/*

 * OpenPIC emulation

 *

 * Copyright (c) 2004 Jocelyn Mayer

 *

 * 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.

 */

/*

 *

 * Based on OpenPic implementations:

 * - Intel GW80314 I/O compagnion chip developper's manual

 * - Motorola MPC8245 & MPC8540 user manuals.

 * - Motorola MCP750 (aka Raven) programmer manual.

 * - Motorola Harrier programmer manuel

 *

 * Serial interrupts, as implemented in Raven chipset are not supported yet.

 *

 */

#include "hw.h"

#include "ppc_mac.h"

#include "pci.h"

//#define DEBUG_OPENPIC

#ifdef DEBUG_OPENPIC

#define DPRINTF(fmt, args...) do { printf(fmt , ##args); } while (0)

#else

#define DPRINTF(fmt, args...) do { } while (0)

#endif

#define ERROR(fmr, args...) do { printf("ERROR: " fmr , ##args); } while (0)

#define USE_MPCxxx /* Intel model is broken, for now */

#if defined (USE_INTEL_GW80314)

/* Intel GW80314 I/O Companion chip */

#define MAX_CPU     4

#define MAX_IRQ    32

#define MAX_DBL     4

#define MAX_MBX     4

#define MAX_TMR     4

#define VECTOR_BITS 8

#define MAX_IPI     0

#define VID (0x00000000)

#define OPENPIC_LITTLE_ENDIAN 1

#define OPENPIC_BIG_ENDIAN    0

#elif defined(USE_MPCxxx)

#define MAX_CPU     2

#define MAX_IRQ    64

#define EXT_IRQ    48

#define MAX_DBL     0

#define MAX_MBX     0

#define MAX_TMR     4

#define VECTOR_BITS 8

#define MAX_IPI     4

#define VID         0x03 /* MPIC version ID */

#define VENI        0x00000000 /* Vendor ID */

enum {

    IRQ_IPVP = 0,

    IRQ_IDE,

};

#define OPENPIC_LITTLE_ENDIAN 1

#define OPENPIC_BIG_ENDIAN    0

#else

#error "Please select which OpenPic implementation is to be emulated"

#endif

#if (OPENPIC_BIG_ENDIAN && !TARGET_WORDS_BIGENDIAN) || \

    (OPENPIC_LITTLE_ENDIAN && TARGET_WORDS_BIGENDIAN)

#define OPENPIC_SWAP

#endif

/* Interrupt definitions */

#define IRQ_FE     (EXT_IRQ)     /* Internal functional IRQ */

#define IRQ_ERR    (EXT_IRQ + 1) /* Error IRQ */

#define IRQ_TIM0   (EXT_IRQ + 2) /* First timer IRQ */

#if MAX_IPI > 0

#define IRQ_IPI0   (IRQ_TIM0 + MAX_TMR) /* First IPI IRQ */

#define IRQ_DBL0   (IRQ_IPI0 + (MAX_CPU * MAX_IPI)) /* First doorbell IRQ */

#else

#define IRQ_DBL0   (IRQ_TIM0 + MAX_TMR) /* First doorbell IRQ */

#define IRQ_MBX0   (IRQ_DBL0 + MAX_DBL) /* First mailbox IRQ */

#endif

#define BF_WIDTH(_bits_) \

(((_bits_) + (sizeof(uint32_t) * 8) - 1) / (sizeof(uint32_t) * 8))

static inline void set_bit (uint32_t *field, int bit)

{

    field[bit >> 5] |= 1 << (bit & 0x1F);

}

static inline void reset_bit (uint32_t *field, int bit)

{

    field[bit >> 5] &= ~(1 << (bit & 0x1F));

}

static inline int test_bit (uint32_t *field, int bit)

{

    return (field[bit >> 5] & 1 << (bit & 0x1F)) != 0;

}

enum {

    IRQ_EXTERNAL = 0x01,

    IRQ_INTERNAL = 0x02,

    IRQ_TIMER    = 0x04,

    IRQ_SPECIAL  = 0x08,

};

typedef struct IRQ_queue_t {

    uint32_t queue[BF_WIDTH(MAX_IRQ)];

    int next;

    int priority;

} IRQ_queue_t;

typedef struct IRQ_src_t {

    uint32_t ipvp;  /* IRQ vector/priority register */

    uint32_t ide;   /* IRQ destination register */

    int type;

    int last_cpu;

    int pending;    /* TRUE if IRQ is pending */

} IRQ_src_t;

enum IPVP_bits {

    IPVP_MASK     = 31,

    IPVP_ACTIVITY = 30,

    IPVP_MODE     = 29,

    IPVP_POLARITY = 23,

    IPVP_SENSE    = 22,

};

#define IPVP_PRIORITY_MASK     (0x1F << 16)

#define IPVP_PRIORITY(_ipvpr_) ((int)(((_ipvpr_) & IPVP_PRIORITY_MASK) >> 16))

#define IPVP_VECTOR_MASK       ((1 << VECTOR_BITS) - 1)

#define IPVP_VECTOR(_ipvpr_)   ((_ipvpr_) & IPVP_VECTOR_MASK)

typedef struct IRQ_dst_t {

    uint32_t pctp; /* CPU current task priority */

    uint32_t pcsr; /* CPU sensitivity register */

    IRQ_queue_t raised;

    IRQ_queue_t servicing;

    qemu_irq *irqs;

} IRQ_dst_t;

typedef struct openpic_t {

    PCIDevice pci_dev;

    int mem_index;

    /* Global registers */

    uint32_t frep; /* Feature reporting register */

    uint32_t glbc; /* Global configuration register  */

    uint32_t micr; /* MPIC interrupt configuration register */

    uint32_t veni; /* Vendor identification register */

    uint32_t pint; /* Processor initialization register */

    uint32_t spve; /* Spurious vector register */

    uint32_t tifr; /* Timer frequency reporting register */

    /* Source registers */

    IRQ_src_t src[MAX_IRQ];

    /* Local registers per output pin */

    IRQ_dst_t dst[MAX_CPU];

    int nb_cpus;

    /* Timer registers */

    struct {

	uint32_t ticc;  /* Global timer current count register */

	uint32_t tibc;  /* Global timer base count register */

    } timers[MAX_TMR];

#if MAX_DBL > 0

    /* Doorbell registers */

    uint32_t dar;        /* Doorbell activate register */

    struct {

	uint32_t dmr;    /* Doorbell messaging register */

    } doorbells[MAX_DBL];

#endif

#if MAX_MBX > 0

    /* Mailbox registers */

    struct {

	uint32_t mbr;    /* Mailbox register */

    } mailboxes[MAX_MAILBOXES];

#endif

    /* IRQ out is used when in bypass mode (not implemented) */

    qemu_irq irq_out;

} openpic_t;

static inline void IRQ_setbit (IRQ_queue_t *q, int n_IRQ)

{

    set_bit(q->queue, n_IRQ);

}

static inline void IRQ_resetbit (IRQ_queue_t *q, int n_IRQ)

{

    reset_bit(q->queue, n_IRQ);

}

static inline int IRQ_testbit (IRQ_queue_t *q, int n_IRQ)

{

    return test_bit(q->queue, n_IRQ);

}

static void IRQ_check (openpic_t *opp, IRQ_queue_t *q)

{

    int next, i;

    int priority;

    next = -1;

    priority = -1;

    for (i = 0; i < MAX_IRQ; i++) {

	if (IRQ_testbit(q, i)) {

            DPRINTF("IRQ_check: irq %d set ipvp_pr=%d pr=%d\n",

                    i, IPVP_PRIORITY(opp->src[i].ipvp), priority);

	    if (IPVP_PRIORITY(opp->src[i].ipvp) > priority) {

		next = i;

		priority = IPVP_PRIORITY(opp->src[i].ipvp);

	    }

	}

    }

    q->next = next;

    q->priority = priority;

}

static int IRQ_get_next (openpic_t *opp, IRQ_queue_t *q)

{

    if (q->next == -1) {

        /* XXX: optimize */

	IRQ_check(opp, q);

    }

    return q->next;

}

static void IRQ_local_pipe (openpic_t *opp, int n_CPU, int n_IRQ)

{

    IRQ_dst_t *dst;

    IRQ_src_t *src;

    int priority;

    dst = &opp->dst[n_CPU];

    src = &opp->src[n_IRQ];

    priority = IPVP_PRIORITY(src->ipvp);

    if (priority <= dst->pctp) {

	/* Too low priority */

        DPRINTF("%s: IRQ %d has too low priority on CPU %d\n",

                __func__, n_IRQ, n_CPU);

	return;

    }

    if (IRQ_testbit(&dst->raised, n_IRQ)) {

	/* Interrupt miss */

        DPRINTF("%s: IRQ %d was missed on CPU %d\n",

                __func__, n_IRQ, n_CPU);

	return;

    }

    set_bit(&src->ipvp, IPVP_ACTIVITY);

    IRQ_setbit(&dst->raised, n_IRQ);

    if (priority < dst->raised.priority) {

        /* An higher priority IRQ is already raised */

        DPRINTF("%s: IRQ %d is hidden by raised IRQ %d on CPU %d\n",

                __func__, n_IRQ, dst->raised.next, n_CPU);

        return;

    }

    IRQ_get_next(opp, &dst->raised);

    if (IRQ_get_next(opp, &dst->servicing) != -1 &&

        priority < dst->servicing.priority) {

        DPRINTF("%s: IRQ %d is hidden by servicing IRQ %d on CPU %d\n",

                __func__, n_IRQ, dst->servicing.next, n_CPU);

        /* Already servicing a higher priority IRQ */

        return;

    }

    DPRINTF("Raise OpenPIC INT output cpu %d irq %d\n", n_CPU, n_IRQ);

    qemu_irq_raise(dst->irqs[OPENPIC_OUTPUT_INT]);

}

/* update pic state because registers for n_IRQ have changed value */

static void openpic_update_irq(openpic_t *opp, int n_IRQ)

{

    IRQ_src_t *src;

    int i;

    src = &opp->src[n_IRQ];

    if (!src->pending) {

        /* no irq pending */

        DPRINTF("%s: IRQ %d is not pending\n", __func__, n_IRQ);

        return;

    }

    if (test_bit(&src->ipvp, IPVP_MASK)) {

	/* Interrupt source is disabled */

        DPRINTF("%s: IRQ %d is disabled\n", __func__, n_IRQ);

	return;

    }

    if (IPVP_PRIORITY(src->ipvp) == 0) {

	/* Priority set to zero */

        DPRINTF("%s: IRQ %d has 0 priority\n", __func__, n_IRQ);

	return;

    }

    if (test_bit(&src->ipvp, IPVP_ACTIVITY)) {

        /* IRQ already active */

        DPRINTF("%s: IRQ %d is already active\n", __func__, n_IRQ);

        return;

    }

    if (src->ide == 0x00000000) {

	/* No target */

        DPRINTF("%s: IRQ %d has no target\n", __func__, n_IRQ);

	return;

    }

    if (src->ide == (1 << src->last_cpu)) {

        /* Only one CPU is allowed to receive this IRQ */

        IRQ_local_pipe(opp, src->last_cpu, n_IRQ);

    } else if (!test_bit(&src->ipvp, IPVP_MODE)) {

        /* Directed delivery mode */

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

            if (test_bit(&src->ide, i))

                IRQ_local_pipe(opp, i, n_IRQ);

        }

    } else {

        /* Distributed delivery mode */

        for (i = src->last_cpu + 1; i != src->last_cpu; i++) {

            if (i == opp->nb_cpus)

                i = 0;

            if (test_bit(&src->ide, i)) {

                IRQ_local_pipe(opp, i, n_IRQ);

                src->last_cpu = i;

                break;

            }

        }

    }

}

static void openpic_set_irq(void *opaque, int n_IRQ, int level)

{

    openpic_t *opp = opaque;

    IRQ_src_t *src;

    src = &opp->src[n_IRQ];

    DPRINTF("openpic: set irq %d = %d ipvp=%08x\n",

            n_IRQ, level, src->ipvp);

    if (test_bit(&src->ipvp, IPVP_SENSE)) {

        /* level-sensitive irq */

        src->pending = level;

        if (!level)

            reset_bit(&src->ipvp, IPVP_ACTIVITY);

    } else {

        /* edge-sensitive irq */

        if (level)

            src->pending = 1;

    }

    openpic_update_irq(opp, n_IRQ);

}

static void openpic_reset (openpic_t *opp)

{

    int i;

    opp->glbc = 0x80000000;

    /* Initialise controller registers */

    opp->frep = ((EXT_IRQ - 1) << 16) | ((MAX_CPU - 1) << 8) | VID;

    opp->veni = VENI;

    opp->pint = 0x00000000;

    opp->spve = 0x000000FF;

    opp->tifr = 0x003F7A00;

    /* ? */

    opp->micr = 0x00000000;

    /* Initialise IRQ sources */

    for (i = 0; i < MAX_IRQ; i++) {

	opp->src[i].ipvp = 0xA0000000;

	opp->src[i].ide  = 0x00000000;

    }

    /* Initialise IRQ destinations */

    for (i = 0; i < MAX_CPU; i++) {

	opp->dst[i].pctp      = 0x0000000F;

	opp->dst[i].pcsr      = 0x00000000;

	memset(&opp->dst[i].raised, 0, sizeof(IRQ_queue_t));

	memset(&opp->dst[i].servicing, 0, sizeof(IRQ_queue_t));

    }

    /* Initialise timers */

    for (i = 0; i < MAX_TMR; i++) {

	opp->timers[i].ticc = 0x00000000;

	opp->timers[i].tibc = 0x80000000;

    }

    /* Initialise doorbells */

#if MAX_DBL > 0

    opp->dar = 0x00000000;

    for (i = 0; i < MAX_DBL; i++) {

	opp->doorbells[i].dmr  = 0x00000000;

    }

#endif

    /* Initialise mailboxes */

#if MAX_MBX > 0

    for (i = 0; i < MAX_MBX; i++) { /* ? */

	opp->mailboxes[i].mbr   = 0x00000000;

    }

#endif

    /* Go out of RESET state */

    opp->glbc = 0x00000000;

}

static inline uint32_t read_IRQreg (openpic_t *opp, int n_IRQ, uint32_t reg)

{

    uint32_t retval;

    switch (reg) {

    case IRQ_IPVP:

	retval = opp->src[n_IRQ].ipvp;

	break;

    case IRQ_IDE:

	retval = opp->src[n_IRQ].ide;

	break;

    }

    return retval;

}

static inline void write_IRQreg (openpic_t *opp, int n_IRQ,

                                 uint32_t reg, uint32_t val)

{

    uint32_t tmp;

    switch (reg) {

    case IRQ_IPVP:

        /* NOTE: not fully accurate for special IRQs, but simple and

           sufficient */

        /* ACTIVITY bit is read-only */

	opp->src[n_IRQ].ipvp =

            (opp->src[n_IRQ].ipvp & 0x40000000) |

            (val & 0x800F00FF);

        openpic_update_irq(opp, n_IRQ);

        DPRINTF("Set IPVP %d to 0x%08x -> 0x%08x\n",

                n_IRQ, val, opp->src[n_IRQ].ipvp);

	break;

    case IRQ_IDE:

	tmp = val & 0xC0000000;

        tmp |= val & ((1 << MAX_CPU) - 1);

	opp->src[n_IRQ].ide = tmp;

        DPRINTF("Set IDE %d to 0x%08x\n", n_IRQ, opp->src[n_IRQ].ide);

	break;

    }

}

#if 0 // Code provision for Intel model

#if MAX_DBL > 0

static uint32_t read_doorbell_register (openpic_t *opp,

					int n_dbl, uint32_t offset)

{

    uint32_t retval;

    switch (offset) {

    case DBL_IPVP_OFFSET:

	retval = read_IRQreg(opp, IRQ_DBL0 + n_dbl, IRQ_IPVP);

	break;

    case DBL_IDE_OFFSET:

	retval = read_IRQreg(opp, IRQ_DBL0 + n_dbl, IRQ_IDE);

	break;

    case DBL_DMR_OFFSET:

	retval = opp->doorbells[n_dbl].dmr;

	break;

    }

    return retval;

}

static void write_doorbell_register (penpic_t *opp, int n_dbl,

				     uint32_t offset, uint32_t value)

{

    switch (offset) {

    case DBL_IVPR_OFFSET:

	write_IRQreg(opp, IRQ_DBL0 + n_dbl, IRQ_IPVP, value);

	break;

    case DBL_IDE_OFFSET:

	write_IRQreg(opp, IRQ_DBL0 + n_dbl, IRQ_IDE, value);

	break;

    case DBL_DMR_OFFSET:

	opp->doorbells[n_dbl].dmr = value;

	break;

    }

}

#endif

#if MAX_MBX > 0

static uint32_t read_mailbox_register (openpic_t *opp,

				       int n_mbx, uint32_t offset)

{

    uint32_t retval;

    switch (offset) {

    case MBX_MBR_OFFSET:

	retval = opp->mailboxes[n_mbx].mbr;

	break;

    case MBX_IVPR_OFFSET:

	retval = read_IRQreg(opp, IRQ_MBX0 + n_mbx, IRQ_IPVP);

	break;

    case MBX_DMR_OFFSET:

	retval = read_IRQreg(opp, IRQ_MBX0 + n_mbx, IRQ_IDE);

	break;

    }

    return retval;

}

static void write_mailbox_register (openpic_t *opp, int n_mbx,

				    uint32_t address, uint32_t value)

{

    switch (offset) {

    case MBX_MBR_OFFSET:

	opp->mailboxes[n_mbx].mbr = value;

	break;

    case MBX_IVPR_OFFSET:

	write_IRQreg(opp, IRQ_MBX0 + n_mbx, IRQ_IPVP, value);

	break;