_init_mondo_queues();

        init_send_mondo_info();

        if (tlb_type == hypervisor) {
                /* Load up the boot cpu's entries.  */
                sun4v_register_mondo_queues(hard_smp_processor_id());
        }

        /* We need to clear any IRQ's pending in the soft interrupt
         * registers, a spurious one could be left around from the
         * PROM timer which we just disabled.
         */
        clear_softint(get_softint());

        /* Now that ivector table is initialized, it is safe
         * to receive IRQ vector traps.  We will normally take
         * one or two right now, in case some device PROM used
         * to boot us wants to speak to us.  We just ignore them.
         */
        __asm__ __volatile__("rdpr      %%pstate, %%g1\n\t"
                             "or        %%g1, %0, %%g1\n\t"
                             "wrpr      %%g1, 0x0, %%pstate"
                             : /* No outputs */
                             : "i" (PSTATE_IE)
                             : "g1");

        irq_desc[0].action = &timer_irq_action;
}