/*
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * OpenRISC QEMU virtual machine.
 *
 * (c) 2022 Stafford Horne <shorne@gmail.com>
 */

#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/guest-random.h"
#include "qapi/error.h"
#include "cpu.h"
#include "exec/address-spaces.h"
#include "hw/irq.h"
#include "hw/boards.h"
#include "hw/char/serial-mm.h"
#include "hw/core/split-irq.h"
#include "hw/openrisc/boot.h"
#include "hw/misc/sifive_test.h"
#include "hw/pci/pci.h"
#include "hw/pci-host/gpex.h"
#include "hw/qdev-properties.h"
#include "hw/rtc/goldfish_rtc.h"
#include "hw/sysbus.h"
#include "hw/virtio/virtio-mmio.h"
#include "system/device_tree.h"
#include "system/system.h"
#include "system/qtest.h"
#include "system/reset.h"

#include <libfdt.h>

#define VIRT_CPUS_MAX 4
#define VIRT_CLK_MHZ 20000000

#define TYPE_VIRT_MACHINE MACHINE_TYPE_NAME("virt")
#define VIRT_MACHINE(obj) \
    OBJECT_CHECK(OR1KVirtState, (obj), TYPE_VIRT_MACHINE)

typedef struct OR1KVirtState {
    /*< private >*/
    MachineState parent_obj;

    /*< public >*/
    void *fdt;
    int fdt_size;

} OR1KVirtState;

enum {
    VIRT_DRAM,
    VIRT_ECAM,
    VIRT_MMIO,
    VIRT_PIO,
    VIRT_TEST,
    VIRT_RTC,
    VIRT_VIRTIO,
    VIRT_UART,
    VIRT_OMPIC,
};

enum {
    VIRT_OMPIC_IRQ = 1,
    VIRT_UART_IRQ = 2,
    VIRT_RTC_IRQ = 3,
    VIRT_VIRTIO_IRQ = 4, /* to 12 */
    VIRTIO_COUNT = 8,
    VIRT_PCI_IRQ_BASE = 13, /* to 17 */
};

static const struct MemmapEntry {
    hwaddr base;
    hwaddr size;
} virt_memmap[] = {
    [VIRT_DRAM] =      { 0x00000000,          0 },
    [VIRT_UART] =      { 0x90000000,      0x100 },
    [VIRT_TEST] =      { 0x96000000,        0x8 },
    [VIRT_RTC] =       { 0x96005000,     0x1000 },
    [VIRT_VIRTIO] =    { 0x97000000,     0x1000 },
    [VIRT_OMPIC] =     { 0x98000000, VIRT_CPUS_MAX * 8 },
    [VIRT_ECAM] =      { 0x9e000000,  0x1000000 },
    [VIRT_PIO] =       { 0x9f000000,  0x1000000 },
    [VIRT_MMIO] =      { 0xa0000000, 0x10000000 },
};

static struct openrisc_boot_info {
    uint32_t bootstrap_pc;
    uint32_t fdt_addr;
} boot_info;

static void main_cpu_reset(void *opaque)
{
    OpenRISCCPU *cpu = opaque;
    CPUState *cs = CPU(cpu);

    cpu_reset(CPU(cpu));

    cpu_set_pc(cs, boot_info.bootstrap_pc);
    cpu_set_gpr(&cpu->env, 3, boot_info.fdt_addr);
}

static qemu_irq get_cpu_irq(OpenRISCCPU *cpus[], int cpunum, int irq_pin)
{
    return qdev_get_gpio_in_named(DEVICE(cpus[cpunum]), "IRQ", irq_pin);
}

static qemu_irq get_per_cpu_irq(OpenRISCCPU *cpus[], int num_cpus, int irq_pin)
{
    int i;

    if (num_cpus > 1) {
        DeviceState *splitter = qdev_new(TYPE_SPLIT_IRQ);
        qdev_prop_set_uint32(splitter, "num-lines", num_cpus);
        qdev_realize_and_unref(splitter, NULL, &error_fatal);
        for (i = 0; i < num_cpus; i++) {
            qdev_connect_gpio_out(splitter, i, get_cpu_irq(cpus, i, irq_pin));
        }
        return qdev_get_gpio_in(splitter, 0);
    } else {
        return get_cpu_irq(cpus, 0, irq_pin);
    }
}

static void openrisc_create_fdt(OR1KVirtState *state,
                                const struct MemmapEntry *memmap,
                                int num_cpus, uint64_t mem_size,
                                const char *cmdline,
                                int32_t *pic_phandle)
{
    void *fdt;
    int cpu;
    char *nodename;
    uint8_t rng_seed[32];

    fdt = state->fdt = create_device_tree(&state->fdt_size);
    if (!fdt) {
        error_report("create_device_tree() failed");
        exit(1);
    }

    qemu_fdt_setprop_string(fdt, "/", "compatible", "opencores,or1ksim");
    qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x1);
    qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x1);

    qemu_fdt_add_subnode(fdt, "/soc");
    qemu_fdt_setprop(fdt, "/soc", "ranges", NULL, 0);
    qemu_fdt_setprop_string(fdt, "/soc", "compatible", "simple-bus");
    qemu_fdt_setprop_cell(fdt, "/soc", "#address-cells", 0x1);
    qemu_fdt_setprop_cell(fdt, "/soc", "#size-cells", 0x1);

    nodename = g_strdup_printf("/memory@%" HWADDR_PRIx,
                               memmap[VIRT_DRAM].base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_cells(fdt, nodename, "reg",
                           memmap[VIRT_DRAM].base, mem_size);
    qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory");
    g_free(nodename);

    qemu_fdt_add_subnode(fdt, "/cpus");
    qemu_fdt_setprop_cell(fdt, "/cpus", "#size-cells", 0x0);
    qemu_fdt_setprop_cell(fdt, "/cpus", "#address-cells", 0x1);

    for (cpu = 0; cpu < num_cpus; cpu++) {
        nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
        qemu_fdt_add_subnode(fdt, nodename);
        qemu_fdt_setprop_string(fdt, nodename, "compatible",
                                "opencores,or1200-rtlsvn481");
        qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu);
        qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency",
                              VIRT_CLK_MHZ);
        g_free(nodename);
    }

    nodename = (char *)"/pic";
    qemu_fdt_add_subnode(fdt, nodename);
    *pic_phandle = qemu_fdt_alloc_phandle(fdt);
    qemu_fdt_setprop_string(fdt, nodename, "compatible",
                            "opencores,or1k-pic-level");
    qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 1);
    qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0);
    qemu_fdt_setprop_cell(fdt, nodename, "phandle", *pic_phandle);

    qemu_fdt_setprop_cell(fdt, "/", "interrupt-parent", *pic_phandle);

    qemu_fdt_add_subnode(fdt, "/chosen");
    if (cmdline) {
        qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
    }

    /* Pass seed to RNG. */
    qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
    qemu_fdt_setprop(fdt, "/chosen", "rng-seed", rng_seed, sizeof(rng_seed));

    /* Create aliases node for use by devices. */
    qemu_fdt_add_subnode(fdt, "/aliases");
}

static void openrisc_virt_ompic_init(OR1KVirtState *state, hwaddr base,
                                    hwaddr size, int num_cpus,
                                    OpenRISCCPU *cpus[], int irq_pin)
{
    void *fdt = state->fdt;
    DeviceState *dev;
    SysBusDevice *s;
    char *nodename;
    int i;

    dev = qdev_new("or1k-ompic");
    qdev_prop_set_uint32(dev, "num-cpus", num_cpus);

    s = SYS_BUS_DEVICE(dev);
    sysbus_realize_and_unref(s, &error_fatal);
    for (i = 0; i < num_cpus; i++) {
        sysbus_connect_irq(s, i, get_cpu_irq(cpus, i, irq_pin));
    }
    sysbus_mmio_map(s, 0, base);

    /* Add device tree node for ompic. */
    nodename = g_strdup_printf("/ompic@%" HWADDR_PRIx, base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible", "openrisc,ompic");
    qemu_fdt_setprop_cells(fdt, nodename, "reg", base, size);
    qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0);
    qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 0);
    qemu_fdt_setprop_cell(fdt, nodename, "interrupts", irq_pin);
    g_free(nodename);
}

static void openrisc_virt_serial_init(OR1KVirtState *state, hwaddr base,
                                     hwaddr size, int num_cpus,
                                     OpenRISCCPU *cpus[], int irq_pin)
{
    void *fdt = state->fdt;
    char *nodename;
    qemu_irq serial_irq = get_per_cpu_irq(cpus, num_cpus, irq_pin);

    serial_mm_init(get_system_memory(), base, 0, serial_irq, 115200,
                   serial_hd(0), DEVICE_BIG_ENDIAN);

    /* Add device tree node for serial. */
    nodename = g_strdup_printf("/serial@%" HWADDR_PRIx, base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible", "ns16550a");
    qemu_fdt_setprop_cells(fdt, nodename, "reg", base, size);
    qemu_fdt_setprop_cell(fdt, nodename, "interrupts", irq_pin);
    qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", VIRT_CLK_MHZ);
    qemu_fdt_setprop(fdt, nodename, "big-endian", NULL, 0);

    /* The /chosen node is created during fdt creation. */
    qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename);
    qemu_fdt_setprop_string(fdt, "/aliases", "uart0", nodename);
    g_free(nodename);
}

static void openrisc_virt_test_init(OR1KVirtState *state, hwaddr base,
                                   hwaddr size)
{
    void *fdt = state->fdt;
    int test_ph;
    char *nodename;

    /* SiFive Test MMIO device */
    sifive_test_create(base);

    /* SiFive Test MMIO Reset device FDT */
    nodename = g_strdup_printf("/soc/test@%" HWADDR_PRIx, base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible", "syscon");
    test_ph = qemu_fdt_alloc_phandle(fdt);
    qemu_fdt_setprop_cells(fdt, nodename, "reg", base, size);
    qemu_fdt_setprop_cell(fdt, nodename, "phandle", test_ph);
    qemu_fdt_setprop(fdt, nodename, "big-endian", NULL, 0);
    g_free(nodename);

    nodename = g_strdup_printf("/soc/reboot");
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible", "syscon-reboot");
    qemu_fdt_setprop_cell(fdt, nodename, "regmap", test_ph);
    qemu_fdt_setprop_cell(fdt, nodename, "offset", 0x0);
    qemu_fdt_setprop_cell(fdt, nodename, "value", FINISHER_RESET);
    g_free(nodename);

    nodename = g_strdup_printf("/soc/poweroff");
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible", "syscon-poweroff");
    qemu_fdt_setprop_cell(fdt, nodename, "regmap", test_ph);
    qemu_fdt_setprop_cell(fdt, nodename, "offset", 0x0);
    qemu_fdt_setprop_cell(fdt, nodename, "value", FINISHER_PASS);
    g_free(nodename);

}

static void openrisc_virt_rtc_init(OR1KVirtState *state, hwaddr base,
                                   hwaddr size, int num_cpus,
                                   OpenRISCCPU *cpus[], int irq_pin)
{
    void *fdt = state->fdt;
    char *nodename;
    qemu_irq rtc_irq = get_per_cpu_irq(cpus, num_cpus, irq_pin);

    /* Goldfish RTC */
    sysbus_create_simple(TYPE_GOLDFISH_RTC, base, rtc_irq);

    /* Goldfish RTC FDT */
    nodename = g_strdup_printf("/soc/rtc@%" HWADDR_PRIx, base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible",
                            "google,goldfish-rtc");
    qemu_fdt_setprop_cells(fdt, nodename, "reg", base, size);
    qemu_fdt_setprop_cell(fdt, nodename, "interrupts", irq_pin);
    g_free(nodename);

}

static void create_pcie_irq_map(void *fdt, char *nodename, int irq_base,
                                uint32_t irqchip_phandle)
{
    int pin, dev;
    uint32_t irq_map_stride = 0;
    uint32_t full_irq_map[PCI_NUM_PINS * PCI_NUM_PINS * 6] = {};
    uint32_t *irq_map = full_irq_map;

    /*
     * This code creates a standard swizzle of interrupts such that
     * each device's first interrupt is based on it's PCI_SLOT number.
     * (See pci_swizzle_map_irq_fn())
     *
     * We only need one entry per interrupt in the table (not one per
     * possible slot) seeing the interrupt-map-mask will allow the table
     * to wrap to any number of devices.
     */
    for (dev = 0; dev < PCI_NUM_PINS; dev++) {
        int devfn = dev << 3;

        for (pin = 0; pin < PCI_NUM_PINS; pin++) {
            int irq_nr = irq_base + ((pin + PCI_SLOT(devfn)) % PCI_NUM_PINS);
            int i = 0;

            /* Fill PCI address cells */
            irq_map[i++] = cpu_to_be32(devfn << 8);
            irq_map[i++] = 0;
            irq_map[i++] = 0;

            /* Fill PCI Interrupt cells */
            irq_map[i++] = cpu_to_be32(pin + 1);

            /* Fill interrupt controller phandle and cells */
            irq_map[i++] = cpu_to_be32(irqchip_phandle);
            irq_map[i++] = cpu_to_be32(irq_nr);

            if (!irq_map_stride) {
                irq_map_stride = i;
            }
            irq_map += irq_map_stride;
        }
    }

    qemu_fdt_setprop(fdt, nodename, "interrupt-map", full_irq_map,
                     PCI_NUM_PINS * PCI_NUM_PINS *
                     irq_map_stride * sizeof(uint32_t));

    qemu_fdt_setprop_cells(fdt, nodename, "interrupt-map-mask",
                           0x1800, 0, 0, 0x7);
}

static void openrisc_virt_pcie_init(OR1KVirtState *state,
                                    hwaddr ecam_base, hwaddr ecam_size,
                                    hwaddr pio_base, hwaddr pio_size,
                                    hwaddr mmio_base, hwaddr mmio_size,
                                    int num_cpus, OpenRISCCPU *cpus[],
                                    int irq_base, int32_t pic_phandle)
{
    void *fdt = state->fdt;
    char *nodename;
    MemoryRegion *alias;
    MemoryRegion *reg;
    DeviceState *dev;
    qemu_irq pcie_irq;
    int i;

    dev = qdev_new(TYPE_GPEX_HOST);
    sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);

    /* Map ECAM space. */
    alias = g_new0(MemoryRegion, 1);
    reg = sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0);
    memory_region_init_alias(alias, OBJECT(dev), "pcie-ecam",
                             reg, 0, ecam_size);
    memory_region_add_subregion(get_system_memory(), ecam_base, alias);

    /*
     * Map the MMIO window into system address space so as to expose
     * the section of PCI MMIO space which starts at the same base address
     * (ie 1:1 mapping for that part of PCI MMIO space visible through
     * the window).
     */
    alias = g_new0(MemoryRegion, 1);
    reg = sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 1);
    memory_region_init_alias(alias, OBJECT(dev), "pcie-mmio",
                             reg, mmio_base, mmio_size);
    memory_region_add_subregion(get_system_memory(), mmio_base, alias);

    /* Map IO port space. */
    alias = g_new0(MemoryRegion, 1);
    reg = sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 2);
    memory_region_init_alias(alias, OBJECT(dev), "pcie-pio",
                             reg, 0, pio_size);
    memory_region_add_subregion(get_system_memory(), pio_base, alias);

    /* Connect IRQ lines. */
    for (i = 0; i < PCI_NUM_PINS; i++) {
        pcie_irq = get_per_cpu_irq(cpus, num_cpus, irq_base + i);

        sysbus_connect_irq(SYS_BUS_DEVICE(dev), i, pcie_irq);
        gpex_set_irq_num(GPEX_HOST(dev), i, irq_base + i);
    }

    nodename = g_strdup_printf("/soc/pci@%" HWADDR_PRIx, ecam_base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 1);
    qemu_fdt_setprop_cell(fdt, nodename, "#address-cells", 3);
    qemu_fdt_setprop_cell(fdt, nodename, "#size-cells", 2);
    qemu_fdt_setprop_string(fdt, nodename, "compatible",
                            "pci-host-ecam-generic");
    qemu_fdt_setprop_string(fdt, nodename, "device_type", "pci");
    qemu_fdt_setprop_cell(fdt, nodename, "linux,pci-domain", 0);
    qemu_fdt_setprop_cells(fdt, nodename, "bus-range", 0,
                           ecam_size / PCIE_MMCFG_SIZE_MIN - 1);
    qemu_fdt_setprop(fdt, nodename, "dma-coherent", NULL, 0);
    qemu_fdt_setprop_cells(fdt, nodename, "reg", ecam_base, ecam_size);
    /* pci-address(3) cpu-address(1) pci-size(2) */
    qemu_fdt_setprop_cells(fdt, nodename, "ranges",
                           FDT_PCI_RANGE_IOPORT, 0, 0,
                           pio_base, 0, pio_size,
                           FDT_PCI_RANGE_MMIO, 0, mmio_base,
                           mmio_base, 0, mmio_size);

    create_pcie_irq_map(fdt, nodename, irq_base, pic_phandle);
    g_free(nodename);
}

static void openrisc_virt_virtio_init(OR1KVirtState *state, hwaddr base,
                                      hwaddr size, int num_cpus,
                                      OpenRISCCPU *cpus[], int irq_pin)
{
    void *fdt = state->fdt;
    char *nodename;
    DeviceState *dev;
    SysBusDevice *sysbus;
    qemu_irq virtio_irq = get_per_cpu_irq(cpus, num_cpus, irq_pin);

    /* VirtIO MMIO devices */
    dev = qdev_new(TYPE_VIRTIO_MMIO);
    qdev_prop_set_bit(dev, "force-legacy", false);
    sysbus = SYS_BUS_DEVICE(dev);
    sysbus_realize_and_unref(sysbus, &error_fatal);
    sysbus_connect_irq(sysbus, 0, virtio_irq);
    sysbus_mmio_map(sysbus, 0, base);

    /* VirtIO MMIO devices FDT */
    nodename = g_strdup_printf("/soc/virtio_mmio@%" HWADDR_PRIx, base);
    qemu_fdt_add_subnode(fdt, nodename);
    qemu_fdt_setprop_string(fdt, nodename, "compatible", "virtio,mmio");
    qemu_fdt_setprop_cells(fdt, nodename, "reg", base, size);
    qemu_fdt_setprop_cell(fdt, nodename, "interrupts", irq_pin);
    g_free(nodename);
}

static void openrisc_virt_init(MachineState *machine)
{
    ram_addr_t ram_size = machine->ram_size;
    const char *kernel_filename = machine->kernel_filename;
    OpenRISCCPU *cpus[VIRT_CPUS_MAX] = {};
    OR1KVirtState *state = VIRT_MACHINE(machine);
    MemoryRegion *ram;
    hwaddr load_addr;
    int n;
    unsigned int smp_cpus = machine->smp.cpus;
    int32_t pic_phandle;

    assert(smp_cpus >= 1 && smp_cpus <= VIRT_CPUS_MAX);
    for (n = 0; n < smp_cpus; n++) {
        cpus[n] = OPENRISC_CPU(cpu_create(machine->cpu_type));
        if (cpus[n] == NULL) {
            fprintf(stderr, "Unable to find CPU definition!\n");
            exit(1);
        }

        qemu_register_reset(main_cpu_reset, cpus[n]);
    }

    ram = g_malloc(sizeof(*ram));
    memory_region_init_ram(ram, NULL, "openrisc.ram", ram_size, &error_fatal);
    memory_region_add_subregion(get_system_memory(), 0, ram);

    openrisc_create_fdt(state, virt_memmap, smp_cpus, machine->ram_size,
                        machine->kernel_cmdline, &pic_phandle);

    if (smp_cpus > 1) {
        openrisc_virt_ompic_init(state, virt_memmap[VIRT_OMPIC].base,
                                 virt_memmap[VIRT_OMPIC].size,
                                 smp_cpus, cpus, VIRT_OMPIC_IRQ);
    }

    openrisc_virt_serial_init(state, virt_memmap[VIRT_UART].base,
                              virt_memmap[VIRT_UART].size,
                              smp_cpus, cpus, VIRT_UART_IRQ);

    openrisc_virt_test_init(state, virt_memmap[VIRT_TEST].base,
                            virt_memmap[VIRT_TEST].size);

    openrisc_virt_rtc_init(state, virt_memmap[VIRT_RTC].base,
                           virt_memmap[VIRT_RTC].size, smp_cpus, cpus,
                           VIRT_RTC_IRQ);

    openrisc_virt_pcie_init(state, virt_memmap[VIRT_ECAM].base,
                            virt_memmap[VIRT_ECAM].size,
                            virt_memmap[VIRT_PIO].base,
                            virt_memmap[VIRT_PIO].size,
                            virt_memmap[VIRT_MMIO].base,
                            virt_memmap[VIRT_MMIO].size,
                            smp_cpus, cpus,
                            VIRT_PCI_IRQ_BASE, pic_phandle);

    for (n = 0; n < VIRTIO_COUNT; n++) {
        openrisc_virt_virtio_init(state, virt_memmap[VIRT_VIRTIO].base
                                         + n * virt_memmap[VIRT_VIRTIO].size,
                                  virt_memmap[VIRT_VIRTIO].size,
                                  smp_cpus, cpus, VIRT_VIRTIO_IRQ + n);
    }

    load_addr = openrisc_load_kernel(ram_size, kernel_filename,
                                     &boot_info.bootstrap_pc);
    if (load_addr > 0) {
        if (machine->initrd_filename) {
            load_addr = openrisc_load_initrd(state->fdt,
                                             machine->initrd_filename,
                                             load_addr, machine->ram_size);
        }
        boot_info.fdt_addr = openrisc_load_fdt(machine, state->fdt, load_addr,
                                               machine->ram_size);
    }
}

static void openrisc_virt_machine_init(ObjectClass *oc, void *data)
{
    MachineClass *mc = MACHINE_CLASS(oc);

    mc->desc = "or1k virtual machine";
    mc->init = openrisc_virt_init;
    mc->max_cpus = VIRT_CPUS_MAX;
    mc->is_default = false;
    mc->default_cpu_type = OPENRISC_CPU_TYPE_NAME("or1200");
}

static const TypeInfo or1ksim_machine_typeinfo = {
    .name       = TYPE_VIRT_MACHINE,
    .parent     = TYPE_MACHINE,
    .class_init = openrisc_virt_machine_init,
    .instance_size = sizeof(OR1KVirtState),
};

static void or1ksim_machine_init_register_types(void)
{
    type_register_static(&or1ksim_machine_typeinfo);
}

type_init(or1ksim_machine_init_register_types)