/*
 * OpenPIC emulation
 *
 * Copyright (c) 2004 Jocelyn Mayer
 *               2011 Alexander Graf
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/kvm_host.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
#include <linux/uaccess.h>
#include <asm/mpic.h>
#include <asm/kvm_para.h>
#include <asm/kvm_ppc.h>
#include <kvm/iodev.h>

#define MAX_CPU     32
#define MAX_SRC     256
#define MAX_TMR     4
#define MAX_IPI     4
#define MAX_MSI     8
#define MAX_IRQ     (MAX_SRC + MAX_IPI + MAX_TMR)
#define VID         0x03        /* MPIC version ID */

/* OpenPIC capability flags */
#define OPENPIC_FLAG_IDR_CRIT     (1 << 0)
#define OPENPIC_FLAG_ILR          (2 << 0)

/* OpenPIC address map */
#define OPENPIC_REG_SIZE             0x40000
#define OPENPIC_GLB_REG_START        0x0
#define OPENPIC_GLB_REG_SIZE         0x10F0
#define OPENPIC_TMR_REG_START        0x10F0
#define OPENPIC_TMR_REG_SIZE         0x220
#define OPENPIC_MSI_REG_START        0x1600
#define OPENPIC_MSI_REG_SIZE         0x200
#define OPENPIC_SUMMARY_REG_START    0x3800
#define OPENPIC_SUMMARY_REG_SIZE     0x800
#define OPENPIC_SRC_REG_START        0x10000
#define OPENPIC_SRC_REG_SIZE         (MAX_SRC * 0x20)
#define OPENPIC_CPU_REG_START        0x20000
#define OPENPIC_CPU_REG_SIZE         (0x100 + ((MAX_CPU - 1) * 0x1000))

struct fsl_mpic_info {
        int max_ext;
};

static struct fsl_mpic_info fsl_mpic_20 = {
        .max_ext = 12,
};

static struct fsl_mpic_info fsl_mpic_42 = {
        .max_ext = 12,
};

#define FRR_NIRQ_SHIFT    16
#define FRR_NCPU_SHIFT     8
#define FRR_VID_SHIFT      0

#define VID_REVISION_1_2   2
#define VID_REVISION_1_3   3

#define VIR_GENERIC      0x00000000     /* Generic Vendor ID */

#define GCR_RESET        0x80000000
#define GCR_MODE_PASS    0x00000000
#define GCR_MODE_MIXED   0x20000000
#define GCR_MODE_PROXY   0x60000000

#define TBCR_CI           0x80000000    /* count inhibit */
#define TCCR_TOG          0x80000000    /* toggles when decrement to zero */

#define IDR_EP_SHIFT      31
#define IDR_EP_MASK       (1 << IDR_EP_SHIFT)
#define IDR_CI0_SHIFT     30
#define IDR_CI1_SHIFT     29
#define IDR_P1_SHIFT      1
#define IDR_P0_SHIFT      0

#define ILR_INTTGT_MASK   0x000000ff
#define ILR_INTTGT_INT    0x00
#define ILR_INTTGT_CINT   0x01  /* critical */
#define ILR_INTTGT_MCP    0x02  /* machine check */
#define NUM_OUTPUTS       3

#define MSIIR_OFFSET       0x140
#define MSIIR_SRS_SHIFT    29
#define MSIIR_SRS_MASK     (0x7 << MSIIR_SRS_SHIFT)
#define MSIIR_IBS_SHIFT    24
#define MSIIR_IBS_MASK     (0x1f << MSIIR_IBS_SHIFT)

static int get_current_cpu(void)
{
#if defined(CONFIG_KVM) && defined(CONFIG_BOOKE)
        struct kvm_vcpu *vcpu = current->thread.kvm_vcpu;
        return vcpu ? vcpu->arch.irq_cpu_id : -1;
#else
        /* XXX */
        return -1;
#endif
}

static int openpic_cpu_write_internal(void *opaque, gpa_t addr,
                                      u32 val, int idx);
static int openpic_cpu_read_internal(void *opaque, gpa_t addr,
                                     u32 *ptr, int idx);
static inline void write_IRQreg_idr(struct openpic *opp, int n_IRQ,
                                    uint32_t val);

enum irq_type {
        IRQ_TYPE_NORMAL = 0,
        IRQ_TYPE_FSLINT,        /* FSL internal interrupt -- level only */
        IRQ_TYPE_FSLSPECIAL,    /* FSL timer/IPI interrupt, edge, no polarity */
};

struct irq_queue {
        /* Round up to the nearest 64 IRQs so that the queue length
         * won't change when moving between 32 and 64 bit hosts.
         */
        unsigned long queue[BITS_TO_LONGS((MAX_IRQ + 63) & ~63)];
        int next;
        int priority;
};

struct irq_source {
        uint32_t ivpr;          /* IRQ vector/priority register */
        uint32_t idr;           /* IRQ destination register */
        uint32_t destmask;      /* bitmap of CPU destinations */
        int last_cpu;
        int output;             /* IRQ level, e.g. ILR_INTTGT_INT */
        int pending;            /* TRUE if IRQ is pending */
        enum irq_type type;
        bool level:1;           /* level-triggered */
        bool nomask:1;  /* critical interrupts ignore mask on some FSL MPICs */
};

#define IVPR_MASK_SHIFT       31
#define IVPR_MASK_MASK        (1 << IVPR_MASK_SHIFT)
#define IVPR_ACTIVITY_SHIFT   30
#define IVPR_ACTIVITY_MASK    (1 << IVPR_ACTIVITY_SHIFT)
#define IVPR_MODE_SHIFT       29
#define IVPR_MODE_MASK        (1 << IVPR_MODE_SHIFT)
#define IVPR_POLARITY_SHIFT   23
#define IVPR_POLARITY_MASK    (1 << IVPR_POLARITY_SHIFT)
#define IVPR_SENSE_SHIFT      22
#define IVPR_SENSE_MASK       (1 << IVPR_SENSE_SHIFT)

#define IVPR_PRIORITY_MASK     (0xF << 16)
#define IVPR_PRIORITY(_ivprr_) ((int)(((_ivprr_) & IVPR_PRIORITY_MASK) >> 16))
#define IVPR_VECTOR(opp, _ivprr_) ((_ivprr_) & (opp)->vector_mask)

/* IDR[EP/CI] are only for FSL MPIC prior to v4.0 */
#define IDR_EP      0x80000000  /* external pin */
#define IDR_CI      0x40000000  /* critical interrupt */

struct irq_dest {
        struct kvm_vcpu *vcpu;

        int32_t ctpr;           /* CPU current task priority */
        struct irq_queue raised;
        struct irq_queue servicing;

        /* Count of IRQ sources asserting on non-INT outputs */
        uint32_t outputs_active[NUM_OUTPUTS];
};

#define MAX_MMIO_REGIONS 10

struct openpic {
        struct kvm *kvm;
        struct kvm_device *dev;
        struct kvm_io_device mmio;
        const struct mem_reg *mmio_regions[MAX_MMIO_REGIONS];
        int num_mmio_regions;

        gpa_t reg_base;
        spinlock_t lock;

        /* Behavior control */
        struct fsl_mpic_info *fsl;
        uint32_t model;
        uint32_t flags;
        uint32_t nb_irqs;
        uint32_t vid;
        uint32_t vir;           /* Vendor identification register */
        uint32_t vector_mask;
        uint32_t tfrr_reset;
        uint32_t ivpr_reset;
        uint32_t idr_reset;
        uint32_t brr1;
        uint32_t mpic_mode_mask;

        /* Global registers */
        uint32_t frr;           /* Feature reporting register */
        uint32_t gcr;           /* Global configuration register  */
        uint32_t pir;           /* Processor initialization register */
        uint32_t spve;          /* Spurious vector register */
        uint32_t tfrr;          /* Timer frequency reporting register */
        /* Source registers */
        struct irq_source src[MAX_IRQ];
        /* Local registers per output pin */
        struct irq_dest dst[MAX_CPU];
        uint32_t nb_cpus;
        /* Timer registers */
        struct {
                uint32_t tccr;  /* Global timer current count register */
                uint32_t tbcr;  /* Global timer base count register */
        } timers[MAX_TMR];
        /* Shared MSI registers */
        struct {
                uint32_t msir;  /* Shared Message Signaled Interrupt Register */
        } msi[MAX_MSI];
        uint32_t max_irq;
        uint32_t irq_ipi0;
        uint32_t irq_tim0;
        uint32_t irq_msi;
};


static void mpic_irq_raise(struct openpic *opp, struct irq_dest *dst,
                           int output)
{
        struct kvm_interrupt irq = {
                .irq = KVM_INTERRUPT_SET_LEVEL,
        };

        if (!dst->vcpu) {
                pr_debug("%s: destination cpu %d does not exist\n",
                         __func__, (int)(dst - &opp->dst[0]));
                return;
        }

        pr_debug("%s: cpu %d output %d\n", __func__, dst->vcpu->arch.irq_cpu_id,
                output);

        if (output != ILR_INTTGT_INT)   /* TODO */
                return;

        kvm_vcpu_ioctl_interrupt(dst->vcpu, &irq);
}

static void mpic_irq_lower(struct openpic *opp, struct irq_dest *dst,
                           int output)
{
        if (!dst->vcpu) {
                pr_debug("%s: destination cpu %d does not exist\n",
                         __func__, (int)(dst - &opp->dst[0]));
                return;
        }

        pr_debug("%s: cpu %d output %d\n", __func__, dst->vcpu->arch.irq_cpu_id,
                output);

        if (output != ILR_INTTGT_INT)   /* TODO */
                return;

        kvmppc_core_dequeue_external(dst->vcpu);
}

static inline void IRQ_setbit(struct irq_queue *q, int n_IRQ)
{
        set_bit(n_IRQ, q->queue);
}

static inline void IRQ_resetbit(struct irq_queue *q, int n_IRQ)
{
        clear_bit(n_IRQ, q->queue);
}

static void IRQ_check(struct openpic *opp, struct irq_queue *q)
{
        int irq = -1;
        int next = -1;
        int priority = -1;

        for (;;) {
                irq = find_next_bit(q->queue, opp->max_irq, irq + 1);
                if (irq == opp->max_irq)
                        break;

                pr_debug("IRQ_check: irq %d set ivpr_pr=%d pr=%d\n",
                        irq, IVPR_PRIORITY(opp->src[irq].ivpr), priority);

                if (IVPR_PRIORITY(opp->src[irq].ivpr) > priority) {
                        next = irq;
                        priority = IVPR_PRIORITY(opp->src[irq].ivpr);
                }
        }

        q->next = next;
        q->priority = priority;
}

static int IRQ_get_next(struct openpic *opp, struct irq_queue *q)
{
        /* XXX: optimize */
        IRQ_check(opp, q);

        return q->next;
}

static void IRQ_local_pipe(struct openpic *opp, int n_CPU, int n_IRQ,
                           bool active, bool was_active)
{
        struct irq_dest *dst;
        struct irq_source *src;
        int priority;

        dst = &opp->dst[n_CPU];
        src = &opp->src[n_IRQ];

        pr_debug("%s: IRQ %d active %d was %d\n",
                __func__, n_IRQ, active, was_active);

        if (src->output != ILR_INTTGT_INT) {
                pr_debug("%s: output %d irq %d active %d was %d count %d\n",
                        __func__, src->output, n_IRQ, active, was_active,
                        dst->outputs_active[src->output]);

                /* On Freescale MPIC, critical interrupts ignore priority,
                 * IACK, EOI, etc.  Before MPIC v4.1 they also ignore
                 * masking.
                 */
                if (active) {
                        if (!was_active &&
                            dst->outputs_active[src->output]++ == 0) {
                                pr_debug("%s: Raise OpenPIC output %d cpu %d irq %d\n",
                                        __func__, src->output, n_CPU, n_IRQ);
                                mpic_irq_raise(opp, dst, src->output);
                        }
                } else {
                        if (was_active &&
                            --dst->outputs_active[src->output] == 0) {
                                pr_debug("%s: Lower OpenPIC output %d cpu %d irq %d\n",
                                        __func__, src->output, n_CPU, n_IRQ);
                                mpic_irq_lower(opp, dst, src->output);
                        }
                }

                return;
        }

        priority = IVPR_PRIORITY(src->ivpr);

        /* Even if the interrupt doesn't have enough priority,
         * it is still raised, in case ctpr is lowered later.
         */
        if (active)
                IRQ_setbit(&dst->raised, n_IRQ);
        else
                IRQ_resetbit(&dst->raised, n_IRQ);

        IRQ_check(opp, &dst->raised);

        if (active && priority <= dst->ctpr) {
                pr_debug("%s: IRQ %d priority %d too low for ctpr %d on CPU %d\n",
                        __func__, n_IRQ, priority, dst->ctpr, n_CPU);
                active = 0;
        }

        if (active) {
                if (IRQ_get_next(opp, &dst->servicing) >= 0 &&
                    priority <= dst->servicing.priority) {
                        pr_debug("%s: IRQ %d is hidden by servicing IRQ %d on CPU %d\n",
                                __func__, n_IRQ, dst->servicing.next, n_CPU);
                } else {
                        pr_debug("%s: Raise OpenPIC INT output cpu %d irq %d/%d\n",
                                __func__, n_CPU, n_IRQ, dst->raised.next);
                        mpic_irq_raise(opp, dst, ILR_INTTGT_INT);
                }
        } else {
                IRQ_get_next(opp, &dst->servicing);
                if (dst->raised.priority > dst->ctpr &&
                    dst->raised.priority > dst->servicing.priority) {
                        pr_debug("%s: IRQ %d inactive, IRQ %d prio %d above %d/%d, CPU %d\n",
                                __func__, n_IRQ, dst->raised.next,
                                dst->raised.priority, dst->ctpr,
                                dst->servicing.priority, n_CPU);
                        /* IRQ line stays asserted */
                } else {
                        pr_debug("%s: IRQ %d inactive, current prio %d/%d, CPU %d\n",
                                __func__, n_IRQ, dst->ctpr,
                                dst->servicing.priority, n_CPU);
                        mpic_irq_lower(opp, dst, ILR_INTTGT_INT);
                }
        }
}

/* update pic state because registers for n_IRQ have changed value */
static void openpic_update_irq(struct openpic *opp, int n_IRQ)
{
        struct irq_source *src;
        bool active, was_active;
        int i;

        src = &opp->src[n_IRQ];
        active = src->pending;

        if ((src->ivpr & IVPR_MASK_MASK) && !src->nomask) {
                /* Interrupt source is disabled */
                pr_debug("%s: IRQ %d is disabled\n", __func__, n_IRQ);
                active = false;
        }

        was_active = !!(src->ivpr & IVPR_ACTIVITY_MASK);

        /*
         * We don't have a similar check for already-active because
         * ctpr may have changed and we need to withdraw the interrupt.
         */
        if (!active && !was_active) {
                pr_debug("%s: IRQ %d is already inactive\n", __func__, n_IRQ);
                return;
        }

        if (active)
                src->ivpr |= IVPR_ACTIVITY_MASK;
        else
                src->ivpr &= ~IVPR_ACTIVITY_MASK;

        if (src->destmask == 0) {
                /* No target */
                pr_debug("%s: IRQ %d has no target\n", __func__, n_IRQ);
                return;
        }

        if (src->destmask == (1 << src->last_cpu)) {
                /* Only one CPU is allowed to receive this IRQ */
                IRQ_local_pipe(opp, src->last_cpu, n_IRQ, active, was_active);
        } else if (!(src->ivpr & IVPR_MODE_MASK)) {
                /* Directed delivery mode */
                for (i = 0; i < opp->nb_cpus; i++) {
                        if (src->destmask & (1 << i)) {
                                IRQ_local_pipe(opp, i, n_IRQ, active,
                                               was_active);
                        }
                }
        } else {
                /* Distributed delivery mode */
                for (i = src->last_cpu + 1; i != src->last_cpu; i++) {
                        if (i == opp->nb_cpus)
                                i = 0;

                        if (src->destmask & (1 << i)) {
                                IRQ_local_pipe(opp, i, n_IRQ, active,
                                               was_active);
                                src->last_cpu = i;
                                break;
                        }
                }
        }
}

static void openpic_set_irq(void *opaque, int n_IRQ, int level)
{
        struct openpic *opp = opaque;
        struct irq_source *src;

        if (n_IRQ >= MAX_IRQ) {
                WARN_ONCE(1, "%s: IRQ %d out of range\n", __func__, n_IRQ);
                return;
        }

        src = &opp->src[n_IRQ];
        pr_debug("openpic: set irq %d = %d ivpr=0x%08x\n",
                n_IRQ, level, src->ivpr);
        if (src->level) {
                /* level-sensitive irq */
                src->pending = level;
                openpic_update_irq(opp, n_IRQ);
        } else {
                /* edge-sensitive irq */
                if (level) {
                        src->pending = 1;
                        openpic_update_irq(opp, n_IRQ);
                }

                if (src->output != ILR_INTTGT_INT) {
                        /* Edge-triggered interrupts shouldn't be used
                         * with non-INT delivery, but just in case,
                         * try to make it do something sane rather than
                         * cause an interrupt storm.  This is close to
                         * what you'd probably see happen in real hardware.
                         */
                        src->pending = 0;
                        openpic_update_irq(opp, n_IRQ);
                }
        }
}

static void openpic_reset(struct openpic *opp)
{
        int i;

        opp->gcr = GCR_RESET;
        /* Initialise controller registers */
        opp->frr = ((opp->nb_irqs - 1) << FRR_NIRQ_SHIFT) |
            (opp->vid << FRR_VID_SHIFT);

        opp->pir = 0;
        opp->spve = -1 & opp->vector_mask;
        opp->tfrr = opp->tfrr_reset;
        /* Initialise IRQ sources */
        for (i = 0; i < opp->max_irq; i++) {
                opp->src[i].ivpr = opp->ivpr_reset;

                switch (opp->src[i].type) {
                case IRQ_TYPE_NORMAL:
                        opp->src[i].level =
                            !!(opp->ivpr_reset & IVPR_SENSE_MASK);
                        break;

                case IRQ_TYPE_FSLINT:
                        opp->src[i].ivpr |= IVPR_POLARITY_MASK;
                        break;

                case IRQ_TYPE_FSLSPECIAL:
                        break;
                }

                write_IRQreg_idr(opp, i, opp->idr_reset);
        }
        /* Initialise IRQ destinations */
        for (i = 0; i < MAX_CPU; i++) {
                opp->dst[i].ctpr = 15;
                memset(&opp->dst[i].raised, 0, sizeof(struct irq_queue));
                opp->dst[i].raised.next = -1;
                memset(&opp->dst[i].servicing, 0, sizeof(struct irq_queue));
                opp->dst[i].servicing.next = -1;
        }
        /* Initialise timers */
        for (i = 0; i < MAX_TMR; i++) {
                opp->timers[i].tccr = 0;
                opp->timers[i].tbcr = TBCR_CI;
        }
        /* Go out of RESET state */
        opp->gcr = 0;
}

static inline uint32_t read_IRQreg_idr(struct openpic *opp, int n_IRQ)
{
        return opp->src[n_IRQ].idr;
}

static inline uint32_t read_IRQreg_ilr(struct openpic *opp, int n_IRQ)
{
        if (opp->flags & OPENPIC_FLAG_ILR)
                return opp->src[n_IRQ].output;

        return 0xffffffff;
}

static inline uint32_t read_IRQreg_ivpr(struct openpic *opp, int n_IRQ)
{
        return opp->src[n_IRQ].ivpr;
}

static inline void write_IRQreg_idr(struct openpic *opp, int n_IRQ,
                                    uint32_t val)
{
        struct irq_source *src = &opp->src[n_IRQ];
        uint32_t normal_mask = (1UL << opp->nb_cpus) - 1;
        uint32_t crit_mask = 0;
        uint32_t mask = normal_mask;
        int crit_shift = IDR_EP_SHIFT - opp->nb_cpus;
        int i;

        if (opp->flags & OPENPIC_FLAG_IDR_CRIT) {
                crit_mask = mask << crit_shift;
                mask |= crit_mask | IDR_EP;
        }

        src->idr = val & mask;
        pr_debug("Set IDR %d to 0x%08x\n", n_IRQ, src->idr);

        if (opp->flags & OPENPIC_FLAG_IDR_CRIT) {
                if (src->idr & crit_mask) {
                        if (src->idr & normal_mask) {
                                pr_debug("%s: IRQ configured for multiple output types, using critical\n",
                                        __func__);
                        }

                        src->output = ILR_INTTGT_CINT;
                        src->nomask = true;
                        src->destmask = 0;

                        for (i = 0; i < opp->nb_cpus; i++) {
                                int n_ci = IDR_CI0_SHIFT - i;

                                if (src->idr & (1UL << n_ci))
                                        src->destmask |= 1UL << i;
                        }
                } else {
                        src->output = ILR_INTTGT_INT;
                        src->nomask = false;
                        src->destmask = src->idr & normal_mask;
                }
        } else {
                src->destmask = src->idr;
        }
}

static inline void write_IRQreg_ilr(struct openpic *opp, int n_IRQ,
                                    uint32_t val)
{
        if (opp->flags & OPENPIC_FLAG_ILR) {
                struct irq_source *src = &opp->src[n_IRQ];

                src->output = val & ILR_INTTGT_MASK;
                pr_debug("Set ILR %d to 0x%08x, output %d\n", n_IRQ, src->idr,
                        src->output);

                /* TODO: on MPIC v4.0 only, set nomask for non-INT */
        }
}

static inline void write_IRQreg_ivpr(struct openpic *opp, int n_IRQ,
                                     uint32_t val)
{
        uint32_t mask;

        /* NOTE when implementing newer FSL MPIC models: starting with v4.0,
         * the polarity bit is read-only on internal interrupts.
         */
        mask = IVPR_MASK_MASK | IVPR_PRIORITY_MASK | IVPR_SENSE_MASK |
            IVPR_POLARITY_MASK | opp->vector_mask;

        /* ACTIVITY bit is read-only */
        opp->src[n_IRQ].ivpr =
            (opp->src[n_IRQ].ivpr & IVPR_ACTIVITY_MASK) | (val & mask);

        /* For FSL internal interrupts, The sense bit is reserved and zero,
         * and the interrupt is always level-triggered.  Timers and IPIs
         * have no sense or polarity bits, and are edge-triggered.
         */
        switch (opp->src[n_IRQ].type) {
        case IRQ_TYPE_NORMAL:
                opp->src[n_IRQ].level =
                    !!(opp->src[n_IRQ].ivpr & IVPR_SENSE_MASK);
                break;

        case IRQ_TYPE_FSLINT:
                opp->src[n_IRQ].ivpr &= ~IVPR_SENSE_MASK;
                break;

        case IRQ_TYPE_FSLSPECIAL:
                opp->src[n_IRQ].ivpr &= ~(IVPR_POLARITY_MASK | IVPR_SENSE_MASK);
                break;
        }

        openpic_update_irq(opp, n_IRQ);
        pr_debug("Set IVPR %d to 0x%08x -> 0x%08x\n", n_IRQ, val,
                opp->src[n_IRQ].ivpr);
}

static void openpic_gcr_write(struct openpic *opp, uint64_t val)
{
        if (val & GCR_RESET) {
                openpic_reset(opp);
                return;
        }

        opp->gcr &= ~opp->mpic_mode_mask;
        opp->gcr |= val & opp->mpic_mode_mask;
}

static int openpic_gbl_write(void *opaque, gpa_t addr, u32 val)
{
        struct openpic *opp = opaque;
        int err = 0;

        pr_debug("%s: addr %#llx <= %08x\n", __func__, addr, val);
        if (addr & 0xF)
                return 0;

        switch (addr) {
        case 0x00:      /* Block Revision Register1 (BRR1) is Readonly */
                break;
        case 0x40:
        case 0x50:
        case 0x60:
        case 0x70:
        case 0x80:
        case 0x90:
        case 0xA0:
        case 0xB0:
                err = openpic_cpu_write_internal(opp, addr, val,
                                                 get_current_cpu());
                break;
        case 0x1000:            /* FRR */
                break;
        case 0x1020:            /* GCR */
                openpic_gcr_write(opp, val);
                break;
        case 0x1080:            /* VIR */
                break;
        case 0x1090:            /* PIR */
                /*
                 * This register is used to reset a CPU core --
                 * let userspace handle it.
                 */
                err = -ENXIO;
                break;
        case 0x10A0:            /* IPI_IVPR */
        case 0x10B0:
        case 0x10C0:
        case 0x10D0: {
                int idx;
                idx = (addr - 0x10A0) >> 4;
                write_IRQreg_ivpr(opp, opp->irq_ipi0 + idx, val);
                break;
        }
        case 0x10E0:            /* SPVE */
                opp->spve = val & opp->vector_mask;
                break;
        default:
                break;
        }

        return err;
}

static int openpic_gbl_read(void *opaque, gpa_t addr, u32 *ptr)
{
        struct openpic *opp = opaque;
        u32 retval;
        int err = 0;

        pr_debug("%s: addr %#llx\n", __func__, addr);
        retval = 0xFFFFFFFF;
        if (addr & 0xF)
                goto out;

        switch (addr) {
        case 0x1000:            /* FRR */
                retval = opp->frr;
                retval |= (opp->nb_cpus - 1) << FRR_NCPU_SHIFT;
                break;
        case 0x1020:            /* GCR */
                retval = opp->gcr;
                break;
        case 0x1080:            /* VIR */
                retval = opp->vir;
                break;
        case 0x1090:            /* PIR */
                retval = 0x00000000;
                break;
        case 0x00:              /* Block Revision Register1 (BRR1) */
                retval = opp->brr1;
                break;
        case 0x40:
        case 0x50:
        case 0x60:
        case 0x70:
        case 0x80:
        case 0x90:
        case 0xA0:
        case 0xB0:
                err = openpic_cpu_read_internal(opp, addr,
                        &retval, get_current_cpu());
                break;
        case 0x10A0:            /* IPI_IVPR */
        case 0x10B0:
        case 0x10C0:
        case 0x10D0:
                {
                        int idx;
                        idx = (addr - 0x10A0) >> 4;
                        retval = read_IRQreg_ivpr(opp, opp->irq_ipi0 + idx);
                }
                break;
        case 0x10E0:            /* SPVE */
                retval = opp->spve;
                break;
        default:
                break;
        }

out:
        pr_debug("%s: => 0x%08x\n", __func__, retval);
        *ptr = retval;
        return err;
}

static int openpic_tmr_write(void *opaque, gpa_t addr, u32 val)
{
        struct openpic *opp = opaque;
        int idx;

        addr += 0x10f0;

        pr_debug("%s: addr %#llx <= %08x\n", __func__, addr, val);
        if (addr & 0xF)
                return 0;

        if (addr == 0x10f0) {
                /* TFRR */
                opp->tfrr = val;
                return 0;
        }

        idx = (addr >> 6) & 0x3;
        addr = addr & 0x30;

        switch (addr & 0x30) {
        case 0x00:              /* TCCR */
                break;
        case 0x10:              /* TBCR */
                if ((opp->timers[idx].tccr & TCCR_TOG) != 0 &&
                    (val & TBCR_CI) == 0 &&
                    (opp->timers[idx].tbcr & TBCR_CI) != 0)
                        opp->timers[idx].tccr &= ~TCCR_TOG;

                opp->timers[idx].tbcr = val;
                break;
        case 0x20:              /* TVPR */
                write_IRQreg_ivpr(opp, opp->irq_tim0 + idx, val);
                break;
        case 0x30:              /* TDR */
                write_IRQreg_idr(opp, opp->irq_tim0 + idx, val);
                break;
        }

        return 0;
}

static int openpic_tmr_read(void *opaque, gpa_t addr, u32 *ptr)
{
        struct openpic *opp = opaque;
        uint32_t retval = -1;
        int idx;

        pr_debug("%s: addr %#llx\n", __func__, addr);
        if (addr & 0xF)
                goto out;

        idx = (addr >> 6) & 0x3;
        if (addr == 0x0) {
                /* TFRR */
                retval = opp->tfrr;
                goto out;
        }

        switch (addr & 0x30) {
        case 0x00:              /* TCCR */
                retval = opp->timers[idx].tccr;
                break;
        case 0x10:              /* TBCR */
                retval = opp->timers[idx].tbcr;
                break;
        case 0x20:              /* TIPV */
                retval = read_IRQreg_ivpr(opp, opp->irq_tim0 + idx);
                break;
        case 0x30:              /* TIDE (TIDR) */
                retval = read_IRQreg_idr(opp, opp->irq_tim0 + idx);
                break;
        }

out:
        pr_debug("%s: => 0x%08x\n", __func__, retval);
        *ptr = retval;
        return 0;
}

static int openpic_src_write(void *opaque, gpa_t addr, u32 val)
{
        struct openpic *opp = opaque;
        int idx;

        pr_debug("%s: addr %#llx <= %08x\n", __func__, addr, val);

        addr = addr & 0xffff;
        idx = addr >> 5;

        switch (addr & 0x1f) {
        case 0x00:
                write_IRQreg_ivpr(opp, idx, val);
                break;
        case 0x10:
                write_IRQreg_idr(opp, idx, val);
                break;
        case 0x18:
                write_IRQreg_ilr(opp, idx, val);
                break;
        }

        return 0;
}

static int openpic_src_read(void *opaque, gpa_t addr, u32 *ptr)
{
        struct openpic *opp = opaque;
        uint32_t retval;
        int idx;

        pr_debug("%s: addr %#llx\n", __func__, addr);
        retval = 0xFFFFFFFF;

        addr = addr & 0xffff;
        idx = addr >> 5;

        switch (addr & 0x1f) {
        case 0x00:
                retval = read_IRQreg_ivpr(opp, idx);
                break;
        case 0x10:
                retval = read_IRQreg_idr(opp, idx);
                break;
        case 0x18:
                retval = read_IRQreg_ilr(opp, idx);
                break;
        }

        pr_debug("%s: => 0x%08x\n", __func__, retval);
        *ptr = retval;
        return 0;
}

static int openpic_msi_write(void *opaque, gpa_t addr, u32 val)
{
        struct openpic *opp = opaque;
        int idx = opp->irq_msi;
        int srs, ibs;

        pr_debug("%s: addr %#llx <= 0x%08x\n", __func__, addr, val);
        if (addr & 0xF)
                return 0;

        switch (addr) {
        case MSIIR_OFFSET:
                srs = val >> MSIIR_SRS_SHIFT;
                idx += srs;
                ibs = (val & MSIIR_IBS_MASK) >> MSIIR_IBS_SHIFT;
                opp->msi[srs].msir |= 1 << ibs;
                openpic_set_irq(opp, idx, 1);
                break;
        default:
                /* most registers are read-only, thus ignored */
                break;
        }

        return 0;
}

static int openpic_msi_read(void *opaque, gpa_t addr, u32 *ptr)
{
        struct openpic *opp = opaque;
        uint32_t r = 0;
        int i, srs;

        pr_debug("%s: addr %#llx\n", __func__, addr);
        if (addr & 0xF)
                return -ENXIO;

        srs = addr >> 4;

        switch (addr) {
        case 0x00:
        case 0x10:
        case 0x20:
        case 0x30:
        case 0x40:
        case 0x50:
        case 0x60:
        case 0x70:              /* MSIRs */
                r = opp->msi[srs].msir;
                /* Clear on read */
                opp->msi[srs].msir = 0;
                openpic_set_irq(opp, opp->irq_msi + srs, 0);
                break;
        case 0x120:             /* MSISR */
                for (i = 0; i < MAX_MSI; i++)
                        r |= (opp->msi[i].msir ? 1 : 0) << i;
                break;
        }

        pr_debug("%s: => 0x%08x\n", __func__, r);
        *ptr = r;
        return 0;

}

static int openpic_summary_read(void *opaque, gpa_t addr, u32 *ptr)
{
        uint32_t r = 0;

        pr_debug("%s: addr %#llx\n", __func__, addr);

        /* TODO: EISR/EIMR */

        *ptr = r;
        return 0;
}

static int openpic_summary_write(void *opaque, gpa_t addr, u32 val)
{
        pr_debug("%s: addr %#llx <= 0x%08x\n", __func__, addr, val);

        /* TODO: EISR/EIMR */
        return 0;
}

static int openpic_cpu_write_internal(void *opaque, gpa_t addr,
                                      u32 val, int idx)
{
        struct openpic *opp = opaque;
        struct irq_source *src;
        struct irq_dest *dst;
        int s_IRQ, n_IRQ;

        pr_debug("%s: cpu %d addr %#llx <= 0x%08x\n", __func__, idx,
                addr, val);

        if (idx < 0)
                return 0;

        if (addr & 0xF)
                return 0;

        dst = &opp->dst[idx];
        addr &= 0xFF0;
        switch (addr) {
        case 0x40:              /* IPIDR */
        case 0x50:
        case 0x60:
        case 0x70:
                idx = (addr - 0x40) >> 4;
                /* we use IDE as mask which CPUs to deliver the IPI to still. */
                opp->src[opp->irq_ipi0 + idx].destmask |= val;
                openpic_set_irq(opp, opp->irq_ipi0 + idx, 1);
                openpic_set_irq(opp, opp->irq_ipi0 + idx, 0);
                break;
        case 0x80:              /* CTPR */
                dst->ctpr = val & 0x0000000F;

                pr_debug("%s: set CPU %d ctpr to %d, raised %d servicing %d\n",
                        __func__, idx, dst->ctpr, dst->raised.priority,
                        dst->servicing.priority);

                if (dst->raised.priority <= dst->ctpr) {
                        pr_debug("%s: Lower OpenPIC INT output cpu %d due to ctpr\n",
                                __func__, idx);
                        mpic_irq_lower(opp, dst, ILR_INTTGT_INT);
                } else if (dst->raised.priority > dst->servicing.priority) {
                        pr_debug("%s: Raise OpenPIC INT output cpu %d irq %d\n",
                                __func__, idx, dst->raised.next);
                        mpic_irq_raise(opp, dst, ILR_INTTGT_INT);
                }

                break;
        case 0x90:              /* WHOAMI */
                /* Read-only register */
                break;
        case 0xA0:              /* IACK */
                /* Read-only register */
                break;
        case 0xB0: {            /* EOI */
                int notify_eoi;

                pr_debug("EOI\n");
                s_IRQ = IRQ_get_next(opp, &dst->servicing);

                if (s_IRQ < 0) {
                        pr_debug("%s: EOI with no interrupt in service\n",
                                __func__);
                        break;
                }

                IRQ_resetbit(&dst->servicing, s_IRQ);
                /* Notify listeners that the IRQ is over */
                notify_eoi = s_IRQ;
                /* Set up next servicing IRQ */
                s_IRQ = IRQ_get_next(opp, &dst->servicing);
                /* Check queued interrupts. */
                n_IRQ = IRQ_get_next(opp, &dst->raised);
                src = &opp->src[n_IRQ];
                if (n_IRQ != -1 &&
                    (s_IRQ == -1 ||
                     IVPR_PRIORITY(src->ivpr) > dst->servicing.priority)) {
                        pr_debug("Raise OpenPIC INT output cpu %d irq %d\n",
                                idx, n_IRQ);
                        mpic_irq_raise(opp, dst, ILR_INTTGT_INT);
                }

                spin_unlock(&opp->lock);
                kvm_notify_acked_irq(opp->kvm, 0, notify_eoi);
                spin_lock(&opp->lock);

                break;
        }
        default:
                break;
        }

        return 0;
}

static int openpic_cpu_write(void *opaque, gpa_t addr, u32 val)
{
        struct openpic *opp = opaque;

        return openpic_cpu_write_internal(opp, addr, val,
                                         (addr & 0x1f000) >> 12);
}

static uint32_t openpic_iack(struct openpic *opp, struct irq_dest *dst,
                             int cpu)
{
        struct irq_source *src;
        int retval, irq;

        pr_debug("Lower OpenPIC INT output\n");
        mpic_irq_lower(opp, dst, ILR_INTTGT_INT);

        irq = IRQ_get_next(opp, &dst->raised);
        pr_debug("IACK: irq=%d\n", irq);

        if (irq == -1)
                /* No more interrupt pending */
                return opp->spve;

        src = &opp->src[irq];
        if (!(src->ivpr & IVPR_ACTIVITY_MASK) ||
            !(IVPR_PRIORITY(src->ivpr) > dst->ctpr)) {
                pr_err("%s: bad raised IRQ %d ctpr %d ivpr 0x%08x\n",
                        __func__, irq, dst->ctpr, src->ivpr);
                openpic_update_irq(opp, irq);
                retval = opp->spve;
        } else {
                /* IRQ enter servicing state */
                IRQ_setbit(&dst->servicing, irq);
                retval = IVPR_VECTOR(opp, src->ivpr);
        }

        if (!src->level) {
                /* edge-sensitive IRQ */
                src->ivpr &= ~IVPR_ACTIVITY_MASK;
                src->pending = 0;
                IRQ_resetbit(&dst->raised, irq);
        }

        if ((irq >= opp->irq_ipi0) && (irq < (opp->irq_ipi0 + MAX_IPI))) {
                src->destmask &= ~(1 << cpu);
                if (src->destmask && !src->level) {
                        /* trigger on CPUs that didn't know about it yet */
                        openpic_set_irq(opp, irq, 1);
                        openpic_set_irq(opp, irq, 0);
                        /* if all CPUs knew about it, set active bit again */
                        src->ivpr |= IVPR_ACTIVITY_MASK;
                }
        }

        return retval;
}

void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu)
{
        struct openpic *opp = vcpu->arch.mpic;
        int cpu = vcpu->arch.irq_cpu_id;
        unsigned long flags;

        spin_lock_irqsave(&opp->lock, flags);

        if ((opp->gcr & opp->mpic_mode_mask) == GCR_MODE_PROXY)
                kvmppc_set_epr(vcpu, openpic_iack(opp, &opp->dst[cpu], cpu));

        spin_unlock_irqrestore(&opp->lock, flags);
}

static int openpic_cpu_read_internal(void *opaque, gpa_t addr,
                                     u32 *ptr, int idx)
{
        struct openpic *opp = opaque;
        struct irq_dest *dst;
        uint32_t retval;

        pr_debug("%s: cpu %d addr %#llx\n", __func__, idx, addr);
        retval = 0xFFFFFFFF;

        if (idx < 0)
                goto out;

        if (addr & 0xF)
                goto out;

        dst = &opp->dst[idx];
        addr &= 0xFF0;
        switch (addr) {
        case 0x80:              /* CTPR */
                retval = dst->ctpr;
                break;
        case 0x90:              /* WHOAMI */
                retval = idx;
                break;
        case 0xA0:              /* IACK */
                retval = openpic_iack(opp, dst, idx);
                break;
        case 0xB0:              /* EOI */
                retval = 0;
                break;
        default:
                break;
        }
        pr_debug("%s: => 0x%08x\n", __func__, retval);

out:
        *ptr = retval;
        return 0;
}

static int openpic_cpu_read(void *opaque, gpa_t addr, u32 *ptr)
{
        struct openpic *opp = opaque;

        return openpic_cpu_read_internal(opp, addr, ptr,
                                         (addr & 0x1f000) >> 12);
}

struct mem_reg {
        int (*read)(void *opaque, gpa_t addr, u32 *ptr);
        int (*write)(void *opaque, gpa_t addr, u32 val);
        gpa_t start_addr;
        int size;
};

static const struct mem_reg openpic_gbl_mmio = {
        .write = openpic_gbl_write,
        .read = openpic_gbl_read,
        .start_addr = OPENPIC_GLB_REG_START,
        .size = OPENPIC_GLB_REG_SIZE,
};

static const struct mem_reg openpic_tmr_mmio = {
        .write = openpic_tmr_write,
        .read = openpic_tmr_read,
        .start_addr = OPENPIC_TMR_REG_START,
        .size = OPENPIC_TMR_REG_SIZE,
};

static const struct mem_reg openpic_cpu_mmio = {
        .write = openpic_cpu_write,
        .read = openpic_cpu_read,
        .start_addr = OPENPIC_CPU_REG_START,
        .size = OPENPIC_CPU_REG_SIZE,
};

static const struct mem_reg openpic_src_mmio = {
        .write = openpic_src_write,
        .read = openpic_src_read,
        .start_addr = OPENPIC_SRC_REG_START,
        .size = OPENPIC_SRC_REG_SIZE,
};

static const struct mem_reg openpic_msi_mmio = {
        .read = openpic_msi_read,
        .write = openpic_msi_write,
        .start_addr = OPENPIC_MSI_REG_START,
        .size = OPENPIC_MSI_REG_SIZE,
};

static const struct mem_reg openpic_summary_mmio = {
        .read = openpic_summary_read,
        .write = openpic_summary_write,
        .start_addr = OPENPIC_SUMMARY_REG_START,
        .size = OPENPIC_SUMMARY_REG_SIZE,
};

static void add_mmio_region(struct openpic *opp, const struct mem_reg *mr)
{
        if (opp->num_mmio_regions >= MAX_MMIO_REGIONS) {
                WARN(1, "kvm mpic: too many mmio regions\n");
                return;
        }

        opp->mmio_regions[opp->num_mmio_regions++] = mr;
}

static void fsl_common_init(struct openpic *opp)
{
        int i;
        int virq = MAX_SRC;

        add_mmio_region(opp, &openpic_msi_mmio);
        add_mmio_region(opp, &openpic_summary_mmio);

        opp->vid = VID_REVISION_1_2;
        opp->vir = VIR_GENERIC;
        opp->vector_mask = 0xFFFF;
        opp->tfrr_reset = 0;
        opp->ivpr_reset = IVPR_MASK_MASK;
        opp->idr_reset = 1 << 0;
        opp->max_irq = MAX_IRQ;

        opp->irq_ipi0 = virq;
        virq += MAX_IPI;
        opp->irq_tim0 = virq;
        virq += MAX_TMR;

        BUG_ON(virq > MAX_IRQ);

        opp->irq_msi = 224;

        for (i = 0; i < opp->fsl->max_ext; i++)
                opp->src[i].level = false;

        /* Internal interrupts, including message and MSI */
        for (i = 16; i < MAX_SRC; i++) {
                opp->src[i].type = IRQ_TYPE_FSLINT;
                opp->src[i].level = true;
        }

        /* timers and IPIs */
        for (i = MAX_SRC; i < virq; i++) {
                opp->src[i].type = IRQ_TYPE_FSLSPECIAL;
                opp->src[i].level = false;
        }
}

static int kvm_mpic_read_internal(struct openpic *opp, gpa_t addr, u32 *ptr)
{
        int i;

        for (i = 0; i < opp->num_mmio_regions; i++) {
                const struct mem_reg *mr = opp->mmio_regions[i];

                if (mr->start_addr > addr || addr >= mr->start_addr + mr->size)
                        continue;

                return mr->read(opp, addr - mr->start_addr, ptr);
        }

        return -ENXIO;
}

static int kvm_mpic_write_internal(struct openpic *opp, gpa_t addr, u32 val)
{
        int i;

        for (i = 0; i < opp->num_mmio_regions; i++) {
                const struct mem_reg *mr = opp->mmio_regions[i];

                if (mr->start_addr > addr || addr >= mr->start_addr + mr->size)
                        continue;

                return mr->write(opp, addr - mr->start_addr, val);
        }

        return -ENXIO;
}

static int kvm_mpic_read(struct kvm_vcpu *vcpu,
                         struct kvm_io_device *this,
                         gpa_t addr, int len, void *ptr)
{
        struct openpic *opp = container_of(this, struct openpic, mmio);
        int ret;
        union {
                u32 val;
                u8 bytes[4];
        } u;

        if (addr & (len - 1)) {
                pr_debug("%s: bad alignment %llx/%d\n",
                         __func__, addr, len);
                return -EINVAL;
        }

        spin_lock_irq(&opp->lock);
        ret = kvm_mpic_read_internal(opp, addr - opp->reg_base, &u.val);
        spin_unlock_irq(&opp->lock);

        /*
         * Technically only 32-bit accesses are allowed, but be nice to
         * people dumping registers a byte at a time -- it works in real
         * hardware (reads only, not writes).
         */
        if (len == 4) {
                *(u32 *)ptr = u.val;
                pr_debug("%s: addr %llx ret %d len 4 val %x\n",
                         __func__, addr, ret, u.val);
        } else if (len == 1) {
                *(u8 *)ptr = u.bytes[addr & 3];
                pr_debug("%s: addr %llx ret %d len 1 val %x\n",
                         __func__, addr, ret, u.bytes[addr & 3]);
        } else {
                pr_debug("%s: bad length %d\n", __func__, len);
                return -EINVAL;
        }

        return ret;
}

static int kvm_mpic_write(struct kvm_vcpu *vcpu,
                          struct kvm_io_device *this,
                          gpa_t addr, int len, const void *ptr)
{
        struct openpic *opp = container_of(this, struct openpic, mmio);
        int ret;

        if (len != 4) {
                pr_debug("%s: bad length %d\n", __func__, len);
                return -EOPNOTSUPP;
        }
        if (addr & 3) {
                pr_debug("%s: bad alignment %llx/%d\n", __func__, addr, len);
                return -EOPNOTSUPP;
        }

        spin_lock_irq(&opp->lock);
        ret = kvm_mpic_write_internal(opp, addr - opp->reg_base,
                                      *(const u32 *)ptr);
        spin_unlock_irq(&opp->lock);

        pr_debug("%s: addr %llx ret %d val %x\n",
                 __func__, addr, ret, *(const u32 *)ptr);

        return ret;
}

static const struct kvm_io_device_ops mpic_mmio_ops = {
        .read = kvm_mpic_read,
        .write = kvm_mpic_write,
};

static void map_mmio(struct openpic *opp)
{
        kvm_iodevice_init(&opp->mmio, &mpic_mmio_ops);

        kvm_io_bus_register_dev(opp->kvm, KVM_MMIO_BUS,
                                opp->reg_base, OPENPIC_REG_SIZE,
                                &opp->mmio);
}

static void unmap_mmio(struct openpic *opp)
{
        kvm_io_bus_unregister_dev(opp->kvm, KVM_MMIO_BUS, &opp->mmio);
}

static int set_base_addr(struct openpic *opp, struct kvm_device_attr *attr)
{
        u64 base;

        if (copy_from_user(&base, (u64 __user *)(long)attr->addr, sizeof(u64)))
                return -EFAULT;

        if (base & 0x3ffff) {
                pr_debug("kvm mpic %s: KVM_DEV_MPIC_BASE_ADDR %08llx not aligned\n",
                         __func__, base);
                return -EINVAL;
        }

        if (base == opp->reg_base)
                return 0;

        mutex_lock(&opp->kvm->slots_lock);

        unmap_mmio(opp);
        opp->reg_base = base;

        pr_debug("kvm mpic %s: KVM_DEV_MPIC_BASE_ADDR %08llx\n",
                 __func__, base);

        if (base == 0)
                goto out;

        map_mmio(opp);

out:
        mutex_unlock(&opp->kvm->slots_lock);
        return 0;
}

#define ATTR_SET                0
#define ATTR_GET                1

static int access_reg(struct openpic *opp, gpa_t addr, u32 *val, int type)
{
        int ret;

        if (addr & 3)
                return -ENXIO;

        spin_lock_irq(&opp->lock);

        if (type == ATTR_SET)
                ret = kvm_mpic_write_internal(opp, addr, *val);
        else
                ret = kvm_mpic_read_internal(opp, addr, val);

        spin_unlock_irq(&opp->lock);

        pr_debug("%s: type %d addr %llx val %x\n", __func__, type, addr, *val);

        return ret;
}

static int mpic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
        struct openpic *opp = dev->private;
        u32 attr32;

        switch (attr->group) {
        case KVM_DEV_MPIC_GRP_MISC:
                switch (attr->attr) {
                case KVM_DEV_MPIC_BASE_ADDR:
                        return set_base_addr(opp, attr);
                }

                break;

        case KVM_DEV_MPIC_GRP_REGISTER:
                if (get_user(attr32, (u32 __user *)(long)attr->addr))
                        return -EFAULT;

                return access_reg(opp, attr->attr, &attr32, ATTR_SET);

        case KVM_DEV_MPIC_GRP_IRQ_ACTIVE:
                if (attr->attr > MAX_SRC)
                        return -EINVAL;

                if (get_user(attr32, (u32 __user *)(long)attr->addr))
                        return -EFAULT;

                if (attr32 != 0 && attr32 != 1)
                        return -EINVAL;

                spin_lock_irq(&opp->lock);
                openpic_set_irq(opp, attr->attr, attr32);
                spin_unlock_irq(&opp->lock);
                return 0;
        }

        return -ENXIO;
}

static int mpic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
        struct openpic *opp = dev->private;
        u64 attr64;
        u32 attr32;
        int ret;

        switch (attr->group) {
        case KVM_DEV_MPIC_GRP_MISC:
                switch (attr->attr) {
                case KVM_DEV_MPIC_BASE_ADDR:
                        mutex_lock(&opp->kvm->slots_lock);
                        attr64 = opp->reg_base;
                        mutex_unlock(&opp->kvm->slots_lock);

                        if (copy_to_user((u64 __user *)(long)attr->addr,
                                         &attr64, sizeof(u64)))
                                return -EFAULT;

                        return 0;
                }

                break;

        case KVM_DEV_MPIC_GRP_REGISTER:
                ret = access_reg(opp, attr->attr, &attr32, ATTR_GET);
                if (ret)
                        return ret;

                if (put_user(attr32, (u32 __user *)(long)attr->addr))
                        return -EFAULT;

                return 0;

        case KVM_DEV_MPIC_GRP_IRQ_ACTIVE:
                if (attr->attr > MAX_SRC)
                        return -EINVAL;

                spin_lock_irq(&opp->lock);
                attr32 = opp->src[attr->attr].pending;
                spin_unlock_irq(&opp->lock);

                if (put_user(attr32, (u32 __user *)(long)attr->addr))
                        return -EFAULT;

                return 0;
        }

        return -ENXIO;
}

static int mpic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
        switch (attr->group) {
        case KVM_DEV_MPIC_GRP_MISC:
                switch (attr->attr) {
                case KVM_DEV_MPIC_BASE_ADDR:
                        return 0;
                }

                break;

        case KVM_DEV_MPIC_GRP_REGISTER:
                return 0;

        case KVM_DEV_MPIC_GRP_IRQ_ACTIVE:
                if (attr->attr > MAX_SRC)
                        break;

                return 0;
        }

        return -ENXIO;
}

static void mpic_destroy(struct kvm_device *dev)
{
        struct openpic *opp = dev->private;

        dev->kvm->arch.mpic = NULL;
        kfree(opp);
        kfree(dev);
}

static int mpic_set_default_irq_routing(struct openpic *opp)
{
        struct kvm_irq_routing_entry *routing;

        /* Create a nop default map, so that dereferencing it still works */
        routing = kzalloc((sizeof(*routing)), GFP_KERNEL);
        if (!routing)
                return -ENOMEM;

        kvm_set_irq_routing(opp->kvm, routing, 0, 0);

        kfree(routing);
        return 0;
}

static int mpic_create(struct kvm_device *dev, u32 type)
{
        struct openpic *opp;
        int ret;

        /* We only support one MPIC at a time for now */
        if (dev->kvm->arch.mpic)
                return -EINVAL;

        opp = kzalloc(sizeof(struct openpic), GFP_KERNEL);
        if (!opp)
                return -ENOMEM;

        dev->private = opp;
        opp->kvm = dev->kvm;
        opp->dev = dev;
        opp->model = type;
        spin_lock_init(&opp->lock);

        add_mmio_region(opp, &openpic_gbl_mmio);
        add_mmio_region(opp, &openpic_tmr_mmio);
        add_mmio_region(opp, &openpic_src_mmio);
        add_mmio_region(opp, &openpic_cpu_mmio);

        switch (opp->model) {
        case KVM_DEV_TYPE_FSL_MPIC_20:
                opp->fsl = &fsl_mpic_20;
                opp->brr1 = 0x00400200;
                opp->flags |= OPENPIC_FLAG_IDR_CRIT;
                opp->nb_irqs = 80;
                opp->mpic_mode_mask = GCR_MODE_MIXED;

                fsl_common_init(opp);

                break;

        case KVM_DEV_TYPE_FSL_MPIC_42:
                opp->fsl = &fsl_mpic_42;
                opp->brr1 = 0x00400402;
                opp->flags |= OPENPIC_FLAG_ILR;
                opp->nb_irqs = 196;
                opp->mpic_mode_mask = GCR_MODE_PROXY;

                fsl_common_init(opp);

                break;

        default:
                ret = -ENODEV;
                goto err;
        }

        ret = mpic_set_default_irq_routing(opp);
        if (ret)
                goto err;

        openpic_reset(opp);

        smp_wmb();
        dev->kvm->arch.mpic = opp;

        return 0;

err:
        kfree(opp);
        return ret;
}

struct kvm_device_ops kvm_mpic_ops = {
        .name = "kvm-mpic",
        .create = mpic_create,
        .destroy = mpic_destroy,
        .set_attr = mpic_set_attr,
        .get_attr = mpic_get_attr,
        .has_attr = mpic_has_attr,
};

int kvmppc_mpic_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu,
                             u32 cpu)
{
        struct openpic *opp = dev->private;
        int ret = 0;

        if (dev->ops != &kvm_mpic_ops)
                return -EPERM;
        if (opp->kvm != vcpu->kvm)
                return -EPERM;
        if (cpu < 0 || cpu >= MAX_CPU)
                return -EPERM;

        spin_lock_irq(&opp->lock);

        if (opp->dst[cpu].vcpu) {
                ret = -EEXIST;
                goto out;
        }
        if (vcpu->arch.irq_type) {
                ret = -EBUSY;
                goto out;
        }

        opp->dst[cpu].vcpu = vcpu;
        opp->nb_cpus = max(opp->nb_cpus, cpu + 1);

        vcpu->arch.mpic = opp;
        vcpu->arch.irq_cpu_id = cpu;
        vcpu->arch.irq_type = KVMPPC_IRQ_MPIC;

        /* This might need to be changed if GCR gets extended */
        if (opp->mpic_mode_mask == GCR_MODE_PROXY)
                vcpu->arch.epr_flags |= KVMPPC_EPR_KERNEL;

out:
        spin_unlock_irq(&opp->lock);
        return ret;
}

/*
 * This should only happen immediately before the mpic is destroyed,
 * so we shouldn't need to worry about anything still trying to
 * access the vcpu pointer.
 */
void kvmppc_mpic_disconnect_vcpu(struct openpic *opp, struct kvm_vcpu *vcpu)
{
        BUG_ON(!opp->dst[vcpu->arch.irq_cpu_id].vcpu);

        opp->dst[vcpu->arch.irq_cpu_id].vcpu = NULL;
}

/*
 * Return value:
 *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 *  = 0   Interrupt was coalesced (previous irq is still pending)
 *  > 0   Number of CPUs interrupt was delivered to
 */
static int mpic_set_irq(struct kvm_kernel_irq_routing_entry *e,
                        struct kvm *kvm, int irq_source_id, int level,
                        bool line_status)
{
        u32 irq = e->irqchip.pin;
        struct openpic *opp = kvm->arch.mpic;
        unsigned long flags;

        spin_lock_irqsave(&opp->lock, flags);
        openpic_set_irq(opp, irq, level);
        spin_unlock_irqrestore(&opp->lock, flags);

        /* All code paths we care about don't check for the return value */
        return 0;
}

int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
                struct kvm *kvm, int irq_source_id, int level, bool line_status)
{
        struct openpic *opp = kvm->arch.mpic;
        unsigned long flags;

        spin_lock_irqsave(&opp->lock, flags);

        /*
         * XXX We ignore the target address for now, as we only support
         *     a single MSI bank.
         */
        openpic_msi_write(kvm->arch.mpic, MSIIR_OFFSET, e->msi.data);
        spin_unlock_irqrestore(&opp->lock, flags);

        /* All code paths we care about don't check for the return value */
        return 0;
}

int kvm_set_routing_entry(struct kvm *kvm,
                          struct kvm_kernel_irq_routing_entry *e,
                          const struct kvm_irq_routing_entry *ue)
{
        int r = -EINVAL;

        switch (ue->type) {
        case KVM_IRQ_ROUTING_IRQCHIP:
                e->set = mpic_set_irq;
                e->irqchip.irqchip = ue->u.irqchip.irqchip;
                e->irqchip.pin = ue->u.irqchip.pin;
                if (e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS)
                        goto out;
                break;
        case KVM_IRQ_ROUTING_MSI:
                e->set = kvm_set_msi;
                e->msi.address_lo = ue->u.msi.address_lo;
                e->msi.address_hi = ue->u.msi.address_hi;
                e->msi.data = ue->u.msi.data;
                break;
        default:
                goto out;
        }

        r = 0;
out:
        return r;
}