/*

 * QEMU Sparc SLAVIO interrupt controller emulation

 *

 * Copyright (c) 2003-2005 Fabrice Bellard

 *

 * 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 "hw.h"

#include "sun4m.h"

#include "console.h"

//#define DEBUG_IRQ_COUNT

//#define DEBUG_IRQ

#ifdef DEBUG_IRQ

#define DPRINTF(fmt, args...) \

do { printf("IRQ: " fmt , ##args); } while (0)

#else

#define DPRINTF(fmt, args...)

#endif

/*

 * Registers of interrupt controller in sun4m.

 *

 * This is the interrupt controller part of chip STP2001 (Slave I/O), also

 * produced as NCR89C105. See

 * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt

 *

 * There is a system master controller and one for each cpu.

 *

 */

#define MAX_CPUS 16

#define MAX_PILS 16

struct SLAVIO_CPUINTCTLState;

typedef struct SLAVIO_INTCTLState {

    uint32_t intregm_pending;

    uint32_t intregm_disabled;

    uint32_t target_cpu;

#ifdef DEBUG_IRQ_COUNT

    uint64_t irq_count[32];

#endif

    qemu_irq *cpu_irqs[MAX_CPUS];

    const uint32_t *intbit_to_level;

    uint32_t cputimer_lbit, cputimer_mbit;

    uint32_t pil_out[MAX_CPUS];

    struct SLAVIO_CPUINTCTLState *slaves[MAX_CPUS];

} SLAVIO_INTCTLState;

typedef struct SLAVIO_CPUINTCTLState {

    uint32_t intreg_pending;

    SLAVIO_INTCTLState *master;

    uint32_t cpu;

} SLAVIO_CPUINTCTLState;

#define INTCTL_MAXADDR 0xf

#define INTCTL_SIZE (INTCTL_MAXADDR + 1)

#define INTCTLM_SIZE 0x14

#define MASTER_IRQ_MASK ~0x0fa2007f

#define MASTER_DISABLE 0x80000000

#define CPU_SOFTIRQ_MASK 0xfffe0000

#define CPU_HARDIRQ_MASK 0x0000fffe

#define CPU_IRQ_INT15_IN 0x0004000

#define CPU_IRQ_INT15_MASK 0x80000000

static void slavio_check_interrupts(SLAVIO_INTCTLState *s);

// per-cpu interrupt controller

static uint32_t slavio_intctl_mem_readl(void *opaque, target_phys_addr_t addr)

{

    SLAVIO_CPUINTCTLState *s = opaque;

    uint32_t saddr, ret;

    saddr = addr >> 2;

    switch (saddr) {

    case 0:

        ret = s->intreg_pending;

        break;

    default:

        ret = 0;

        break;

    }

    DPRINTF("read cpu %d reg 0x" TARGET_FMT_plx " = %x\n", cpu, addr, ret);

    return ret;

}

static void slavio_intctl_mem_writel(void *opaque, target_phys_addr_t addr,

                                     uint32_t val)

{

    SLAVIO_CPUINTCTLState *s = opaque;

    uint32_t saddr;

    saddr = addr >> 2;

    DPRINTF("write cpu %d reg 0x" TARGET_FMT_plx " = %x\n", cpu, addr, val);

    switch (saddr) {

    case 1: // clear pending softints

        if (val & CPU_IRQ_INT15_IN)

            val |= CPU_IRQ_INT15_MASK;

        val &= CPU_SOFTIRQ_MASK;

        s->intreg_pending &= ~val;

        slavio_check_interrupts(s->master);

        DPRINTF("Cleared cpu %d irq mask %x, curmask %x\n", s->cpu, val,

                s->intreg_pending);

        break;

    case 2: // set softint

        val &= CPU_SOFTIRQ_MASK;

        s->intreg_pending |= val;

        slavio_check_interrupts(s->master);

        DPRINTF("Set cpu %d irq mask %x, curmask %x\n", s->cpu, val,

                s->intreg_pending);

        break;

    default:

        break;

    }

}

static CPUReadMemoryFunc *slavio_intctl_mem_read[3] = {

    NULL,

    NULL,

    slavio_intctl_mem_readl,

};

static CPUWriteMemoryFunc *slavio_intctl_mem_write[3] = {

    NULL,

    NULL,

    slavio_intctl_mem_writel,

};

// master system interrupt controller

static uint32_t slavio_intctlm_mem_readl(void *opaque, target_phys_addr_t addr)

{

    SLAVIO_INTCTLState *s = opaque;

    uint32_t saddr, ret;

    saddr = addr >> 2;

    switch (saddr) {

    case 0:

        ret = s->intregm_pending & ~MASTER_DISABLE;

        break;

    case 1:

        ret = s->intregm_disabled & MASTER_IRQ_MASK;

        break;

    case 4:

        ret = s->target_cpu;

        break;

    default:

        ret = 0;

        break;

    }

    DPRINTF("read system reg 0x" TARGET_FMT_plx " = %x\n", addr, ret);

    return ret;

}

static void slavio_intctlm_mem_writel(void *opaque, target_phys_addr_t addr,

                                      uint32_t val)

{

    SLAVIO_INTCTLState *s = opaque;

    uint32_t saddr;

    saddr = addr >> 2;

    DPRINTF("write system reg 0x" TARGET_FMT_plx " = %x\n", addr, val);

    switch (saddr) {

    case 2: // clear (enable)

        // Force clear unused bits

        val &= MASTER_IRQ_MASK;

        s->intregm_disabled &= ~val;

        DPRINTF("Enabled master irq mask %x, curmask %x\n", val,

                s->intregm_disabled);

        slavio_check_interrupts(s);

        break;

    case 3: // set (disable, clear pending)

        // Force clear unused bits

        val &= MASTER_IRQ_MASK;

        s->intregm_disabled |= val;

        s->intregm_pending &= ~val;

        slavio_check_interrupts(s);

        DPRINTF("Disabled master irq mask %x, curmask %x\n", val,

                s->intregm_disabled);

        break;

    case 4:

        s->target_cpu = val & (MAX_CPUS - 1);

        slavio_check_interrupts(s);

        DPRINTF("Set master irq cpu %d\n", s->target_cpu);

        break;

    default:

        break;

    }

}

static CPUReadMemoryFunc *slavio_intctlm_mem_read[3] = {

    NULL,

    NULL,

    slavio_intctlm_mem_readl,

};

static CPUWriteMemoryFunc *slavio_intctlm_mem_write[3] = {

    NULL,

    NULL,

    slavio_intctlm_mem_writel,

};

void slavio_pic_info(void *opaque)

{

    SLAVIO_INTCTLState *s = opaque;

    int i;

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

        term_printf("per-cpu %d: pending 0x%08x\n", i,

                    s->slaves[i]->intreg_pending);

    }

    term_printf("master: pending 0x%08x, disabled 0x%08x\n",

                s->intregm_pending, s->intregm_disabled);

}

void slavio_irq_info(void *opaque)

{

#ifndef DEBUG_IRQ_COUNT

    term_printf("irq statistic code not compiled.\n");

#else

    SLAVIO_INTCTLState *s = opaque;

    int i;

    int64_t count;

    term_printf("IRQ statistics:\n");

    for (i = 0; i < 32; i++) {

        count = s->irq_count[i];

        if (count > 0)

            term_printf("%2d: %" PRId64 "\n", i, count);

    }

#endif

}

static void slavio_check_interrupts(SLAVIO_INTCTLState *s)

{

    uint32_t pending = s->intregm_pending, pil_pending;

    unsigned int i, j;

    pending &= ~s->intregm_disabled;

    DPRINTF("pending %x disabled %x\n", pending, s->intregm_disabled);

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

        pil_pending = 0;

        if (pending && !(s->intregm_disabled & MASTER_DISABLE) &&

            (i == s->target_cpu)) {

            for (j = 0; j < 32; j++) {

                if (pending & (1 << j))

                    pil_pending |= 1 << s->intbit_to_level[j];

            }

        }

        pil_pending |= (s->slaves[i]->intreg_pending & CPU_SOFTIRQ_MASK) >> 16;

        for (j = 0; j < MAX_PILS; j++) {

            if (pil_pending & (1 << j)) {

                if (!(s->pil_out[i] & (1 << j)))

                    qemu_irq_raise(s->cpu_irqs[i][j]);

            } else {

                if (s->pil_out[i] & (1 << j))

                    qemu_irq_lower(s->cpu_irqs[i][j]);

            }

        }

        s->pil_out[i] = pil_pending;

    }

}

/*

 * "irq" here is the bit number in the system interrupt register to

 * separate serial and keyboard interrupts sharing a level.

 */

static void slavio_set_irq(void *opaque, int irq, int level)

{

    SLAVIO_INTCTLState *s = opaque;

    uint32_t mask = 1 << irq;

    uint32_t pil = s->intbit_to_level[irq];

    DPRINTF("Set cpu %d irq %d -> pil %d level %d\n", s->target_cpu, irq, pil,

            level);

    if (pil > 0) {

        if (level) {

#ifdef DEBUG_IRQ_COUNT

            s->irq_count[pil]++;

#endif

            s->intregm_pending |= mask;

            s->slaves[s->target_cpu]->intreg_pending |= 1 << pil;

        } else {

            s->intregm_pending &= ~mask;

            s->slaves[s->target_cpu]->intreg_pending &= ~(1 << pil);

        }

        slavio_check_interrupts(s);

    }

}

static void slavio_set_timer_irq_cpu(void *opaque, int cpu, int level)

{

    SLAVIO_INTCTLState *s = opaque;

    DPRINTF("Set cpu %d local timer level %d\n", cpu, level);

    if (level) {

        s->intregm_pending |= s->cputimer_mbit;

        s->slaves[cpu]->intreg_pending |= s->cputimer_lbit;

    } else {

        s->intregm_pending &= ~s->cputimer_mbit;

        s->slaves[cpu]->intreg_pending &= ~s->cputimer_lbit;

    }

    slavio_check_interrupts(s);

}

static void slavio_intctl_save(QEMUFile *f, void *opaque)

{

    SLAVIO_INTCTLState *s = opaque;

    int i;

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

        qemu_put_be32s(f, &s->slaves[i]->intreg_pending);

    }

    qemu_put_be32s(f, &s->intregm_pending);

    qemu_put_be32s(f, &s->intregm_disabled);

    qemu_put_be32s(f, &s->target_cpu);

}

static int slavio_intctl_load(QEMUFile *f, void *opaque, int version_id)

{

    SLAVIO_INTCTLState *s = opaque;

    int i;

    if (version_id != 1)

        return -EINVAL;

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

        qemu_get_be32s(f, &s->slaves[i]->intreg_pending);

    }

    qemu_get_be32s(f, &s->intregm_pending);

    qemu_get_be32s(f, &s->intregm_disabled);

    qemu_get_be32s(f, &s->target_cpu);

    slavio_check_interrupts(s);

    return 0;

}

static void slavio_intctl_reset(void *opaque)

{

    SLAVIO_INTCTLState *s = opaque;

    int i;

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

        s->slaves[i]->intreg_pending = 0;

    }

    s->intregm_disabled = ~MASTER_IRQ_MASK;

    s->intregm_pending = 0;

    s->target_cpu = 0;

    slavio_check_interrupts(s);

}

void *slavio_intctl_init(target_phys_addr_t addr, target_phys_addr_t addrg,

                         const uint32_t *intbit_to_level,

                         qemu_irq **irq, qemu_irq **cpu_irq,

                         qemu_irq **parent_irq, unsigned int cputimer)

{

    int slavio_intctl_io_memory, slavio_intctlm_io_memory, i;

    SLAVIO_INTCTLState *s;

    SLAVIO_CPUINTCTLState *slave;

    s = qemu_mallocz(sizeof(SLAVIO_INTCTLState));

    if (!s)

        return NULL;

    s->intbit_to_level = intbit_to_level;

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

        slave = qemu_mallocz(sizeof(SLAVIO_CPUINTCTLState));

        if (!slave)

            return NULL;

        slave->cpu = i;

        slave->master = s;

        slavio_intctl_io_memory = cpu_register_io_memory(0,

                                                         slavio_intctl_mem_read,

                                                         slavio_intctl_mem_write,

                                                         slave);

        cpu_register_physical_memory(addr + i * TARGET_PAGE_SIZE, INTCTL_SIZE,

                                     slavio_intctl_io_memory);

        s->slaves[i] = slave;

        s->cpu_irqs[i] = parent_irq[i];

    }

    slavio_intctlm_io_memory = cpu_register_io_memory(0,

                                                      slavio_intctlm_mem_read,

                                                      slavio_intctlm_mem_write,

                                                      s);

    cpu_register_physical_memory(addrg, INTCTLM_SIZE, slavio_intctlm_io_memory);

    register_savevm("slavio_intctl", addr, 1, slavio_intctl_save,

                    slavio_intctl_load, s);

    qemu_register_reset(slavio_intctl_reset, s);

    *irq = qemu_allocate_irqs(slavio_set_irq, s, 32);

    *cpu_irq = qemu_allocate_irqs(slavio_set_timer_irq_cpu, s, MAX_CPUS);

    s->cputimer_mbit = 1 << cputimer;

    s->cputimer_lbit = 1 << intbit_to_level[cputimer];

    slavio_intctl_reset(s);

    return s;

}