xref: /linux/arch/powerpc/kvm/mpic.c (revision ead5d1f4d877e92c051e1a1ade623d0d30e71619)

/*
 * 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;
}